Importance of extended blood group genotyping in multiply transfused patients

Blood group antigen systems are not limited to the ABO blood groups. There is increasing interest in the detection of extended blood group systems on the red cell surface. The conventional method used to determine extended blood group antigens or red cell phenotype is by serological testing, which is based on the detection of visible haemagglutination or the presence of haemolysis. The method relies on the use of monoclonal or polyclonal antibodies designed to detect specific epitopes of the antigens on the red cell surface. However, this technique has many limitations. The replacement of the conventional serologic method is needed in cases where blood group antigen detection by this method is not reliable. This may be due to recent exposure to donor red cell, certain drugs or medications or other diseases that may alter the red cell membrane. The main aim of this study is to determine the red cell blood group genotype by PCR and to compare the results with the conventional serological methods in multiply transfused patients. Sixty-three patients participated in this study. Peripheral blood was collected and blood group phenotype was determined by serological tube method while the genotype was performed using TaqMan Single Nucleotide Polymorphism (SNP) RT-PCR assays for RHEe, RHCc, Kidd and Duffy blood group systems. Discrepancies were found between the phenotype and genotype results for all blood groups tested. Accurate red blood cell antigen profiling is important for patients requiring multiple transfusions. The SNP RT-PCR platform is a reliable alternative to the conventional method