• chronic type B hepatitis;
  • interferon;
  • 2–5 oligoadenylate synthetase;
  • steroid hormone

ABSTRACT— Changes in the host interferon system during short-term steroid hormone (prednisolone) withdrawal therapy in seven patients with HBeAg-positive chronic hepatitis B were investigated by estimating the in vitro interferon-α production in peripheral blood lymphocytes and 2–5 oligoadenylate synthetase activity in the serum. The interferon-α production induced by the Sendai virus and estimated in lymphocyte cultures was rapidly and significantly (p < 0.01) reduced by prednisolone administration and subsequently followed by a recovery corresponding to its withdrawal. The serum 2–5 oligoadenylate synthetase activity showed a similar tendency to diminish under prednisolone administration and to revive during its withdrawal. In all four patients who developed an acute and transient post-prednisolone withdrawal exacerbation a significant initial increase in serum HBV-DNA levels was noted in accordance with the reduction in the host interferon system activity. The results suggest that the changes in the host interferon system activity, i.e. an initial fall and subsequent recovery as caused by a short-term steroid administration with gradual withdrawal, appear to promote viral replication in the early phase and the development of acute and transient exacerbation of hepatitis in the post-steroid withdrawal phase, which may lead to HBeAg/anti-HBe seroconversion in HBeAg-positive chronic hepatitis B patients.