Probable reinfection with hepatitis C virus in a chronic hepatitis C patient with a sustained response to combination therapy.

Superinfection with hepatitis C virus (HCV) in already chronically infected subjects has been documented. Whether a complete response to antiviral therapy is associated with protective immunity against reinfection with HCV remains unknown. We describe a patient who had a sustained biochemical and virologic response with loss of intrahepatic HCV RNA after a course of combination therapy using interferon plus ribavirin. Histopathologically, the chronic hepatitis was in remission on follow-up biopsy 6 months post-therapy. Unfortunately, 34 weeks post-therapy, a flare of hepatitis with reappearance of hepatitis C viremia was noted 2 months after he received injections from a non-licensed medical provider. Analysis of the core gene sequences showed a 95% homology between the HCV strains isolated before antiviral treatment and during the hepatitis flare. The data indicated that the hepatitis flare after a period of sustained response to combination therapy in this patient could have been caused by reinfection with homotypic HCV. Our observation indicates the lack of protective immunity against reinfection with HCV in patients with chronic hepatitis C, even after successful clearance of the virus. Therefore, reinforcing the education of these subjects to avoid HCV reinfection should be stressed.