A case of antiphospholipid syndrome associated with myasthenia gravis

We report a 40-year-old Japanese woman with antiphospholipid antibody syndrome (APS) associated with myasthenia gravis (MG). She had a history of miscarriage at the age of 27 followed by pulmonary embolism 3 weeks later. At the age of 40, she developed diplopia, bilateral ptosis and easy fatigability. Serum anti-acetylcholine receptor antibody and tensilon test were positive. She was diagnosed as having MG. The laboratory test revealed mild thrombocytopenia, prolonged activated partial thromboplastin time (aPTT) and positive findings for both β ₂ glycoprotein I-dependent anticardiolipin antibody and lupus anticoagulant. She fulfilled the diagnostic criteria of APS, but did not the criteria proposed by American Rheumatism Association for SLE. An extended total thymectomy was performed after administration of oral prednisolone and low-dose aspirin. This is a patient who had APS associated with MGs: both are known to result from autoimmune abnormality. The clinical and laboratory manifestations of APS were ameliorated after removal of the thymus, suggesting that thymectomy alleviates APS symptoms.