Prevalence of Rh Antigens among Voluntary Blood Donors in Chennai

Abstract

Background : The Rh system is the clinically most important blood group system next to ABO system. Even after proper blood grouping and cross matching there is a possibility of alloimmunization in the recipients against the Rh or minor blood group antigens like Kell, MNSs, Duffy etc. The determination of prevalence of Rh antigens can play a major role in preventing alloimmunization and adverse events in multitransfused recipients. Aim : The aim of the study was to find out the prevalence of 5 major types of Rh antigens in voluntary blood donors, to determine the Rh composition of the population in Chennai and to generate a database of donors for all future activities. Materials and methods : Rh determination was done by the Hemagglutination test by tube method on 100 voluntary blood donors. Statistical analysis was done using Microsoft office Excel software. Results : Rh D antigen was positive in 91 and negative in 9. Amongst the Rh antigens, e was the most common (98) followed by D (91), C (84), c (67) and E (25). Since genotyping was not done, 8 predicted phenotypes were found to be present in our population. The most common predicted phenotype was DCeDCe (R1R1-35) and dcedce (rr-7) was the most common predicted phenotype among Rh negatives. DcEDcE (R2R2), dCedce (r'r) were the rare predicted phenotypes observed. Conclusion : This study helped in establishing a database of donors for future preparation of indigenous cell panels, and to provide antigen negative compatible blood to multitransfused patients with problems of alloimmunization. Further studies on a large sample size are required to establish the genetic make-up of Rh system in the Indian population. And we have performed only serological investigations, while molecular investigations will be conclusive.