The True Association of Systemic Sclerosis with Myasthenia Gravis and the Myth of D-Penicillamine-Induced Myasthenia

Abstract

It has been long considered that d-penicillamine may induce various autoimmune conditions, including myasthenia gravis (MG), whereas early observations suggested that about 1.5% of patients with systemic sclerosis (SSc) develop MG. Along this line it has been thought that the association of SSc and MG was due to d-penicillamine, which was the standard therapy for SSc in the past. We report a 66-year-old woman with SSc who developed MG in the absence of d-penicillamine exposure. We found seven other similar cases in the literature, as well as seven additional cases in whom SSc followed MG. Since it has been clear now that different autoimmune diseases frequently cluster within families, we suggest a true association of these two autoimmune diseases which could be under-reported.