[Prognosis of life in polymyositis/dermatomyositis].

Although substantial patients are dead in the course of PM/DM, little papers have precisely investigated the cause of death and factors which may relate to death in PM/DM. The purpose of the present study is to evaluate the prognosis for life, causes of death and risk factors for life in PM/DM. Clinical records of 76 adult PM/DM patients were retrospectively reviewed. Seven patients died of associated malignancy. Five-year survival rate was 69.7% in PM/DM patients without malignancy. During the last 24 years, there was no significant change in survival rate. Among causes of death in 19 cases without malignancy, 7 cases died of respiratory failure and 7 patients died of cardiac involvement. There seems to be two types of pulmonary involvement causing respiratory failure; i.e. acute interstitial pneumonitis and chronic interstitial pneumonitis. In the former cases, the courses were very rapid, and patients died during 4 months after appearance of the first symptom. Risk factors were chosen by comparing clinical manifestation in dead patients with those in control subject. Control subjects were selected from non-dead patients by matching with sex, age, and duration after start of the first therapy. Acute onset disease, fever, arthritis, hypergammaglobulinemia, elevated ESR (greater than or equal to 30 mm/hr), lung fibrosis, and heart involvement are risk factors for life.