Background Occult hepatitis C virus infection is defined by the presence of hepatitis C virus-RNA in liver but with undetectable anti-hepatitis C virus and serum viral RNA.
Aim To study the response to anti-viral therapy in occult hepatitis C virus infection to assess the pathogenic effect of occult hepatitis C virus.
Methods Ten patients with occult hepatitis C virus infection were treated with pegylated-interferon plus ribavirin for 24 weeks and were followed-up 24 weeks after therapy. All patients had abnormal alanine aminotransferase, hepatitis C virus-RNA positive in peripheral blood mononuclear cells and liver necroinflammation.
Results At the end of treatment and follow-up, the percentage of patients with normal alanine aminotransferase was 80% (95% CI: 48–96%) and 60% (95% CI: 31–84%) respectively, and hepatitis C virus-RNA in peripheral blood mononuclear cells was negative in 80% (95% CI: 48–96%) and 70% (95% CI: 40–90%) cases. At the end of follow-up sustained response was observed in 30% (95% CI: 11–61%) of cases. Five patients underwent a second liver biopsy. In all cases, liver hepatitis C virus-RNA persisted, although hepatitis C virus-RNA load was significantly lower (3.2 × 104 ± 5.1 × 104 copies/μg RNA) than in the basal biopsy (2.4 × 105 ± 3.8 × 105 copies/μg RNA); (P = 0.043). Necroinflammation and fibrosis decreased in three cases.
Conclusion The biochemical, virological and histological response to therapy achieved in patients with occult hepatitis C virus infection demonstrates the pathologic effects of occult hepatitis C virus.