Australia antigen and primary biliary cirrhosis.

Sera from 64 patients with primary biliary cirrhosis have been examined for Australia antigen (Au). On immunodiffusion and immunoelectrophoresis all sera were negative. Using a radioimmunoprecipitation technique 15.6% of sera contained antigen compared with an incidence of 3.1% in matched controls, a significant difference (p = 0.015). Anti-Au was found in 9.4% of patients and in 7.8% of controls. In lymphocyte transformation studies lymphocytes from one of 24 patients with primary biliary cirrhosis transformed on stimulation with an Au-rich serum.