Final 3.indd

Abstract Background: The possible prognostic signi¿cance of the expression of a variety of markers has been investigated in acute lymphoblastic leukemia (ALL). Methods: In the present study we investigated the prognostic signi¿cance of CD13 and CD33 myeloid antigens (MY) aberrantly expressed on the blasts of ALL patients and Bcl-2 anti-apoptotic molecule expression in childhood ALL. Results: Aberrant expression of MY occurred in 8.8% of cases. Variant levels of Bcl-2 were expressed in patients (44.2±25.5%), with more than 20% positivity for Bcl-2 in 64.7% of patients. Bcl-2 + patients survived 959±242 days compared to 1059+230 days for Bcl-2 -patients (P=0.2). Corresponding data for complete remission duration was 682±170 and 716±173 days (P=0.3), respectively, indicating no signi¿cant association between survival and complete remission duration of patients with expression of the Bcl-2 molecule. Analysis of clinical response according to MY expression, however, showed signi¿cant association with survival and complete remission duration. MY + patients had shorter complete remission duration (383±58 days) and survival (473±68 days) than MY -patients (complete remission duration, 724±144 days; survival, 1045±186 days; P<0.001). Expression of Bcl-2 along with MY was not associated with a signi¿cant decrease in survival or complete remission duration. Conclusion: Results of this study indicated that expression of MY was a poor prognostic factor in childhood ALL. Bcl-2 expression in MY + patients could not inÀuence the response to therapy