ALBERT

Description: The structure of factor IX gene was analyzed in a hemophilia B patient with inhibitor. Genomic DNA, digested with a variety of restriction endonucleases, was hybridized with the cDNA and various genomic factor IX probes. A large subtotal deletion of the gene was observed. The borders of the deletion span from a approximately 125 nucleotide region within the last exon to an unknown domain at least 7.5 kb upstream from the first exon: it thus involves approximately 33 kb of the factor IX locus. The abnormal gene was inherited by the daughter of the propositus, who showed both the normal and the deleted allele.

Description: Two molecular defects involving the spectrin heterodimer (SpD) contact site of the alpha chain (the alpha I domain) were previously identified using limited tryptic digestion followed by two-dimensional isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both are characterized by atypical peptide maps which reveal a marked decrease of the 80,000-dalton alpha I domain and a formation of new major peptides of either 74,000 (Sp alpha I/74) or 46,000 (Sp alpha I/46) daltons. We now report a third variant of the spectrin alpha chain, designated Sp alpha I/65, in three unrelated black families. In all three probands, the percentage of SpD in the low ionic strength (O degrees C) membrane extracts was increased to 19% to 32%. One- and two- dimensional electrophoretic separations of limited tryptic digests of spectrin from all three probands revealed a decrease of the alpha I domain of spectrin and the concomitant appearance of peptides at 65,000 daltons and isoelectric points ranging from 5.2 to 5.3. The abnormal 65,000-dalton peptides could be stained with an antiserum which had been raised against the alpha I domain, indicating that it was derived from the alpha I domain.

Description: Monoclonal antibodies (MoAbs) to myeloid differentiation antigens have a potential use in purging bone marrow of leukemia cells in autologous bone marrow transplantation (ABMT) therapy for acute myelogenous leukemia (AML). Because the efficiency of purging by MoAb and complement (C) is important to the success of ABMT, we have designed an assay to determine optimal conditions for leukemia cell lysis. In order to mimic the conditions of remission bone marrow, normal buffy coat cells were mixed with cells from the HL-60 promyelocytic leukemia cell line at a concentration that approximated the normal-leukemia cell ratio found in remission marrow. The cell mixture was treated at variable times and temperatures in the presence of C and PM-81, an IgM MoAb that reacts with both normal granulocytes and monocytes as well as with HL-60 cells. PM-81 binds to the majority of cells from 90% of patients with AML yet does not react significantly with normal stem cell populations. Because of the potential use of PM-81 in ABMT, it seemed especially important to show that the antibody was capable of mediating cytotoxicity of HL-60 cells in the presence of an excess of antigen-positive cells. A clonogenic assay that permitted the growth of HL-60 cell colonies but not normal progenitor cells in methylcellulose cultures was used to measure the efficiency of HL-60 cell lysis. We found that under certain conditions, PM-81 was capable of removing the small percentage of HL-60 clonogenic cells admixed with normal buffy coat cells. This information was useful for determining the optimal conditions for purging bone marrow of leukemia cells for ABMT.

Description: The expression of Rhesus antigens on hematopoietic progenitor cells was studied using monoclonal antibodies. Because these antibodies are not capable of lysing mature red blood cells in a complement-dependent cytotoxicity assay, fluorescence-activated cell sorting was performed. Using the monoclonal anti-Rh 29 antibody B10, 68% +/- 6% of the mature erythroid progenitor cells (CFU-E) were sorted into the positive fraction, while only 2% +/- 1% of the relatively immature erythroid progenitor cells (BFU-E), and 3% +/- 1% of the granulocyte-macrophage progenitor cells (CFU-GM) were cultured from this same fraction. Thus up to a 15-fold enrichment of CFU-E could be obtained. In two experiments more than 4% of the cells in the positive fraction consisted of CFU-E; in one experiment even more than 7% did. Using fractionated cell sorting, the Rhesus antigens appeared to have a lower density on CFU-E than HLA-DR determinants. Antibodies against the Rhesus antigens can be applied to enrich erythroid-committed stem cells and to separate mature from immature erythroid progenitor cells.

Description: Surface membrane glycoproteins (SMGs) of cells from the parental wild- type HL-60 cell line and from three sublines variably cross-resistant to the granulocyte differentiation-inducing effects of retinoic acid (RA), dimethylsulfoxide (DMSO), and certain purine bases (6-thioguanine [6TG] or hypoxanthine) were studied by one-dimensional and two- dimensional gel electrophoresis. After both oligosaccharide (periodate/borotritide) and peptide (1,3,4,6-tetrachloro-3 alpha, 6 alpha-diphenylglycouril) ectolabeling procedures, striking common changes were noted in the gel electrophoretic patterns of the SMGs from the RA- and 6TG-resistant sublines compared to those from the wild-type HL-60 line or the DMSO-resistant subline. Most prominently, this included the presence in the RA- and 6TG-resistant cells of an apparent high molecular weight acidic glycoprotein(s) (mol wt, 200 to 285 kilodaltons [kD]; isoelectric point range [pl], 4.5 to 6.0) not observed in the wild-type or DMSO-resistant cells and, conversely, the presence of a lower molecular weight glycoprotein(s) (mol wt, 120 to 165 kD; pl, 4.2 to 5.9) in the wild-type and DMSO-resistant cells, which was absent or much reduced in the RA- and 6TG-resistant cells. These acidic SMGs did not change as a function of the induction of granulocyte differentiation. However, some other more basic SMGs varied as a function of granulocyte differentiation in both the wild-type and differentiation inducer-resistant sublines, including the loss of the transferrin receptor and the gain of a mol wt 55- to 60-kD neutrophil- associated protein. In the context of previously reported information, these results indicate (1) that the overall pattern of SMG changes in the RA- and 6TG-resistant cells closely resembles that associated with multidrug (pleiotropic) resistance to cytotoxic agents in a variety of mammalian cells; (2) that the RA/6TG resistance-associated SMG changes are not granulocyte differentiation stage-specific; and (3) that either the RA/6TG resistance-associated SMG changes are not related to the resistance mechanism or they are involved in the resistance/cross- resistance mechanism(s) for RA/purine bases but not for DMSO.

Description: The platelet membrane glycoproteins, IIb and IIIa, form a Ca2+- dependent heterodimer complex that functions as the fibrinogen receptor in activated platelets to mediate platelet aggregation. Little is known about factors that affect the IIb-IIIa complex within the platelet membrane. It has been observed that platelets incubated with ethylene glycol tetra-acetic acid (EGTA) at 37 degrees C are unable to aggregate or to bind monoclonal antibodies specific for the IIb-IIIa complex. To determine whether this is due to a dissociation of IIb from IIIa, we developed a method for quantitating the complex on nondenaturing, polyacrylamide gradient gels. Platelets were surface-labeled with 125I and then solubilized and electrophoresed in 0.2% Triton and 10 mmol/L CHAPS. Under these conditions and in the presence of 1 mmol/L Ca2+, glycoproteins IIb and IIIa migrated on the gels as a discrete band at Rf = 0.33. Protein that was eluted from this band bound to an immunoaffinity column specific for the IIb-IIIa complex. In contrast, when the IIb-IIIa complex was solubilized and then dissociated with EGTA, the discrete band at Rf = 0.33 was no longer present, and IIb and IIIa were now found in a broad band at Rf = 0.45 to 0.50. To study IIb and IIIa within the surface membrane, the 125I-labeled platelets were first incubated with 0.5 mmol/L EGTA (1 nmol/L free Ca2+) at 22 degrees C and then solubilized in the absence of EGTA. The IIb and IIIa from these platelets migrated at Rf = 0.33, indicating the presence of the intact IIb-IIIa complex. In contrast, when the platelets were incubated at 37 degrees C for one hour with the EGTA, the discrete band at Rf = 0.33 representing the IIb-IIIa complex gradually disappeared. This phenomenon could not be reversed by adding Ca2+ back to the platelets before solubilization and electrophoresis. This loss of the IIb-IIIa complex from intact platelets was accompanied by (a) a progressive and irreversible decrease in adenosine diphosphate (ADP)-induced platelet aggregation and (b) decreased binding of a complex-dependent monoclonal antibody to the platelets. These studies demonstrate that when platelets are exposed to low Ca2+ at 37 degrees C, the IIb-IIIa heterodimer complexes in their surface membranes are irreversibly disrupted. Because intact IIb-IIIa complexes are required for platelet aggregation, the loss of these complexes may account for the failure of these platelets to aggregate in response to ADP.

Description: The density and size of human erythrocytes has been roughly correlated with cell age, with the denser and smaller cells being older. Observations of this type have led to a hypothesis that the membranes of circulating erythrocytes are dynamic with respect to composition and that material is lost from the membrane during cell maturation and circulation. In this study, flow cytofluorimetry was used to investigate the distribution of the human erythrocyte anion transport protein (protein 3) in heterogeneous samples of circulating red cells. We verified that protein 3 can be specifically and quantitatively labeled in intact human erythrocytes with eosin-5-maleimide, a luminescent probe. Individual cells were accordingly analyzed for size by forward light scattering and for protein 3 content by quantitation of eosin fluorescence. Initial results indicated that the smallest erythrocytes had a protein 3 content equal to that of the largest circulating erythrocytes. This result was independently verified by light scatter-activated cell sorting; direct measurement of cell diameters by microscopy verified that the cell sizes of erythrocytes showing the 10% greatest and 10% smallest light-scattering signal were indeed distinct. Independent analysis of the size-sorted erythrocytes for protein 3 content was accomplished by gel electrophoresis of stroma from 150,000 large and small erythrocytes. Quantitative scanning densitometry of silver-stained gels of prepared stroma showed that protein 3 content of each set of fractionated cells was equal and did not vary as a function of cell size. Taken in combination with the reported correlation between increasing red blood cell age and decreasing cell size, these results indicate that any loss of membranous material during the cell aging process is not random.

Description: A long-term liquid culture system of hemopoietic tissue derived from adult hamster spleen has been described. These primary liquid cultures can maintain stem cell proliferation and differentiation for more than three months without secondary repopulation. A characteristic of the liquid cultures is the formation of clusters of hemopoietic cells around adherent stromal cells. Some islands were composed exclusively of megakaryocytes and adherent cells. Isolation of these clusters of differentiating megakaryocytes and their adherent cellular substrate permitted the analysis of the morphological and ultrastructural features of the interaction between cells of megakaryocytic lineage with the adherent stroma.

Description: We have used immunogold staining to locate thrombospondin (TSP) on thrombin-activated human platelets, and have compared its distribution with that of fibrinogen (or fibrin) on thrombin- and ADP-stimulated platelets. To do this, isolated platelets were incubated with monospecific antibodies to TSP or fibrinogen (fib) and the bound IgG located with a second antibody adsorbed to gold particles. Thrombin- induced secretion in Tyrode-Ca2+ was followed by both anti-TSP and anti- fib binding, with large clusters of gold particles observed on the platelet surface. Little or no labeling was observed on unstimulated platelets with either antibody. When secretion was effected in Tyrode- EDTA, anti-TSP IgG still bound to the activated platelets, but the number of particle clusters was significantly reduced. Little binding of anti-fib IgG now occurred. Platelets activated with ADP in the presence of added fib, and subsequently incubated with anti-fib IgG, showed small particle clusters over the whole platelet surface. Thrombin-stimulated platelets from two patients with thrombasthenia bound anti-TSP IgG similarly to normal platelets activated in Tyrode- EDTA. No anti-fib binding occurred. Our results suggest that fib and TSP bind to specific domains on the stimulated platelet membrane. Such sites may be responsible for the mediation of platelet surface contact interactions.

Description: Protein-heparin complexes, prepared by a water-soluble carbodiimide coupling technique, were used to produce anti-heparin antibodies in rabbits. Antiserums that recognized carbodiimide-treated heparin, but not untreated heparin, were obtained. Carbodiimide-treated heparan sulfate exhibited 10% to 20% cross-reactivity compared with a similarly treated heparin, whereas there was no cross-reactivity with five other carbodiimide-treated mucopolysaccharides. 3H-1-ethyl-3-(3- trimethylammoniumpropyl) carbodiimide iodide was used to demonstrate that carbodiimide forms a stable adduct with heparin and other mucopolysaccharides. Using an antibody fraction that eluted from 1- ethyl-3-(3-trimethylammoniumpropyl) carbodiimide iodide-treated heparin- Sepharose with 2 mol/L KI, it was demonstrated that, for the antibody population studied, the addition of one carbodiimide per heparin molecule resulted in complete epitope expression without loss of anticoagulant activity. The addition of up to eight additional carbodiimide molecules to heparin did not increase the extent of epitope formation, although anticoagulant activity was lost. Except for heparan sulfate, the addition of radiolabeled carbodiimide to other mucopolysaccharides did not result in epitope formation. These data demonstrate that antibodies to an epitope derived from heparin can be formed, that the epitope is fully expressed while anticoagulant activity is present, and that the antibody is specifically directed against an altered portion of the polysaccharide.

