Childhood acute lymphoblastic leukemia: Immunophenotypic profile and aberrant expression of CD13, CD33, CD117, CD11b, CD16, and CD64

Abstract

BACKGROUND: Childhood acute lymphoblastic leukemia (ALL) is the most prevalent malignant disease (25%–30%) and the most common type of leukemia (75%–80%) among children. It is not a single disease with significant phenotypic and genotypic variability that has diagnostic and prognostic implications. This study aims to provide the immunophenotypic profile of childhood ALL in Iraqi patients and to explore the frequency of aberrant myeloid antigen expression and their association with hematological parameters. PATIENTS, MATERIALS AND METHODS: The records of 67 pediatric patients diagnosed as ALL were reviewed for their flow cytometric immunophenotyping results at presentation. RESULTS: B-ALL constituted 76.1% of the cases and 23.9% were T-ALL. There was a highly significant statistical relation between higher age interval and T-ALL phenotypes (P = 0.001). Higher hemoglobin (Hb) level and white blood cell count were significantly related with T-ALL subtype (P = 0.039 and < 0.001, respectively). CD34, HLA-DR, CD10, and CD79a were significantly correlated with B-ALL compared to T-ALL (P = 0.007, <0.001, <0.001, and <0.001, respectively). With no significant differences, aberrant myeloid antigen expression was found in 51% of B-ALL and in 25% of T-ALL cases; however, CD34 expression was substantially related with aberrant myeloid antigen expression (P = 0.001). CONCLUSION: Aberrant myeloid antigens were expressed in 44.9% of ALL patients with insignificant differences between B- and T-ALL phenotypes. CD34 was significantly associated with B-lineage ALL and with aberrant myeloid antigen expression. T-ALL children are older and have significantly higher Hb concentration and white blood cell count. No correlation was found between aberrant myeloid expression and hematological parameters in B-ALL.

Keywords

• acute lymphoblastic leukemia
• immunophenotyping
• aberrant expression