1Dept. of Immunology, Medical Sciences / University of Tehran
2Clinic of Hematology, Iran University of Medical Sciences
3Clinic of Hematology and Oncology, Medical Sciences / University of Tehran
4Cancer Center Karolinska, Karolinska Inst, Stockholm, Sweden
5Monoclonal Antibody Research Center, Avesina Research Inst, Tehran
6Dept. of Immunology, Reproductive Biotechnology Research Center, Avesina Research Inst
7National Cell Bank of Iran, Pasteur Inst of Iran, Tehran, Iran
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.