Association of HLA-E polymorphism with severe bacterial infection and early transplant-related mortality in matched unrelated bone marrow transplantation.

Despite prophylactic measures, susceptibility to severe infections in patients who had undergone bone marrow transplantation (BMT) is quite variable. To evaluate the potential role of human leukocyte antigen (HLA)-E polymorphism on the incidence of early infections, we analyzed 77 unrelated-donor (UD) BMT pairs identically matched for classical HLA class I and class II alleles. Multivariate analysis taking into account the patient-, donor- and transplant-related factors showed that bacterial infections and transplant-related mortality (TRM) at day 180 were high when the donor genotype was HLA-E*0101/E*0101 (hazard ratio [HR]=2.20; P=0.03 and HR=2.12, P=0.048, respectively), suggesting that homozygous state for HLA-E*0101 allele is a risk factor for early severe bacterial infections and TRM in UD-BMT.