SEN virus infection in patients with chronic hepatitis C: preferential coinfection with hepatitis C genotype 2a and no effect on response to therapy with interferon plus ribavirin.

To clarify the influence that a recently identified SEN virus (SENV) has on hepatitis C virus (HCV) response to therapy with interferon plus ribavirin, 2 SENV variants, SENV-D and SENV-H, were studied in 100 patients with chronic hepatitis C; 57 of these patients were positive for SENV-D/H DNA, and there were no differences, in clinicopathological features, between patients with and without SENV coinfection. However, patients with SENV coinfection had a higher prevalence of HCV genotype 2a than did those without it. The sustained HCV response rate after combination therapy was comparable between patients with and without SENV coinfection. Of the 57 patients with SENV coinfection, 18 (32%) had a sustained SENV response to combination therapy, and SENV-D had a higher sustained response rate than did SENV-H. These results suggest that SENV has a specific link to HCV genotype 2a and that SENV infection has no apparent effect on coexisting chronic hepatitis C.