Serum sCD30 (soluble CD30) is a marker of cells producing Th2-type (T-helper-2-type) cytokines. High levels of sCD30 have been found in the active phase of HBV infection. The Th2-type cytokine profile has been documented in alcoholic liver diseases, which have particularly high IgE and IgA serum levels. The aims were: 1) to evaluate sCD30 levels in patients with (a) alcoholic liver diseases and (b) HCV-related chronic hepatitis before and after interferon treatment; 2) to correlate sCD30 concentrations with IgE and IgA serum levels. Serum samples from 34 HCV-related chronic hepatitis patients, before and after interferon treatment, and 17 alcoholic liver disease patients were tested for sCD30 using the ELISA method (Dako, CD30-Ki-1 Antigen, Denmark). Significantly higher levels of sCD30 were found in alcoholic liver disease than in HCV-related chronic hepatitis patients (73.3 +/- 120 vs. 27.5 +/- 44 U/mL, P < 0.05). Alcoholic liver disease patients also exhibited significantly higher levels of IgA than HCV-related chronic hepatitis patients (P < 0.0001). No correlation was found between sCD30 and serum IgA or IgE or response to interferon. Th2 cells are strongly expanded in alcoholic liver diseases, though the particular immunoglobulin profile observed in this condition has yet to be explained. Th2 function also plays a crucial part in chronic HCV infection, but seems unrelated to interferon response.