Varied distribution of RhD epitopes in the Indian population.
BACKGROUND
Inhabited by more than 4000 caste and tribal groups, India has an extremely heterogenous population. For thousands of years many tribal groups have practised endogamy and are practically genetically isolated. Traditionally, polyclonal anti-D reagent has been used for RhD typing; though monoclonal antibodies are increasingly being used. As a result, blood banks find it difficult to assign the RhD status to an increasing number of people. As monoclonal anti-D typing reagents may not detect all RhD antigen epitopes, we studied the RhD antigen epitope heterogeneity in different population groups in India.


METHODS
Red cells of 5315 RhD-positive individuals belonging to different castes and tribes of India were tested with 30 different epitope-specific monoclonal anti-D antibodies.


RESULTS
No single monoclonal antibody could detect all RhD-positive red cells detected by polyclonal antisera. The highest proportion of D antigen was detected by LHM 76/55 and BRAD-8 (98%) monoclonal antibodies.


CONCLUSIONS
We need to determine the correct mix of monoclonal antibodies that will detect nearly all RhD antigens detected by polyclonal anti-D sera. Similarly, before accepting monoclonal anti-D for therapeutic use, it would be necessary to determine the appropriate ones for use in the Indian population.
Kulkarni
S S
SS
Institute of Immunohaematology (ICMR), K.E.M. Hospital Campus, Parel, Mumbai, Maharashtra, India.
Gupte
S C
SC
Vasantha
K
K
Mohanty
D
D
Ghosh
K
K
D000918:Antibody Specificity; D001789:Blood Group Antigens / Q000032:analysis; D001787:Blood Group Incompatibility; D001788:Blood Grouping and Crossmatching; D003710:Demography; D000939:Epitopes; D005006:Ethnicity; D006801:Humans; D015994:Incidence; D007194:India; D007518:Isoantibodies / Q000032:analysis*; D010865:Pilot Projects; D044382:Population Groups; D012204:Rh-Hr Blood-Group System / Q000032:analysis*; D018029:Rho(D) Immune Globulin; D012923:Social Class
D001789:Blood Group Antigens; D000939:Epitopes; D007518:Isoantibodies; C061961:RHO(D) antibody; D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin; C026410:Rho(D) antigen