Background: In spite of designing and applying an effective vaccine against Hepatitis B virus (HBV), chronic infection with this virus is still one of the most important health problems worldwide. Host genetic background including single nucleotide polymorphisms play a significant role in chronicity or clearance of the infection. The final product of programmed cell death 1 gene (PDCD1) is expressed frequently on T-cells and in chronic viral infections, prevent the virus-specific T-cell response against the virus. In this study, the association of a single nucleotide polymorphism (+7146A/G) in intron 4 of PD1 gene with chronic hepatitis B infection in Iranian population has been assessed.

  Materials and Methods: 212 chronic HBV patients and 208 healthy controls were analyzed in this case-control study. Genomic DNA of the studied individuals was extracted and after performing polymerase chain reaction (PCR), polymorphism of +7146 was determined via RFLP method.

  Results: Frequencies of GG, GA and AA genotypes on position 7146 of the intron 4 of PD1 gene were 77.4%, 20.7% and 1.9% in patient group and 80.8%, 15.4% and 3.8% in control group, respectively. After statistical analysis, No significant difference was observed between patient and control groups (p=0.198).

  Conclusion: Genotype frequencies in the studied population are in accordance with the results of previous studies. Results of the present study suggest that there is not any association between A/G single nucleotide polymorphism in intron 4 of PD1 gene and susceptibility to chronic hepatitis B in Iranian population.