Expression of apoptosis regulators Bcl-2 and Bax in childhood acute lymphoblastic leukemia.

Twenty-five children (19 M:6 F) with newly diagnosed ALL with median age of 5.5 years (1 month-12 years) were enrolled in the study. Apoptosis regulator proteins bcl-2 and bax were measured in all patients using alkaline phosphatase anti-alkaline phosphatase method. Twenty-one patients were positive for bcl-2 and 23 cases for Bax, although expression levels varied. Patients who presented with splenomegaly or hepatomegaly < 5 cm expressed significantly higher levels of bcl-2 and bax protein expression. Neither of age ( < or >10 years), sex, generalized lymphadenopathy, WBC ( < or >50,000/mul) or FAB subtype was associated with high levels of bcl-2 or bax protein expression. Patients with higher mean hemoglobin levels (p = 0.009), high blast % in bone marrow (p = 0.02), immature immunophenotype (p = 0.001) exhibited signifxicantly higher bcl-2 levels. Bcl-2/bax ratio correlated inversely with TLC at presentation (p = 0.022; r = - 0.456) and in B-lineage leukemic cells as compared to T-lineage cells (p = 0.002). Bcl-2/bax ratio did not correlate with any other variable measured. Bcl-2 and bax protein co-express in ALL and high bcl-2/bax ratio correlates with good prognosis features.