APOPTOSIS IN ACUTE MYELOBLASTIC-LEUKEMIA - FOLLOW-UP-STUDY ON TREPHINE BIOPSIES OF THE BONE-MARROW

A clinicopathological study on 87 adult patients presenting with ''de novo'' acute myeloblastic leukemia (AML) was performed to assess the r ate of apoptosis before and during chemotherapy and its predictive imp act on clinical course. Evaluation included trephine biopsies of the b one marrow and the in situ end-labeling technic (ISEL) for the identif ication of programmed cell death in large and intact hemopoietic tissu e areas. In comparison with a control group of 21 patients without any hematological disorder, morphometric analysis revealed no significant ly different numbers of apoptotic cells in AML at the onset of disease and following sequential examinations at intervals ranging between 10 to 19 months. Moreover, the incidence of programmed cell death was no t associated with the subgroups of the FAB classification and statisti cs failed to show a relationship with survival or remission status. In conclusion, these findings are in keeping with the assumption that ap optosis occurs with the same frequency in recovering normal hemopoiesi s in complete or partial remission, in manifest AML and relapse. In th e latter conditions, enhancement of proliferation is not associated wi th an increase in the apoptotic index.