Description: We tested conditioned media from 12 patients with T lymphocyte neoplasms and four T cell lines for their ability to stimulate the in vitro growth of erythroid-burst-forming units (BFU-E) from bone marrow mononuclear cells in a methylcellulose culture system. Nine patients suffered from acute lymphocytic leukemia, two from chronic lymphocytic leukemia, and one from non-Hodgkin's lymphoma. The T lymphocytes were characterized by a series of monoclonal antibodies and their stage of development was correlated with their ability to produce burst- promoting activity (BPA). Conditioned media from cells classified as prothymocytes (three cases), common thymocytes (one case), mature thymocytes (three cases), and mature lymphocytes of the helper subtype (two cases) increased BFU-E proliferation four- to 19-fold over control values using normal bone marrow as target cells. Conditioned media from OKT8+ malignant T lymphocytes (three cases) did not enhance BFU-E proliferation. Conditioned media from cells classified as immature T cells stimulated CFU-GM proliferation in only one of seven cases even though they secreted BPA. Conditioned media from three of the four cell lines stimulated by phytohemagglutinin, enhanced BFU-E growth. Our results indicate that malignant cells that have characteristics of immature T cells are able to produce BPA. Studies using techniques to isolate homogeneous populations of normal T cell subsets are required to determine whether normal immature T lymphocytes have the same capability.

Description: Cultured adherent human macrophages and a promonocytic cell line, U 937, were previously shown to produce a Mr 95,000 gelatin-binding protein. The protein has no immunologic cross-reactivity with the well- characterized gelatin-binding protein fibronectin and the Mr 70,000 gelatin-binding protein produced by a variety of mesenchymal or epithelial cell types (T. Vartio et al, J Biol Chem 257:8862, 1982). In the present study the Mr 95,000 protein was found in Triton X-100 extracts of granulocytes purified from human blood buffy coat. The protein, as isolated by gelatin-agarose, was immunologically cross- reactive with the corresponding macrophage protein in immunoblotting assay. When peripheral blood and bone marrow cells were examined for the presence of the Mr 95,000 protein by indirect immunofluorescence, positive staining was detected only in differentiated granulocytes but not to any significant extent in metamyelocytes, myelocytes, promyelocytes, or in normal or leukemic blasts. In granulocytes the protein had a granular cytoplasmic distribution. In freshly prepared monocyte cultures, the Mr 95,000 protein was detected in low amounts in the cytoplasm, while along with differentiation of the cells into macrophages, the immunofluorescence increased in a reticular and vesicular cytoplasmic pattern and in a juxtanuclear cap, probably representing the Golgi complex. In conclusion, the Mr 95,000 gelatin- binding protein was specifically detected in macrophages and granulocytes and may thus serve as a differentiation marker for these phagocytic cells.

Description: The inhibition of delta-aminolevulinic acid (ALA) synthase activity by heme is commonly thought to regulate the overall rate of heme synthesis in erythroid cells. However, since heme inhibits erythroid cell uptake of iron from transferrin, we have tested the hypothesis that in reticulocytes heme regulates its own synthesis by controlling the cellular acquisition of iron from transferrin rather than by controlling the synthesis of ALA. We found that hemin added to reticulocytes in vitro inhibits not only the total cell incorporation of 59Fe from transferrin but also the incorporation of [2–14C]-glycine and transferrin-bound 59Fe into heme. However, hemin did not inhibit [2 –14C]-glycine incorporation into protoporphyrin. Furthermore, cycloheximide, which increases the level of non-hemoglobin heme in reticulocytes, also inhibited [2–14C]-glycine into heme but not into protoporphyrin. With high concentrations of ferric pyridoxal benzoylhydrazone (Fe-PBH), which, independent of transferrin and transferrin receptors, can be used as a source of iron for heme synthesis in reticulocytes, significantly more iron is incorporated into heme than from saturating concentrations of Fe-transferrin. This suggests that some step (or steps) in the pathway of iron from extracellular transferrin to protoporphyrin limits the overall rate of heme synthesis in reticulocytes. In addition, hemin in concentrations that inhibit the utilization of transferrin-bound iron for heme synthesis has no effect on the incorporation of iron from Fe-PBH into heme. Our results indicate that in reticulocytes heme inhibits and controls the utilization of iron from transferrin but has no effect on the enzymes of porphyrin biosynthesis and ferrochelatase. This mode of regulation of heme synthesis may be a specific characteristic of the hemoglobin biosynthetic pathway.

Description: Leukemic blasts from 774 children with newly diagnosed acute lymphocytic leukemia (ALL) have been phenotyped by microcytotoxicity testing with a panel of monoclonal antibodies and heteroantisera as part of a Pediatric Oncology Group classification study of acute leukemia. One hundred twenty-two cases, or 16% were designated as T cell leukemia based on the reactivity of blast cells with previously well-characterized antisera (PT) against a T lymphocyte-associated antigen. Using this antisera-based definition as a standard, we looked for a monoclonal antibody combination that would be a suitable substitute. An algorithm calling for reactivity with either monoclonal antibody 3A1 or Leu-1 was a 92% sensitive and 97% specific predictor of PT reactivity. Only 27 of 755 cases of leukemia were incorrectly classified using this algorithm. Subsequently, Ficoll-Hypaque-separated bone marrow cells from 118 additional patients with ALL (21 of whom had T cell ALL) were stained by immunofluorescence using a combination of directly fluoresceinated 3A1 and Leu-1. Reactivity of 20% or more of the cells with this antibody combination was a 100% sensitive and 94% specific indicator of T cell ALL defined by PT positivity; with a higher cutoff value for positive values, or the use of supplemental tests, even this small number of false-positives could be eliminated. We conclude that this monoclonal antibody combination is a satisfactory replacement for our heteroantisera definition of T cell ALL.

Description: The effect of a zinc metalloprotease from Serratia marcescens on platelet surface glycoproteins (GP) Ib and V was analyzed. Increasing protease treatments caused progressive loss of GP Ib with appearance of the major fragment, glycocalicin, in the supernatant solution. No GP V was detected in the supernatant solution, and protease-pretreated platelets had the same capacity as control platelets to release fragment 1 of GP V in response to thrombin. The Serratia protease- pretreated platelets did show the lag before thrombin-induced dense granule secretion, characteristic of platelets modified by pretreatment with other nonstimulating proteases. Treatment with Serratia protease gives the only demonstrated selective loss of GP Ib without apparent effect on GP V. It suggests that GP V (1) does not depend on GP Ib for its association with platelets and (2) is not the substrate for protease modification of platelet function.

Description: The blood platelet is the only human cell known to have a circumferential band of microtubules. However, the mechanisms involved in assembly of the multi-looped coil, its interaction with the cell membrane to support discoid shape, and constriction into tight rings around centrally concentrated organelles in activated platelets are unknown. Separation of the microtubule rings from intact platelets would permit new approaches to solution of these questions. The present study has used simultaneous detergent extraction and fixation to isolate intact microtubule coils in significant numbers from suspended platelets for the first time. Isolated coils closely resembled the circumferential band observed in thin sections of plastic embedded platelets and in platelets prepared by the negative-stain whole-mount method. Enough microtubule coils could be recovered from suspensions of concentrated platelets to permit counting and quantitation on microscope grids. Results of this study will permit new approaches to clarification of the structural physiology of platelet microtubule coils.

Description: Twenty-two patients with hairy cell leukemia were treated with biosynthetic (recombinant) alpha-2-interferon in an open-label, single- arm efficacy study. Patients received 2 X 10(6) U/m2 recombinant alpha- 2-interferon three times weekly. Therapy was well tolerated subjectively with minimal short-term hematologic toxicity. Two patients had bacterial infections during the period of study, and one patient experienced a short-lived readily reversible rejection of a corneal transplant. Statistical comparison of the mean hematologic indices at study entry and after three to six months of therapy with recombinant alpha-2-interferon indicates a significant improvement in hemoglobin, granulocyte, and platelet counts. Bone marrow biopsies in six of 14 patients after six months of therapy showed a greater than 50% decrease in the infiltration of leukemia cells. We conclude that recombinant alpha-2-interferon is highly effective therapy for hairy cell leukemia.

Description: Mitogen-stimulated murine spleen cells produce humoral substances capable of supporting murine hematopoiesis and pluripotent stem cell proliferation in vitro. Thus, we evaluated conditioned media generated by human spleen cells (SCM) in the presence or absence of mitogens for factors stimulatory for human pluripotent (CFU-GEMM), erythroid (BFU- E), and myeloid (CFU-GM) precursors. Two and one half percent to 10% SCM stimulated proliferation of all three types of precursor cells from nonadherent buoyant human marrow target cells. Mitogen-stimulated SCM augmented CFU-GM (175% to 225%), whereas CFU-GEMM and BFU-E growth was essentially unchanged. Cell separation procedures used to determine which cells provided these microenvironmental stimuli indicated that nonadherent mononuclear spleen cells provided the bulk of the CSF-GM, whereas adherent cells (95% nonspecific esterase + monocyte- macrophages) and nonadherent cells provided similar proportions of CSF- mix and erythroid burst-promoting activity (BPA). The nonadherent cells generating high levels of CSF-mix, BPA, and CSF-GM were predominantly Leu-1-negative, ie, non-T, cells. In the presence or absence of mitogens, SCM was a more potent source (1.3- to 3.8-fold) than peripheral leukocyte CM of the growth factors for the three progenitor cell types. Specific in situ cytochemical stains for analyzing morphology of myeloid colonies demonstrated that SCM stimulated the proliferation of the same types and proportions of colonies as human placental CM, suggesting that these CMs may contain similar CSF-GMs. These data show the contribution of spleen cell subsets to the generation of hematopoietic growth factors and the responsiveness of these cells to various mitogenic stimuli.

Description: Pregnancy in female carriers of abnormal hemoglobins with great avidity for oxygen provides a unique opportunity to assess the importance of the usual difference in oxygen affinity between fetal and maternal blood. Outcome of pregnancy was recorded for carriers of hemoglobins Bethesda, Osler, and Yakima, whose p50s (9.5, 9.1, and 12 mm Hg at pH 7.4) were far lower than that of a normal fetus (23 mm Hg at pH 7.3). Neither spontaneous abortions nor intrauterine growth retardation could be attributed to the presence of high oxygen affinity in the mothers. In vitro simulations suggested that neither maternal or fetal polycythemia alone was sufficient to adjust for perturbation of the normal situation, and increased uterine and/or fetal blood flow probably provided additional compensation.

Description: Neutrophil function was studied in a patient with polymorphonuclear leukocyte (PMN) glycoprotein-180 deficiency and in her parents. PMNs of the patient had abnormal chemotaxis, phagocytosis, adherence, surface charge, and membrane-associated events of activation. Selective defects to C3b, immunoglobulin G (IgG), phorbol myristate acetate (PMA) and N- formyl-methionyl-leucyl-phenylalanine (FMLP) are described, although C3b receptor density was normal. The parents were found to have abnormal adherence to nylon-wool fibers, abnormal transmembrane potential depolarization with PMA, and reduced amounts of glycoprotein- 180 in their PMNs. These studies provide further evidence that the oxidative burst has several different pathways for activation. They demonstrate that the absence of a single PMN surface glycoprotein is associated with a broad spectrum of PMN functional abnormalities. Finally, the observations made in the parents support an autosomal recessive mode of inheritance.

Description: Ecto-5′nucleotidase (5′NT) activity of peripheral blood (PB) lymphocytes was determined in 31 patients with serum monoclonal gammopathies (MG). Twenty-one patients had a diagnosis of multiple myeloma (MM), and ten patients had monoclonal gammopathy of undetermined significance (MGUS). The proliferative activity of the bone marrow plasma cells (LI%) was investigated in 28 of these MG patients by means of tritiated thymidine uptake evaluated by simultaneous autoradiography and cytoplasmic immunofluorescence. 5′NT activity was significantly lower in MG patients as compared with normal controls. MM patients had lower 5′NT activity than MGUS patients, but the difference was not significant. By contrast, MM had significantly higher LI% than MGUS patients. There was a linear regression of 5′NT on LI% which was statistically significant: the higher the LI%, the lower the 5′NT. Because the LI% is an accurate prognostic and monitoring factor in MG, this correlation indicates that 5′NT may be of assistance in predicting the clinical progress of MG patients. In seven MGs, the PB T and B lymphocytes were studied separately. The T cell subpopulation was 5′NT deficient compared to the normal controls, shown as a significant linear regression of T cell 5′NT on the LI%. This suggests that in MG there may be an alteration of nonneoplastic T lymphocytes correlated with tumor growth. The OKT8+ lymphocytes were mainly responsible for the 5′NT deficiency of unseparated T lymphocytes.

Description: Peripheral blood leukemia cells from patients with acute monoblastic leukemia (AMoL) were tested for killer cell activity against target cells that detected natural killer cell-mediated or monocyte-mediated spontaneous cytotoxicity. The fibrosarcoma cell line Wehi 164, pretreated with actinomycin D to induce susceptibility to lysis, specifically detects the activity of unstimulated human monocytes. In four of six cases of AMoL, high killer cell activity could be measured against this target. In three of these four cases, the killer cell activity could be assigned exclusively to the leukemic clone, based on the high leukocyte counts and the resultant dilution of normal cells, as evidenced by marker and by functional analysis. While leukemic cells with killer cell activity against Wehi 164 contained 34% to 45% cells that were positive for binding of the 63D3 monoclonal antibody, the two leukemic samples without killer cell activity contained only 1% and 12% 63D3-positive cells. Cell sorting of 63D3-positive and -negative cells from two leukemias with killer cell activity demonstrated that the killer cell activity was restricted to the 63D3-positive fraction of AMoL cells. These data demonstrate that monoblastic leukemia cells can be potent killer cells and that killing activity is linked to the 63D3- defined cell surface molecule.

