Tumor necrosis factor-alpha -308G/A polymorphism and risk of hepatocellular carcinoma in hepatitis C virus-infected patients

Tumor necrosis factor-alpha (TNF-α) is an important cytokine in generating an immune response against infection with hepatitis C virus (HCV). The functions of TNF-α may be altered by single-nucleotide polymorphisms (SNPs) in its gene structure. We hypothesized that SNPs in TNF-α may be important in determining the outcome of an HCV infection. To test this hypothesis, we investigated the role of the polymorphism -308G/A, which is located in the promoter region of the TNF-α gene, in the progression of HCV infection in Egyptian patients using a quantitative real-time polymerase chain reaction (qRT-PCR). The distribution of this polymorphism and its impact on the serum level of TNF-α was compared between 90 HCV-infected patients [45 with HCV-induced cirrhosis and 45 with HCV-related hepatocellular carcinoma (HCC)] and 45 healthy Egyptian volunteers without any history of liver disease. Our results showed that at the TNF-α -308 position, the G/G allele was most common (78.5% ) in the study population, with the G/A and A/A alleles occurring less frequently (13.3% and 8.1% , respectively). Frequencies of G/G, G/A, and A/A genotypes were 87%, 7%, and 6% in patients with liver cirrhosis and were 94% , 4% , and 2% in patients with HCC, respectively. Serum levels of TNF-α were significantly higher in HCV-infected patients than in healthy controls, indicating that the TNF-α -308 polymorphism does not influence the production of TNF-α. The serum level of TNF-α was positively correlated with HCV infection. Taken together, these findings suggest that the TNF-α -308 polymorphism may not be a host genetic factor associated with the severity of HCV infection, but may be an independent risk factor for HCC.

Tumor necrosis factor-α-G308A polymorphism is associated with liver pathological changes in hepatitis C virus patients

AIM To investigate the association of tumor necrosis factor alpha(TNFα)-G308 A polymorphism with different liver pathological changes in treatment-na?ve Egyptian patients infected with hepatitis C virus(HCV) genotype 4.METHODS This study included 180 subjects,composed of 120 treatment-na?ve chronic HCV patients with different fibrosis grades(F0-F4) and 60 healthy controls. The TNFα-G308 A region was amplified by PCR and the different genotypes were detected by restriction fragment length polymorphism analysis. The TNFα protein was detected by enzyme-linked immunosorbent assay. The influence of different TNFα-G308 A genotypes on TNFα expression and liver disease progression were statistically analyzed. The OR and 95%CI were calculated to assess the relative risk confidence.RESULTS Current data showed that the TNFα-G308 A SNP frequency was significantly different between controls and HCV infected patients(P = 0.001). Both the AA genotype and A allele were significantly higher in late fibrosis patients(F2-F4,n = 60) than in early fibrosis patients(F0-F1,n = 60)(P = 0.05,0.04 respectively). Moreover,the GA or AA genotypes increased the TNFα serum level greater than the GG genotype(P = 0.002). The results showed a clear association between severe liver pathological conditions(inflammation,steatosis and fibrosis) and(GA + AA) genotypes(P = 0.035,0.03,0.04 respectively). The stepwise logistic regression analysis showed that the TNFα genotypes(GA + AA) were significantly associated with liver inflammation(OR = 3.776,95%CI: 1.399-10.194,P = 0.009),severe steatosis(OR = 4.49,95%CI: 1.441-14.0,P = 0.010) and fibrosis progression(OR = 2.84,95%CI: 1.080-7.472,P = 0.034). Also,the A allele was an independent risk factor for liver inflammation(P = 0.003),steatosis(P = 0.003) and fibrosis(P = 0.014). CONCLUSION TNFα SNP at nucleotide-308 represents an important genetic marker that can be used for the prognosis of different liver pathological changes in HCV infected