Haematopoietic response and bcl-2 expression in patients with acute myeloid leukaemia.

Bcl-2 expression, the number of apoptotic cells and the growth and differentiation of early bone marrow progenitor cells were studied in patients with confirmed diagnosis of acute myeloid leukaemia (AML). Bone marrow cells from normal individuals were used as controls. We observed an increased percentage of bcl-2-mononuclear bone marrow cells expression in AML patients in relation to controls (p =0.002). Accordingly, the number of apoptotic cells was reduced (p = 0.001) and there was a negative correlation between bcl-2 expression and the number of apoptotic cells (r=-0.664, p<0.001). In addition, bcl-2 expression was significantly increased in the chemotherapy resistant group in relation to the responsive group (p = 0.03). Lower rate of survival was observed in the group of AML patients with autonomous proliferation (p=0.01). These results suggest that a high bcl-2 expression and the presence of autonomous proliferation are related to a poor prognosis in AML.