Autonomic nervous system function in patients with chronic hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection can be associated with various extrahepatic manifestations, including peripheral and central nervous system complications. Autonomic function has not been investigated in patients with chronic HCV infection before, although impaired autonomic function has already been described in patients with chronic liver diseases from different etiologies, and has proven to be a poor prognostic indicator. In addition, the current treatment of interferon-alpha plus ribavirin is known to affect neurological manifestations in patients with chronic HCV infection.;In our first, cross-sectional study we aimed to determine cardiovagal autonomic function in patients with chronic HCV infection, comparing to healthy controls. In our second study we followed-up the patients during the course of antiviral therapy and aimed to examine the possible changes of cardiovagal autonomic function.;Autonomic function was assessed in 45 treatment-naive patients with chronic HCV infection and in 40 healthy controls by determining spontaneous baroreflex sensitivity (BRS) and heart rate variability (HRV) indices with non-invasive methods. Then, we followed up 22 patients and assessed BRS and HRV indices at the beginning of treatment and at week 12, 24 and 48 of antiviral therapy. Besides, laboratory analyses and quantitative polymerase chain reaction for serum HCV RNA level were performed.;BRS and HRV indices were lower in patients with HCV infection compared to healthy controls, and independently correlated with serum ALT levels. Further, both HRV and BRS indices decreased after 12 weeks of therapy compared to pretreatment values; then they increased significantly by week 24 and continued to improve by week 48 of therapy. These changes were independent from the presence of cryoglobulins and from the virological response.;Our results suggest that impaired autonomic function is caused by chronic HCV infection. The increase of autonomic dysfunction at the beginning of the antiviral therapy may be caused by the immunomodulatory actions of interferon alfa-2. Further studies are needed, however, to understand the exact mechanisms..