Description: The Belgrade laboratory rat (b/b rat) has hereditary, hypochromic, microcytic anemia with a variety of red cell abnormalities. Although this anemic syndrome has been recently ascribed to the defective delivery of iron to the developing red cell, the basic hematopoietic defect is still unknown. In this article we present evidence that the b/b rat has an additional hematologic defect. We have found that the megakaryocyte number in the marrow of the b/b rat is decreased to one half that of the normal rat, but the maturation rate of recognizable megakaryocytes is accelerated and the size is increased. The platelet count is moderately reduced. These findings indicate that megakaryocytopoiesis in the anemic b/b rat is abnormal and suggest that the genetic defect may involve the progenitors of the megakaryocyte cell lineage. Alternatively, the megakaryocytic abnormalities may be secondary to the severe anemia.

Description: DNA from mononuclear blood and tumor cells from 33 patients undergoing bone marrow transplantation for leukemia was examined for the presence of Epstein-Barr virus (EBV) genomes by blot hybridization. Four groups of patients were studied soon after engraftment, during long-term remission, after relapse of the original leukemia, and after development of secondary B cell neoplasms. Only the cells of patients with secondary neoplasms demonstrated EBV genomes, where all five adequately studied samples were positive. Samples from all other patient categories were negative for EBV genomes. We conclude that EBV genomes do not frequently persist in normal engrafted lymphocytes or in mononuclear cells of patients suffering recurrent leukemia. These results are consistent with EBV playing a role in the genesis of secondary B cell neoplasms following bone marrow transplantation.

Description: Fibrinogen from plasma was compared with fibrinogen from platelets using two-dimensional electrophoresis. The source of platelet fibrinogen was isolated alpha-granules, thrombin- and collagen-released platelet material. The B beta- and gamma-chains from the different sources showed similar two-dimensional patterns, while gamma'-chains were not observed in platelet fibrinogen preparations. Furthermore, the A alpha-chain could hardly be identified in platelet preparations. When individual fibrinogen was studied in persons heterozygous for genetic B beta- and gamma-chain variants, the two-dimensional variant pattern could be demonstrated in plasma fibrinogen as well as in platelet fibrinogen. This observation strongly indicates that the structural genes for plasma and platelet fibrinogen B beta- and gamma-chains are identical.

Description: The mechanism of drug-dependent immunologic thrombocytopenic purpura (DITP) was investigated by studying the sera of four patients with classic DITP (two with quinidine-, one with acetaminophen-, and one with phenazopyridine-dependent antiplatelet antibody) using a solid- phase radioimmunoassay with 125I-staphylococcal protein A. Two forms of antiplatelet antibody could be demonstrated: one that required drug to bind to platelets and one that bound to platelets in the absence of drug. Drug-dependent antiplatelet antibody required the simultaneous addition of drug and the Fc domain of the drug-dependent IgG molecule for binding to platelets. It did not require serum complement or factor VIII-related antigen for binding to platelets. Drug-dependent binding of antibody to platelets was saturation-dependent. Non-drug-dependent antiplatelet antibody of two patients (one with quinidine-induced thrombocytopenia and the other with acetaminophen-induced thrombocytopenia) reacted with autologous platelets as well as with homologous platelets, indicating that they were autoantibodies. Both autoantibodies had disappeared when their sera were tested 23 and 138 days, respectively, after withdrawal of their initial positive sera. Non-drug-dependent antiplatelet antibody binding could be demonstrated with the F(ab')2 fragment of the purified IgG of the serum of the second patient with quinidine DITP, who did not have detectable alloantibodies against HLA. None of the four patients with non-drug- dependent antiplatelet antibody had a past or present history of autoimmune thrombocytopenic purpura.

Description: The role in platelet function of the cell-binding region of fibronectin was explored by the use of synthetic peptides. The prototypical peptide gly-arg-gly-asp-ser was capable of inhibiting thrombin-induced platelet aggregation without altering the degree of platelet activation as judged by the secretion of 14C-serotonin. The peptide also effectively inhibited, in a concentration-dependent manner, the binding of radiolabeled fibronectin to platelets and the adhesion of platelets to fibronectin substrates. The smallest peptide from the cell-binding region of fibronectin which retained full activity was arg-gly-asp-ser. Transposition of amino acids or conservative substitutions of amino acids within this short sequence resulted in inactive peptides. Peptides containing the arg-gly-asp-ser sequence were also capable of inhibiting the adhesion of platelets to fibrinogen and von Willebrand factor substrates. Examination of the entire panel of synthetic peptides for ability to inhibit adhesion to fibrinogen or von Willebrand factor substrates revealed the same structure-function relationships that had been determined in the studies with fibronectin.

Description: Polymorphonuclear leukocytes (PMNs) adhere to endothelial cells at sites of acute inflammation. To examine this phenomenon in vitro, we have developed a new assay to measure adherence of PMNs to cultured endothelial cells. Human PMNs were labeled with 111indium-oxine and incubated in microtiter wells with monolayers of either human umbilical vein or bovine aortic endothelial cells. Following incubation, the wells were sealed, inverted, and centrifuged at varying speeds. Results are expressed as the percentage of PMNs added initially that remained attached to the monolayers after being subjected to dislodgment forces (ie, relative centrifugal forces) ranging from 1 to 1,200 g. Adherence of PMNs to endothelial monolayers was temperature dependent, dependent on the concentration of extracellular Mg2+ (but not Ca2+), and enhanced significantly by the chemotactic peptides, N-formyl-methionyl-leucyl- phenylalanine (fMLP) and human C5a. It was found that fMLP and C5a not only increased the number of PMNs that adhered to endothelial cells, but also increased the strength of adherence.

Description: Two families with polycythemia inherited as an autosomal dominant trait are described. Serial hemoglobin determinations in multiple family members and RBC volume measurements in selected affected subjects documented their polycythemia. Measurements of arterial p02s, p50s, and blood oxygen affinity were normal in all affected individuals from each family who were tested. Erythropoietin (EPO) levels were low in affected individuals from family 1 and normal in affected members of family 2. Stimulation of in vitro CFU-E colony growth by low levels of EPO was significantly increased in subjects from family 1, but normal in those affected from family 2. We conclude that although the inheritance pattern for the polycythemia in both of these families appeared to be the same, the biologic defect leading to the disorder in each of these unique families was different. The precise mechanism of the increased EPO sensitivity noted in affected subjects from family 1 awaits elucidation.

Description: Two human diseases of platelet storage pool deficiency (SPD), Hermansky- Pudlak syndrome and Chediak-Higashi syndrome, are recessively inherited disorders characterized by hypopigmentation, prolonged bleeding, and normal platelet counts accompanied by a reduction in dense granule number. We have recently described seven independent recessive mutations in the mouse regulated by separate genes which are likely animal models for human SPD. Reciprocal bone marrow transplants were carried out between normal C57BL/6J mice and two of these mutants, beige and pallid, in order to test whether the platelet defects are due to a defect in platelet progenitor cells or to humoral factors. Normal and congenic mutant mice were transplanted with marrow after 950 rad whole body radiation. The long bleeding times and low serotonin concentrations of the two mutants were converted to normal values after transplantation with normal marrow. Likewise, normal mice displayed symptoms of SPD when transplanted with mutant marrow. These studies demonstrate that with each of the two mutations, platelet SPD results from a defect in bone marrow precursor cells. Also, the studies suggest that in severe cases, platelet SPD may be successfully treated by bone marrow transplantation.

Description: In a previous report (Blood 60:265, 1982), we described a family with an abnormal RBC membrane protein doublet, which we considered a shortened protein 4.1 on the basis of biochemical and genetic data. Using an anti-4.1 monoclonal antibody, we confirm here that the shortened protein derives from protein 4.1. One of the members of the family contemporaneously displayed the 4.1 (-) trait, eg, the heterozygous state of this variety of hereditary elliptocytosis that lacks protein 4.1. The 4.1a/4.1b ratio was low whenever the 4.1 trait was present, regardless of the type of protein 4.1 involved. The RBCs of the compound heterozygote, containing only the shortened species of protein 4.1, made it possible to analyze without interference the contact between shortened protein 4.1 and sialoglycoprotein beta, or glycoconnectin. Shortened protein 4.1 did not alter the amount of glycoconnectin in the ghosts nor did it change its extractability into the Triton shells. Limited proteolysis of shortened polypeptides 4.1a and 4.1b showed that they are sequence related. It is conflicting that the persons carrying the shortened protein 4.1 are devoid of specific clinical and morphological abnormalities, apart from those pertaining to the 4.1- trait, when the latter is present.

Description: Two patients with aplastic anemia were treated with high-dose cyclophosphamide and marrow transplantation from their normal, genetically identical twin. Both patients rapidly recovered normal marrow function, but marrow failure recurred 13 and 18 months later. Because donor and host pairs were identical twins, these cases of graft failure could not have resulted from the usual cause of graft failure, ie, immunological reactivity of host cells against unshared minor histocompatibility antigens of the donor. These results imply that there are at least two mechanisms responsible for graft failure after marrow transplantation for severe aplastic anemia.

Description: Seven patients with hairy cell leukemia were treated by intensive chemotherapy because they were considered to have a progressive disease and a poor short-term prognosis. The mean age was 47 years (range, 36 to 58). Six of seven patients had prior splenectomies with minor or transient hematologic responses. One patient had no spleen enlargement. The seven patients had never received any cytotoxic drugs and had prolonged granulocytopenia (less than 300/microL) with recurrent, severe infectious episodes. Chemotherapy included Rubidazone (zorubicine hydrochloride) 450 mg/m2 on day 1, arabinosyl cytosine 200 mg/m2/d from day 1 to day 5, and cyclophosphamide, 2,000 mg/m2 on day 5. Responses were assessed through examination of repeat bone marrow biopsy specimens and blood counts. A complete response was defined as normal blood counts associated with the disappearance of hairy cell infiltration and fibrosis on the bone marrow biopsy specimens. A partial response was defined as normal blood counts with persistence of leukemic cells in the bone marrow. Three patients achieved a complete response, and one patient had a partial response. Three patients died of infectious complications during induction chemotherapy. For the responding patients, the mean duration of aplasia was 37 +/- 5 days. Follow-up for the responding patients has been 44+, 24, 32+, and 23+ months. One patient with a complete response died while on maintenance therapy. We conclude that complete and prolonged histologic remission of hairy cell leukemia can be obtained with intensive chemotherapy. The toxicity of chemotherapy is such, however, that progressive disease after splenectomy needs to be more clearly defined.

Description: Fibrinogen synthesis was investigated in guinea pig megakaryocytes. Purified megakaryocytes were incubated with 35S-methionine in methionine-free incubation medium for 18 hours. Newly synthesized fibrinogen in megakaryocyte lysates enriched with purified carrier guinea pig fibrinogen was immunoprecipitated with a specific anti- guinea pig fibrinogen antiserum produced in rabbits. Proteins in the immunoprecipitates were analyzed with a 3.5% to 10.0% gradient polyacrylamide slab gel electrophoresis and auto-radiography. Radioactivity was detected in a protein band of 340,000 daltons. In order to verify fibrinogen synthesis, immunoprecipitate was analyzed by two-dimensional slab gel electrophoresis: (1) the first dimension separated unreduced fibrinogen using a 3.5% to 10.0% gradient gel; (2) following reduction by 2-beta-mercaptoethanol, fibrinogen chains were separated in the second dimension using a 10% gel. Alpha, beta, and gamma fibrinogen chains, which represented carrier guinea pig plasma fibrinogen, were visualized by Coomassie brilliant blue. Autoradiography identified the incorporation of radioactivity into the three fibrinogen chains. In control experiments, immunoprecipitates, produced by exposing megakaryocyte lysates to preimmune rabbit serum and goat anti-rabbit IgG, were also analyzed by the two-dimensional gel system. Radioactivity was not detected in sites corresponding to the migration of fibrinogen subunits. The study demonstrates that isolated guinea pig megakaryocytes can synthesize fibrinogen. The electrophoretic mobility of newly synthesized fibrinogen and subunits is similar to that of guinea pig plasma fibrinogen.

Description: A murine monoclonal antibody specific for glycoprotein (GP)IIIa was prepared by immunization with a GPIIb- and GPIIIa-enriched Triton X-114 extract of platelet membranes. This antibody, designated AP-3, was shown by indirect immunoprecipitation to react solely with GPIIIa derived from either P1A1-positive or -negative individuals. The epitope on GPIIIa recognized by AP-3 is expressed on dissociated GPIIIa as well as on Ca+2-dependent complexes of GPIIb and GPIIIa, as shown by crossed immunoelectrophoresis in the presence or absence of EDTA. A previously described monoclonal antibody specific for the GPIIb/IIIa complex (AP- 2) inhibited platelet aggregation induced by ADP, thrombin, collagen, or arachidonic acid (Pidard et al, J Biol Chem 258:12582–12586, 1983). In contrast, AP-3 had no effect on aggregation induced by any of these reagents, a finding similar to that previously reported for the GPIIb- specific monoclonal antibody, Tab (McEver et al, J Clin Invest 66:1311- 1318, 1980). At saturation, 40,200 AP-3 molecules were bound per platelet, a value similar to that obtained for AP-2 or Tab. Thus, data derived using AP-3 indicate that significant amounts of free GPIIIa are not present, thereby supporting the hypothesis that GPIIb and GPIIIa exist complexed in a 1:1 stoichiometry in the plasma membrane of intact, nonactivated platelets.

