Treatment of putative non-A, non-B, non-C hepatitis with alpha interferon: a preliminary trial

Chronic hepatitis due to putative non-A, non-B, non-C hepatitis occurring in an individual who is negative for HBV and HCV markers has been identifiable only recently. Little or nothing is known about its natural history or response to interferon therapy. In the present study, 13 subjects with chronic non-A, non-B, non-C hepatitis were treated with interferon for 6 months (5 million units, three times per week). Prior to and after 6 months of therapy and again 6 weeks after discontinuing interferon therapy, each subject underwent a liver biopsy. These tissues were used to define the histopathology, the character of the cellular infiltrate within the liver, and the changes in histopathology and inflammatory infiltrate achieved in response to interferon therapy and withdrawal. No differences for age, gender, initial AST, bilirubin, histopathology, or Knodell score were evident between responders (n = 7) and non-responders (n = 6). Only the number of NK cells was altered significantly as a result of IFN treatment and distinguished responders from non-responders. These data demonstrate that: (1) chronic non-A, non-B, non-hepatitis can be treated with interferon; (2) interferon activates NK cells and enhances hepatocyte expression of Class II MHC antigens; and (3) interferon also increases the number of CD3, CD4, and CD8 cells found within the liver but these changes do not distinguish between responders and non-responders.