The Genotyping And Alloimmunization Study Of RhD Antigen Among Rh Negative Perinatal Women

Objective： The Rh blood group system is the most polymorphic andimmunogenic system of human blood group systems. It is also the mostclinically significant blood group system except ABO system. The highlyimmunogenic RhD antigen is often involved in hemolytic disease of thefetal and newborn(HDFN) and other diseases. The HDFN caused by anti-Dantiboy will lead to anemia, edema, stillbirth of fetus and kernicterus, evendeath of newborn in RhD negative perinatal women. Timely testing of RhDantigen and antibody, monitoring of anti-D leve will provide importantinformation for the treatment of HDFN in RhD negative perinatal women.The aim of the study is to research the genotyping of RhD antigen and RhDisoimmunization situation in RhD negative perinatal women in Shandongarea, explore the factors which affect the production of anti-D antibodyamong RhD negative preganant women, seek for the regularity of RhDisoimmunization, adopt different preventation and treatment measuresaccording to different situation of RhD isoimmunization and set up thecorrect prenatal testing, preventation and treatment measures of RhDhaemolytic disease of the fetus and the newborn.Methods：Detailed data of pregnancy history was collected of1017cases ofpregnant women in the year2012.1. We identified the ABO and RhD typesof pregnant women and their husbands with standard serological methods.2.With the negative result of RhD antigen for the first serological screen, wetested their D antigen with indirect antiglobulin test, absorption-elution testand PCR-SSP method to confirm the result of weak D type, partial D typeand DEL type.3. The RhCcEe antigens were typed to all D negative womenand their husbands.4. The irregular antibodies were screened in all RhDnegative women and the specificity and titre of the antibodies were determined if the result is positive.Results：1. Among1017cases of maternal specimens,266cases wereidentified to be RhD negative by serological screening, of which9wererecognized as weak D or partial D type,56were recognized as DEL typewith further antiglobulin test, absorption-elution test and PCR-SSP methods.2. Among all of the pregnant women which were identified to be RhDnegative by primary screening,15cases of them had produced the anti-Dantibody. Proportion of Rh negative pregnant women with anti-D antibodyin this study is5.64%.3. Among the15cases of RhD negative pregnantwomen who had produced anti-D,those who carried compatible ABOantigens with their husbands(86.7%) are apparently more than those whocarried incompatible ABO antigens with their husbands(13.3%, P<0.05).4.Identified by serology and molecular biology methods,15cases ofRh-negative pregnant women who had produced anti-D were excluded fromthe DEL phenotype.Conclusion：1. The RhD isoimmunization of D-negative pregnant women isaffected by their pregnancy and DELivery history, the couples’ ABO bloodgroup, being DEL type or not and so on. With compatible ABO types for thecouples, more pregnancy and DELivery history and not being DEL typeapparently increase the possibility of RhD isoimmunization for the RhDnegative pregnant women.2. The probability of producing anti-D is lowerin DEL type pregnant women and therefor the antenatal testing of anti-Dantibody and anti-D immunoglobulin therapy could be omit.3.Timelytesting of RhD antigen and antibody will provide important information forthe treatment of HDFN in RhD negative perinatal women.