در بیماران تالاسمی دارای آلوآنتی بادی Kell بررسی ژنوتیپ سیستم گروه خونی

Background and Objectives Alloimmunization is the most serious problem in thalassemia patients and Anti-K is the most prevalent antibody in these patients. So accurate identification of this antigen can significantly decrease the rate of alloimmunization. Serological phenotyping is usually not reliable in multitransfused patients. Molecular genotyping can overcome limitations of hemagglutination assays, resolve discrepant serologic typing and guide RBC selection for them. In this regard, we intended to determine the K and k among alloimmunized thalassemia patients using molecular methods and compare the results between different methods. Materials and Methods In this descriptive study, a total of 200 blood samples were collected randomly from alloimmunized thalassemia patients of Tehran Adult Thalassemia Clinic. The phenotype of all samples was determined for K and k. PCR-SSP was performed for all samples. The discrepant results between the phenotype and genotype were re-evaluated by PCR-RFLP and were confirmed by DNA sequencing. Results Sixty-three (28%) out of 200 patients developed Anti-K. Molecular typing of samples for K and k antigens revealed 96% (192 patients) KEL*02/KEL*02 and 4% (8 patients) KEL*01/KEL*02 among our samples. Discrepancy between the serology and genotyping results were detected in 8 cases that in all cases correction of genotype results was confirmed by DNA sequencing. Conclusions This study demonstrates that antibodies against K antigen continue to develop in thalassemia patients at high rate. Our findings suggest that RBC molecular genotyping is superior to serological phenotyping and is a good alternative and more reliable method especially in multi transfusion patients such as thalassemia patients. [ABSTRACT FROM AUTHOR]