Aberrant Antigen Expression in Acute Lymphoblastic Leukemia and Its Correlation with Post-Induction Remission

Abstract

Objective: To determine the aberrant expression of antigens in newly diagnosed patients of Acute Lymphoblastic Leukemia and its correlation with post induction remission

Methodology: This Descriptive cross-sectional study was carried out at department of Hematology, Armed Forces Institute of Pathology (AFIP), from April 2024 to August 2025. A total of 183 newly diagnosed patients with ALL of all ages and both genders were enrolled. Morphology, cytochemistry and flow cytometric immunophenotyping were used to analyze bone marrow and peripheral blood samples to identify lineage and aberrant antigen expression. Induction chemotherapy was given to patients over a period of 29 days and the remission was assessed by bone marrow biopsy. Analysis of the data was done by SPSS 22.0, Chi-square test was used; a p-value of ? 0.05 was taken as significant.

Results: Aberrant antigen expression was identified in 36 (19.7%) of 183 ALL patients (median age 13 years; 69.9% male). B-ALL and T-ALL comprised 152 (83.1%) and 31 (16.9%) cases respectively. CD33 and CD13 were most frequently expressed aberrant antigens. The total number of patients who achieved remission were 149 (81.4%), however, it was significantly less among patients who had aberrant antigen expression (24 (66.7%) vs. 125 (85.0%), p = 0.011). Persistent thrombocytopenia, increased residual blasts and persistently raised WBC counts were also linked to aberrant antigen expression.

Conclusions: Aberrant antigen expression in ALL was associated with sub-optimal treatment response and poor post-induction outcome, highlighting its significance as a prognostic variable in the therapeutic decision-making.

Keywords: Acute Lymphoblastic Leukemia, Aberrant antigen expression, Immunophenotyping, Remission, Flow Cytometry.