Global Journal of Transfusion Medicine (Jan 2021)
RH phenotype, ABO and kell antigens, alleles and haplotypes frequencies in North Indian blood donor population
Abstract
Background and Objectives: ABO, RH and Kell blood group systems are clinically significant blood group systems among 36 blood group systems having total of 360 blood group antigens which cause most cases of alloimmunization following blood transfusions or pregnancy. India has regionally and ethnically very diverse population in different demographic areas. Due to different antigenic expression in different population, knowledge of antigen frequencies among their local and regional donor population is important to assess the risk of antibody formation, probability of antigen negative blood for patients having alloantibodies, inventory management and database for rare antigens thus enhancing patient safety. Aim: To know and compare phenotype prevalence, frequency distribution of ABO, RH and Kell antigens and Alleles in blood donors. Methods: A prospective study was conducted in a tertiary care hospital in North India over three years period. ABO, RH D grouping, RH and Kell phenotypes were performed on blood donors. Hardy Weinberg's equations were used to calculate ABO, RH and Kell allele frequencies and were analyzed. Results: During the study period, 24745 healthy individuals donated blood at Tertiary Care hospital; with 97.26% male and 2.74% female population. Prevalence of ABO antigens were B =37.74%, O = 31.38%, A = 21.77% and AB = 9.09% with allele frequency for O = 0.560, B = 0.266, A = 0.169 and AB = 0.091. The commonest RH phenotype observed was DCCee followed by DCcee, DCcEe, DccEe while commonest RH negative phenotype were ccee and Ccee. Homozygous phenotypes were absent in our population. Amongst five RH antigens phenotyped serologically, highest prevalence was of e antigen followed by D, C, c and E being the lowest. Prevalence of Kell phenotype was 2.57% (K) while that of k as 97.43% with allele frequencies of K and k as 0.0252 and 0.986 respectively. Discussion: Genetic variability in different population result in varied expression of red cell antigens in different races. Knowledge of varied frequency and phenotypic expression of major clinically relevant antigens and RH haplotypes in these blood groups systems would help in more rational approach for blood transfusion, decreasing alloimmunization thus enhancing blood safety.
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