Objectives To describe disease outcome and the influence of treatment modalities in a cohort of patients with polymyositis (PM) and dermatomyositis (DM) prospectively followed by our Internal Medicine Department, between 1985 and 2013.
Methods We reviewed the medical notes of 91consecutive patients with PM and DM diagnosed according to the Bohan and Peter criteria. Since the diagnosis each patient have been followed by a standardised protocol. In March-May 2013 all of patients were enrolled in this study with the objective to evaluate a) the disease outcome b) disease activity, c) damage due to disease and treatment d) and the influence of treatment in outcome in the course of the disease.
Results The series comprised 91 subjects with either PM (43) or DM (48) (Table 1). Myogenic abnormalities were detected by EMG in all of the cases, whereas muscle biopsy confirmed the diagnosis in 78% of the cases. All patients were treated with glucocorticoids. 72 patients (78%) received one (n=18) or more (n=31) agents, such as immunosuppressants, IVIg (in 39 patients), SCIg (n=18). Twenty-two patients (24%) (12F =55%; mean age 66 years) died after a mean follow-up of 91±84 months. According to the age-adjusted Cox regression model, male sex and a high MITAX value at the onset significantly correlate with mortality [HR =2.4, 95% CI =1.0 to 5.6 and HR =1.5 (95% CI =1.1 to 2.1), respectively]. Kaplan-Meyer estimates higher mortality for patients treated with corticosteroids or with corticosteroids and immunosuppressants as compared to patients treated with IVIG and/or SCIg (LR test p-value =0.3). Five-, 10- and 15-year survivals were higher in patients treated with immunoglobulin as compared with those treated with glucocorticoids or glucocorticoids plus immunosuppressants (p<0.08,0.1 and 0.06,respectively).
Conclusions PM and DM represent complex systemic disorders with a high rate of mortality. Patients initially treated with glucocorticoids and/or immunosuppressants had poorer outcome as compared with those treated with immunoglobulin (IV or SC).
Disclosure of Interest None declared