Prognostic value of myeloid antigens expression in childhood acute lymphoblastic leukemia


BACKGROUND: Leukemic blasts in acute lymphoblastic leukemia (ALL) may have immunologicalfeatures of both lymphoid and myeloid lineages known as aberrant myeloid antigens expression inALL, which are explained as abnormal genetic program of leukemic cells that lead to lineage infidelity.In this study, CD13, CD14, and CD33 (which are the most frequent myeloid antigens associated withaberrant antigens expression in ALL) were investigated.OBJECTIVES: To evaluate the occurrence of aberrant myeloid antigens expression in childhoodALL and its effects on complete remission and other parameters.MATERIALS AND METHODS: This study was conducted on 31 pediatric patients with newlydiagnosed de novo ALL (27 B‑ALL, 4 T‑ALL) in Children Welfare Teaching Hospital/Medical Cityof Baghdad; diagnosis of ALL based on morphology and cytochemistry, CD13, CD14, CD33 wereinvestigated as myeloid antigens using four‑color flow cytometry.RESULTS: Five cases of ALL (16.13%) out of 31 cases were confirmed to have aberrant myeloidantigens expression (CD13 was expressed in all five cases, CD33 was expressed in three cases,and CD14 was not expressed in any of these five cases). Complete remission was achieved in90.30% (28 patients) and all cases with aberrant myeloid antigens expression achieved completeremission; however, despite this, there was no significant difference in complete remission betweenmyeloid‑positive (MY+) and myeloid‑negative (MY−) cases, P > 0.05. Regarding other parameters,there were significant statistical differences in lactate dehydrogenase (LDH), hemoglobin value, andbone marrow (B.M.) blasts percent at diagnosis between MY+ and MY− cases, P < 0.05; however,there was no significant differences in leukocytes count, platelets count, peripheral blood blast percentat diagnosis, age, and gender, P > 0.05.CONCLUSIONS: The most frequent aberrant myeloid antigens expression in childhood ALL is CD13and less frequently is CD33 while CD14 showed no expression; myeloid antigens expression in ALLmay have better prognosis as they have lower B.M. blast percent and LDH value.