Prevalence of Secretor Antigen and Association with Blood Group among Blood Donors Attending a Tertiary Care Blood Bank in Kerala

Introduction and Rationale About 80 % of the population secretes soluble blood group substances with A, B and O (H) specificity corresponding to each individuals blood type, the remaining 20 %, the non-secretors do not. Secretor status assessment serves as a supportive investigation in confirmation of blood groups, in case of blood group discrepancies, and in Forensic Medicine, for clarification of medico legal cases. By determining secretor status, predisposition to certain diseases also could be assessed. Objectives The study aimed to look for the prevalence of secretor antigen among blood donors and the association between blood group of the individual and secretor status. Materials and Methods: The study was a cross-sectional prevalence study. Prevalence of secretor status in the population was ascertained to be 80 % from literature. With this prevalence and a margin of error of 10 % of prevalence, sample size was calculated to be 100 blood donors. Blood Group and secretor status of donors were determined, analysed using Chi-Square Results: Of the 220 donor samples studied, secretor positivity come to be 129 (58.6 %) and the rest of the donors were non-secretors. The main blood group associated with secretor positivity was A, even though the main prevalent blood group was O.57.1 % of Rh Positive individuals were secretor positive and 80 % of Rh Negative individuals were secretor positive (P=0.082).55 % of males were secretor positive where as 75 % of females were secretor positive (P =0.042. ) Conclusion: Main blood group associated with secretor positivity is A group. There was a significant association between secretor antigen and gender, with more of females having secretor positivity. A statistical significance between Rh status and secretor reactivity could not be established.