Genetic variations of PD1 and TIM3 are differentially and interactively associated with the development of cirrhosis and HCC in patients with chronic HBV infection.

Cooperation or interaction of programmed cell death-1 (PD-1) and T cell immunoglobulin and mucin domain-containing molecule-3 (Tim-3) molecules is more relevant than either molecule alone to immune dysfunction in chronic viral infection and cancers. This study simultaneously investigated polymorphisms at PD1 +8669 and TIM3 -1516 loci in 845 hepatitis B virus (HBV) chronically infected patients [151 asymptomatic carriers, 202 chronic hepatitis, 221 cirrhosis and 271 hepatocellular carcinoma (HCC)], 141 HBV infection resolvers and 318 healthy controls. Multivariate analysis showed that, in addition to gender, age, ALT, albumin and HBV DNA, PD1 +8669 genotype AA was associated with cirrhosis compared with patients without cirrhosis (OR, 2.410; P=0.001). TIM3 -1516 genotypes GT+TT, together with gender, age, ALT, AST, direct bilirubin, albumin and HBeAg status, were associated with HCC compared with cirrhosis patients without HCC (OR, 2.142; P=0.011). The combined carriage of PD1 +8669 AA/TIM3 -1516 GT or TT was higher in cirrhosis and HCC pooled patients than in patients without cirrhosis (OR, 2.326; P=0.020) and in HCC patients than in cirrhosis patients (OR, 2.232; P=0.013). These data suggest that PD1 and TIM3 polymorphisms may differentially and interactively predispose cirrhosis and HCC in chronic HBV infection.