Association of Secretor And Nonsecretor Status with Lewis Phenotyping Among Blood Donors: A Prospective Observational Study from Tertiary Care Hospital

ABO (ABH) antigen expression on red cell antigens and secretion of ABH substances in body fluids are governed by different genes. The presence or absence of the Secretor gene is the basis of secretor status positivity and negativity, respectively. Determination of the secretor status has an essential role in the medical field. It was a prospective observational study to determine the association of secretor and nonsecretor status with Lewis phenotyping among voluntary blood donors. It was conducted from Jan 2020 to December 2021 at the Department of Transfusion Medicine in a tertiary care hospital in South India. Among 318 donors, secretors were 229 (72%), and nonsecretors were 89 (28%). The Lewis phenotype was consistent with secretor status, i.e., All Le (a-b +) were secretors accounting for 213 (66.9%), and All Le(a + b-) were nonsecretors accounting for 80(25.1%)donors. In the Le(a-b-) phenotype, 16(5.0%) were secretors with Se positivity but defective Lewis expression, and 9(2.8%) were nonsecretors with sese. Detection of Lewis phenotype indirectly reflects the blood group secretor status. Hence, in case of discrepancies in ABO blood groups, Bombay and Para Bombay groups, testing for Le(b) confirmation will be useful.