PCNA CYCLIN - A DIAGNOSTIC AND PROGNOSTIC FACTOR FOR MYELODYSPLASTIC SYNDROME PATIENTS/

The proliferative activity of the bone marrow cells in Myelodysplastic Syndromes (MDS) was determined by Proliferative Nuclear Antigen (PCNA /cyclin) in 20 patients. We also determined PCNA/cyclin in 10 reactive and in 10 normal bone marrow biopsies. PCNA immunostaining was studie d in order to determine a prognostic and diagnostic factor for MDS pat ients. We evaluated the PCNA in immature erythroblasts, myeloblasts, p romyelocytes, myelocytes, metamyelocytes and megakaryocytes. We used t he method of streptavidine biotine peroxidase with the monoclonal anti body PC-10 against PCNA antigen. MDS patients showed very high values of PCNA (mean value = 50.7%) in relation with reactive bone marrow (9. 8%) and normal bone marrow (0.4%). Six patients with MDS with very hig h percentages of PCNA positive cells developed acute myeloid leukemia. Our results suggest that the growth fraction, as determined by the PC NA immunostaining, represents a prognostic factor in patient with myel odysplastic syndromes.