Description: Using clinical, morphological, genetic, and biochemical criteria, we studied ten white and North African families with hereditary elliptocytosis (HE). In four families, elliptocytic individuals displayed a highly significant reduction of band 4.1, which was recorded using two electrophoretic procedures. The 4.1a/4.1b ratio was also significantly reduced, as is usually observed in suspensions enriched in young red cells. This form of HE was invariably associated with the following characteristics: absence of clinical signs; numerous, smooth and well-elongated elliptocytes; dominant transmission; and, when investigated, normal osmotic fragility. Its frequency, among all forms of HE, is about one third as a first estimate, at least in whites and North Africans. In the other six families studied, elliptocytic subjects presented normal 4.1 bands. Again, the 4.1a/4.1b ratio was decreased, reflecting the red cell age- dependent changes in these two components. In three of these families, elliptocytosis was accompanied by clinical signs of variable intensity, and the mode of inheritance could not be unequivocally determined. Therefore, HE with a partially reduced band 4.1 defines a homogeneous variety of HE that can be isolated from other forms of HE. We suggest that it be termed the 4.1 (-) trait, so as to correspond with a previously proposed terminology.

Description: The expression of carbonic anhydrase (CA) as a marker of erythroid differentiation was investigated by immunologic and enzymatic procedures. A polyclonal anti-CA antibody was obtained by immunizing rabbits with purified CA I isozyme. This antibody is reactive with CA I but not with CA II. Within blood cells, CA I was only present in erythrocytes, whereas CA II was also detected in platelet lysates by enzymatic assay. Concerning marrow cells, identifiable erythroblasts and some blast cells expressed CA I. Most of the glycophorin A-positive marrow cells were clearly labeled by the anti-CA I antibody. However, rare CA I-positive cells were not reactive with anti-glycophorin A antibodies. We therefore investigated whether these cells were erythroid precursors or progenitors. In cell sorting experiments of marrow cells with the FA6 152 monoclonal antibody, which among hematopoietic progenitors is reactive only with CFU-E and a part of BFU- E, was performed, CA I+ cells were found mainly in the positive fraction. The percentage of CA I+ cells nonreactive with anti- glycophorin A antibodies contained in the two fractions was in the same range as the percentage of erythroid progenitors identified by their capacity to form colonies. In addition, the anti-CA I antibody labeled blood BFU-E-derived colonies as early as day 6 of culture, whereas in similar experiments with the anti-glycophorin A antibodies, they were stained three or four days later. No labeling was observed in CFU-GM- or CFU-MK-derived colonies. The phenotype of the day 6 cells expressing CA I was similar to that of erythroid progenitors (CFU-E or BFU-E): negative for glycophorin A and hemoglobin, and positive for HLA-DR antigen, the antigen identified by FA6 152, and blood group A antigen. Among the cell lines tested, only HEL cells expressed CA I, while K562 was unlabeled by the anti-CA I antibody. In contrast, HEL and K562 cells expressed CA II as detected by a biochemical technique. Synthesis of CA I, as with other erythroid markers such as glycophorin A and hemoglobin, was almost abolished after 12-O-tetradecanoyl-phorbol-13 acetate treatment of HEL cells. In conclusion, CA I appears to be an early specific marker of the erythroid differentiation, expressed by a cell with a similar phenotype as an erythroid progenitor.

Description: Studies of the ability of Plasmodium falciparum to grow in vitro in the red blood cells of subjects with certain beta-thalassemia syndromes are often difficult to interpret because of the known inhibitory effect of an elevated cellular content of human fetal hemoglobin (HbF). P falciparum therefore was cultured in vitro in the erythrocytes of subjects with hemoglobin H (HbH) disease and various other alpha- thalassemia genotypes that are unaccompanied by increased levels of HbF. Growth of the malaria parasite was markedly retarded in HbH red blood cells, when compared with growth in blood from normal control subjects. No consistent impairment of growth was seen in the erythrocytes of subjects having deletion of only one or two alpha- globin genes. These results indicate that erythrocytes with a severe thalassemia phenotype provide a less hospitable growth environment for P falciparum than normally hemoglobinized red blood cells, even in the absence of increased levels of HbF.

Description: The purine metabolic enzymes adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) are important in lymphocyte differentiation, and genetic deficiencies of either enzyme have been associated with hereditary immunodeficiency states. Both ADA and PNP activity were measured in null cell-enriched and T cell-enriched peripheral blood lymphocytes from 16 patients with the acquired immune deficiency syndrome (AIDS), seven patients with the AIDS-related symptom complex (ARC), and seven asymptomatic homosexuals. ADA activity in nmol/10(6) lymphocytes/h was significantly elevated in null lymphocytes from AIDS (161 +/- 12) as compared with 23 healthy heterosexual controls (127 +/- 8;P less than .025). PNP activity was also significantly increased in null lymphocytes from AIDS patients (96 +/- 10;P less than .005) as well as those from ARC patients (84 +/- 11:P less than .025) relative to controls (61 +/- 5). No significant differences in enzyme activity were noted in T cell-enriched cells in any group. Along with elevated enzyme activity, AIDS patients had small yet significant increases in the percentages of HLA-DR (P less than .025), terminal deoxynucleotidyl transferase (TdT) (P less than .0001), and peanut agglutinin receptor (P less than .0001) positive lymphocytes in the null fraction compared with controls. TdT-positive cells appeared morphologically as large lymphoblasts with irregular nuclei. The data imply that the cellular immune deficiency in AIDS is not a result of deficiencies in lymphocyte ADA or PNP activity, but is more likely associated with an increase in an immature and/or activated lymphocyte subset.

Description: To determine the feasibility of obtaining bone marrow cells from cadaver donors for transplantation, marrow cells were prepared from 17 cadaver donors. After surgical removal of the iliac crest, as many as 2 X 10(9) cells were isolated. Cadaver marrow had a lower percentage of T cells (mean of 10%) than did marrow from living donors. The T cells were lysed by a monoclonal antibody and human complement to a point at which no sheep red blood cell-rosetting cells were detected. Low levels of T colonies, however, grew out from the monoclonal antibody-treated cells. Although cell loss inevitably occurs from purification, antibody treatment, freezing, and thawing, sufficient numbers can be recovered for transplantation. The yield of stem cells was 84% for CFU-C, 39% for CFU-E, 81% for BFU-E, and 48% for CFU-GEMM. We suggest that T cell- depleted marrow cells from cadaver donors could be used for transplantation. Improved immunosuppressive therapy may be required, however, to prevent graft rejection of allogeneic marrow that may have minor histocompatibility differences.

Description: Human gamma interferon (HuIFN gamma) was assessed for its capacity to enhance release of granulocyte-macrophage colony stimulating factors (GM-CSF) from human peripheral blood monocytes. Natural HuIFN gamma (2 X 10(7) NIH reference units per milligram) at concentrations as low as 0.01 U/mL to 10 U/mL reproducibly enhanced release of GM-CSF. This enhancement was detected when T lymphocytes were depleted from monocyte preparations and when T lymphocytes and monocytes were depleted from populations of human bone marrow cells stimulated by monocyte- conditioned media to form colonies and clusters. T lymphocytes alone or in the presence of HuIFN gamma did not release GM-CSF. The enhancing activity of HuIFN gamma was removed by preincubating HuIFN gamma with neutralizing concentrations of monoclonal anti-HuIFN gamma, and recombinant HuIFN gamma mimicked the effects of natural HuIFN gamma, suggesting that the effects were due to HuIFN gamma itself. HuIFN gamma suppression of the release of inhibitory activity from monocytes was ruled out as a reason for the noted enhancing activity of HuIFN gamma. The enhancing activity of HuIFN gamma was confined to the MHC class II antigen-positive population of monocytes. Removal of these cells with monoclonal antibody plus complement (c') ablated the enhancing activity, high concentrations of certain monoclonal antibodies in the absence of c' blocked the enhancing activity and, when monocytes were sorted into MHC class II antigen-positive and -negative cells by fluorescence-activated cell sorting, it was only the positive cell fraction that responded to the enhancing activity of HuIFN gamma.

Description: The neutrophil response to inflammatory stimuli involves the formation of reactive oxygen species and secretion of granule enzymes. In studying secretion of vitamin B12 binding protein by human neutrophils, we noted a major decrease in total recoverable activity from the extracellular fluid plus the stimulated cells (54% of resting cells). Recovery of B12 binding protein from neutrophils exposed to phorbol myristate acetate or opsonized zymosan was significantly enhanced on addition of heme enzyme inhibitors (azide, cyanide) or catalase or when halide-free medium was used. The changes in B12 binding protein recovery were attributable entirely to increases in extracellular fluid levels, and cell pellet content was unaffected. These data indicate extracellular destruction of functional B12 binding protein by the halide-dependent heme enzyme myeloperoxidase and H2O2. Kinetic studies demonstrated rapid secretion of B12 binding protein in the first two to five minutes, followed by its inactivation over the next 20 to 30 minutes. A cell-free extract of vitamin B12 binding protein was readily inactivated on exposure to purified myeloperoxidase, H2O2, and a halide. These findings document a functional interaction among products of the neutrophil specific granules (B12 binding protein), azurophil granules (myeloperoxidase), and metabolic burst (H2O2). They provide an interesting model for the modulation of the inflammatory response by oxidation of secretory products of neutrophils.

Description: Colloidal gold was used as a marker for immunoelectron microscopy to localize lactoferrin (LF) and myeloperoxidase (MPO) in human peripheral blood neutrophils. Cells were reacted with monospecific antibodies against LF or MPO and then with gold-labeled antiglobulin. MPO cytochemistry was also associated with immunologic detection of LF. Immunologic labeling of thin sections after embedding in glycol methacrylate gave good ultrastructural morphology and specific localization of both proteins. MPO was detected in the large azurophil granules, whereas LF was consistently localized in the matrix of another population of morphologically distinct granules, smaller and more numerous than azurophil granules. When cytochemical detection of MPO was coupled with immunologic detection of LF, LF was observed in the population of MPO-negative granules, which were identified as specific. This was confirmed on cells that were permeabilized with saponin and stained for LF and MPO before embedding. No other neutrophil organelles displayed labeling for LF; other blood cells also were unreactive for LF. In the bone marrow, myeloblast and promyelocyte granulations were not stained and LF-containing granules appeared at the myelocyte stage. In conclusion, we confirm previous biochemical and light microscopic studies by ultrastructural demonstration of LF and MPO in two categories of granules, the specific and azurophil granules, respectively. The method described in this article avoids disruption caused by cell fractionation procedures. In the future, other intragranular proteins can be localized by a similar approach.

Description: Whether migration of granulocytes across pulmonary vascular endothelium in the absence of structural evidence of endothelial injury causes increased production of thromboxane or prostacyclin is not known. Using bovine pulmonary artery intimal explants mounted in Boyden chambers and homologous separated granulocytes, concentrations of thromboxane B2 and 6-keto-PGF1 alpha in the upper-well fluid were measured by radioimmunoassay over a three-hour period under the following conditions: (1) granulocyte chemotaxis (zymosan-activated plasma in the lower well, granulocytes in the upper well); (2) unstimulated granulocyte migration (serum or plasma in the lower well, granulocytes in the upper well); (3) granulocyte activation without migration (zymosan-activated plasma and granulocytes in the upper well); (4) granulocyte chemotaxis in the absence of endothelium (identical to condition 1 above except that endothelium was scraped from the explant surface); and (5) explants incubated in the absence of granulocytes. Minimal increases in thromboxane B2 concentrations in upper-well fluid occurred under all conditions. In contrast, granulocyte chemotaxis was accompanied by large increases in concentrations of 6-keto-PGF1 alpha evident by two hours of incubation and increasing markedly by three hours, to 524.3 +/- 69.0 ng/mL (m +/- SEM). Unstimulated migration of granulocytes toward serum or plasma and granulocyte activation without migration were accompanied, at three hours, by more modest increases in 6-keto-PGF1 alpha (296.5 +/- 46.4; 128.0 +/- 38.6, and 236.7 +/- 47.0 ng/mL, respectively) and, in the absence of granulocytes or in the absence of endothelium, only minimal increases in this prostacyclin metabolite occurred (137.2 +/- 16.9 and 53.9 +/- 12.6 ng/mL, respectively). The large rises in prostacyclin metabolite occurred at a time when the majority of granulocytes had migrated through the endothelial layer rather than during their adherence or transendothelial passage. We conclude that chemotaxis of granulocytes through pulmonary vascular endothelium causes endothelial production of large amounts of prostacyclin, but this occurs late in the chemotactic process, after granulocytes have transversed the endothelium.

Description: Forty-eight patients with chronic myelocytic leukemia, aged 11 to 47, were treated with high-dose cyclophosphamide and fractionated total body irradiation, followed by infusion of marrow from HLA-identical siblings. They were randomized to receive either methotrexate (MTX) (n = 23) or cyclosporine (CSP) (n = 25) as postgrafting prophylaxis for graft-v-host disease (GVHD). All patients had evidence of sustained hematopoietic engraftment. Seventeen of the 25 patients receiving CSP and 17 of the 23 patients receiving MTX are alive between one and almost four (median, 1.7) years, with an actuarial survival rate at three years of 62% and 66%, respectively (P = .60). Also, with respect to most other parameters studied, the two drugs were identical. The probability of acute GVHD was .42 and .46, respectively (P = .70), that of chronic GVHD, .50 and .63 (P = .44), and that of death from transplant-related causes, .30 and .24 (P = .51). There were no differences in the speed of granulocyte and platelet engraftment (P = .82 and .94, respectively), and the duration of hospitalization was comparable (P = .58). Patients receiving MTX required red cell transfusions for a shorter period of time (P = .02), but had a slightly increased morbidity from early oral mucositis. The leukemia recurrence rates were comparable (P = .60). With the regimens used in this study, we conclude that CSP failed to reduce the incidence of GVHD and improve the survival of patients with chronic myelocytic leukemia when compared to results with standard MTX.

