ALBERT

Description: This article concerns a study on the endocytic functions of circulating monocytes from 12 patients with acute or chronic monocytic leukemia. The results show that phagocytosis and intracellular killing of Staphylococcus aureus are impaired in only two patients and that the opsonic activity of the serum of all patients is normal. With respect to the intracellular killing of ingested Staphylococcus aureus, an interesting phenomenon was found in that the cells of patients with monocytic leukemia proved to be in a state of activation, as shown by the finding that patients' monocytes with normal phagocytosis killed about 64% of the ingested bacteria in the absence of extracellular stimulation by serum factors. When extracellular serum was present, the mean killing index rose to only 69%. This is unlike the situation seen in monocytes from healthy donors, where no killing occurs in the absence of extracellular serum and extracellular stimulation by serum factors is mandatory for optimal intracellular killing.

Description: Surface marker analysis with rosette tests and a large panel of xenoantisera and monoclonal antibodies was done on the malignant cells of 55 patients with acute myeloid leukemia (AML). The diagnosis was made on morphological and cytochemical grounds, and the leukemias were classified according to the quantified FAB criteria. The marker tests included the E- and EA-rosette test, immunofluorescence with rabbit- polyclonal antisera against human Ig, kappa, and lambda light chains, thymocytes, granulocytes, erythrocytes, platelets, lysozyme, (leukemic) myeloblasts, the common ALL antigen, SB cell-line cells (anti-Ia), and a mouse anti-Ia serum. The monoclonal mouse antibodies applied were anti-T-cell antibody (3A1), two anti-granulocyte-monocyte antibodies (OKM1 and B2.12), four antigranulocyte antibodies (MI/N1, UJ 308, B4.3, and B13.9), an antiplatelet antibody (C17.28), anti-HLA heavy chains (w6/32.HLK), anti-Ia antigen (OKI1), and OKT10. AML cells from many patients lacked the expression of myeloid markers, and we found that a correlation existed between the relative maturity of the leukemia subtype and the extent of positivity for these markers. Surface marker analysis discriminated poorly between the “myeloid” and “monocytoid” subtypes; OKT10 and the “T-cell marker” 3A1 were often expressed on AML cells. In two cases of AML, there was an unexpected expression of platelet antigens with the monoclonal antiplatelet antibody. One of them, classified as M1, was ultrastructurally a megakaryoblastic proliferation with a positive reaction for platelet peroxidase. Only with the help of computerized analysis, was it possible to prove a clear correlation between the surface marker profile and the FAB classification.

Description: Surface marker analysis with rosette tests and a large panel of xenoantisera and monoclonal antibodies was done on the malignant cells of 55 patients with acute myeloid leukemia (AML). The diagnosis was made on morphological and cytochemical grounds, and the leukemias were classified according to the quantified FAB criteria. The marker tests included the E- and EA-rosette test, immunofluorescence with rabbit- polyclonal antisera against human Ig, kappa, and lambda light chains, thymocytes, granulocytes, erythrocytes, platelets, lysozyme, (leukemic) myeloblasts, the common ALL antigen, SB cell-line cells (anti-Ia), and a mouse anti-Ia serum. The monoclonal mouse antibodies applied were anti-T-cell antibody (3A1), two anti-granulocyte-monocyte antibodies (OKM1 and B2.12), four antigranulocyte antibodies (MI/N1, UJ 308, B4.3, and B13.9), an antiplatelet antibody (C17.28), anti-HLA heavy chains (w6/32.HLK), anti-Ia antigen (OKI1), and OKT10. AML cells from many patients lacked the expression of myeloid markers, and we found that a correlation existed between the relative maturity of the leukemia subtype and the extent of positivity for these markers. Surface marker analysis discriminated poorly between the “myeloid” and “monocytoid” subtypes; OKT10 and the “T-cell marker” 3A1 were often expressed on AML cells. In two cases of AML, there was an unexpected expression of platelet antigens with the monoclonal antiplatelet antibody. One of them, classified as M1, was ultrastructurally a megakaryoblastic proliferation with a positive reaction for platelet peroxidase. Only with the help of computerized analysis, was it possible to prove a clear correlation between the surface marker profile and the FAB classification.

