STUDYING OF FAS(APO-1 CD95) ANTIGEN EXPRE SSION BY FLOW-CYTOMETRY WITH MONOCLONAL-ANTIBODIES IPO-4/

With the help of monoclonal antibodies IPO-4 we examined Fas(APO-1/CD9 5) expression on the peripheral blood lymphocytes of healthy donors an d on the cells of leukemia patients. Antigen expression was studied ta y indirect immunofluorescence assay using flow cytometry (FACScan, Bec ton Dickinson, USA). Fas(APO-1/CD95) antigen was found on 22.3 +/- 12. 6% lymphocytes of healthy donors, on blast cells of 29.5% patients wit h chronic myeloid leukemia in blastic phase. The antigen was absent in chronic phase of disease. Fas(APO-1/CD95) antigen was presented on bl ast cells of 34.1% patients with acute lymphoblastic leukemia, of 22.7 % patients with acute myeloblastic leukemia, on the cells of 48.3% chr onic lymphocyte leukemia patients and on bone marrow cells of multiple myeloma patients. Correlation between Fas(APO-1/CD95) and CD34 antige n expression (r = 0.76) and between Fas(APO-I/CD95) and CD10 antigen ( r = 0.56) was found.