Insights into the role of HCV Plus-/Minus strand RNA, IFN-γ and IL-29 in relapse outcome in patients infected with HCV.

Abstract

Approximately one-third of hepatitis C virus (HCV) infected patients who complete antiviral therapy with undetectable serum HCV RNA at the end of therapy (ETR), will experience relapse. The reasons for the failure of treatment have not been elucidated. It was showed that HCV RNA can persist and replicate in extra hepatic sites, e.g. in peripheral blood mononuclear cells (PBMCs), but the relevance of its presence with relapse over time is still unknown. Moreover, interferon-gamma (IFN-γ) and IFN-lambdas [IFN-λ1, interleukin-29 (IL-29)], possess potent antiviral activity. We studied if the presence of plus-/minus strand RNA in PBMCs of patients and the serum level of IFN-γ and IL-29, which is the most abundant IFN-lambdas in serum, can be considered as predictive factors in relapse outcomes. Patients were screened for plus-/minus strand RNA at ETR and after 6 months. Also, we measured the serum level of IFN-γ and IL-29 and compared the result with those who developed a sustained virological response (SVR). Levels of IL-29 and IFN-? serum were significantly higher in SVR at ETR and 6 months later compared to those of the relapsed patients, but there was no difference between the two groups regarding the presence or absence of plus-/minus HCV strand in PBMCs. Our novel findings showed that the serum level of IL-29 and IFN-γ are predictive of relapse outcomes to HCV treatment, but there was no association between the presence of plus-γminus HCV RNA in PBMCs of patients with an outcome of therapy at ETR and later.