Immunophenotyping of Childhood Acute Lymphoblastic Leukemia in Qazvin City, Iran: A Cross-Sectional Study

Background: Acute lymphoblastic leukemia (ALL) is the most prevalent childhood cancer. ALL is a heterogeneous type of malignancy and treatment protocols vary based on the immunological classification of ALL. The critical step for treating ALL is to identify immunological subgroups by flow cytometry findings.  Objective: In this study, immunophenotypic information was evaluated for the first time in children with ALL in Qazvin City, Iran. Methods: This cross-sectional study reviewed the clinical and laboratory data of children with ALL during 2019-2020. Next, children with ALL were immunophenotyped by flow cytometry applying a panel of the specific monoclonal antibodies for some clusters of differentiation (CD) molecules, including CD20, CD21, CD10, CD34, CD38, and terminal deoxynucleotidyl transferase (TdT). The data were separately analyzed using SPSS software, version 24. Findings: Of 52 children with ALL in the age range of 6 months to 15 years, 23 children (44.23%) had B-ALL-ProB (pro-B) cell immunotyping features, 26 (50%) had B-ALL-PreB (pre-B) cell immunotyping features, and 3 (5.7%) had T-cell immunotyping features. The ages of T-cell group children were higher than those of B-cell group children. The most common clinical and laboratory findings were fever (26 cases, 55.31%). In 55% of children, periodic acid-schiff (PAS) staining was positive. The presence of the terminal deoxynucleotidyl transferase (TdT) enzyme was higher in B-cell patients than in T-cell cases. Children with CD34+ were higher in the pro-B group than in the pre-B group.  Conclusion: our study shows that the immunophenotypic characteristics of children with ALL are more similar to previous reports and can be used for monitoring and prognosis of children with ALL in Qazvin City.