[Analysis of immunophenotype of B-lineage acute lymphoblastic leukemia cells by 4-color flow cytometry]

Area of Science:

• Hematology
• Immunology
• Oncology

Background:

• B-lineage acute lymphoblastic leukemia (B-ALL) is a heterogeneous malignancy.
• Accurate immunophenotypic characterization is vital for diagnosis, classification, and treatment strategies.
• Understanding variations in antigen expression across different age groups is essential for personalized medicine.

Purpose of the Study:

• To investigate the immunophenotypic characteristics of B-ALL cells in a Chinese cohort.
• To analyze age-specific differences in antigen expression and B-ALL subtypes.
• To correlate immunophenotype with Bcr/abl status.

Main Methods:

• Analysis of B-ALL cells from 181 patients using 4-color flow cytometry with CD45/SSC gating.
• Evaluation of antigen expression frequencies, including CD19, HLA-DR, CD38, CD10, CD34, CD117, CD2, CD7, CD13, and CD33.
• Assessment of Bcr/abl mRNA in a subset of patients (n=43).

Main Results:

• Typical B-ALL cells expressed CD19 (100%), HLA-DR (98.9%), and CD38 (88.5%).
• CD10 and CD34 expression varied with age, with higher CD10 in children and increased CD10(-)/CD34(+) subtypes with age.
• Myeloid antigen (CD13/CD33) co-expression was higher in adolescents and adults compared to children, and more frequent in CD10(-)/CD34(+) subtypes.

Conclusions:

• B-ALL immunophenotype exhibits distinct age-related patterns, with adolescents and adults sharing similarities.
• CD45 expression correlates with CD10 negativity, and CD45-negative/dim cases show higher CD10 expression.
• Bcr/abl positivity was primarily observed in the CD10(+)/CD34(+) subtype, with no significant difference in myeloid antigen co-expression based on Bcr/abl status.