Penicillamine-associated myasthenia gravis, antiacetylcholine receptor and antistriational antibodies.

Myasthenia gravis with thymic hyperplasia developed in a patient with Wilson's disease after eight years of penicillamine treatment. Four months prior to the onset of myasthenia, penicillin hypersensitivity was observed. Immunofluorescence on the excised thymus revealed immunoglobulin and complement deposition, but the myasthenia persisted after thymectomy and continuation of penicillamine therapy. Increased antiacetylcholine receptor antibody was demonstrable throughout. This patient subsequently became pregnant, enabling studies to be performed on the transplacental transfer of the immunoglobulin G (IgG) class antiacetylcholine receptor antibody. Eleven cases of rheumatoid arthritis with penicillamine-associated antistriational antibodies have also been observed; in three of these cases there was evidence of myasthenia gravis. These observations extend earlier reports of the association of penicillamine with myasthenia gravis and suggest that antistriational antibody, antiacetylcholine receptor antibody and thymic hyperplasia may be independent effects of penicillamine therapy.