Studies in myasthenia gravis: Part 2. The relation of some clinical and immunological data

Abstract

The clinical and serological findings in 125 patients with myasthenia gravis are compared. The patients were classified according to their age, sex, type and gravity of their myasthenia and to the presence or absence of a thymoma. The sera of patients and matched controls were studied for the presence of antibodies against skeletal muscle, thymus, thyroid, gastric mucosa, adrenocortex and for the rheumatoid factor, the antinuclear factor and positive LE-cell test and immunoelectrophoretic aberrations. No definite relationship could be established between the clinical condition and the presence of antibodies. However all patients with thymomas had antibodies reacting with skeletal muscle and thymus. They also exceeded the patients without thymomas in the production of antinuclear factor. No influence on the frequency of serological abnormalities could be found according to sex or the duration of the disease; some antibodies and the total antibody production increased with age. Antibodies reacting with muscle were present in nearly 40% of the patients; antibodies reacting with epithelial cells of the thymus were demonstrated in 26%. One or more antibodies occurred in 68% of the patients in contrast to 19% of the controls. Although multiple antibody formation and some clinical traits place myasthenia gravis in the group of idiopathic autoimmune diseases, this provides no causal relationship with the observed defect of acetylcholine metabolism at the neuromuscular junction.