Ward, A. Milford, Ellis, Graham, and Goldberg, David M.: Serum immunoglobulin concentrations and autoantibody titers in diseases of the liver and biliary tree. Am J Clin Pathol 70: 352–358, 1978. Determinations of serum immunoglobulins G, A, and M were performed, together with tests for anti-nuclear, antimitochondrial and smooth-muscle antibodies, on sera from 580 patients with identifiable hepatobiliary diseases and 456 subjects with conditions not primarily affecting the liver or biliary tree. These tests were useful in distinguishing diseases of the liver from those of the biliary passages, where results were generally normal. Serum IgG was most frequently elevated in chronic active hepatitis, and also helped to distinguish cholangitis from cholecystitis. IgA was usually elevated in portal cirrhosis, and was useful in differentiating cholangitis from cholecystitis. The greatest frequency of abnormal IgM and the highest values occurred in primary biliary cirrhosis. There was also a very high incidence in acute and chronic hepatitis, but values in biliary tract diseases were generally normal. Positive antinuclear factor titers occurred in 43% of patients with chronic active hepatitis. Antimitochondrial antibody was positive in 83% of patients with primary biliary cirrhosis. More than 40% of patients who had acute or chronic hepatitis had positive smooth-muscle antibody titers, with lower incidences recorded for patients with portal cirrhosis and primary biliary cirrhosis. In patients who did not have hepatobiliary disease, abnormalities of immunoglobulins and antibodies were commonest in patients who had cancer or gastrointestinal, respiratory, or renal disease, and less frequent than might have been expected in patients with autoimmune disease.