A new fluorescent mitochondrial antibody: disease association.

The case notes of 34 patients whose sera contained an antibody giving an unusual immunofluorescent staining pattern were reviewed. This antibody designated M2(1) gave a slightly different pattern of staining on composite sections of rat liver, kidney and stomach from the primary biliary cirrhosis associated M2 antimitochondrial antibody. Anaemia was present in 10 patients, endocrine disease in 7 patients and autoimmune liver disease in 6 patients. We did not find the presence of M2(1) antibody to be of specific diagnostic significance. Although the M2(1) antibody is rare, caution is required in order to avoid confusion between this antibody and the M2 antimitochondrial antibody of primary biliary cirrhosis.