Effects of human recombinant interleukin 2 in patients with chronic hepatitis B: a preliminary report

Five patients with HBe antigen-positive chronic active hepatitis were treated with recombinant interleukin 2 (r-IL2) for 3 to 4 wk. r-IL2 inhibited HBV replication during therapy as judged by decrease of serum DNA polymerase activity. Two of five patients lost HBeAg from serum. Furthermore, characteristic increases of serum aminotransferase were observed during r-IL2 therapy. This rise might have been mediated by enhanced immune responses to hepatitis B virus and increased rate of lysis of the infected hepatocytes. No consistent changes in immune markers such as OKT4 positive cells or OKT8 positive cells were demonstrated during or after the therapy. The activities of natural killer cells gradually increased during therapy, although they tended to decrease within 1 wk after the start of r-IL2 injections. In two responders who lost HBeAg from serum, the natural killer activity was high before the therapy, compared with nonresponders. Furthermore, the percentage of OKT4-positive cells in the responders was increased within 1 to 2 wk after starting r-IL2 injections. These findings suggest that the responders might be immunologically different from the nonresponders. Recombinant-IL2 therapy over short periods did not result in complete clearance of hepatitis B virus. Further studies with high doses of r-IL2 given over longer periods are warranted.