Coexistence of primary biliary cirrhosis and myasthenia gravis: a case study.

We present a case that suggests a relationship between primary biliary cirrhosis and myasthenia gravis. A 43-year-old Japanese woman was admitted to the Nagoya City University Medical School, First Department of Internal Medicine with abnormal liver function in August 1991. She had had ptosis of the right eye since 1990. She had not been treated for liver disease. Ptosis of the right eye and hepatomegaly were present. Serum laboratory examinations revealed elevated biliary enzymes and IgM levels; tests were positive for antimitochondrial antibody and anti-acetylcholine antibody. Liver histology revealed chronic non-suppurative destructive cholangitis and led to a diagnosis of primary biliary cirrhosis. The tensilon test was positive. Electromyography with repetitive motor nerve stimulation revealed a neuromuscular junction defect; i.e., the primary characteristic of myasthenia gravis. The patient was diagnosed with myasthenia gravis. Although the development of myasthenia gravis has previously been reported in patients with primary biliary cirrhosis during D-penicillamine administration, this is a very rare case of the coexistence of both diseases before such treatment.