the impact of hla-e polymorphisms in graft-versus-host disease following hla-e matched allogeneic hematopoietic stem cell transplantation

the  non-classical mhc  class-i mainly involves in the  regulation of  innate  immune responses where hla-e  plays a significant role in the cell identification by natural killer cells. hla-e is a main regulatory ligand for natural killer cells and given the importance of these effector cells in hematopoietic stem cell transplantation, we investigated the effect of hla-e polymorphisms on post-hematopoietic stem cell transplantation outcomes. the study group included 56 donor-patient pairs with underlying malignant hematological disorders undergoing hla-e  matched allogeneic hematopoietic stem cell transplantation. they were genotyped for hla-e locus using a sequence specific primer-polymerase chain reaction. the  median follow-up was 20.6 months  (range 0.2-114.8) and  the  parameters assessed were acute and chronic graft-versus-host disease and overall survival. we showed a lower frequency of acute graft-versus-host disease (grade ii or more; p=0.02)and chronic graft-versus-host disease (extensive; p=0.04) in the patients with hla- e*0103/0103 genotype compared to other genotypes of hla-e. there was also an association between hla-e*0103/0103 and improved overall survival (p=0.001). conclusively, our  results  suggest a  protective  role  for  hla-e*0103/0103  genotypeagainst acute graft-versus-host disease (grade ii or more) and chronic graft-versus-host disease (extensive) as well as an association between this genotype and a better overall survival after hla-e matched allogeneic hematopoietic stem cell transplantation.