Frequency of Single Nucleotide Polymorphism of TNF--α Gene (rs1800629) in Iranian Patients with Hepatitis

Aim and Recent studies have claimed that the genetic variation in cytokine production systems has a major effect on immune system potency and strongly associated with the antiviral treatment response. On the other hand, tumor necrosis factor-alpha (TNF-α), a multifunctional pro-inflammatory cytokine, plays an essential role in host immune response to HCV infection. Therefore, current study was done in order to determine the distribution of the rs1800629 (A/G) polymorphism in the promoter of TNF-α gene in Iranian population.
Material and This cross-sectional study, performed on 165 blood samples based on 89 HCV infected patients including 68 SVR positive and 21 negative and 76 healthy individual controls. After DNA extraction the frequency of rs1800629 (A/G) polymorphism was analyzed using PCR-RFLP method. For detection and analysis of the PCR products we used 20% Polyacrylamide gel electrophoresis.
Based on analysis of the data, the distribution of the A/G polymorphism between healthy individuals and patients were obtained as AA: 1.1%, AG: 52.6%, GG: 46.1%, and AA: 1.3%, AG: 20.2%, GG: 78.7% respectively. The GG genotype was identified in 70 patients of whom 55 achieved SVR, while the AG heterozygous was found in 18 patients and SVR was achieved in 12. Finally, the AA was detected only in one patient with positive SVR.
Conclusion In this study, significant difference between the TNF-α-308 locus SNP (rs1800629) and susceptibility to chronic HCV infection in Iranian population (P value= 0.002) was observed. Moreover, the presence of G allele among SVR positive people and non-SVR group did not show strong statistic difference (P value=0.476). However, further studies with more samples seems to be necessary.