Influence of HLA-DQ dimers on the development of graft failure in haploidentical hematopoietic stem cell transplants

HLA-DQ molecules are dimers of polymorphic α and β chains. There are two groups of HLA-DQ molecules, G1 and G2, dimerization is possible only between α and β chains of the same group. A person can have one, two, or four unique molecules (dimers) of HLA-DQ. The purpose of the study was to investigate the effect of the number of unique HLA-DQ molecules of different recipient G-groups on the development of graft failure in patients with acute leukemia after haplo-HSCT. The study included 134 patients with acute leukemia who underwent hematopoietic stem cell transplantation from a related haploidentical donor. It has been found that there is a trend to increased risk of graft failure in patients with four unique HLA-DQG1 molecules; on the contrary, patients with four unique HLA-DQG2 molecules have a reduced risk of graft failure.