Mitogen responsiveness in viral hepatitis and chronic active hepatitis: the role of reversible suppressive influences.

Depressed phytohaemagglutinin and concanavalin-A responsiveness was found in patients with acute viral hepatitis (VH) when a suboptimal mitogen stimulus was used. Normal responsiveness was observed with optimal mitogen stimulation. These findings were independent of extrinsic serum inhibitors. When viral hepatitis lymphocytes were preincubated before mitogen addition an enhanced responsiveness similar to the control group occurred. These in vitro findings are in favour of a primary defect in lymphoproliferation in viral hepatitis and do not suggest the presence of reversible suppressive influences such as an excess of short-lived suppressor cells or the presence of cell bound inhibitors. In chronic active hepatitis (CAH) lymphoproliferation induced by immediate mitogen stimulation was similar to control studies. However when CAH cells were preincubated before mitogen addition, enhanced responsiveness significantly greater than in controls occurred. It is suggested that suppressive influences are present in CAH and that their effect can be reversed by cellular preincubation.