Bcl-2 in Combination to Myeloid Antigen Expression in Adult Acute Lymphoblastic Leukemia and Prognostic Outcome

The present study was performed to find the importance of two myeloid (CD13 and CD33) antigens aberrantly expressed on the blasts of acute lymphoblastic leukemia (ALL) patients and Bcl-2 expression in relation to clinical and biological features and treatment outcome. Bone marrow or peripheral blood samples of 50 patients were assessed for the expression of markers by immunostaining methods. Twenty-one patients (42%) showed more than 20% positivity for Bcl-2. Aberrant expression of myeloid antigens was found in 14% of cases. The expression of Bcl-2 was associated with shorter survival (p = 0.009). A significant correlation between expression of myeloid antigens (MY) and survival and complete remission duration was found. The mean survival was 656 +/- 301 days for MY+ cases and 1,009 +/- 230 days for MY- patients (p < 0.0001). Expression of Bcl-2 in combination to myeloid antigens was associated with a poorer outcome. Survival of MY+ patients expressing Bcl-2 was shorter than MY- Bcl-2(+) and MY+ Bcl-2(-) ALL cases (p = 0.038). In conclusion, results of this study indicated the prognostic value of Bcl-2 and myeloid antigen expression in ALL patients. Presence of these markers together on the leukemic cells was associated with a poorer response to therapy and may implicate modified therapeutic strategies in the patients.