SAT0208 Inflammatory Myopathies Associated with Sjögren's Syndrome Do Not Differ from Those without Sjögren's Syndrome Aside from Older Age at Diagnosis and Less Frequent Normal Muscle Biopsy

Background Prevalence of Sjogren9s syndrome (SS) in inflammatory myopathies (IM) and whether IM patients with SS represent a distinct disease subset are currently unknown. Objectives To assess the signification of SS in IM with regard to phenotype and prognosis. Methods IM patients with SS (IM-SS group) were identified among a cohort of 270 patients with IM using European-American Consensus Group (EACG) classification criteria. Clinical, serological, muscle pathological features, management and outcomes of IM-SS patients were retrospectively studied and compared to the IM patients who had been assessed for SS but did not fulfill these criteria (IM-noSS group). Results EACG criteria were available in 63 IM patients of the total cohort and 29 (46%) were diagnosed as having SS. These IM-SS patients were older at IM diagnosis than the 34 IM-noSS patients (56±3.1 vs 47.7±2.8 years, p=0.05), sex ratio wasn9t different. SS was mostly diagnosed at the time of IM diagnosis (n=23, 79%) and less frequently preceded (n=3: 1, 3 and 4 years) or followed (n=3, 3, 6 and 30 years) IM diagnosis. IM-SS patients had subjective sicca syndrome (29/29, 100%) with objective dryness (10/12, 92%), anti-SSA/SSB antibodies (14/29, 48%) and/or focus score ≥3 in minor salivary glands biopsy (n=21/24, 88%). Creatine kinase level was not different between IM-SS and IM-noSS (1400±320 vs 2538±214 UI/L, p=0.5). A normal muscle biopsy was less frequently found in IM-SS than in IM-noSS patient (7/28 vs 1/24 p=0.05). According to the ENMC criteria, DM was the more frequent muscle histological finding in IM-SS patients (n=10, 42%) but all histological patterns were represented (including nonspecific IM: 6 (25%), inclusion body myositis: 4 (17%), polymyositis: 2 (8%), necrotizing myopathy: 1 (4%). This distribution was not different from the IM-noSS group. IM-SS patients also suffered from interstitial lung disease (n=10, 34%), arthralgia and/or arthrithis (n=17, 59%), skin involvement (n=14 48%) and Raynaud syndrome (n=14, 48%) which occurrence characteristics were not different from IM-noSS group. Anti-SSA (n=13, 45% vs n=1, 3%, p=0.0001) and anti-SSB (n=6, 21% vs n=0, 0% p 7 years, 6 patients died in both groups, whithout any significant difference in survival (p=0.23). Conclusions SS is frequently observed in IM. No difference was found between IM-SS and IM-noSS with regards to phenotype, serotype and survival aside from older age at diagnosis and less frequent normal muscle biopsy. Disclosure of Interest None declared