Polymyositis associated with severe interstitial lung disease: remission after three doses of IV immunoglobulin

Interstitial lung disease associated with polymyositis/dermatomyositis (ILD-PM/DM) often confers a poor prognosis, and optimal treatment of this condition is not well defined. This report describes a 63-year-old man with severe ILD-PM/DM who presented with 5 months of progressive dyspnea and weakness. He had an initial carbon-monoxide-diffusing capacity of 35% predicted and a creatine kinase level of 2,112 U/L. After three monthly doses of immunoglobulin at 2 gm/kg IV, he has sustained clinical remission for > 2 years. IV immunoglobulin has not previously been studied as a first-line agent for rheumatologic diseases, and it is currently used as a salvage therapy. However, if IV immunoglobulin is capable of inducing sustained remission after brief use as a treatment, as demonstrated in this patient, especially in the setting of significant pulmonary involvement, then it merits further consideration for investigation as a first-line therapeutic agent.