ABSTRACT
To study the immunophenotypic profile of acute leukemia cases, using multicolor flow cytometry for lineage subtyping. This is a retrospective review of acute leukemia cases conducted at department of Hematopathology at King Hussein Medical Center between January 2011 to December 2013. A total of 340 acute leukemia cases were analyzed using flow cytometry method. The diagnosis was based on morphological assessment of peripheral blood and bone marrow aspirate smears and immunophenotyping by flow cytometry. A total of 340 cases of acute leukemia were studied. 164 cases [48.2%] were acute lymphoblastic leukemia, 176 [51.8%] were acute myeloid leukemia. Acute leukemia was diagnosed among adults in 51.8% whereas 48.2% were children. Of the acute lymphoblastic leukemia cases, 130 cases [79.3%] were B-cell type and 34 cases [20.7%] were T-cell type. All cases of B-acute lymphoblastic leukemia showed expression of pan B-cell markers [CD19, CD22 and cytoplasmic CD79a] and 117 [90%] of cases expressed CD10. Cytoplasmic CD3 and CD5 were the most sensitive markers for diagnosis of T-acute lymphoblastic leukemia. Of the 176 cases of acute myeloid leukemia, 16 cases [9%] were identified as acute promyelocytic leukemia, while the rest 160 cases showed expression of CD34 and HLA-DR in 41.4% and 68.7% retrospectively. None of the cases of acute promyelocytic leukemia were positive for both CD34 and HLA-DR. CD13 and CD33 were expressed in all cases of acute myeloid leukemia studied. Flow cytometric immunophenotyping is a powerful method for accurate diagnosis, identification and subtyping of acute leukemia. Furthermore, it has a great therapeutic and prognostic implications on such cases with unique usefulness in differentiation between acute lymphoblastic leukemia and acute myeloid leukemia-M0. Immunophenotyping results of acute leukemia in this group of Jordanian patients were comparable to the international data. By combining morphology and immunophenotyping, we were able to diagnose and classify cases of acute leukemia at our center where peripheral blood and adequate bone marrow aspirates are available