---

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.

---

Background: TTV is the first human circoviridae that was isolated from Japanese patients with unknown hepatitis in 1997. Since then, several studies have been done on different aspects of TTV pathogenesis. The aim of this study is to determine the prevalence of TTV in patients with chronic hepatitis using two different primer sets. Materials and Methods: In this descriptive study, blood samples from 240 patients with chronic hepatitis C at Professor Alborzi Clinical Microbiology Research Center were assessed in terms of the presence of TTV DNA in plasma through the nested polymerase chain reaction using two primer sets. Results: Of the 240 patients, TTV-DNA was detected in 220 (92%) patients with chronic hepatitis C using 5΄-UTR primer and in 12 (5%) patients using N22 primer. According to the demographic data, there was not a significant difference between male female patients in prevalence of TTV infection. Conclusion: The prevalence of TTV DNA in plasma samples from patients with chronic HCV by using 5΄-UTR primer was high and it was congruent with studies done in other countries however, N22 primer showed a lower prevalence of viral DNA in the samples. Overall, there was not a significant correlation between sex and the presence of viral DNA in patients. Controversial or high prevalence of this virus in HCV infected people necessitate further studies for determining the relationship between HCV and TTV infection.

---

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.

---

Background: Parvovirus 4 (PARV4) was first discovered in 2005, in a hepatitis B virus–infected injecting drug user (IDU). To date, the best evidence about PARV4 transmission is parenteral roots and comes from IDU individuals. It seems that the prevalence of the virus in the normal population is very low. In this study, we investigated the prevalence of PARV4 virus among patients with chronic HCV infection compared with healthy controls and related risk factors among these groups.

Materials and Methods: A total of 206 patients, including 103 patients with chronic HCV infection and 103 healthy controls, were studied by use of nested-PCR and also real-time PCR techniques.

Results: AST enzyme levels with a mean of 40.45+34.84 and 18.58+5.9 in patients and healthy group respectively and the amount of enzyme ALT among patients with a mean of 40.45+35.75 and 21.50+11.35 in patients and healthy group respectively, were reported. Finally, after screening all DNA samples from patients and controls, we discovered that none of these people are infected with the PARV4 virus.

Conclusion: This study is the first to investigate the occurrence of PARV4 among HCV patients in Iran. The results show that, the virus is not important in Iranian population, even in patients with blood born infections such as HCV and further studies in other areas and various groups are required.