The PTPN22 R620W polymorphism is associated with severe bacterial infections after human leukocyte antigen geno-identical haematopoietic stem-cell transplantations.

PTPN22 is a negative regulator of T-cell activation. The C1858T PTPN22 polymorphism has been associated with autoimmune diseases. The role of PTPN22 in immune response and autoimmune diseases suggested that PTPN22 polymorphism could impact outcome of allogeneic hematopoietic stem-cell transplantations that is impaired by immunological and infectious complications. One hundred ninety-two patients who received a non-T-depleted bone marrow transplant from a human leukocyte antigen-identical sibling donor were included in this study. Donor PTPN22 C1858Tpolymorphism was not associated with severe acute graft-versus-host disease, relapse, survival, cytomegalovirus, and fungal infections, but significant with severe bacterial infections (24% for donor CC vs. 0% for donor CT+TT genotypes, P=0.003). The association was confirmed by a multivariate analysis (P=0.036, hazard ratio=2.28, 95% confidence interval=1.06-4.90). This could improve the genetic risk assessment of severe bacterial infections in allogeneic hematopoietic stem-cell transplantations.

Homozygous status for HLA-E*0103 confers protection from acute graft-versus-host disease and transplant-related mortality in HLA-matched sibling hematopoietic stem cell transplantation.

BACKGROUND: The posttransplant period following hematopoietic stem cell transplantation (HSCT) is potentially high risk for developing survival-compromising complications, many of which are known to be under the control of immunogenetic factors. Given the dual role of human leukocyte antigen (HLA)-E molecules in innate and adaptive immune processes, we analyzed the impact of HLA-E polymorphism in genoidentical HSCT setting. METHODS: We analyzed 187 HLA-genoidentical sibling pairs for HLA-E polymorphism. To explore its potential association with the incidence of acute and chronic graft versus host disease (aGVHD, cGVHD), severe infections, risk for transplant-related mortality (TRM), and overall survival, HLA-E locus was genotyped by a polymerase chain-reaction-sequence-specific primer (PCR-SSP) strategy. RESULTS: Multivariate analysis, taking into account the patient-, donor- and transplant-related factors, showed that the incidence of aGVHD and TRM at day 180 were low when the genotype was HLA-E*0103/E*0103, either in the donor or in the recipient, the pairs being identical for HLA-E alleles (hazard ratio [HR]=0.71, P=0.009; and HR=0.42, P=0.04, respectively). We also found a trend towards association between E*0103 homozygosity and improved survival (P=0.05). There was no association between HLA-E polymorphism and incidence of severe infections. CONCLUSIONS: These data suggest that the homozygous state for HLA-E*0103 allele behaves as a protective genetic factor against aGVHD and TRM and likely contributes to improved survival in HLA-genoidentical bone marrow transplantation.