Immunological evidence for the co-existence of the Lambert-Eaton myasthenic syndrome and myasthenia gravis in two patients.

Two patients are described in whom a clinical and electromyographic diagnosis of the Lambert-Eaton myasthenic syndrome (LEMS) was made. Serum antibodies to voltage-gated calcium channels (VGCCs), the antigenic target in LEMS and to acetylcholine receptors (AChRs), the antigen in myasthenia gravis, were detected at raised titres in both cases, using radioimmunoassays based on 125I-omega-Conotoxin labelled VGCCs and 125I-alpha-Bungarotoxin labelled AChRs. These data provide immunological evidence for the coexistence of the two disorders in these patients.