Bcr-Abl1 Positive Acute Lymphoblastic Leukaemia In Ghanaian Patients

ABSTRACT Background: Acute lymphoblastic leukaemia (ALL) is the accumulation of lymphoblasts in the bone marrow as a result of malignant transformation resulting in proliferation of immature lymphoid progenitors or lymphoblasts. It results from perturbation of several genetic loci. The chimeric BCR-ABL1 gene fusion is one of such genetic alterations. Even though the presence of BCR-ABL1 has been associated with poor prognosis, the incorporation of tyrosine kinase inhibitors in treatment protocols has been shown to be of enormous benefit. In Ghana as well as most African countries, research work on its prevalence and clinical associations is limited. Aim: To determine the frequency and associated laboratory and clinical features of the chimeric BCR-ABL1 gene in patients diagnosed with acute lymphoblastic leukaemia at the Department of Haematology, Korle Bu Teaching Hospital (KBTH). Methods: This is retrospective cross-sectional study. Methanol-fixed archived bone marrow aspirate slides of patients diagnosed with ALL at the Department of Haematology, KBTH were retrieved. Data on clinical features (signs) and haematological parameters was obtained from the patients’ medical records. The presence of the chimeric BCR-ABL1 fusion gene was determined on the bone marrow aspirate slides by fluorescent in situ hybridization (FISH). Results: A total of 17 cases were studied of which 13 (76.5%) were males and 4 (23.5%) were females. The ages of the participants ranged from 15 to 67 years ((mean = 31.5 years, SD = 16.9 years). A frequency of 29.4% was obtained for the BCR-ABL1 fusion gene. Of the clinical features studied, lymphadenopathy was present in 7 (40%) of study cases whereas splenomegaly and hepatomegaly were present in 4 (23.5%) and 5 (35.7%) respectively. No significant association was established between BCR-ABL1 positivity and these clinical features. All  subjects had severe to moderate anaemia with haemoglobin concentration ranging from 3.7 to 8.7g/dL. The mean haemoglobin concentration for BCR-ABL1 positive cases was higher than that of the negative cases (7.26 versus 6.62 g/dL respectively), however, statistical significance was not reached (P = 0.506). The mean white blood cell count, bone marrow blast percentages and platelet counts were lower in BCR-ABL1 positive cases than in the negative cases (36.83, 73.00 and 54.60 ×109 /L versus 73.53, 82.18 and 74.33×109 /L respectively) although no significant association was established between these haematological parameters and BCR-ABL1 positivity (P = 0.879, 0.721 and 0.506 respectively). Also, there was no statistically significant difference in clinical outcome between the BCR-ABL1 positive and negative cases. Conclusion: The BCR-ABL1 fusion gene is present in nearly one third of adult acute lymphoblastic leukaemia cases seen in this study and has no significant association with the clinical features and haematological parameters of the disease. A larger study will be needed to make a decision with regard to the modification of treatment regimen for adult BCR-ABL1 positive ALL.