ALBERT

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: Ten dogs were given 9.2 Gy of total body irradiation and autologous bone marrow infusion followed by ten daily transfusions of leukocytes for a total of 11.5 to 36.2 (median, 18.8) x 10(8)/kg obtained via leukapheresis from histoincompatible unrelated donors. Four dogs were given unirradiated leukocytes, and all developed graft-versus-host disease (GVHD). In contrast, only two of three dogs given leukocytes irradiated with 20 mJ/cm2 of ultraviolet (UV) light (200 to 300 nm), and none of three dogs given leukocytes irradiated with 1,000 mJ/cm2 developed GVHD. These data indicate that UV irradiation abrogates the alloreactive potential of transfused leukocytes, and suggest that UV irradiation can be used to prevent the development of transfusion- induced GVHD.

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: Erythrocytes and progenitor-derived erythroblasts of sickle cell anemia patients from the Eastern Province of Saudi Arabia contain increased fetal hemoglobin and G gamma globin. A distinctive DNA polymorphism haplotype in the beta globin gene cluster (++- +-), tightly coupled to a C----T substitution at position -158 5′ to the cap site of the G gamma globin gene, is strongly associated with sickle cell disease in this region. To determine whether the increased fetal hemoglobin production and/or elevated G gamma globin content are tightly linked to this haplotype, we studied 55 members of five Saudi families in which sickle cell disease is present. The results did not suggest a tight linkage of the haplotype to increased fetal hemoglobin production. On the other hand, several sickle trait family members heterozygous for the haplotype had normal fetal hemoglobin production in culture but elevated G gamma to A gamma ratios in peripheral blood. This observation suggests that in this genetic background increased expression of the G gamma globin gene may occur without a measurable increase in total fetal hemoglobin production. The family studies also clearly demonstrate that increased fetal hemoglobin production by erythroid progenitors is dependent on zygosity for the sickle gene in this population. These findings strongly suggest that other factors, such as the products of genes stimulated by hemolytic stress or other genetic determinants associated with the Saudi beta S chromosome, may interact with the -158 C----T substitution and influence gamma globin gene expression in this population.

Description: The present studies demonstrate that platelets from patients with platelet-type von Willebrand disease show specific and saturable binding of asialo von Willebrand factor (AS-vWF) under conditions where such binding is not observed with normal platelets. Although specific binding of 125I-AS-vWF to formalin-fixed normal platelets could not be demonstrated, specific binding to fixed patient platelets was seen with an apparent Kd of 1.3 micrograms/mL and specific maximally bound ligand of 0.40 micrograms/10(8) platelets. Preincubation of patient platelets with the antiglycoprotein Ib (anti-GPIb) monoclonal antibody AS-2 reduced total binding close to the level of computer-estimated nonspecific binding. In contrast, binding was not reduced by preincubation with anti-GPIIb/IIIa monoclonal antibody or with 5 mmol/L EDTA. Under stirring conditions, the binding of AS-vWF to fixed patient platelets was accompanied by a strong agglutination response. AS-vWF- induced agglutination was similarly observed in patient but not normal platelet-rich plasma (PRP) in the presence of 5 mmol/L EDTA. In the absence of EDTA, AS-vWF produced a full aggregation response in patient PRP at concentrations as low as 0.1 microgram/mL in contrast to the 2 to 20 micrograms/mL required by normal PRP. Both thromboxane B2 formation and adenosine triphosphate secretion showed an AS-vWF concentration dependence paralleling the aggregation responses. These studies show that a major difference in the platelets from patients with platelet-type von Willebrand disease is the presence of an exposed, high-affinity binding site associated with GPIb that recognizes AS-vWF.

Description: A second BamHI DNA polymorphism has been identified in the factor IX gene in an American black population at an allelic frequency of 0.13. This site has been localized within 500 basepairs (bp) 5′ to the XmnI intron 3 polymorphic site and increases the heterozygosity of black females at the factor IX gene locus. In addition, haplotype analysis of factor IX genes at five polymorphic loci indicates that although there is conservation of sequences between the races, factor IX genes show more heterogeneity in an American black population and thus more heterozygosity is observed in black females compared with whites. This increased heterogeneity is due to DNA polymorphisms unique to black populations and to linkage equilibrium between the most 5′ and 3′ polymorphic sites in factor IX genes in blacks.

