Abstract
We measured 2'-5' oligoadenylate synthetase (2-5AS) activity in peripheral mononuclear cells (PBMC) and serum during interferon (IFN) treatment of 17 patients with chronic hepatitis non-A, non-B (CH-NANB). All 17 patients received IFN-α or-β in doses of 1 to 3 million units (MU) daily for 4 to 7 weeks. Before treatment, the levels of 2-5AS in PBMC and serum were not significantly different from those of chronic hepatitis B (CH-B) and of normal subjects. During treatment, the levels of 2-5AS in PBMC and serum increased from 2-to 81-fold greater than initial levels in all patients, although the peak levels varied widely between patients. The changes of 2-5AS activity in PBMC and serum were similar to those observed during IFN treatment of CH-B. During treatment, ALT levels normalized in 10 of the 17 (Group I), while in the remaining 7 (Group II), the levels did not normalize. All patients of Group II had significantly elevated levels of 2-5AS in PBMC just before treatment, while the 10 of Group I had normal levels of 2-5AS. This finding suggests that patient whose ALT levels did not normalize during IFN treatment may have an activation of in vivo IFN system before treatment, and such patients may become resistant to IFN treatment.
