Flowcytometry Immunophenotyping: Role in Acute Leukemia and Detection of Aberrant Expressions in the Indian Population

Aim: To study the distribution of Acute Leukemia cases, and the expression of commonly used Cluster of Differentiation (CD markers) in sub-classification of Acute Leukemia and aberrant expression of these markers.

Methods: The retrospective study was conducted at a Global Reference Lab in Mumbai from January 2017 to December 2021 on 1538 Acute Leukemia cases diagnosed based on 20% & more blasts on morphology and Flowcytometry immunophenotyping.

Results: Out of 1538 Acute Leukemia(AL) cases, Acute Myeloid Leukemia (AML) was found to be more common (59.49%) than Acute Lymphoid Leukemia (ALL) (39.27%). Age distribution showed that ALL was more common in paediatric age group whereas AML was seen more common in adults and old age. In further analysis of ALL, B-ALL was found higher as compared to T-ALL. CD33 (92.74%), CD19 (100%) and CD7 (97.79%) were most sensitive markers for AML, B-cell and T-cell respectively. CD7, CD33 and CD13 were most common expressed aberrant markers found in them respectively.

Conclusion: Flowcytometry immunophenotyping is indispensable, fastest and very precise tool in defining lineage of Acute Leukemia and identification of Mixed Phenotypic Acute Leukemia (MPAL) and Undifferentiated Leukemia. Aberrant expression of markers guides for further cytogenetic and molecular studies to great extent and identification of blasts during assessment of minimal residual disease.