Three-year observation of a myasthenic syndrome concurrent with other autoimmune syndromes in a patient with thymoma

Abstract

The authors present the results of 3 years of clinical observation and of concurrent immunopathological investigations in a case of myasthenia, in which skin lesions of pemphigus erythematosus and symptoms of lupus erythematosus developed soon after thymectomy. No correlation was demonstrated between the level of circulating antibodies on the one hand and the severity of the clinical myasthenic symptoms on the other. In spite of marked clinical improvement after thymectomy the titre of muscle antibodies did not decline; on the contrary it rose significantly at the time of the most pronounced clinical improvement after treatment with azathioprine (Imuran). The level of antibodies to the intercellular substance of the epidermis (“pemphigus” antibodies), however, clearly correlated with the intensity of the skin lesions and these antibodies are, in the authors' opinion, of pathogenetic significance, whereas the role of antibodies in myasthenia seems to be secondary. The diagnostic significance of nuclear antibodies, and the favourable therapeutic effect of Imuran are also discussed.