Long-term efficacy of intravenously administered immunoglobulin in a case of polymyositis with limited application of steroid therapy.

A 72-year-old man who had been diagnosed with polymyositis (PM) was admitted to our hospital for pneumonia with exacerbation of muscle weakness, elevation of muscle enzymes, and positive magnetic resonance imaging findings. The patient had been refractory to cyclosporine A or azathioprine and hoped to avoid administration of high-dose steroids; IV immunoglobulin (IVIG) was therefore administered after improvement of the pneumonia. Two weeks after the IVIG therapy, muscle test scores, activities of daily living, and muscle enzymes were drastically improved. Twenty months after IVIG, no relapse of PM was observed.