The association of myasthenia gravis and connective tissue diseases--the role of Sjøgren's syndrome.

The symptoms of myasthenia gravis (MG) reflect the loss of neuromuscular transmission due to the functional loss of the acetylcholine receptor. We reviewed the reported association of MG and connective tissue diseases including rheumatoid arthritis, systemic lupus erythematosus, progressive systemic sclerosis (PSS), polymyositis and dermatomyositis, mixed connective tissue disease (MCTD) and Sjøgren's syndrome (SjS). We found that the association of MG and MCTD or PSS is rare. We also reviewed the role of D-penicillamine, thymus abnormalities and the coexistence of SjS as one of the underlying pathological conditions for the association of MG and various connective tissue diseases.