Production of IFN-gamma and IL-12 by peripheral whole blood is maintained in hepatitis C virus patients with persistently normal alanine transferase activity; A preliminary report.

The current study was designed to investigate the immune status in hepatitis C virus (HCV) patients with persistently normal alanine transferase activity (ALT) (patients with normal alanine transferase). For this purpose, serum levels and lipopolysaccharide (LPS)-induced IFN-gamma, IL12 p70, IL12 p40 and IL-10 as well as NK cell activity were assayed in six patients with normal ALT, 22 HCV-infected individuals with chronic hepatitis (CH), 13 cases of liver cirrhosis (LC) and 26 age-matched controls. Cytokine production was assayed with the whole blood induction method. IFN-gamma levels were significantly lower in patients with HCV-infected chronic hepatitis and liver cirrhosis than in controls ( [Formula: see text], [Formula: see text] and [Formula: see text] pg/ml, respectively, [Formula: see text] ). However, IFN-gamma production in those individuals with normal ALT was not reduced ( [Formula: see text] pg/ml). Although variation was observed, four of the six patients showed moderate to strong IFN-gamma production. No intergroup differences were observed for IL12 p70, IL12 p40 and IL-10 production and NK cell activity. Our results suggest that preserved IFN-gamma production in patients with normal ALT, in contrast to the reduction in chronic hepatitis and liver cirrhosis, may be related to a slow rate of disease progression.