Description: Thirty-eight children between the ages of 0.8 and 17 years with acute nonlymphoblastic leukemia in first remission induced by chemotherapy were given cyclophosphamide, total body irradiation, and bone marrow transplants from HLA-matched donors. Six patients died of pneumonia, one died of metabolic problems, and one died of chronic graft-v-host disease complications. Five patients relapsed between six months and 3.2 years after transplantation. Three of the five died of leukemia, one survives with leukemia three years after transplantation, and one survives in remission off treatment following chemotherapy for 22 months. Twenty-five survive in continuous remission from 1.7 to 8.4 years after transplantation, and the actuarial analysis shows a disease- free survival rate of 64%, with a plateau extending from 3.5 to 8.4 years. All lead normal lives.

Description: Cytochemical and immunologic analysis of cells obtained from two patients with chronic myeloid leukemia (CML) during blast crisis reveals markers suggestive of an immature lymphoid phenotype. Peripheral blood mononuclear cells from both patients generated spontaneous lymphoblastoid colonies in methylcellulose, a phenomenon observed in T cell acute lymphoblastic leukemias and T cell non- Hodgkin's lymphomas but not in any other type of leukemia. Colonies derived from one patient were composed predominantly of OKT3+ cells (89%), whereas those from the second patient displayed 42% OKT3+ and OKT6+ cells. In the second patient's colonies, each of five mitoses contained the Philadelphia chromosome (Ph1) and two of five displayed the same additional karyotypic abnormalities as the blast crisis cells. Cells obtained from the two patients during remission still gave rise to spontaneous T cell colonies (greater than 85% OKT3+) and Ph1 was detected in 33% and 60% of the metaphases, respectively. However, when colony growth was induced by an interleukin 2-containing conditioned medium, less than 5% of mitoses were Ph1-positive. These data suggest that: (1) the T cell lineage might be involved in CML; (2) a subset of T cells may remain unaffected by the leukemic process, as demonstrated by the virtual absence of Ph1 in induced T cell colonies; and (3) the spontaneous colony assay seems to select for the growth of malignant T cells.

Description: The requirements of clonogenic cells of B cell-type chronic lymphocytic leukemia (B CLL) for interleukin 2 (IL 2) were analyzed. Using the cells of five patients, we measured IL 2 receptor expression on the cell surface and the colony-forming abilities of the cells in response to IL 2. In four of the cases, significant percentages of the CLL cells expressed IL 2 membrane receptors (as assessed with the monoclonal antibody anti-Tac), indicative of their potential sensitivity to IL 2. Pure recombinant interleukin 2 (r-IL2) was added to colony cultures that also contained the lectin phytohemagglutinin (PHA) or the phorbol ester 12–0-tetradecanoylphorbol-13-acetate (TPA) to activate the CLL cells. Colony formation completely depended on the presence of r-IL 2 and PHA or TPA in culture, with the exception of one case, in which the addition of IL 2 was not required for colony growth in TPA-supplemented cultures. Twenty-five to fifty units of r-IL 2 per milliliter of culture medium provided optimal stimulation. Under these conditions, a linear relationship was observed between plated cell numbers and colony numbers formed. Morphological and immunologic analysis of colony cells indicated that these were monoclonal CLL cells that had matured toward plasmacellular lymphocytes and plasma cells.

Description: Circulating lymphocytes leave the blood by binding to specialized high endothelial cells lining postcapillary venules in lymphoid organs or sites of chronic inflammations, migrating through the vessel wall into the surrounding tissue. The capacity of lymphocytes to recognize and bind to high endothelial venules (HEVs) is thus central to the overall process of lymphocyte traffic and recirculation. We show that viable human lymphocytes bind selectively to HEVs in frozen sections of normal human lymph nodes, thus defining a simple in vitro model for the study of human lymphocyte homing properties. Optimal conditions for the quantitative analysis of lymphocyte-HEV interaction are described. Furthermore, by using this assay, we demonstrate that the ability of human lymphocyte populations to bind to HEVs parallels their presumed migratory status in vivo. Thus, thymocytes and bone marrow cells, which are sessile in vivo, bind poorly to HEVs in comparison with mature circulating lymphocytes in peripheral blood or in peripheral lymphoid tissues. These results indicate that HEV-binding ability is a regulated property of mature lymphocytes and, as demonstrated previously in animal models, probably plays a fundamental role in controlling lymphocyte traffic in humans. The in vitro model of lymphocyte-HEV interaction thus provides a unique means to assay the migratory properties of normal and neoplastic human lymphocyte subsets, to analyze the role of lymphocyte traffic mechanisms in normal and pathologic inflammatory reactions, and to define some of the molecular mechanisms responsible for the control of lymphocyte migration and positioning in humans.

Description: This study was undertaken to determine the levels of protein C antigen and activity and protein C inhibitor in sequential plasma samples of disseminated intravascular coagulation (DIC) patients. Our normal range for both protein C antigen and activity is 70 to 130 U/dL, and protein C inhibitor is 65 to 135 U/dL. A decreased level of protein C activity was found in 96% of the plasma samples from individuals with DIC; the protein C antigen was decreased in 73%. The inhibitor of protein C was decreased in all samples. Analysis of serial samples from patients with DIC reveals that protein C activity and antigen and protein C inhibitor decrease progressively during the initial stages of DIC and remain at a low level for 24 to 48 hours before gradually returning toward normal in nonfatal cases. The protein C activity decreases in parallel with protein C inhibitor and is lower than protein C antigen. In a fatal case of DIC, protein C activity and protein C inhibitor rapidly decreased to undetectable levels; however, protein C antigen was gradually decreasing but still detectable at time of death. In DIC, a discrepancy initially occurs between the activity and antigen of protein C, suggesting a complex with the inhibitor or other inactive forms of protein C. Protein C appears to play a major role in the control of DIC.

Description: Peripheral blood specimens were obtained from 22 patients with Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) (16 in chronic phase, 2 in an accelerated phase, and 4 in blast crisis). Studies were performed to determine the frequency of the presence of the Ph1 chromosome in cells of lymphoid lineages. Rosetted (E+) lymphocytes (T lymphocytes) from nine patients in chronic phase and one patient in blast crisis were stimulated with T cell growth factor interleukin 2 (IL-2) and/or phytohemagglutinin (PHA). All ten patients had sufficient T lymphocyte metaphases for analysis and of a total of 461 metaphases examined, only one contained the Ph1 chromosome. Nucleated cells of density less than 1.077 g/mL were infected with Epstein-Barr virus (EBV). Following infection, cell lines were established from individual colonies attached to egg albumin- coated Lab-Tek slide chambers (clonal cell lines) or from suspension culture in 96-well tissue culture cluster dishes (nonclonal cell lines). Cell surface and intracellular marker analysis confirmed the B lymphocyte phenotype of all the cell lines examined. B lymphoblastoid cell lines were established from 16 of the 22 patients. All lines from 12 patients were Ph1-negative. From two chronic phase patients, both Ph1-positive and Ph1-negative lines were established. From one patient in an accelerated phase, only Ph1-positive lines were established. From another patient in blast crisis (of myeloblastic phenotype), only Ph1- positive lines were established initially; however, five months later, after the patient had been treated with mitoxantrone, only Ph1-negative lines were derived from this patient. Based on these results, it appears that most B cells and mature T cells in most CML patients are Ph1-negative, but that about 25% of patients have predominantly Ph1- positive B cells or a mixture of Ph1-positive and Ph1-negative B cells that are capable of growing as established cell lines after transformation with EBV.

Description: In order to study the pattern of B cell involvement in acute nonlymphocytic leukemia (ANLL), multiple B lymphoid cell lines were established by Epstein-Barr virus transformation of peripheral blood mononuclear cells from two patients with the disease who were heterozygous for the X chromosome-linked glucose-6-phosphate dehydrogenase (G6PD). In one patient, the progenitor cells involved by the leukemia exhibited multipotent differentiative expression, whereas in the other patient the cells showed differentiative expression restricted to the granulocytic pathway. In the patient whose abnormal clone showed multipotent expression, the ratio of B-A G6PD in B lymphoid cell lines was skewed in the direction of type B (the enzyme characteristic of the leukemia clone) and significantly different from the 1:1 ratio expected. It is, therefore, likely that the neoplastic event occurred in a stem cell common to the lymphoid series as well as to the myeloid series. In contrast, evidence for B cell involvement was not detected in the patient whose ANLL progenitor cells exhibited restricted differentiative expression. These findings underscore the heterogeneity of ANLL. Clinically and morphologically similar malignancies in these two patients originated in progenitors with different patterns of stem cell differentiative expression. This difference may reflect differences in cause and pathogenesis.

Description: A murine hybridoma cell line that produces a monoclonal antibody to human Hageman factor (HF, factor XII) is described. The antibody (P 5–2– 1) consists of mouse IgG2b heavy chains and lambda light chains, selectively neutralizes HF procoagulant activity, and prevents the proteolytic cleavage of HF during contact activation in plasma. When HF is exposed to P 5–2–1 before the absorption of HF to kaolin, HF procoagulant activity is markedly inhibited. In contrast, P 5–2–1 does not interfere with HF activity after the adsorption of HF to kaolin. P 5–2–1 does not inactivate the prekallikrein–activating activity of 28,000–mol wt HF fragments (HFf). P 5–2–1 binds exclusively to the 40,000mol wt portion of a heavy chain of HF and inhibits the adsorption of HF to negatively charged surfaces. P 5–2–1 immobilized on Sepharose can be used to deplete HF from normal human plasma. This immunoaffinity-depleted plasma is indistinguishable from congenital HF- deficient plasma and can be used as the substrate for HF procoagulant activity assay.

Description: A monoclonal antibody to human Hageman factor (HF, factor XII) was derived from BALB/c mouse spleen cells fused with NS-1 mouse myeloma cells. This antibody, purified from ascites fluid, reacted with HF to inhibit the activation of HF, purified or in normal pooled plasma, as measured by a coagulation assay. The antibody did not inhibit the coagulant activity of activated HF. The antibody also inhibited the generation of amidolytic activity in HF-ellagic acid mixtures, but failed to inhibit the amidolytic properties of the carboxy-terminal fragment of HF (HFf). Amidolytic activity, absent in an HF-monoclonal antibody mixture, was generated upon treatment with insoluble trypsin. Monoclonal antibody, bound to CNBr Sepharose 4B gel (Pharmacia Fine Chemicals, Piscataway, NJ), reversibly bound HF in plasma or in buffer, without activating it. HF was then eluted with 4 mol/L guanidine HCI. The passage of 125I-labeled HF enzymatically cleaved by trypsin through a column of monoclonal antibody-CNBr Sepharose 4B gel resulted in flow- through of HFf with a molecular weight (mol wt) of 30,000 and HF fragments of mol wt 12,000. Elution with 4 mol/L guanidine HCI yielded several HF fragments (mol wt 80,000, 52,000, and 40,000) but not HFf. These data suggest that the single determinant recognized by the murine monoclonal antibody is not on HFf, but rather on the amino-terminal fragment thought to be involved in the binding activity of HF. The monoclonal anti-HF bound to CNBr-activated Sepharose 4B gel could be used to artificially deplete plasma samples of HF.

Description: Preliminary studies have suggested that depletion of T lymphocytes from donor marrow might be an effective method for preventing acute graft-v- host disease (GVHD) after allogeneic bone marrow transplantation in humans (Lancet 1:369, 472, 1984). However, the minimum degree of T cell depletion required to assure the prevention of GVHD in a population of marrow graft recipients has not been defined, largely because quantitative assays with sufficient sensitivity for detecting small numbers of residual viable T cells have not been developed. We have investigated three methods for the detection and enumeration of T cells after treatment of bone marrow with murine monoclonal anti-T cell antibodies and complement. Cell populations prepared by adding graded numbers of T cells to treated bone marrow were analyzed by immediate indirect immunofluorescence, by indirect immunofluorescence after culture of cells in medium containing phytohemagglutinin (PHA), or by a limiting-dilution assay. Immediate indirect immunofluorescence could reliably detect 300 T cells per 10(5) treated bone marrow cells. Indirect immunofluorescence after culture in PHA was tenfold more sensitive and could reliably detect 30 T cells per 10(5) treated bone marrow cells. The limiting dilution assay could be 300-fold more sensitive than immediate indirect immunofluorescence and 30-fold more sensitive than indirect immunofluorescence after culture in PHA. Sensitive, quantitative assays will be useful in guiding the development of methods for efficient removal of T cells in donor marrow, and will be essential for monitoring and interpreting the results of clinical trials.

