CD95(Fas/APO-1) Antigen Expression on the Cells of Myelodysplastic Syndromes, Acute Myelogenous Leukemia, and Chronic Myelogenous Leukemia Patients

CD95(Fas/APO-1) antigen is a member of TNF/NGF receptor superfamily that includes the TNF-RI and TNF-RII tumour necrosis factor receptors, nerve growth factor receptor, the T-cell activation marker CD27, the Hodgkin disease-associated antigen CD30, B-cell surface antigen CD40 and some other mammalian and viral homologues. In this study we analyzed the expression of CD95(Fas/APO-1) antigen on bone marrow cells of myelodysplastic syndrome patients (MDS), on peripheral blast cells of acute myelogenous leukemia patients (AML) and bone marrow and peripheral blood cells of chronic myelogenous leukemia (CML) patients in chronic phase (CP) and blastic crises (BC).Antigen expression was studied by indirect immunofluorescence assay using flow cytometry (FACS-can, Becton Dickinson) and apoptosis was investigated using flow cytometric method of measurement of hypodiploid DNA, labeled with propidium iodide. CD95(Fas/APO1) antigen was found on 38.1±19.2% bone marrow cells of 8 of 19 (36.8%) MDS patients, on 45.5±22.8% of blast cells in 6 (45%) of 15 AML patients, Fas/APO-1 antigen was totally absent in CML chronic stage; and its expression was found in 34% (12 of 35) of our patients with CML BC on peripheral blood blasts and in 45% (5 of 11) on bone marrow blasts. According to our data at studing the expression of CD95(Fas/APO-1) antigen in MDS patients we suggested that the absence of CD95(Fas/APO-1) antigen on bone marrow cells of MDS patients is an unfavourable sign and CD95- MDS patients represent a risk group for both short overall survival and progression to acute leukemia. In AML patients we also noted a negative influence of CD95(Fas/APO-1) absence on overall survival, though this conclusion needs to be confirmed. In the case of CML BC patients remissions were achieved in the lymphoid and mixed variants. No remissions were obtained in CD13+ and CD95+ groups regardless of CD10 expression. Fas antigen has no prognostic value in CML BC.