Circulating IL-2 and IL-10 in chronic active hepatitis C with respect to the response to IFN treatment

Background: The importance of circulating immunoregulatory cytokines in res ponse to IFN treatment and the change of in vivo production of these cytoki nes during interferon (IFN) treatment are not well known. We aimed to deter mine whether pretreatment serum levels of IL-2 and IL-10 are predictive of the response to IFN treatment and to investigate if treatment response or n onresponse has any effect on the circulating levels of these cytokines. Patients and Methods: 37 patients (18 responders and 19 non-responders) wit h chronic hepatitis C virus (HCV) infection who received IFN-alpha 2b for 6 months were studied. Responders were defined by complete alanine aminotran sferase (ALT) normalization and loss of HCV RNA as detected by bDNA assay w hile patients who had elevated ALT levels and positive HCV RNA after 6 mont hs were considered as nonresponders. Results: Genotype distribution, ALT and HCV RNA levels were similar in resp onders and nonresponders. A significant number of patients with chronic hep atitis C (20/37 = 54%) had elevated IL-2 levels while IL-10 levels were not different from controls. No difference in baseline cytokine levels was obs erved between responders and non-responders. In the posttreatment serum sam ples some patients lost their detectable IL-2 or IL-10; some patients devel oped detectable cytokine levels after treatment irrespective of the treatme nt response. Conclusion: These results suggest that active liver injury in chronic hepat itis C is associated with increased circulating Th1 cytokine IL-2 but not w ith Th2 cytokine IL-10 and that circulating levels of these cytokines do no t predict the response to IFN treatment. There is no constant and regular c hange in circulating levels of these cytokines under IFN treatment with res pect to treatment response.