Description: The presence of circulating tumor idiotype interferes with the in vivo effectiveness of anti-idiotype antibodies. We developed two assays that permit identification of patients with high levels of serum idiotype without the need for first producing an anti-idiotype antibody. A cell suspension made from the tumor was cultured for seven days with or without phytohemagglutin (PHA) and/or phorbol myristic acetate (PMA). Ig secretion in vitro by patients' tumor cells varied. In 4 patients, no secretion in vitro occurred, 5 patients had low levels, and 5 patients had high levels of Ig secretion. In three patients, Ig secretion occurred only after stimulation with PHA, PMA, or both. Spontaneous or induced immunoglobulin secretion in vitro is related to the levels of tumor idiotype secretion that exist in vivo. Eight patients with serum idiotype levels greater than 100 micrograms/mL (mean 265 micrograms/mL), had a minimum of 1.0 microgram/10(6) cells of idiotype secretion in vitro. Nine patients with serum idiotype levels less than 30 micrograms/mL (mean 3.7 micrograms/mL), had less than or equal to 0.5 microgram/10(6) cells of idiotype secretion in vitro. In another assay, the levels of IgM kappa and IgM lambda in patients' sera were compared with those in normal serum. An imbalance in the relative amounts of IgM kappa and IgM lambda indicated high levels of circulating idiotype in the serum, but this assay was less sensitive than the in vitro secretion assay and limited to IgM-secreting tumors. These assays will be useful for future clinical studies using anti- idiotype antibodies.

Description: With the exception of the major platelet glycoproteins IIb/IIIa and Ib, which function as receptors for fibrinogen and von Willebrand factor, little is presently known regarding the possible role of other platelet surface proteins in mediating platelet aggregation. We report the production of a murine monoclonal antibody (AG-1) recognizing human platelet membrane surface protein of relatively low molecular weight (mol wt) that may be involved in this process. AG-1 added to human platelet-rich plasma induces dense granule secretion and aggregation, with lag phase and maximal extent of aggregation dependent on antibody concentration. Aggregation induced by AG-1 is inhibited by AG-1 Fab fragments, indicating that the response is not Fc receptor-mediated. Although AG-1 continues to produce platelet shape change in the presence of EDTA, aggregation is fully inhibited and appears to be mediated by fibrinogen binding to glycoproteins IIb/IIIa. AG-1 is a potent stimulus of thromboxane formation, but full inhibition of thromboxane production by 30 mumol/L indomethacin does not significantly inhibit platelet aggregation induced by 25 micrograms/mL AG-1, indicating that aggregation induced by AG-1 may proceed by way of an endoperoxide-independent pathway. Quantitation of AG-1 Fab binding to platelets reveals approximately 65,000 binding sites per platelet. When intact platelets are radioiodinated, immunoprecipitation of NP-40 lysates by AG-1 reveals an intensely labeled protein with an apparent mol wt of approximately 21,000 daltons, and several additional bands in the mol wt range of 22,000 to 28,000 daltons, all sharing the AG-1 epitope. These bands appear to be distinct from glycoprotein IX or from the beta-chains of glycoprotein Ib or IIb. Finally, studies with platelets labeled by the periodate-[3H]borohydride procedure suggest the possibility of complex formation between subpopulations of glycoprotein Ib and the low-mol-wt glycoproteins recognized by AG-1.

Description: The clinical significance of immunophenotyping of the non-Hodgkin's lymphomas is controversial. Therefore, we conducted the present study of 103 consecutively accrued diffuse large-cell lymphoma (DLCL) patients to define, independently of histologic subtypes, the prognostic importance of phenotyping. We used an extensive panel of monoclonal antibodies to T- and B-cell antigens to assign all patients immunologically into the T-cell (20 patients) or B-cell group (83 patients). The only significant differences in pretreatment clinical variables between the two patient groups were the higher frequency of bulky disease (greater than 10 cm) in B-cell patients (P = .008) and more frequent skin involvement in the T-cell group (P less than or equal to .001). Multiagent doxorubicin-containing chemotherapy regimens were employed as initial therapy in over 83% of the patients in each group. Our study revealed that disease-free survival (DFS) was significantly shorter in the T-cell patients than in the B-cell DLCL patients (median DFS, 10.8 months for T-cell and 42.7 months for B- cell; P = .01, log rank). No patient with T-cell DLCL remained disease free for longer than 2 years, whereas 55% of the B-cell group were disease free at 2 years. Univariate and multivariate analyses of all major prognostic factors of DFS suggest that the T-cell phenotype indicates an incurable subset of DLCL patients. Although the B-cell group had a twofold advantage in median survival (35 months v 18 months), actuarial overall survival was not significantly different between the two patient groups (P = .23). Our results indicate the need for new approaches in the search for a curative treatment for T-cell DLCL.