Increased serum soluble IL-2 receptor levels following interferon therapy in patients with chronic hepatitis C

To clarify whether the response of host cellular immunity to IFN therapy can be an indicator of efficacy, we monitored serum levels of soluble IL-2 receptor (sIL2R) before and after IFN therapy.

Serum sIL2R levels before and after interferon therapy were monitored in 53 patients with chronic hepatitis C. Natural Interferon(IFN)-alpha, 9 MU/day (everyday for 2 weeks followed by 3 times/week for 22 weeks), was administered to all patients.

After the IFN therapy, sIL2R levels were significantly increased (before, 403.4+/-221.1 U/mL, and after, 542.0+/-307.6 U/mL, p<0.01). The patients were divided into two groups: the complete response (CR) group who were negative for serum hepatitis C virus (HCV)-RNA 6 months after the therapy, and the recurrence group who were positive for HCV-RNA 6 months after the therapy. Between these two groups, sIL2R levels before therapy were not significantly different, and sIL2R levels after therapy were also not significantly different. Although the ratio of sIL2R levels before and after was monitored, there was no significant difference between the CR group and recurrence group ((sIL2R after IFN)/(sIL2R before IFN)): 1.39+/-0.65 in the CR group and 1.99+/-2.07 in the recurrence group).

sIL2R increased due to IFN administration, but it is not a good indicator for the efficacy of IFN therapy. It seems that the response of cellular immunity to IFN therapy does not play an important role in its efficacy.