Association of PTPN22 gene polymorphisms with chronic hepatitis B virus infection in Chinese Han population

Lymphoid protein tyrosine phosphatase encoded by protein tyrosine phosphatase non-receptor 22 (PTPN22) gene plays an important regulatory role in T- and B-cell activation. This study investigated PTPN22 ?1123G/C and intron 16 T/C polymorphisms in 372 patients with chronic hepatitis B virus (HBV) infection, 72 HBV infection resolvers and 273 healthy controls. Genotypic association tests between groups assuming codominant, dominant or log-additive genetic models were performed. In recessive model, PTPN22 ?1123G/C genotype GG in healthy controls was more frequent than infection resolvers (P = 0.037, OR = 3.606, 95%CI = 1.079–12.053) and this genotype in HBV patients was more frequent than resolvers although the difference was not significant (P = 0.059). The PTPN22 intron 16 T/C genotype TC in cirrhosis patients was significantly higher than asymptomatic carriers (ASC) in codominant (P = 0.028, OR = 9.792, 95%CI = 1.281–74.832) and overdominant (P = 0.025, OR = 10.142, 95%CI = 1.332–77.214) models. This genotype in hepatocellular carcinoma (HCC) patients was significantly higher than ASC in codominant (P = 0.034, OR = 9.200, 95%CI = 1.176–71.990) and overdominant (P = 0.030, OR = 9.677, 95%CI = 1.241–75.442) models. These findings suggest that PTPN22 polymorphisms may predispose the chronicity or the development of cirrhosis and HCC in HBV infection.