Association Of Single Nucleotide Polymorphisms Of Tumor Necrosis Factor-alpha Gene Promoter With Mutations Of C Region Of HBV Gene In Patients Of Chronic HBV Infected

Objective1. To explore whether the tumor necrosis factor-alpha(TNF-α) promoter single nucleotide polymorphisms(SNPs) are associated with the mutations of C region of hepatitis B virus(HBV) gene in patients of chronic HBV infected with and without liver function failure(groupⅡVS groupⅠ) .2. To explore whether the distributions of TNF-αpromoter's SNPs and mutations of C region of HBV gene are different between groupⅠandⅡ.3. To explore whether TNF-αpromoter's SNPs are associated with the grade of imflamation and the stage of fibrosis of hepatitic biopsies in groupⅠ.Method1. By using the restriction fragment length polymorphism(RFLP) assay of ploymerase chain reaction(PCR) products,the single nucleotide polymorphisms(SNPs) of -238 and–308 site within patients'TNF-αpromoter were analyzed in groupⅠ(107 cases)and groupⅡ(94 cases).2. Mutations of C region of HBV in patients of groupⅠ(51 cases)and groupⅡ(44 cases) were analyzed by taking gene sequencing technique.3. Liver biopsy was done in all of patients without liver function failure( groupⅠ).By using regular pathological test and reticular fiber staining, the grade of imflamation and the stage of fibrosis was acquired.Results1. The SNPs frequencies within TNF-α-238 and -308 site between groupⅠand groupⅡhad no significant difference.2. The SNPs of TNF-α-238 site was not associated with hot mutations of C region of HBV gene in statistics.3. The patients whose SNPs within TNF-α-308 site were G/A or A/A genotype have lower mutational frequencies in AA87 and AA97 sites of HBV C region in statistics.(P<0.05)4. Comparing hot mutations of HBV C region between groupⅠand groupⅡ, the mutational frequencies of nt1896,AA60,AA87 and AA97 were higher in groupⅡ.5. The SNPs frequencies of TNF-α-238 and -308 site were not associated with the grade of imflamation and the stage of fibrosis of liver biopsy in patients of groupⅠin statistics.6. In groupⅠ, the imflamation grade of liver biopsy was associated with double mutations of HBV C region in nt1762/1764,with mutation of nt1896 G to A in statistics(P<0.05).Also in these patients, the fibrosis stage of liver biopsy was associated with double mutations of HBV C region in nt1762/1764,with mutation of AA87 and AA97 in statistics(P<0.05).Conclusions1. There was no significant association between the SNPs within TNF-α-238 and -308 site and the occurrence of liver function failure after chronic HBV infected. Also there was no significant association between such SNPs with the severity of liver injury.2. HBcAg antigenicity may be not easy to change in patients of chronic HBV infected with genotype of G/A or A/A at TNF-α-308 site.3. The possibility that patients of HBV chronic infected develop liver function failure may increase if existing mutations of nt1896, AA60, AA87 and AA97 in HBV C region.4. The hot mutations in C region of HBV including double mutations in nt1762 and nt1764, mutation of nt1896 G to A ,may aggravate the severity of liver injury. And double mutations in nt1762 and nt1764, mutations of AA87 and AA97, may promote the liver fibrosis in these patients.