AB0632 Paraneoplastic Myositis: the Features of Debut, Clinic Tendency, and Responsiveness to Steroid Therapy

Abstract

Background Similarity of muscle and skin symptoms during idiopathic polymyositis/dermatomyositis (DM/PM) and paraneoplasic myositis (PNM) makes clear the clinical tendencies of PNM. Objectives To determine the clinical tendencies of PNM. Methods We investigated 139 patients with PM/DM and 22 patients with PNM (4 males, 18 females). Laboratory investigation included definition of liver ferments, erythrocyte sedimentation rate (ESR), antibodies to Jo-1, creatinkinase (CK). The manual muscle testing (MMT) was performed according to IMACS recommendations. Results Duration of PNM was 8,68±11,6 months at the moment of investigation. Duration of investigation was 36,5±21,2 months. The mean age of patients with debut of PNM was 55,9 years. The tumor was diagnosed in 10 patients before the clinical manifestations of myositis, and in 12 (54,5%) patients after manifestation. Tumor localization was in ovaries (10 patients (45%)), breast (4 patients (18%)), lungs (4 patients (18%)), uterus (2 patients (10%)), colon (1 patient (4,5%)), and stomach (1 patient (4,5%)). Clinical presentation in debut of PNM included skin erythema (8 patients (81%)), ulcer vasculitis (3 patients (13,6%)), muscle syndrome (3 patients (13,6%)), and fever (1 patient (4,5%)). Dysphagia was determined in 19 patients (86,4%). MMT in patients with PNM before and the year after steroid therapy was similar to the patients with DM/PM. All patients with PNM were Jo-1 antibodies and interstitial lung disease negative. CK level in patients with PNM was lower to compare with patients with DM/PM (1893±1846 vs 3704±3916, p≤0,027); opposite, ESR level in patients with PNM was higher to compare with patients with DM/PM (31,65±15,16 vs 17,35+10,9, p≤0,0001). Levels of CK and ESR were the same after 12 months of steroid therapy. During the period of investigation 9 patients died, 9 patients survived. 4 patients had 5 years survival rate. The fate of 4 patients is unknown. 16 (72,7%) patients had skin erythema and 2 (9,09%) patients had ulcer vasculitis in period of normalized muscle power. The aggravation of PNM in 50% of patients was related to metastasis. Conclusions PNM occurs in 9,9% patients with DM/PM. Most of the patients are older 50 years. PNM has clinical features of DM. The main features are Jo-1 antibodies and interstitial lung disease negative, the high level of dysphagia, increasing of muscle power during steroid therapy, and not sufficient effect of steroid concerning skin syndrome. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.3641