Description: This article concerns a study on the endocytic functions of circulating monocytes from 12 patients with acute or chronic monocytic leukemia. The results show that phagocytosis and intracellular killing of Staphylococcus aureus are impaired in only two patients and that the opsonic activity of the serum of all patients is normal. With respect to the intracellular killing of ingested Staphylococcus aureus, an interesting phenomenon was found in that the cells of patients with monocytic leukemia proved to be in a state of activation, as shown by the finding that patients' monocytes with normal phagocytosis killed about 64% of the ingested bacteria in the absence of extracellular stimulation by serum factors. When extracellular serum was present, the mean killing index rose to only 69%. This is unlike the situation seen in monocytes from healthy donors, where no killing occurs in the absence of extracellular serum and extracellular stimulation by serum factors is mandatory for optimal intracellular killing.

Description: We have studied the role of factor VIII-von Willebrand factor (FVIII- vWF) in both platelet adherence to subendothelium and ristocetin- induced platelet aggregation using monoclonal antibodies to human FVIII- vWF. Twenty-five monoclonal antibodies were obtained, two of which were directed to the factor VIII moiety of FVIII-vWF; one of these two completely inhibited the procoagulant activity (FVIII:C). The remaining 23 monoclonal antibodies were directed to the von Willebrand factor moiety of FVIII-vWF. The ability of the latter monoclonal antibodies to inhibit platelet adherence to arterial subendothelium was investigated with a perfusion model. According to the number of platelets adhering to the subendothelium, three groups of monoclonal antibodies could be discerned: (A) antibodies not affecting platelet adherence; (B) antibodies that inhibited platelet adherence to the level as observed when von Willebrand's disease plasma was tested; and (C) antibodies that completely inhibited both platelet adherence to subendothelium and ristocetin-induced platelet aggregation. The two antibodies present in group C competed for the same or closely related epitope(s) present on FVIII-vWF. These results demonstrate that a domain is present on the FVIII-vWF molecule that is associated both with ristocetin-induced aggregation and with the ability of FVIII-vWF to support platelet adherence to the subendothelium. Based on these observations, it is concluded that ristocetin-induced binding of FVIII-vWF to platelets reflects, at least in part, a physiologic mechanism regulating the function of FVIII-vWF in primary hemostasis.

Description: This article deals with a prospective study on the cytochemical, functional, and proliferative characteristics of promonocytes and bone marrow and peripheral blood monocytes of 20 patients with acute monocytic leukemia and 7 patients with chronic monocytic leukemia. The results show a wide variation in the peroxidase and esterase activities in these cells, whereas the percentages of mononuclear phagocytes with Fc gamma and C3b receptors did not differ appreciably from those in normal individuals. A discriminant analysis of these data and corresponding data from normal individuals showed that a below-normal peroxidase activity of circulating monocytes has predictive value for the presence of monocytic leukemia; a below-normal esterase activity has less, but nevertheless some, predictive value in this respect. An increase in the percentage of circulating monocytes, a decrease in the percentage of Fc gamma or C3b receptors, and a decline in the ability to phagocytose bacteria has no predictive value for the presence of monocytic leukemia. The mean percentage of patients' promonocytes that incorporated 3H-thymidine amounted to 80.9%, which is close to the control value in normal individuals. The mean values for the labeling indices of cultured bone marrow and peripheral blood monocytes are 1.0% and 0.74%, respectively; when 3H-thymidine was added to whole blood, the labeling index of the monocytes amounted to 3.6%. These percentages are only a little higher than those found for monocytes of normal individuals. These results indicate that the majority of the circulating monocytes in acute and chronic monocytic leukemia are not actively dividing or blast cells.

Description: In a patient with Richter's syndrome, the chronic lymphocytic leukemia (CLL) expressed lambda, mu, and delta immunoglobulin (lg) chains and the non-Hodgkin lymphoma (NHL) kappa, mu, and delta lg chains. The difference in lg light chain expression suggests that the CLL and NHL are independent malignancies, or that the oncogenic event occurred in a B cell differentiation stage after the heavy chain gene rearrangements but before the selection of the light chain. Analysis of DNA by Southern blotting revealed that the lg heavy chain genes of the two malignancies were rearranged in a different way. We therefore conclude that in this patient the NHL cannot be regarded as a progression of the CLL but should most likely be considered as an independent B cell malignancy, which arose in a susceptible host.

