Anti-Ku antibody-positive scleroderma-dermatomyositis overlap syndrome developing Graves' disease and immune thrombocytopenic purpura.

Graves' disease (GD) has been reported to be frequently complicated with other autoimmune diseases. However, it is rarely complicated with scleroderma-polymyositis overlap syndrome. Recently, we encountered a 35-year-old woman who developed GD and immune thrombocytopenic purpura during follow-up observation of scleroderma-dermatomyositis overlap syndrome. Platelet counts recovered after high-dose gamma-globulin therapy and bolus methylprednisolone therapy. The present case is the first report of a combination of scleroderma, dermatomyositis, GD, and immune thrombocytopenic purpura. The patient was anti-Ku antibody-positive and had relatively low natural killer T cell counts, both of which might contribute to the complication of multiple autoimmune diseases.