Anti-extractable nuclear antigens (ENA) antibodies in patients with chronic hepatitis C before and after treatment with interferon.

A high prevalence of serological markers classically associated with autoimmune hepatitis or other autoimmune diseases has been reported in patients with chronic hepatitis C. However, the prevalence of antibodies to extractable nuclear antigens (anti-ENA) are rarely reported in such patients and the effect of treatment with interferon (IFN) on their prevalence is not known. In the present study, serum samples collected from 44 patients with chronic hepatitis C and 44 patients with non-hepatitis C virus (HCV) infected liver diseases were tested for anti-ENAs (U1 RNP, Sm, Ro/SS-A, La/SS-B and Scl-70) antibodies by enzyme-linked immunosorbent assay (ELISA). In 26 patients with chronic hepatitis C who received IFN treatment, serum samples were also collected just after completion of IFN treatment, and/or at 6-40 months after completion of the treatment, and tested for these antibodies. Sixteen (36%) of 44 sera from patients with chronic hepatitis C were positive for at least one of the above anti-ENA antibodies, whereas only 7 (16%) of 44 sera from patients with non-HCV infected liver diseases were positive for such antibodies (p = 0.0290). There was no significant difference in the prevalence of each of anti-ENA antibody between men and women. Results of anti-ENA antibodies in most IFN-treated patients with chronic hepatitis C did not change after treatment. However, in some cases serum anti-U1 RNP, anti-La/SS-B and anti-Scl-70 became negative or converted to the gray zone after completion of IFN treatment regardless of HCV elimination. Our results showed that the overall prevalence of anti-ENA antibodies was significantly higher in patients with chronic hepatitis C than in those with non-HCV-infected liver diseases. However, the disappearance of anti-ENA antibodies after IFN treatment in patients with chronic hepatitis C may be due to the immunomodulating effects of IFN rather than HCV elimination.