Non-association of IL-12+1188 and IFN-γ+874 polymorphisms with cytokines serum level in occult HBV infected patients

Background/Aim: Occult hepatitis B infection (OBI) is identified as a form of hepatitis in which despite the absence of detectable HBsAg, HBV-DNA is observed in peripheral blood of patients. The main aim of this study has been to investigate the association between polymorphisms in 874 of IFN- and 1188 of IL-12 with their serum level in patients suffering from OBI. Materials and Methods: In this experimental study, plasma samples of 3700 blood donors were tested for the presence of hepatitis B surface antigen (HBsAg) and anti-HBc by ELISA. The HBsAg (-) /anti-HBc samples were selected and screened for HBV-DNA by PCR. HBV-DNA positive samples were assigned as OBI cases and ARMS-PCR techniques were performed to examine the two known polymorphisms within IL-12 and IFN-. In addition, the serum levels of IL-12 and IFN- were also determined by ELISA. Results: Results of this study demonstrated that, 352 (9.5) out of 3700 blood samples were HBsAg (-) /anti-HBc and HBV-DNA was detected in 57/352 (16.1) of HBsAg (-) /anti-HBc samples. Our results showed that groups showed significant difference in CC allele of 1188 region of IL-12 and no difference was observed in the other evaluated genes. Our results also showed that the alleles of 1188 region of IL-12 and alleles of 874 of IFN- were also not associated with serum level of cytokines. Conclusion: According to the results of this study, it may be concluded that the polymorphisms in 1188 region of IL-12 and 874 region of IFN- would not affect the expression of both cytokines at serum level in OBI patients.