An epitope mapping of the Weak D phenotype with RHD 1227A allele

【Objective】 To analyze the D antigen epitopes of the weak D phenotype individuals with RHD 1227A alleles.【Methods】 Rh blood group D,C,c,E and e antigen phenotypes were tested by the routine serological methods,and the D antigen were further determioned through the indirect antiglobulin test(IAT).A sequence-specific primer PCR(PCR-SSP) method was applied for detection of RHD,and the RHD zygosity was also detected through a PCR method.To the identified samples,D antigen epitope mapping was performed using 12 monoclonal antibodies specific to different D-epitopes,respectively.【Results】 Three samples were determined as weak D phenotype,carrying RHD1227A alleles,by serological tests and the PCR-SSP detections.All samples were tested D+C+c+E-e+.The zygosity test showed all were RHD+/RHD-heterozygotes,which shows 3 donors being CDe/cde genotypes.The Red cell D antigen epitoping tests showed the sample possessing grossly intact D antigen molecules,same as the Rh(D)-positive controls.【Conclusion】 Three weak D individuals with RHD1212CA were found.All individuals possess grossly intact D antigen in spite of RHD1212CA expressing DEL or weak D type,which showed that the different expressions of the allele might be affected by other regulating factors.