CD66C EXPRESSION IN PEDIATRIC B-CELL ACUTE LYMPHOBLASTIC LEUKEMIA: CORRELATION WITH CD38, CD58, CD81, AND ITS ROLE IN MINIMAL RESIDUAL DISEASE DETECTION.

Abstract

Background: This study aims to characterize the expression of CD66c in leukemic blasts of B-cell acute lymphoblastic leukemia (B-ALL) and evaluate its role in detecting Minimal Residual Disease (MRD).

Methodology: A hospital-grounded prospective observational investigation was done from November 2017 to March 2019 at Lady Hardinge Medical College along with Kalawati Saran Children Hospital, New Delhi, involving 30 patients diagnosed with B-ALL. Inclusion criteria were patients under 18 years, newly diagnosed with B-ALL. Exclusion criteria included patients with relapsed B-ALL or those who had received corticosteroids for ≥8 days prior. Routine investigations included a complete hemogram, and special investigations involved immunophenotyping by flow cytometry. MRD was defined as ≥0.01% leukemic cells.

Results: CD38 Expression: 96.67% (29/30) showed under expression; MRD positivity at day 35 was 91.66%. CD58 Expression: 90% (27/30) showed overexpression; MRD positivity at day 35 was 91.67%. CD81 Expression: All cases (25/25) showed expression; MRD sensitivity was 100%. CD66c Expression: 43.3% had <5% gated, 46.7% had >20% gated; dim expression in 60%, moderate in 40%. MRD sensitivity was 58.3%.

Conclusion: CD66c is a significant marker in B-ALL, but its sensitivity for MRD detection is lower compared to CD38, CD58, and CD81. The investigation highlights the importance of utilising multiple markers for effective MRD detection.