Membranous Expression of pan CD66, CD66a, CD66b, and CD66c and their Clinical Impact in Acute Leukemia: Cross Sectional Longitudinal Cohort Study in Saudi Arabia

CD66 and its isoforms modulate several physiologic processes and have a role in aggressiveness of malignancies. We aimed at investigating pan CD66, CD66 a, b, and c expression and their clinical implication in acute leukemia. This study included 85 cases, 50 AML, 33 ALL and 2 mixed lineage leukemia from King Abdullah Medical City, Saudi Arabia. Pan CD66, CD66a, CD66b and CD66c were detected by flow cytometry at diagnosis and pan CD66 was reanalyzed at day28. Pan CD66 and CD66c expression rate was 51.8% in B-ALL and significantly correlated with BCR/ABL gene, P-value 0.037. CD66a was detected in 11.1% and significantly associated with shorter overall survival (OS), P-value 0.045. In AML, the expression rates were 40%, 28% and 32% for pan CD66, CD66b and CD66c respectively. CD66b was significantly correlated with favorable cytogenetic and prolonged OS, P-value 0.001 and 0.025 respectively. CD66c was correlated with CD25 positivity, P-value 0.003. The expression of pan CD66 at diagnosis and day 28, were significantly correlated, P-value u003c0.0001. Accordingly, pan CD66 could be added to the panel for MRD. Our data were encouraging to our center to follow other centers that already included CD66c in their panel for MRD detection. CD66c may be tried as a target for monoclonal antibody therapy in CD66c positive acute leukemia. Large-scale studies are needed to verify the association of CD66b expression with cytogenetics and survival in AML