Immunohistochemical expression of BCL-2 oncogene in chronic myeloid leukemia in Iraqi patients

BACKGROUND: Chronic myeloid leukemia (CML) occurs when a pluripotent stem cell undergoes malignant transformation and clonal myeloproliferation, leading to a striking overproduction of immature granulocytes. It accounted for about 15% of all adult leukemias and can strike at any age but rare in childhood. Many studies revealed a significant role of antiapoptotic B-cell lymphoma-2 oncogene (Bcl-2) in disease progression. OBJECTIVES: The aim of this study was to assess Bcl-2 expression across CML phases and its diagnostic value through immunohistochemistry compared to conventional morphology. MATERIALS AND METHODS: A cross-sectional retrospective study of Bcl-2 expression in histological sections of bone marrow trephine biopsies of randomly selected 60 patients diagnosed with CML with age ranged between 14 and 81 years and presented with different clinical phases (30 with chronic phase, 15 with accelerated phase and other 15 with blastic transformation) which stained immunohistochemically for BCL-2 protein (Dakopatts Corporation) and evaluated by a hemopathologist. RESULTS: The expression of the antiapoptotic protein Bcl-2 differs significantly with different clinical phases of CML and increases with more advanced stages. Bcl-2 oncoprotein expression increases significantly with high bone marrow blast percentage. CONCLUSIONS: Immunohistochemistry is a useful method for the detection of Bcl-2 oncoprotein. There is a relatively great relationship between Bcl-2 oncoprotein expression with high bone marrow blast count and advanced stages of the disease.