Pattern of distribution of 35 red cell antigens in regular voluntary blood donors of South Gujarat, India.

BACKGROUND: Extended phenotyping is one of the important method of reducing red cell alloimmunisation. Extended phenotyping of red cells from voluntary donors have many uses in addition to its application in population genetics. As there was very little data extended phenotyping on a cohort of Indian Voluntary blood donors this project was undertaken.

STUDY DESIGN & METHODOLOGY: 200 regular voluntary blood donors having 'O' blood group were included for red cell antigen typing of Rh (D,C,E,c,e), Kell (K, k, Kpa , Kpb ), Duffy (Fya , Fyb ), Kidd (Jka , Jkb ), Lewis(Lea , Leb ), P(P1), MNS (M, N,S,s), and Lutheran (Lua , Lub ), Colton (Coa , Cob ), Diago (Diaa , Wra ), Vw and Xga antigens using conventional antisera provided by DIAGAST. Calculations of antigen and phenotypes frequencies were expressed as percentages.

RESULTS: Out of 200 'O' group blood donors, 96.5% were Rh D and 2.5% were K positive. Amongst Rh antigens, e was the most common (100%) followed by D, C (91.0%), c (50.5%) and E (16.5%) with DCe/DCe (R1R1, 48.0%) being the most common phenotype. In Kell blood group system, we found k antigen to be 100% and a rare phenotype Kp (a + b+) was found in 1% of the donors. For Kidd and Duffy blood group systems, Jk (a + b+) and Fy (a + b-) were the most common phenotypes (39.0% and 64.0%, respectively). In the MNS blood group system, M + N+ (67.5%) and S + s+(43.5%) were the most common phenotypes. There were antigens like Cw (3.5%), K(2.3%), Kpa (1.2%), Ina (1.0%), Vw (1.2%), Coa (4.5%), Cob (1%), Lua (1.75%), Dia+ (1.2%), and Wra+ (0.6%) with frequency < 5% in the donor population.

CONCLUSION: Extensively antigen phenotypes group 'O' red cells showed significant variation with other population from India as well as with Caucasian and black population. Extensive phenotyping 'O' group regular blood donors of red cell antigens is very useful to prepare in-house red cell panels for identification of alloantibodies.