Background & aims: Interleukin (IL)-10 is a cytokine that down-regulates the proinflammatory response and has a modulatory effect on hepatic fibrogenesis. The aim of this study was to determine the effect of IL-10 on hepatic injury in patients with chronic hepatitis C.
Methods: Twenty-four patients with chronic hepatitis C who had not previously responded to interferon-based therapy were enrolled in a randomized, double-blinded 2-dose trial in which they received either 4 or 8 microgram/kg IL-10 subcutaneously daily for 90 days. Liver biopsies were performed before and at the end of therapy.
Results: IL-10 was well tolerated with 22 patients completing the study. Serum ALT levels normalized in 19 of 22 patients by the end of therapy and were sustained in 5 of 22. Hepatic inflammation decreased in 19 of 22 patients, with 11 having a decrease by >/=2. Fibrosis decreased in 14 of 22 patients (mean change, 3.6-2.6; P = 0.001). There was no change in serum HCV RNA levels. IL-10 therapy was associated with changes in serological markers, suggesting a reduction of immune response and fibrogenesis.
Conclusions: IL-10 therapy is safe and well tolerated in patients with chronic hepatitis C. Although it has no apparent antiviral activity, IL-10 normalizes serum ALT levels, improves liver histology, and reduces liver fibrosis in a large proportion of patients receiving treatment. Therefore, IL-10 may have therapeutic potential in patients with chronic hepatitis C patients who do not respond to interferon-based therapy.