Detection of the CCR5-d32 Mutation in Patients Infected with Occult Hepatitis B

Background: Occult hepatitis B infection (OBI) is a form of viral hepatitis in which the HBV-DNA is present in blood while the HBsAg is undetectable. As differences in genetics and immunological responses have important role on OBI we were persuaded to analyze the known CCR5-D32 mutation (a chemokine receptor) in patients with OBI. Materials and Methods: In this descriptive study, 3700 blood samples that were HBsAg negative were collected during March 2006 to February 2007, from Rafsanjan blood transfusion services. All samples were tested for anti-HBc antibody. The HBsAg negative and anti-HBc positive samples were analyzed for HBV-DNA by PCR technique. The HBV-DNA positive samples were regarded as OBI cases. Finally, the Gap-PCR was performed to examine the d32 mutation in OBI patients. Results: The analysis of results showed that 352 (9.51%) cases of HBsAg negative samples were positive for anti-HBc. Following examination of HBsAg negative and anti-HBc positive samples for HBV-DNA by PCR based methods we found that 57(16.1%) cases had HBV-DNA. None of the OBI patients had d32 mutation in CCR5 chemokine receptor whereas 2(2%) of controls had heterozigotic form of this mutation. Conclusion: Based on the results of this study it seems that CCR5-D32 mutation does not affect the immune response against HBV to make OBI. Occult Hepatitis B Infection, CCR5, HBsAg, HBV-DNA, d32 Mutation