Objectives: Philadelphia chromosome (Ph) is common cytogenetic abnormality in B-ALL. Patients with Ph-chromosome have resistance to chemotherapy treatment with shorter event free survival, however, tyrosine kinase inhibitor (imatinib mesylate) has shown to improve the survival of Ph-positive ALL patients. The aim of the study was to examine immunophenotypic profile associated with BCR/ABL1 gene rearrangement and to put forward a model for gene rearrangement based on immunophenotypic analysis at diagnosis. Methods: We had carried out a retrospective analysis of 130 patients with B-ALL diagnosed at The Gujarat Cancer and Research Institute. Immunophenotyping of leukemic blasts was carried out using flowcytometry and BCR/ABL1 fusion gene was detected by FISH analysis. Results: BCR/ABL1 fusion was observed in 24% of B-ALL. All patients with BCR/ABL1 gene rearrangement were positive for CD10 and Tdt. BCR/ABL1-positive cases exhibited a greater MFI value of Tdt, CD10, CD34, CD13, CD33, but a lower MFI value of CD22, CCD79a as compared to BCR/ABL1 negative cases. Multivariate logistic regression analysis showed that high MFI of Tdt, CD10 and low MFI of CD22 and CCD79a predict the presence of BCR/ABL1 rearrangement. Conclusion: Immunophenotypic profile of B-ALL patients can be used as primary screening to predict occurrence of BCR/ABL1 gene rearrangement. Keywords: B ALL, BCR/ABL1 gene rearrangemnt, flowcytometric immunophenotyping
Corresponding Author: Vora H.