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Introduction: A high prevalence of HCV infection among hemodialysis patients has been reported worldwide. Risk factors such as history of blood transfusion, duration of hemodialysis and recently nosocomial transmission of HCV in hemodialysis units have been identified. In this study the prevalence of Hepatitis C virus antibody and risk factors in hemodialysis patients in Markazi province is investigated. Materials and Methods: In this cross-sectional analythical study, blood samples were obtained from all 204 hemodialysis patients. Samples were tested for anti-HCV antibodies by using third generation enzyme immunoassay. The reactive samples on ELISA were confirmed by the third generation RIBA. Risk factors were evaluated by a questionnaire. Data was analysed using Chi square and logistic regression. Results: The prevalence of anti-HCV antibody among hemodialysis patients was 4.9%.Duration of hemodialysis was identified as a major risk factor in transmission of HCV (p=0.004). There was a significant relationship between anti-HCV positivity and previous renal transplantation (p=0.032). Female sex was another risk factor for HCV infection (p=0.030). There was no significant relationship between anti-HCV positivity and history of blood transfusion. Conclusion: Nosocomial transmission of HCV within hemodialysis units seems to be a route of infection in patients on hemodialysis in Markazi province. Application of dialysis precautions recommended by CDC can reduce the prevalence of HCV infection among hemodialysis patients in this province.

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Background: Hypervariability of hepatitis C virus (HCV) proteins is an important obstacle to design an efficient vaccine for the infection. To construct a protective vaccine against HCV, a DNA vaccine containing conserved epitopes of the virus was designed. To enhance the induced immune responses, adjuvant activity of N-terminal domain of gp96 (NT(gp96)) was used.

Materials and Methods: A multi-epitope (PT) DNA vaccine encoding four HCV immunodominant cytotoxic T lymphocyte epitopes (HLA-A2 and H2-D^d) from Core, E2, NS3 and NS5B antigens in addition to a T-helper CD4+ epitope from NS3 protein and a B-cell epitope from E2 protein was designed and constructed. Then, NT(gp96) was fused to the PT DNA (PT-NT(gp96)). The stimulated cellular and humoral immune responses of PT and PT-NT(gp96) were evaluated in mice model.

Results: According to multicolor flow cytometry assay, the frequency of CD8+ T-cells producing IFNγ and TNFα in the splenocytes of immunized mice with PT-NT(gp96) (6.8%, 4%) was significantly higher than those of immunized with PT (0.9% , 0.8%), respectively. The same results have obtained in hepatic lymphocytes of the vaccinated mice. The level of IgG, IgG1 and IgG2a in the mice vaccinated with PT-NT (gp96) was significantly higher than the value obtained from the mice immunized with PT.

Conclusion: The results showed that PT DNA vaccine induces immune responses in mice model. Fusion of NT (gp96) to PT DNA vaccine causes to enhance cellular and humoral immune responses against HCV compared to sole PT vaccine.