Description: Human peripheral blood polymorphonuclear leukocytes (PMNs) have recently been recognized as a heterogeneous population of cells. Consideration has not been given to the possibility that size may be an additional physical characteristic demonstrating heterogeneity. Using counterflow centrifugal elutriation, we have demonstrated that PMNs can be isolated into at least six volume-dependent fractions. A positive correlation exists for PMN size and superoxide anion release upon stimulation with f-Met-Leu-Phe or phorbol myristate acetate. Total granule contents were also noted to be greater in larger PMN fractions, with a constant percent of release upon stimulation. The implications of these findings are discussed.

Description: Of 50 consecutive patients (30 female and 20 male; median age,70 years) with a myeloproliferative disorder and a 5q- chromosome, 12 (24%) had refractory anemia, 16 (32%) had refractory anemia with excess blasts, 13 (26%) had acute nonlymphocytic leukemia, six (12%) had the 5q- syndrome, and three (6%) had an unclassifiable myeloproliferative disease. Twenty-five patients had only a 5q- anomaly (group 1), and 25 had a 5q- plus additional chromosome abnormalities (group 2). Four types of 5q- anomalies were recognized: a del(5)(q13q33) occurred in 39 patients, a del(5)(q31q35) in nine, a del(5)(q22q33) in one, and a del(5)(q13q35) in one. The survival distribution for patients in group 1 was significantly better (P = .012) than for those in group 2. Cox- model analyses indicated that having a 5q- chromosome and other abnormalities is significantly (P less than .01) associated with poor survival even after adjustment for the effects of other important factors such as type of disease, age, and sex. The two groups had similar distributions of most variables, including age, sex, and disease types. However, patients in group 1 had a significantly higher platelet count and mean corpuscular volume than those in group 2. Only two patients in group 1 had had prior chemotherapy, but nine in group 2 had had either prior chemotherapy or radiation or both, and one patient in group 2 had had heavy exposure to pesticides.

Description: In view of bone marrow purging before autologous transplantation in T cell malignancies, an anti-human T cell immunotoxin (IT) has been prepared by coupling ricin A-chain to the monoclonal antibody T101 that binds the T1 differentiation antigen expressed by T lymphocytes as well as by T cell-derived hematologic malignancies. Using a sensitive and reliable clonogenic assay, optimal conditions were defined for the elimination of clonogenic human T leukemic cells among bone marrow cells. Maximal cytoreduction was obtained with IT at a dose of 2 micrograms/mL in the presence of 10 mmol/L NH4Cl. This treatment led to the reduction of more than six orders of magnitude of T101-positive clonogenic leukemic cells, with no harm to T101-negative cells. Moreover, we observed no toxicity of IT to human hematopoietic stem cells (CFU-GEMMT) derived from bone marrow of healthy volunteers. Thus, pretreatment of bone marrow samples with IT plus NH4Cl offers a safe, simple, reliable, and highly efficient means to eliminate undesirable leukemic T cells from the graft.

Description: Adult T cell leukemia (ATL) is an almost uniformly fatal malignancy of mature T cells associated with human T cell leukemia/lymphoma virus type 1 (HTLV-1) infection. Cells from this leukemia are characterized by the expression of large numbers of receptors for interleukin 2 (IL- 2). In an attempt to prepare an immunotoxin with selective cytotoxicity for ATL cells, we conjugated anti-Tac, a monoclonal anti-IL-2 receptor antibody, to purified ricin A chains. Although unmodified anti-Tac had no effect on the protein synthesis of these cells, anti-Tac-ricin A chain conjugates produced half-maximal inhibition of protein synthesis in HTLV-1-infected leukemic T cell lines at concentrations of 2 to 6 X 10(-10) mol/L (ID50). An essentially identical ID50 was obtained with leukemic peripheral blood T lymphocytes isolated from two patients with ATL. In contrast, half-maximal inhibition of protein synthesis in HTLV- uninfected, IL-2 receptor-negative T and B cell lines required 200- to 1,000-fold higher concentrations of anti-Tac-ricin A chain conjugates. Both unconjugated anti-Tac and immunoaffinity-purified IL-2 completely inhibited the toxic effects of anti-Tac-ricin A, confirming the specificity of the conjugate-IL-2 receptor interaction. Clonogenic assays demonstrated that anti-Tac-ricin A chain was able to eliminate greater than 99.9% of an HTLV-1-infected T cell population at concentrations only marginally affecting IL-2 receptor-negative cells. The data presented demonstrate that anti-Tac-ricin A is selectively cytotoxic for HTLV-1-infected leukemic T cells in vitro and raises the future possibility of specific therapeutic intervention with immunotoxins in this disease.

Description: At least 22 members of a large kindred have a bleeding tendency resulting from an autosomal dominant disorder of platelet production and function. Phenotypic manifestations include mild to moderate thrombocytopenia, bleeding time prolongation, and abnormal platelet aggregation. Platelet survival time is normal. The platelet disorder in this family appears to differ from known hereditary thrombocytopenic or thrombocytopathic syndromes and may represent a new genetic disease. Six family members reportedly developed hematologic neoplasms: acute monocytic leukemia nine years after treatment for congenital neuroblastoma; lymphosarcoma at age 10 years; myeloid leukemia at age 23 years; acute myelocytic leukemia at age 62 years; leukemia of unknown type at age 48 years; and lymphocytic lymphoma at age 52 years.

Description: The effects of in vivo administration of three monoclonal antibodies specific for T11, the E rosette receptor on T lymphocytes, were examined in the rhesus monkey (Macaca mulatta). These three monoclonal antibodies were of different isotypes and were shown in in vitro studies to have differing affinities for the monkey T11 structure. Furthermore, each antibody induced antigenic modulation of T11 from the cell membrane of the lymphocytes to varying degrees in vitro. In vivo infusion of each of these antibodies into normal rhesus monkeys caused remarkably different effects on the circulating T lymphocyte pool. Infusion of these antibodies at doses of 2 mg/kg caused the coating of circulating T lymphocytes with antibody, the modulation of T11 off the T cell surface and the transient clearance of T cells from the circulation. Yet, the variation in the extent to which these effects were seen with these different antibodies indicates that extrapolating from studies of the in vivo use of one antibody to the use of another may be quite difficult. These studies clearly indicate the strengths of this nonhuman primate system for exploring the uses of monoclonal antilymphocyte antibodies as therapeutic agents. They, however, also demonstrate that differences may exist in the affinity of a particular antibody for homologous lymphocyte surface structures in humans and in a nonhuman primate species. These differences may make it difficult to predict the precise effects that the infusion of an antibody will cause in humans on the basis of alterations it induces in nonhuman primates.

Description: Whole blood and Stractan-Percoll fractions of blood from splenectomized patients with homozygous hemoglobin C (CC) disease were studied under aerobic and anaerobic conditions. Erythrocytes containing typical CC crystals are found in the densest fraction as documented by freeze- fracture electron microscopy. We report that the intraerythrocytic Hb C circulating crystals are in the oxygenated liganded state as demonstrated by melting upon deoxygenation and by absorption spectroscopy. Furthermore, crystals are more likely to form in cells with low concentration of Hb F. Changes of ligand state (which results in melting of the intraerythrocytic crystal) might be involved in the pathophysiology of this disease, removing the danger of vasoocclusive episodes.

Description: Platelet Activating Factor (PAF) (1-O-alkyl-2-acetyl sn-glycerol 3- phosphocholine) has been characterized by its ability to aggregate platelets at low concentrations and its profound hypotensive effects. There is evidence that the rate of catabolism of this compound in the plasma regulates its concentration. In humans, we and others have shown that a PAF acetylhydrolase is associated with low density lipoprotein (LDL). The LDL particle in the plasma of patients with Tangier disease is quite different from normal as its lipid core appears to be enriched with triacylglycerol. Thus, we have studied the potential of this abnormal lipoprotein to degrade PAF. The assay for PAF acetylhydrolase was based on the release of 3H from PAF that was labelled in the acetate moiety of the sn-2 position. Tangier disease plasma had approximately 3.3-fold higher PAF acetylhydrolase activity (208 +/- 9 nmol/min/mL) than controls (63 +/- 18 nmol/min/mL). This increase was brought about by an increase in the Vmax (400 +/- 40, Tangier disease; 54 +/- 5, controls) and Km for PAF (120 +/- 20 mumol/L, Tangier disease; 28 +/- 4 mumol/L, controls). The activity appears to be a specific acetylhydrolase rather than a phospholipase A2 as preincubation of the substrate with 0 to 100 mumol/L phosphatidylcholine did not affect the amount of [3H] acetate released. The role of PAF, and its degradation by LDL-bound PAF acetylhydrolase in the phenotypic expression of this patient with Tangier disease, is not known. However, this is the first patient so far described who has an increased ability to degrade PAF in the plasma.

Description: This study was undertaken to determine whether diabetes alters the viscoelastic properties of erythrocytes. The oldest and youngest 10% fractions of circulating red cells were separated by centrifugation of freshly drawn blood obtained from ten diabetics with disease of one to 20 years' duration and from an equal number of age- and sex-matched control subjects. Cells from each fraction were suspended in phosphate- buffered saline, and their rheologic behavior was examined in a rheoscope. The elongation of cells, the percentage of cells that tank- treaded in response to shear stress, tank-treading frequency, and the rate of recovery of cell shape upon cessation of shear stress were determined in the oldest and youngest 10% of cells for diabetics as well as for controls. All four parameters were virtually identical for diabetics and controls. Additional aliquots of cells were taken for assessment of nonenzymatic glucosylation of hemoglobin and cell membrane protein. The absence of any measurable difference in rheologic behavior of cells from diabetic and control subjects, despite substantial differences in nonenzymatic glucosylation of hemoglobin and cell membrane proteins, suggests that the magnitude of glucosylation observed in these cellular constituents does not alter the viscoelastic properties of the cells. The implication of these observations is that microvascular complications of diabetes are not attributable to altered deformability of red cells.

Description: We have previously reported that the addition of monocytes results in enhanced modulation of the T65 antigen when normal or leukemic lymphoid cells were cultured in vitro with the T101 monoclonal antibody. In the present investigation, we extend these findings to demonstrate that monocyte-enhanced modulation is a phenomenon that occurs with a variety of T and B lymphoid antigens identified by murine monoclonal antibodies. Two patterns of monocyte-enhanced modulation were observed: (1) augmentation by monocytes of existing antigen modulation by the T101 and anti-Leu-4 antibodies, and (2) induction by monocytes of previously unrecognized modulation with the anti-Leu-2 and anti-Leu-9 antibodies. Enhancement of modulation by monocytes was also detected with antibodies to surface IgM and HLA-DR antigens. Antigen modulation on lymphoid cell lines appeared to be more variable than on fresh cells, with or without monocytes. Monocyte-enhanced antigen modulation was not demonstrated with two monoclonal antibodies against solid tumors. Monocyte-enhanced modulation was shown to be dependent upon the Fc portion of the antibody, but independent of proteolytic or oxidative compounds released by monocytes. These findings indicate that the results obtained during in vitro studies of antigen modulation may vary with the source of cells and the extent to which monocytic cells are present. In addition, these findings suggest an enhanced role for Fc receptor-bearing cells of monocytic origin in antigen modulation following in vivo administration of monoclonal antibodies.

Description: The efficacy of four separate methods of human bone marrow T lymphocyte depletion was assessed, and the effect of T cells and monocytes on in vitro growth of marrow (CFU-GEMM, BFU-E, and CFU-GM) and peripheral blood (BFU-E) hematopoietic progenitors was determined. Extent of T cell depletion was assessed by multiparameter fluorescent cell sorter (FACS) analysis and by functional studies. Cells staining positively by FACS analysis for one or more of three separate fluorescent pan-T cell monoclonal antibodies (MCAbs) comprised 8.4% to 9.5% of control marrow mononuclear cells (MNCs). T cells constituted 3.2% to 5.1% of marrow following single, sequential, or combination treatment with two different pan-T cell MCAbs (Leu 1 and TM1) plus complement, 1.5% to 2.2% of marrow following solid-phase immunoabsorption (“panning”), 0.2% of marrow after sheep cell rosetting, and only 0.05% of marrow after FACS selective cell sorting and gated separation. T cells made up 59% to 73% of control peripheral blood MNCs and 0.8% to 2.8% of peripheral MNCs following sheep cell rosetting plus treatment with Leu 1 MCAb and complement. Mitogen (PHA, Con A) and allogeneic MLC-induced blastogenic responses (stimulation indices, experimental/control or E/C) revealed a concordant decrement in marrow T cell function after MCAb plus complement (E/C of 3.9 to 9.0), after panning (E/C of 1.6 to 3.5) and after sheep cell rosetting (E/C of 0.7 to 1.3), compared with control marrow (E/C of 5.3 to 15.7). After T cell depletion, marrow BFU-E growth was 95% to 120% of control, CFU-GM growth was 90% to 108% of control, and CFU-GEMM growth was 89% to 111% of control. Marrow T cell and/or monocyte depletion did not alter erythropoietin-dependent BFU-E growth in the absence of Mo-conditioned medium (81% to 95% of control), and the addition of as many as 50 to 100 X 10(3) purified marrow monocytes or T cells to 10(5) autologous nonadherent T cell-depleted marrow target cells had a negligible (P greater than .1) effect on marrow BFU-E growth in vitro. Peripheral blood (PB) BFU-E/10(5) T- depleted target cells were 106% +/- 19% of expected; PB BFU-E growth was significantly diminished after monocyte depletion alone (7% +/- 6% of expected) or after monocyte plus T cell depletion (8% +/- 4% of expected).(ABSTRACT TRUNCATED AT 400 WORDS)

Description: Mouse monoclonal anti-idiotype antibodies have been used to treat two patients with progressive advanced B cell non-Hodgkin's lymphoma. Transient falls in the level of circulating malignant cells and idiotypic immunoglobulin were produced, and free unbound monoclonal antibody was identified in the serum. Homing of the antibodies to tumor cells in the blood, bone marrow, ascites, and lymph nodes was demonstrated in both patients. Although large amounts of anti-idiotype antibody were given (3.8 g and 5.8 g), no toxic effects were seen, and no antibodies to the foreign mouse protein were made. There was no modulation of the antigen from the tumor cells and no indication of immunoselection. There was evidence of large-scale tumor cell destruction, but only a modest reduction in tumor size. The killing of the tumor cells was mediated by the reticuloendothelial system and not by complement.

