Outcome of idiopathic inflammatory myopathies: complications, survival andprognostic factors

OBJECTIVES: TO describe the clinical and epidemiological characteristics, c omplications, survival and prognostic factors of a series of patients with idiopathic inflammatory myopathy (IIM) diagnosed with homogeneous criteria in the same center. PATIENTS AND METHODS: Patients with the diagnosis of IIM during an inclusio n period of 20 years were studied. They were classified following the crite ria of Bohan and Peter, and Dalakas, Epidemiological, clinical and therapeu tical data were obtained in all cases. Evolution and survival were analyzed with the Kaplan-Meier and Cox multiple regression models. RESULTS: One-hundred thirty-five patients with IIM were included in the stu dy: 32 polymyositis (PM), 90 dermatomyositis (DM) and 13 inclusion body myo sitis (IBM). Forty-six percent presented some complications attributed to t he disease or treatment, and 10 with PM, 29 with DM and 3 with IBM died dur ing the follow-up. The probabilities of survival were 86% the first year, 8 0% the second year, 71% the fifth year, and 57% the tenth year. Infections and cancer were the main death causes. While survival analyses did not show independent risk factors for PM, advanced age, presence of associated neop lasm, raised erythrocyte sedimentation rate (ESR) and muscle relapse were i dentified as a poor prognostic indicators for DM, whereas raised ESR and lo ng lasting symptoms prior to diagnosis of the myopathy were for IBM, CONCLUSION: In spite of the therapeutic advances, IIM are still diseases wi th high mortality and morbidity.