Increased soluble IL-2 receptor levels during interferon and ribavirin treatment are associated with a good response in genotype 2a/2b patients with chronic hepatitis C

Objectives Serum levels of soluble interleukin-2 receptor (sIL-2R) are known to serve as a marker for the activation of T lymphocytes. We measured serum levels of sIL-2R in patients with chronic hepatitis C (CHC) during interferon (IFN)-based treatment to determine the correlation between those levels and therapeutic efficacy, and to clarify whether there is a difference in the activation of T lymphocytes among HCV genotypes after the treatment. Methods Forty-four patients received IFN-alpha 2b monotherapy (group IFN-M), whereas 82 patients received the combination therapy with IFN-a2b and ribavirin (group IFN + R). We measured serum sIL-2R levels in these patients before (T-0) and 2 weeks (T-2) after the treatment. Results The sustained virologic response rates in genotype 2a/2b patients were significantly higher than those in genotype 1b patients in both groups (P<0.005). In sustained virologic responders, sIL-2R levels at T-2 were significantly higher than those at T-0 in both groups (P<0.001). In nonresponders, sIL-2R levels at T-2 were not different from those at To in group IFN-M, but were significantly higher than those at To in group IFN + R (P= 0.0072). In genotype 1b patients, sIL-2R levels at T-2 were not different from those at To in group IFN-M, but were significantly higher than those at To in group IFN + R (P=0.0064). In genotype 2a/2b patients, sIL-2R levels at T-2 were significantly higher than those at To in both groups (P<0.0005). Conclusion These findings suggest that the activation of T lymphocytes after IFN-based treatment contributes to a high-sustained virologic response rate, especially in genotype 2a/2b patients.