DNA-based genotyping to assign extended blood group in thalassemic patients

Abstract

Background/aim In multitransfused thalassemic patients, it is mandatory to assign a correct antigen profile for those patients. Unfortunately, hemagglutination fails to phenotype their blood group antigens owing to the presence of donor-derived red blood cells (RBCs). Genotyping can overcome this limitation to determine the correct antigen profile of these patients. The aim of this study is to compare the results of serological phenotyping and DNA-based red cell antigens genotyping in thalassemic patients. Patients and methods This study was conducted on 210 thalassemic patients who were divided into two groups, viz., the newly diagnosed patient group (n=20) and another 190 patients who were previously diagnosed with a history of blood transfusion, where 25 patients of them were selected with a negative screening test for antibodies. Two standard methods, the serological phenotyping and the DNA-based red cell genotyping, of 16 blood group antigens were performed. Results The present study indicated that there were no significant differences between serological phenotyping and DNA-based red cell genotyping results in the newly diagnosed patients with thalassemia (group 1) who had no history of blood transfusion. However, DNA-based genotyping was found to be significantly superior over the serological phenotyping for detection of some significant antigens in previously diagnosed transfused patients. Conclusion Hemagglutination is regarded as the gold standard method in blood group typing, but the results may be inaccurate in certain situations, particularly in the patients with transfused RBCs present in circulation. Hence, genotyping for RBC antigens could be more helpful in determining the blood group antigen profile in multiply transfused patients. Therefore, the integration between the serological phenotyping and DNA-based red cell genotyping will help in the correct interpretation of the results to increase transfusion safety.