2024 Volume 13 Issue 3 Pages 89-95
The impact of HLA matching of patient and donor in allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been analyzed mainly in unrelated hematopoietic stem cell transplantation (UR-HSCT), where large-scale clinical and HLA database are available. Next-generation sequencing based HLA typing have made it possible to detect polymorphisms in the entire HLA gene, and it have provided new insights into the significance of HLA in allo-HSCT. Dimoriphism at -21 of HLA-B exon 1 gives rise to leader peptides with either methionine or threonine at the second position of the leader. Dimorphic HLA-B leader has been demonstrated to be useful for predicting the risk of graft-versus-host disease (GVHD). It has been shown that differences in HLA-DQ heterodimers formed by HLA-DQA1 and-DQB1 gene products may differently affect transplant outcomes. Although allo-HSCT with alternative donors such as HLA haploidentical related donor and unrelated cord blood has become widely performed, the impact of HLA incompatibility on transplant outcomes has been shown to vary depending on the stem cell source. This review outlines our emerging understanding of the impact of HLA on allo-HSCT for optimal donor selection.
