Isoprinosine delays the early appearance of autoimmunity in NZB/NZW F1 mice treated with interferon.

NZB/NZW F1 hybrid mice treated for long periods with type beta interferon developed early symptoms of autoimmune disease. In these animals the level of anti-dsDNA antibody begins to increase at 4-6 months while untreated NZB/NZW mice do not display similar levels until 12 months. The concomitant administration of isoprinosine and interferon delays the early appearance of autoimmune disorders. In interferon-treated NZB/NZW mice the cytotoxic activity of natural killer lymphocytes is maintained at high levels until the age of 5 months. Nevertheless, the natural killer activity is even stronger and detected until at least 7 months in NZB/NZW mice receiving a single dose of interferon 16 hr prior to the test. Lymphoblastoid ascitic tumours appeared early (2-3 months) during interferon treatment in all groups of NZB/NZW mice. However, in the presence of isoprinosine only a few animals developed tumours. Thus, isoprinosine seems to protect NZB/NZW mice both from early autoimmune disorders due to interferon and from early tumour development.