Description: In 22 patients with malignancies, treated with high-dose chemoradiotherapy and autologous bone marrow transplantation (BMT), peripheral blood T cell subsets and functions were studied. In ten cytomegalovirus (CMV)-negative patients, CD4+ and CD8+ T cells (representing T cells of the helper/inducer phenotype and T cells of the suppressor/cytotoxic phenotype, respectively), recovered slowly and simultaneously. In 12 CMV-positive patients, however, CD8+ T cells recovered more rapidly than CD4+ T cells and rose to increased counts. No T cells with an immature phenotype (CD1+, OKT6+) were observed. Lymphocyte stimulation by herpes simplex virus infected fibroblasts (and by CMV-infected fibroblasts in CMV-positive patients) in contrast remained high and even increased after BMT in both groups. These data indicate that T cell recovery after autologous BMT is mainly due to proliferation of mature T cells present in the BM graft and not to generation of new T cells from T cell precursors.

Description: The role of subendothelial fibronectin in platelet interaction with subendothelium was studied. Human umbilical artery subendothelium was exposed to flowing blood containing 111In-labeled platelets in an annular perfusion chamber. Platelet adhesion was determined from the 111In radioactivity on the vessel wall. When perfusions were performed for five minutes at a wall shear rate of 1,800 s-1, platelet adhesion was the same whether normal plasma or fibronectin-free plasma was used. Preincubation of subendothelium with rabbit anti-human fibronectin serum, however, resulted in a marked inhibition of platelet adhesion. Preincubation with normal rabbit serum had no effect. Platelet adhesion was also diminished when the vessel wall was preincubated with anti- fibronectin IgG fraction or F(ab')2 fragment. After the latter preincubations, frozen sections of 4 micron were incubated with fluorescein isothiocyanate-conjugated goat anti-rabbit IgG, F(ab')2 fragment specific. Fluorescence was seen throughout the subendothelium both before and after perfusion. No fluorescence was seen when subendothelium was preincubated with normal rabbit IgG or F(ab')2 or with anti-fibronectin IgG that had been absorbed with purified fibronectin. After absorption of anti-fibronectin IgG with purified fibronectin, the inhibiting effect on platelet adhesion was also no longer present. Preincubation of the vessel wall with anti-fibronectin IgG reduced platelet adhesion significantly at a wall shear rate of 800 s-1. This effect was even greater at 1,800 s-1. At low shear rate (400 s-1), there was no inhibition.

Description: Hybridomas secreting monoclonal antibodies (MoAbs) to human platelet membrane glycoprotein IIb (GPIIb) were prepared by fusing cells of a mouse myeloma line to spleen cells from a BALB/c mouse immunized with purified GPIIb. Six of the hybridomas secreted MoAbs that recognized epitopes on the 23,000-dalton, disulfide-linked subunit of GPIIb, GPIIb beta. All six of these MoAbs agglutinated platelets in the absence of calcium. The agglutination titers of three of the MoAbs, however, were enhanced between 2 and 6 log2 dilutions when titrated in the presence of mmol/L of calcium. The enhancement in titer was the result of MoAb- induced platelet activation followed by platelet aggregation, a reaction that could also be initiated by the monovalent Fab fragments prepared from one of the MoAbs. The MoAbs did not significantly agglutinate platelets from patients with Glanzmann's thrombasthenia, confirming biochemical evidence that there is a paucity of GPIIb beta in the membranes of these cells. Our results show that MoAbs to epitopes on GPIIb beta initiate distinct platelet responses; therefore, they should be useful for studying the ways in which regions of surface glycoproteins are involved in platelet-platelet interactions. In addition, these reagents may prove of value in diagnosing and typing patients with Glanzmann's thrombasthenia.

Description: Monoclonal antibodies (MAbs) to vascular plasminogen activator (vPA), the tissue-type plasminogen activator (tPA) in human plasma, were produced to be used as probes for immunochemical analysis. Human tissue sections and one of these MAbs were used to demonstrate the endothelial origin of plasma-tPA by immunohistochemistry. To produce MAbs, mice were immunized with semipurified vPA isolated from postocclusion human venous blood. Primed spleen cells were fused with the mouse myeloma cell line NS-1. Screening for MAb-producing hybridomas was performed with postocclusion euglobulins as a source of antigen by means of a solid-phase fibrin-vPA immunoassay. The selective and high-affinity binding of vPA for fibrin ensures the specificity and sensitivity of this test. Thus, eight hybridomas secreting MAbs to vPA were selected, cloned, and established as permanent hybridoma cell lines. Immunohistochemical analysis of cryostat sections of human tissues was performed with EA-delta 12D, a MAb having no inhibitory effect against vPA activity but binding to vPA with a high affinity. Thus, the only structures immunostained were endothelial cells of venules, capillaries, and arterioles. The EA-delta 12D monoclonal localization of plasma vPA in the endothelial lining of blood vessels provides evidence that tPA in plasma originates from the vascular wall and validates its designation as vascular plasminogen activator, ie, vPA. Also, our results are consistent with the fact that vPA in blood and tPA in tissues are immunologically identical and have a common endothelial origin.

Description: A girl with Down's syndrome was born with a myeloproliferative disorder. The child had spontaneous regression of the myeloproliferation, with acute leukemia developing at a later date. Morphologic, cytochemical, immunologic, and immunoglobulin gene configuration studies all supported the diagnosis of acute nonlymphocytic leukemia. High-resolution chromosome studies revealed that the leukemic cells consistently contained a translocation between chromosomes 1 and 19: der(19)t(1;19)(q25;p13). Spontaneous regression of the transient myeloproliferative syndrome of the newborn with Down's syndrome may not always be permanent, and the transient myeloproliferative syndrome may sometimes represent an early sign of acute nonlymphocytic leukemia.

Description: Two murine monoclonal antibodies, FMC 25 and AN 51, directed against distinct epitopes on the glycoprotein Ib complex, have been used to further define the mechanism of quinine/quinidine drug-dependent antibody interaction with platelets. FMC 25, directed against an epitope on glycoprotein IX, had no effect on platelet aggregation induced by collagen or adenosine diphosphate and little, if any, effect on ristocetin-induced platelet agglutination. FMC 25 and its (Fab)2 fragment, however, were potent inhibitors of drug-dependent antibody- induced platelet aggregation and blocked binding of drug-dependent antibody to platelets as assessed by indirect platelet immunofluorescence. In contrast, AN 51, directed against an epitope on the alpha-subunit of glycoprotein Ib, blocked ristocetin-induced, factor VIII/von Willebrand factor (FVIII/vWF)-dependent platelet agglutination but not drug-dependent antibody-induced platelet aggregation or binding of drug-dependent antibody to platelets. Selective proteolytic removal of the majority of the alpha-subunit of glycoprotein Ib (glycocalicin) from platelets by treatment with calcium- dependent protease did not affect binding of drug-dependent antibody. In addition, a quinidine-dependent antiplatelet antibody immunoprecipitated glycoprotein Ib complex from normal platelets and the membrane-associated proteolytic remnant of the glycoprotein Ib complex from calcium-dependent protease-treated platelets. Preincubation of drug-dependent antibody with purified glycoprotein Ib complex inhibited subsequent binding of antibody to platelets, but the separated components, glycoprotein Ib and glycoprotein IX, were both ineffective, suggesting that the normal interaction between glycoprotein Ib and glycoprotein IX in the intact complex was necessary for drug-dependent antibody recognition. The functional response of platelets to drug-dependent antibody was not mediated by way of platelet Fc receptor, since aggregation of washed platelets by acetone- aggregated IgG was not inhibited by FMC 25 (Fab)2. FVIII/vWF was not required for drug-dependent antibody-induced platelet aggregation. The combined evidence is consistent with quinine/quinidine-dependent antibody-platelet interaction occurring by way of a FVIII/vWF- independent, Fc receptor-independent mechanism that probably involves binding of antibody to glycoprotein IX or the beta-subunit of glycoprotein Ib or both.

Description: Previously, we have demonstrated a parallel between most-dense (bouyant density) sickle erythrocyte subpopulations and most-dense aged normal red cells in the organization of membrane components in the intact cell. The present study has addressed the possibility that a corresponding similarity may exist between most-dense sickled red cell subpopulations and aged normal erythrocytes in the development of membrane protein components that function as receptors for autologous immunoglobulin (Ig). Autologous IgG retained by density-fractionated erythrocytes has been estimated by a nonequilibrium 125I-protein A (Staphylococcus aureus) binding assay. Results show that most-dense sickle cell fractions contain more (2.7-fold and 1.8-fold, P less than .005) cell-bound IgG in comparison to younger sickle erythrocyte fractions sedimenting at low density. Parallel findings were obtained after similar analyses of normal (homozygous-A) erythrocyte fractions. Detection of the presence of specific IgG was also carried out by direct binding of fluorescein isothiocyanate-conjugated anti-human IgG to density-separated red cell fractions followed by analyses of the fluorescent cell populations by flow cytometry. Results showed significantly higher levels of IgG bound to most-dense (12.1% +/- 2.5% and 8.8% +/- 0.5%-) sickle red cell subpopulations (P less than .005) in comparison to younger sickle erythrocyte fractions sedimenting at low densities (3.8% +/- 0.32% and 4.7% +/- 1.6% IgG-positive red cell subpopulation). These results indicate that some of the same membrane changes that occur at about 120 days in normal red cells are also apparent in the chronologically younger (life span in vivo, ten to 40 days) sickle erythrocyte. The increased retention of IgG by most-dense irreversibly sickled cell-enriched fractions in comparison to least- dense reversibly sickled cells or pre-irreversibly sickled erythrocyte fractions, suggests that alterations in the topography of the sickle cell membrane during the transformation in vivo to the most-dense irreversibly sickled cell morphology may produce the unmasking of cryptic antigenic sites. In addition, these findings may indicate that opsonization of specific erythrocyte subpopulations may play a role in the pathophysiology of sickle cell disease.

Description: We studied ten normal subjects and 20 patients with stable, untreated idiopathic thrombocytopenic purpura (ITP) and platelet counts in the range of 35,000 to 110,000/microL. The diagnosis was made by clinical criteria. Platelet-associated IgG was increased in all nine of the nine patients studied. Autologous platelets were labeled with chromium 51 and reinfused for measurement of mean cell life and platelet production rate. Mean cell life was calculated by two methods, weighted mean and multiple hit, with excellent agreement between the two. As expected, mean cell life was significantly reduced in ITP patients as compared to the normal subjects (2.9 days v. 8.0 days, P less than .001). However, mean platelet production rates in ITP patients and normal subjects, 3.5 and 3.8 X 10(9) platelets/k/d respectively, were not significantly different. Platelet production rate was above and below the normal range (2 to 5.6 X 10(9) platelets/k/d) in two and four patients, respectively. We conclude that the rate of platelet production is not increased in most patients with ITP who have platelet counts greater than 35,000/microL. We did find that platelet size was increased in eight of the 12 patients in whom it was measured, including two of the patients with low platelet production.

Description: The mechanism of clearance of circulating fibrin monomer was investigated in rabbits through (1) study of decay in plasma concentrations of 125I-labeled monomers with variant fibrinopeptide content and (2) concurrent analysis of decay of the monomers relative to coinjected 131I-fibrinogen. Under the conditions employed, essentially all of the fibrin became distributed in a soluble form in plasma and decayed independently of the coinjected fibrinogen. Among the species of fibrin studied, monomer lacking fibrinopeptide A alone (alpha-fibrin) underwent very rapid clearance by a saturable mechanism that was not evident in relatively sluggish clearance of monomer lacking either fibrinopeptide B alone (beta-fibrin) or both fibrinopeptides A and B (alpha beta-fibrin). Decay of alpha-fibrin conformed with a kinetic mechanism involving first-order permeation of the fibrin into extravascular space at a rate equivalent to that of permeation of fibrinogen; unlike fibrinogen, however, the alpha-fibrin underwent immediate absorption in parallel with permeation (t1/2 = 2.6 hours) at doses below an apparent saturating level of 3 mg/kg. At doses near the absorptive limit, the uptake accompanying permeation diminished as in a second-order kinetic mechanism, and at very high doses the plasma decay of the alpha-fibrin approached that of fibrinogen. The beta- and alpha beta-fibrins also permeated extravascular space in parallel with fibrinogen, but absorption proceeded sluggishly (t1/2 = 11 and 16 hours, respectively) at low doses and did not change with increasing dose. The uniquely rapid and saturable clearance of alpha-fibrin is suggested to involve uptake through the fibrin aggregation site that is blocked by fibrinopeptide A in fibrinogen and beta-fibrin and by tight binding to fibrinogen in soluble complexes formed by alpha beta-fibrin. A corollary of this hypothesis is that rapid uptake depends on dissociability of fibrin complexes for access to the aggregation site, a mechanism that is just the converse of uptake through aggregation.

