Association between CTLA-4 rs231775 polymorphism and hepatocellular carcinoma susceptibility

Our study aimed to investigate the association of cytotoxic T-lymphocyte antigen-4 (CTLA-4) rs231775 polymorphism with hepatocellular carcinoma (HCC) susceptibility. Genotypes distribution of the control was tested by Hardy-Weinberg Equilibrium (HWE). CTLA-4 rs231775 polymorphism was analyzed in 80 patients with HCC and 78 healthy controls by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, and the expression level of CTLA-4 in the serum of all subjects was detected using enzyme linked immunosorbent assay (ELISA) kit. Odd ratio (OR) with 95% confidence interval (CI) were calculated by chi-squared test to determine the correlation of CTLA-4 rs231775 polymorphism and the risk of HCC. The genotypes frequencies of the control group were in accordance with HWE. The frequencies of genotype AA and allele A in CTLA-4 rs231775 polymorphism were significantly higher in cases than the control group (AA vs. GG: OR=2.81, P=0.043; A vs. G: OR=1.63, P=0.022). Meanwhile, the expression level of CTLA-4 was remarkably higher in cases compared with the controls. The association analysis indicated that AA genotype carriers exhibited highest level of CTLA-4 (P