Immunophenotypic Subtyping of Leukemic Cells from Iranian Patients with Acute Lymphoblastic Leukaemia: Association to Disease Outcome

Background: Immunophenotypic characterization of the leukemic cells has been widely used as a tool for diagnosis, classification, stratification and prognosis of leukaemia. Objective: To investigate the immunophenotypic subtype profiles of Iranian patients with acute lymphoblastic leukemia (ALL) and its association to disease outcome. Methods: In this study, a total of 60 Iranian patients with ALL were immunophenotyped by flow cytometry using a panel of monoclonal antibodies specific for CD2, CD3, CD5, CD10, CD13, CD14, CD19, CD20, CD33, CD34, CD45, HLA-DR and TdT molecules. Results: The samples were initially categorized into T-ALL (n=9), B-ALL (n=50) and mixed lineage (n=1) based on the expression patterns of CD3 and CD19 molecules. B-ALL patients could further be classified into four subtypes, including Pro-B (n=7, 11.7%), Pre-B I (n=28, 46.7%), Pre-B II (n=13, 21.7%) and immature/mature B cells (n=2, 3.3%) on the basis of expression of CD10, CD19, CD20, HLA-DR and TdT. Clinical manifestations and laboratory findings of the patients did not reveal association with immunophenotypic sub-types of ALL, with the exception of mediastinal mass and WBC count at the time of diag-nosis which were found to be significantly higher in patients with T-ALL compared with B-ALL (p=0.001 and 0.014), respectively. Conclusion: Our results indicate that overall the immunophenotypic profile of Iranian ALL patients is similar to previous reports and it might be used for monitoring of minimal residual disease and prognosis.