Is mitochondrial antibody diagnostic of primary biliary cirrhosis?

In a series of 218 patients diagnosed as having primary biliary cirrhosis only nine exhibited a negative serum mitochondrial antibody. On examining additional specimens from these patients, seven were found to be positive, giving a final incidence of greater than 99%. The two patients whose sera remained negative for the mitochondrial antibody had liver histology compatible with the diagnosis of primary biliary cirrhosis, but a firm diagnosis could not be reached. Three additional mitochondrial antibody positive subjects who were asymptomatic and exhibited normal serum alkaline phosphatase were shown on liver biopsy to have stage I primary biliary cirrhosis. The presence of a positive serum mitochondrial antibody in a patient with or without abnormalities in liver function tests strongly suggests the diagnosis of primary biliary cirrhosis.