Studying of FAS(APO-1/CD95) antigen expression by flow cytometry with monoclonal antibodies IPO-4

With the help of monoclonal antibodies IPO-4 we examined Fas(APO-1/CD95) expression on the peripheral blood lymphocytes of healthy donors and on the cells of leukemia patients. Antigen expression was studied tay indirect immunofluorescence assay using flow cytometry (FACScan, Becton 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 with chronic myeloid leukemia in blastic phase. The antigen was absent in chronic phase of disease. Fas(APO-1/CD95) antigen was presented on blast cells of 34.1% patients with acute lymphoblastic leukemia, of 22.7% patients with acute myeloblastic leukemia, on the cells of 48.3% chronic lymphocyte leukemia patients and on bone marrow cells of multiple myeloma patients. Correlation between Fas(APO-1/CD95) and CD34 antigen expression (r = 0.76) and between Fas(APO-I/CD95) and CD10 antigen (r = 0.56) was found.