Polymyositis, myasthenic syndrome and thymoma in a patient with defective cell-mediated immunity.

We studied a 57-year old woman with severe myasthenic syndrome predominantly proximal. There was no therapeutic effect using cholinesterase inhibitors. Clinical findings, electromyography, whole body scanning and biopsy revealed polymyositis. Thirteen years before the patient was operated of a benign thymoma. The history of the patient showed numerous life threatening episodes of viral and fungal infections. Autoimmune anemia was diagnosed. Investigations of the immune system in vivo and in vitro revealed severe qualitative and quantitative defects in the lymphocyte population spontaneously forming rosettes with sheep red blood cells (SRBC). Thymoma, autoimmune disorder, such as polymyositis and myasthenia gravis, unspecifically elevated antibody titers, multiple severe viral and fungal infections and the defect of the cell-mediated immunity suggest a T-lymphocyte effector- and regulatory dysfunction in this patient.