Description: Inhibition of the iron-mediated generation of toxic oxygen species by polymorphonuclear leukocytes (PMN) might prevent oxidative damage and thus enhance phagocytic function of PMN. To investigate this point, we studied the effect of the specific iron chelator, deferoxamine, on the antibacterial function of PMN. PMN were incubated for 20 hr with various concentrations of deferoxamine at 37 degrees C in medium containing 0.54 microM endogenous iron. The cells were then washed, and the phagocytic cell function was assessed. The results were compared with those for control PMN preincubated for 20 hr without deferoxamine, and those of nonincubated PMN. Compared with that of control PMN, the uptake of radiolabeled Staphylococcus aureus by PMN treated with 1 microM-1 mM deferoxamine was, on average, 10%-20% higher. This effect was not observed when iron-saturated deferoxamine (DFO) was used. Bacterial uptake was similarly increased in nonpreincubated PMN or PMN preincubated for 20 hr at 4 degrees C instead of 37 degrees C. The intracellular killing capacity of both deferoxamine-treated and control PMN exceeded 90%. PMN incubated for 20 hr at 37 degrees C with DFO not only phagocytosed more bacteria than control cells, but were also capable of killing the greater number of bacteria ingested. This increased activity of deferoxamine-treated PMN was accompanied by enhanced generation of chemiluminescence and production of superoxide during phagocytosis of S. aureus. These findings indicate that deferoxamine may enhance the antibacterial activity of PMN by protecting the cells against damage by iron-mediated generation of toxic oxygen metabolites in resting PMN.

Description: The expression of monomorphic Ia-like antigens and polymorphic (allotypic) HLA-DR determinants on CFU-GM, BFU-E, CFU-E, and CFU-GEMM was studied in bone marrow and peripheral blood cells from normal healthy individuals. Using various polyclonal and monoclonal anti-Ia- like antibodies, the presence of HLA-DR backbone antigens was shown on all hematopoietic progenitor cells (HPC) studied, both in complement- dependent cytotoxicity assays and in fluorescence-activated cell sorting (FACS). The expression of allotypic determinants was demonstrated on all HPCs, using the HLA-DR typing sera anti-HLA-DR1, 2, 3, 4, 5, and 7. The Class II antigen MT-2 was also shown on all HPCs, using both monoclonal and alloantisera, whereas the MB-1 (DC-1) determinant could not be demonstrated on HPCs. This might open the possibility of removing MB-1-positive malignant cells from the graft in autologous bone marrow transplantation.

Description: Lymphocytes from patients with acute and chronic T-cell malignancy or chronic T gamma lymphocytosis were characterized by studying the activity of three enzymes involved in purine metabolism and by determining the isoenzyme pattern of lactate dehydrogenase (LDH) in addition to analysis of surface marker expression with monoclonal antibodies. Four clinically different types of disease were distinguished on the basis of the enzyme parameters. Lymphocytes from patients with acute lymphocytic leukemia (T-ALL) showed an enzyme profile similar to that of normal thymocytes, i.e., an elevated level of adenosine deaminase (ADA) activity as compared with normal T lymphocytes, reduced activities of purine 5′nucleotidase (5′NT) and purine nucleoside phosphorylase (PNP), and a binomial distribution of the LDH isoenzyme pattern. Cells from “null”-ALL patients had an ADA/PNP ratio that was intermediate between that of normal T cells and that of T-ALL cells or thymocytes, but their 5′NT activity and LDH isoenzyme pattern were thymocyte-like. Patients with chronic T-cell proliferation were subdivided into those with chronic T gamma lymphocytosis and those with proven chronic T malignancy. The lymphocytes from these patients had ADA and PNP activities within the ranges of those of normal T lymphocytes. However, the ADA activity and/or the ADA/PNP ratio were consistently higher in the cells from the patients with chronic T gamma lymphocytosis than in those with chronic T malignancy. The enzyme profile of the cells from the T gamma patients was similar to that of T gamma cells of normal individuals. The cells from patients with chronic T malignancies showed a heterogeneous enzyme pattern as compared with that of normal T lymphocytes. Analysis with monoclonal antibodies enabled us to distinguish null-ALL patients from the other leukemias studied, but a distinction between chronic and acute T-cell proliferation disease, for instance, was not possible with monoclonal antibodies alone. Our data demonstrate that the enzyme profiles studied provide supplementary information for classification and diagnosis of lymphoproliferative diseases to that obtained with cell surface markers alone.