Immune complexes in myasthenia gravis.

Low levels of circulating immune complexes were detected in 42% of 50 patients with myasthenia gravis. Although a number of these had other associated autoimmune disorders, 30% of patients with no clinical evidence of other disorders were positive in the assays used. The nature of the antigen or antigens in the complexes is not known. However, no binding of alpha-bungarotoxin (a specific probe for the acetylcholine receptor) to the complexes was observed. No correlation of presence of complexes and duration or severity of disease or antibody titres to the acetylcholine receptor was found.