Description: Analysis of methylation at the beta-globin gene cluster was carried out on DNA derived from nucleated RBCs (orthochromatic normoblasts) isolated from peripheral blood of patients with beta-thalassemia major or other congenital hemolytic anemia after splenectomy. A procedure to separate these normoblasts from the other nucleated cells of the peripheral blood was developed, providing us with a convenient source of DNA for investigating parameters related to human erythroid differentiation. Blood samples were obtained from six adult patients who express their gamma-globin genes at different levels. Inverse correlation between methylation and gene activity was consistently observed for five of the eight sites analyzed. A site 3′ to the beta gene was always unmethylated, two sites flanking the epsilon gene were always found to be methylated, and two sites 5′ to the two gamma genes, G gamma and A gamma, were hypomethylated in correlation with gamma gene activity of the individual patients. A site 5′ to the delta gene was unmethylated in normoblasts as well as in WBC. No apparent relation between hypomethylation and gene activity was observed for two additional sites. The results suggest that methylation at specific chromosomal locations participate in genetic regulation of the beta- like globin genes in humans.

Description: We have previously used a chromium-release assay to demonstrate that the cocktail of monoclonal antibodies BA-1, BA-2, BA-3, and complement can effectively lyse human leukemic cells in the presence of excess bone marrow. Using a leukemic cell colony assay, we have reinvestigated the variables influencing lysis of human leukemic cells (KM-3, HPB- NULL, NALM-6) in bone marrow using BA-1, BA-2, BA-3, and complement. Specific variables addressed included the concentration of excess bone marrow cells, the number of treatments, the presence or absence of DNase during the treatment, the combination of antibodies, and the sensitivity of different leukemic cell lines to lysis. Using the colony assay, the BA-1,2,3 cocktail was shown to be more effective than any single antibody or combination of two antibodies. We also determined that the concentration of excess bone marrow cells and number of treatments had a direct bearing on leukemic cell lysis. Although two cycles of treatment were significantly superior to one cycle, three cycles were not significantly superior to two cycles. Inclusion of DNase (10 micrograms/mL) was a critical adjunct that eliminated clumping and facilitated plating cells in the colony assay. Finally, we could show that striking differences existed in the sensitivity of the leukemic cell lines to lysis with the BA-1,2,3 cocktail and complement. NALM-6 cells were the most sensitive (approximately four logs of kill), and KM-3 cells were the most resistant (less than two logs of kill). Our results strongly support the utility of sensitive leukemic cell colony assays in the analysis of marrow treatment variables in autologous bone marrow transplantation.

Description: Platelet glycoprotein Ib (GpIb), a receptor for von Willebrand's factor (vWF), was studied by way of fluorescence flow cytometry. Using a sandwich staining technique, GpIb was identified by a monoclonal antibody (6D1) directed against an epitope close to the vWF binding site. Platelets from normal individuals were symmetrically distributed with respect to GpIb content. Treatment of washed platelets with plasmin resulted in progressive loss of GpIb as measured by fluorescence flow cytometry and by loss of agglutination response when combined with ristocetin in the presence of vWF. In mixing experiments with GpIb-deficient and normal platelets, it was possible to detect a subpopulation of deficient cells comprising 2% of the total population. Streptokinase treatment of platelet-rich plasma caused loss of the agglutination response to ristocetin and the emergence of a population of GpIb-deficient platelets. Fluorescence flow cytometry appears to be an important new technique by which to study platelet surface receptors.

Description: Six patients with relapsed hairy cell leukemia after splenectomy were treated with high-dose methotrexate and leucovorin rescue. Five patients had objective responses as determined by improved blood counts. In two of them, the response has continued for more than 14 and 44 months, respectively. Intensive treatment with high-dose methotrexate and leucovorin rescue was well tolerated and no significant myelosuppression was seen.

Description: A qualitative defect of antithrombin III (AT III) has been demonstrated over three generations in eight members of an Italian family by the discrepancy between a normal amount of antigen and decreased antithrombin and anti-Xa activity in the presence or in the absence of heparin. By two-dimensional immunoelectrophoresis in the absence of heparin, two peaks of AT III were present in all patients' plasma. AT III was purified from normal and propositus plasma by sulfate dextran precipitation followed by heparin affinity chromatography. The elution profile of the patient's AT III was abnormal and allowed the separation of two populations of AT III, normal and abnormal. The first fraction (normal AT III) contained AT III activity, migrated as a single peak by two-dimensional immunoelectrophoresis and by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE), demonstrated a single band with a molecular weight (mol wt) identical to that of normal AT III (60,000). Conversely, the last fraction, devoid of AT III activity, migrated as a single abnormal peak by two-dimensional immunoelectrophoresis in the absence of heparin. By SDS-PAGE, two bands were observed: one with a mol wt of 60,000 and a second one with a mol wt of 120,000. Western blots clearly demonstrated cross-reactivity of the 120,000 and 60,000 mol wt bands with monospecific antisera to human AT III. Reduction of the 120,000 mol wt band converted it to a single 60,000 mol wt band, suggesting the presence of an abnormal dimeric form of AT III. The name AT III Milano is proposed for this new variant.

Description: The granulocyte-specific monoclonal antibody, AHN-1, immunoprecipitates two major surface-iodinated proteins of 105,000 and 145,000 to 150,000 daltons from normal human neutrophils. In this study, the effect of AHN- 1 on a number of neutrophil functions was evaluated in vitro. Both complement- and antibody-mediated phagocytosis were inhibited when human neutrophils were pretreated with AHN-1 and opsonized bacteria were used as targets. The inhibition of phagocytosis was specific, in that lysosomal enzyme release and chemotaxis were not altered by treatment with AHN-1. AHN-1 did inhibit superoxide production by neutrophils in response to particulate stimuli, but not in response to the soluble stimulus, 12-O-tetradecanoylphorbol-13-acetate. The data indicate that one or both of these surface proteins may be important in the process of phagocytosis. AHN-1 should be useful in isolating and further characterizing the nature of these molecules.

Description: Cytochemical investigation of leukemic promyelocytes from 25 cases of acute promyelocytic leukemia (M3) disclosed two major cellular differentiation categories: (1) the pure neutrophilic (N) type (16 cases) with strong myeloperoxidase (MPO) and naphthol-ASD chloroacetate esterase (Es-chl), but lacking the monocytic enzyme NaF-sensitive alpha- naphthyl butyrate esterase (Es-b), and (2) the mixed neutrophilic/monocytoid (N/M) type (seven cases) with strong Es-b as well as strong MPO, all cases exhibiting Es-dual (Es-b + Es-chl) positive cells. Two more cases with unusual phenotypes were noted: one with intense lysozyme activity but without Es-b and the other with toluidine blue-methachromasia and negative MPO. Promyelocytes from the control group, consisting of nine cases of t(8;21) M2 AML and ten cases with normal bone marrow, lacked such cytochemical heterogeneity. HL-60, an M3 cell line that can be induced to differentiate toward monocytic lineage in vitro, was almost negative for Es-b in the uninduced condition. Cytogenetically, eight cases of N type and five of N/M type had the t(15;17) abnormality. Thus at least two differentiation patterns were observed in M3 leukemia with fidelity (N type) and infidelity (N/M type) for normal granulocytic differentiation. In this series, there was no statistically significant difference in clinical features (remission rate and survival) between the two types. Our study suggests that the development of M3 leukemia is not exclusively restricted to the neutrophilic pathway, but more heterogeneously related to myelomonocytic differentiation.

Description: The c-abl locus is translocated from chromosome 9 to chromosome 22 in chronic myelogenous leukemia (CML), creating the Philadelphia chromosome (22q-, Ph1), one of the most consistent chromosomal abnormalities found in human hematologic malignancy. The K562 cell line is a human cell line originally derived from a patient with CML. We have isolated cloned human c-abl probes to analyze the organization and expression of abl genes in patients with CML and in K562 cells. With these probes, we confirm the amplification of abl genes in K562 cells. In addition, we demonstrate the presence of increased amounts of a novel RNA species hybridizing to a c-abl probe in K562 cells. This same large RNA species is present in addition to two normal transcripts in the leukemic cells of patients with CML. These results provide evidence that the c-abl locus is abnormally expressed in CML.

Description: To reexamine the influence that T lymphocytes have on the regulation of human peripheral blood burst-forming unit (BFU-E) proliferation in the absence of a statistically significant number of monocytes, very low numbers (3 to 10 X 10(3)/mL) of a null cell fraction highly enriched for BFU-E were cultured alone and in the presence of 5 X 10(5) sheep erythrocyte-purified, autologous T lymphocytes in a methylcellulose culture system containing erythropoietin. T lymphocytes consistently enhanced the growth of BFU-E from the null cell fraction, as reflected in both their number and size. Irradiation of T lymphocytes prior to coculture with null cells markedly reduced this enhancement, strongly suggesting that T lymphocytes synthesize erythroid burst-promoting factors (BPA). To determine whether there were functional differences between the two major T lymphocyte populations as defined by OKT4 (T helper/inducer) and OKT8 (T suppressor/cytotoxic) murine monoclonal antibodies to stimulate the growth of BFU-E, both T cell subpopulations were isolated by negative (panning) or positive (fluorescence-activated cell sorting) selection and cocultured with null cells. No statistically significant differences emerged between unseparated, OKT4+ and OKT8+ T lymphocytes in their ability to stimulate the growth of BFU-E. Thus, these studies provide further evidence that T lymphocytes are a major population of BPA-producing cells and further that OKT4+ and OKT8+ T lymphocytes equally elaborate these factors.

Description: Twenty-two patients with hairy cell leukemia were treated with biosynthetic (recombinant) alpha-2-interferon in an open-label, single- arm efficacy study. Patients received 2 X 10(6) U/m2 recombinant alpha- 2-interferon three times weekly. Therapy was well tolerated subjectively with minimal short-term hematologic toxicity. Two patients had bacterial infections during the period of study, and one patient experienced a short-lived readily reversible rejection of a corneal transplant. Statistical comparison of the mean hematologic indices at study entry and after three to six months of therapy with recombinant alpha-2-interferon indicates a significant improvement in hemoglobin, granulocyte, and platelet counts. Bone marrow biopsies in six of 14 patients after six months of therapy showed a greater than 50% decrease in the infiltration of leukemia cells. We conclude that recombinant alpha-2-interferon is highly effective therapy for hairy cell leukemia.

Description: In this report we describe an Italian patient with chronic T cell leukemia whose proliferating cells were mature T lymphocytes with a helper phenotype (T helper phenotype chronic lymphocytic leukemia, or Thp-CLL). Unlike other reported cases of Thp-CLL, fresh leukemic cells from this patient were positive with the anti-Tac monoclonal antibody, which recognizes the receptor for interleukin-2 (IL-2). Thus, the phenotype of these cells was similar to that expressed by Japanese patients with adult T cell leukemia (ATL) (OKT3+, OKT4+, OKT8-, Tac+). However, the Italian patient had Thp-CLL, not ATL, since his cells, unlike ATL cells, lacked human T cell leukemia virus (HTLV-I)-related DNA sequences. The Tac receptor, which appears to be modulated in vitro by the anti-Tac antibody, was biologically inactive, since the patient's cells did not respond in vitro to IL-2. In addition, they also failed to demonstrate in vitro functional activities. The clinical course was aggressive, as usual, for both Thp-CLL and ATL. Taking advantage of the description of this case, some similarities and differences between Thp-CLL and ATL are discussed, focusing on the importance of screening of HTLV-I in the differential diagnosis.

Description: A cytotoxic (IgG2b) monoclonal antibody (McAb) for a novel erythroid differentiation antigen was generated by hyperimmunizing young mice with mononuclear cells obtained from livers of 20- to 22-week-old fetuses. This McAb, designated SFL 23.6, shows an extremely well- defined reactivity with the cells of the erythroid lineage at all stages of maturation as evident from the labeling of morphologically identifiable erythroid precursors and of erythrocytes present in peripheral blood, bone marrow, and fetal liver, and from its reactivity with culture-derived erythroblasts. The nonerythroid cells present in these and other tissue preparations were not labeled by SFL 23.6. The erythroid lineage specificity of McAb SFL 23.6 was confirmed by a cell- sorting experiment in which 97% of the cells in the fluorescent fraction sorted from SFL 23.6-treated bone marrow cells were erythroid precursors at various stages of maturation. Complement-mediated cytotoxicity and progenitor cell-sorting experiments showed that most (greater than 90%) of the late erythroid progenitors (CFU-E) and only a small proportion of the early erythroid progenitors (BFU-E) express the antigenic determinant identified by SFL 23.6. The myeloid progenitors (CFU-GM) and multilineage progenitors (CFU-GEMM) were negative for the SFL 23.6 antigenic determinant. The antigen recognized by SFL 23.6 has not been determined as yet. Because of the pattern of its reactivity and its dependence on sialic acid residues, the possibility of its relationship to glycophoria A was entertained. However, previous work using antiglycophorin McAbs (R-10) has shown that this determinant is not expressed in CFU-E. Therefore, among the erythroid lineage-specific McAbs described thus far, SFL 23.6 is unique in its reactivity with CFU- E and the mature erythron. Reagents with such specificity may be useful in studies of erythroid differentiation and commitment.