Research On The Association Between IL-28B Gene Polymorphisms And Chronic Hepatitis C

Hepatitis C is a kind of communicable disease resulted from hepatitis C virus (HCV). Not every patient with hepatitis C infection receiving standard-of-care pegylated interferon and ribavirin (PEG-IFN/RBV) could achieve sustained virological response (SVR). What’s more, the treatment is not only costly but also has many side effects which few patients could tolerate. If the predictors of treatment outcome are indentified the situation is greatly improved. In addition to the virus and treatment factors, studies have found that Interleukin-28B (IL28B) gene polymorphism is closely related with the treatment response in hepatitis C infection patients treated with PEG-IFN/RBV recent years. Single nucleotide polymorphism (SNP) rs8099917and rs12979860have a higher association with treatment response in comparison with other SNPs located in IL28B gene and are focused on by studies recent years. Unfortunately, the association is diverse in different races and HCV genotypes in current studies. In the study we detect the genotype and allele frequencies of IL28B rs8099917in Chinese patients with HCV infection and healthy people then assess the influence of IL28B rs8099917gene polymorphisms on treatment responses of chronic hepatitis C patients treated with PEG-IFN/RBV. AIM:We aimed to study the effect of IL28B rs8099917on the antiviral therapy responses in Chinese hepatitis C patients and investigate the association between IL-28B SNP rs8099917and susceptibility of hepatitis C virus infection in China.METHODS:We retrospectively enrolled367patients chronically infected with HCV from2005to2010at Tianjin Third Central Hospital, and244healthy people who received health examination in the department of health of Tianjin Third Central Hospital were selected to be healthy controls. IL-28B rs8099917was genotyped in263patients infected with HCV and244healthy controls in Tianjin using TaqMan SNP genotyping method. The discrepancies of rs8099917genotypes and alleles frequencies between the two groups were analyzed by statistics. The roles of rs8099917and clinical characteristics in antiviral treatment were analyzed by logistic regression.RESULTS:Among263chronic HCV patients,223(84.8%) had the TT genotype,39(14.8%) had the TG genotype, and1(0.40%) carried GG genotype. The frequency of T allele was0.922. Out of244healthy controls, the number of people who carried TT, TG and GG genotype was222(91.0%),21(8.6%) and1(0.4%), respectively. T allele frequency was0.953. Both genotypes distribution of patients and healthy controls were in Hardy-Weinberg equilibrium (x2=0.26;x2=0.43) and P value were both more than0.05. TG/GG genotypes frequencies of hepatitis C patients were significantly different from those of healthy controls (OR=1.810,95%CI:1.042-3.145; P=0.033). Patients with HCV infection had a higher G allele frequency than healthy controls (OR=1.709,95%CI:1.010-2.893; P=0.044). The differences in TT genotype frequency between patients infected with HCV genotype lb and2a/3a were not statistically significant (94.4%vs85.0%; P=0.230).176patients had their HCV genotypes detected, with132(75.0%) infected with HCV genotype lb,43(24.4%) with HCV genotype2a and1(0.6%) with3a. The univariate analysis revealed no significant association between rs8099917and sustained virological response (SVR)(P=0.612). However, it was found that HCV genotypes2a/3a (OR=3.556,95%CI:1.174-10.765; P=0.044), age (OR=0.958,95%CI:0.929-0.987; P=0.005), prothrombin time (PT)(OR=0.780;95%CI:0.631-0.965; P=0.022), albumin (ALB)(OR=1.188,95%CI:1.086-1.300; P=0.000) and cholesterol (CHO)(OR=2.078,95%CI:1.224-3.531; P=0.007) were associated with SVR. In multivariate analysis, only ALB was significant independent predictors of SVR (OR=1.223,95%CI:1.046-1.430; P=0.011).CONCLUSION:Patients with HCV infection had a higher G allele frequency than healthy controls and G is a risk allele in China. IL-28B rs8099917gene polymorphism is correlated with susceptibility of HCV infection in China. Patients with HCV genotypes2a/3a infection are more likely to obtain SVR than lb HCV infection patients. ALB can independently predict SVR. Rs8099917may play a quiet role in predicting treatment response of hepatitis C patients who received PEG-IFN/RBV therapy in China.