Serum levels of soluble interleukin-2 receptor in chronic hepatitis C treated with interferon-alpha

Serum levels of soluble interleukin-2 receptor (sIL-2R) seem to serve as a marker for the activation of T lymphocytes. The aim of this study was to evaluate the clinical significance of such levels in patients with chronic hepatitis C (CHC) treated with interferon.

We measured serum levels of sIL-2R in 37 patients with CHC before and after treatment with recombinant interferon-alpha. Serum receptor levels were then compared with the response of the hepatitis C virus (HCV)-RNA level in serum after interferon.

Receptor levels were significantly higher in the patients with chronic persistent hepatitis and chronic active hepatitis than in normal controls (p < 0.01). There was a weak correlation between serum sIL-2R and alanine aminotransferase (ALAT) levels (r = 0.14, p = 0.010). Patients were then classified into three groups on the basis of the effect of interferon treatment on HCV-RNA levels in serum: sustained response (SR; n = 21), non-sustained response (NSR; n = 14), and nonresponse (NR; n = 2). Before and during interferon treatment the serum sIL-2R level remained increased in the SR group and in the combined groups with NSR or NR. However, after interferon was withdrawn, the serum sIL-2R decreased in the SR group but remained significantly increased in the combined response group (p < 0.01-0.05).

This finding seems to reflect the disappearance of HCV-RNA from the serum of the patients with an SR, and monitoring of sIL-2R levels may therefore be of value as an adjunct to the measurement of serum ALAT and HCV-RNA in evaluating the response to the interferon therapy for CHC.