The aim of the present study was to examine the presence of autoantibodies in patients with hepatitis C virus (HCV) infection receiving combination pegylated interferon (Peg-IFN) and ribavirin therapy. Sera were obtained from 46 patients with HCV infection receiving combination Peg-IFN and ribavirin (Peg-IFN/ribavirin) treatment and 152 patients with HCV infection receiving Peg-IFN therapy only at Chung Shan Medical University Hospital, Taiwan. The serum samples were evaluated for the presence of anticytoplasmic antibody by indirect immunofluorescence assay (IIF) of HEp-2 cells. HEp-2 cells were also cultured with Peg-IFN (100 U/ml), ribavirin (100 μg/ml) and Peg-IFN/ribavirin. Anti-histone antibody (AHA) was determined by ELISA. The rod and ring index (RRI) was calculated by counting the numbers of rods and rings in 100 cells. Patients with HCV infection treated with Peg-IFN/ribavirin had a higher prevalence of anti-cytoplasmic rod and ring (anti-RR) antibodies than those not treated with Peg-IFN/ribavirin. RRI increased with duration of therapy and decreased after discontinuing therapy. When HEp-2 cells were cultured with Peg-IFN/ribavirin or ribavirin, RRI increased with culture time. Further, AHA increased with increasing anti-RR antibody in patients receiving Peg-IFN/ribavirin therapy. In conclusion, anti-RR antibody is found in HCV patients receiving Peg-IFN/ribavirin therapy and the frequency of anti-RR antibody is correlated with therapy time, suggesting that combination Peg- IFN/ribavirin and ribavirin alone play a role in the production of anti-RR antibodies. Anti-RR antibody should be considered a serological marker for patients receiving Peg-IFN/ribavirin therapy.
