SERUM 2',5'-OLIGOADENYLATE SYNTHETASE CONCENTRATIONS IN ACUTE AND CHRONIC HEPATITIS-C

To clarify the role of in vivo interferon activation in the recovery f rom acute hepatitis C and in the prediction of responses to interferon -alpha treatment in chl-c,nic hepatitis C, we measured concentrations of 2',5'-oligoandenylate synthetase in the serum of 14 patients with w ell-documented acute post-transfusion hepatitis C and 40 patients with histologically confirmed chronic hepatitis C. In the latter group, 16 received interferon-alpha treatment, while no specific treatment was given to patients with acute hepatitis C. Serum activity of 2',5'-olig oadenylate synthetase was measured in duplicate by radioimmunoassay. F our out of the 14 patients with acute hepatitis C recovered, and hepat itis in the remaining 10 became chronic. Serum 2',5'-oligoadenylate ad enylate synthetase concentration in the acute stage of hepatitis was a bove 200 pmol/dL in all four patients who recovered and in only two of the remaining 10 patients (p < 0.02, Fisher's exact test). The 16 chr onic hepatitis C patients who received interferon-alpha treatment were classified into sustained responders, relapsed responders and nonresp onders, as judged by their responses to the treatment. Among the three groups, there was no significant difference ill the mean concentratio ns of 2',5'-oligoadenylate synthetase either before the treatment or i n the peak concentrations during the treatment. We conclude that activ ation of in vivo interferon in the acute stage favors recovery from ac ute hepatitis C, and 2',5'-oligoadenylate synthetase concentration can not predict the responses to interferon-alpha treatment in patients wi th chronic hepatitis C.