Serum 2',5'-oligoadenylate synthetase activity during interferon treatment of chronic hepatitis B

We measured 2',5'-oligoadenylate synthetase activities in serum and peripheral blood mononuclear cells from 10 patients with chronic hepatitis B who were being treated with interferon so as to determine whether 2',5'-oligoadenylate synthetase activity in serum reflected 2',5'-oligoadenylate synthetase activity in peripheral blood mononuclear cells, and whether it could be used to monitor interferon treatment. Pretreatment values of 2',5'-oligoadenylate synthetase activity in patients' serum and peripheral blood mononuclear cells were not statistically different from values from control subjects. When interferon was administered, serum levels of 2',5'-oligoadenylate synthetase began to rise within 3 hr, reached peak values at 12 hr and then declined. The levels of 2',5'-oligoadenylate synthetase activity both in serum and peripheral blood mononuclear cells increased substantially during interferon treatment, ranging 2- to 50-fold greater than initial levels. The levels of 2',5'-oligoadenylate synthetase in serum correlated closely with levels in peripheral blood mononuclear cells. In addition, when the levels of 2',5'-oligoadenylate synthetase rose during interferon administration, serum hepatitis B virus DNA polymerase values fell, and, in some cases, DNA polymerase rose again when 2',5'-oligoadenylate synthetase fell after discontinuation of interferon. These findings suggest that 2',5'-oligoadenylate synthetase activity in serum accurately reflects the antiviral effect of interferon and could be used to monitor interferon treatment.