Australia antigen and autoantibodies in chronic hepatitis.

The sera of 110 patients with chronic hepatitis and adequate controls were examined for antibodies to smooth muscle (S.M.), mitochondria (M.), and for antinuclear factors by the immunofluorescence method, and for Australia (Au(1)) antigen by a modified micro-Ouchterlony immunodiffusion technique. Twelve out of 13 patients with primary biliary cirrhosis had M. antibodies, two had antinuclear factor, and none had Au(1) in their sera. In chronic aggressive hepatitis 23.5% of the sera contained antinuclear factor, 13% S.M. antibodies, 10.5% M. antibodies, and 22% Au(1) antigen. Of the 12 patients with chronic persistent hepatitis, one had antinuclear factor, one S.M. antibodies, and three Au(1) antigen.The most striking finding was a mutual exclusion between Au(1) antigen and M. and S.M. antibodies. None of the 33 patients with one or the other form of chronic hepatitis and M. or S.M. antibodies had Au(1) antigen; 22 out of 77 (28%) patients without such antibodies were positive.