Impact of HLA-G 14-bp polymorphism on acute rejection and cytomegalovirus infection in kidney transplant recipients from northwestern China

Human leukocyte antigen (HLA)-G plays an important role in promoting transplant tolerance and helping human cytomegalovirus (CMV) to subvert host defenses. Strong evidence suggests that HLA-G 14-bp insertion/deletion polymorphism influences the stability of HLA-G mRNAs and levels of protein expression. We hypothesized that HLA-G 14-bp polymorphism of recipients has an influence on the risk of acute rejection (AR) and CMV infection. We investigated the impact of HLA-G 14-bp polymorphism on a total of 363 unrelated Chinese Han individuals who included 42 kidney transplant recipients with AR, 43 recipients with CMV infection, 102 recipients with stable allograft function (STA), and 176 healthy controls (HC). No statistically significant difference was found between all kidney transplant patients and HC (P=0.149). But, our data showed an increased frequency of homozygous genotype +14/+14bp (P_c=0.004) and allele +14bp (P_c=0.002) in patients with AR when compared with STA, with the odds ratio of 3.17 and 2.28, respectively. Moreover, we found that the frequency of the -14/-14bp genotype (P_c=0.008) and the -14bp allele (P_c=0.016) was increased in patients with CMV infection when compared with STA, with the OR of 2.66 and 1.96, respectively. Multivariate analysis further demonstrated that HLA-G homozygous +14bp and -14bp genotypes were an independent risk factor for allograft rejection and CMV infection, respectively. In conclusion, this study identified an important genetic risk factor for acute allograft rejection, and it was the first to show a significant correlation between HLA-G 14-bp polymorphism and CMV infection after kidney transplantation from northwestern China.