POS0883 DETECTION OF AUTOANTIBODIES AGAINST MUSCLE-SPECIFIC FOUR-AND-A-HALF-LIM DOMAIN 1 (FHL1) IN INFLAMMATORY MYOPATHIES: RESULTS FROM A SINGLE-CENTER COHORT

Background: Autoantibodies targeting a muscle-specific autoantigen, four-and-a-half-LIM-domain 1 (FHL1), have been previously identified in patients with idiopathic inflammatory myopathies (IIM) (1). Objectives: The aim of this project was to determine the prevalence and associations anti-FHL antibody South Australian histologically-confirmed IIM an autoimmune disease control (systemic sclerosis (SSc)). Methods: Sera from (n=267) Myositis Database (SAMD), SSc (n=174) Scleroderma Cohort Study (ASCS) followed at Royal Adelaide Hospital, healthy controls (HC, n=100) were analyzed for anti-FHL1 autoantibodies by Enzyme-Linked ImmunoSorbent Assay (ELISA). Clinical, serological histological details retrieved SAMD ASCS. Results: FHL1 more frequent (55/267, 20.5%) compared (18/174, 10%) (p<0.001) HC (4/100, 4%) (p<0.001). Muscular vessel inflammation atrophy seen frequently + - (p<0.01 p<0.05). Dysphagia, marked muscle atrophy, high CK levels inclusion body myositis (IBM) immune-mediated necrotizing myopathy (IMNM). In 35/54 patients, there no other myositis-specific present. Anti-FHL1 associated gastric antral vascular ectasia. Conclusion: detected 20.5% patients. IBM IMNM, presence anti-FHL1-autoantibodies severe as suggested dysphagia atrophy. References: [1]Albrecht I, Wick C, Hallgren A, Tjarnlund Nagaraju K, Andrade F, et al. Development against myopathies. J Clin Invest. 2015;125(12):4612-24. Disclosure Interests: Angeles Shunashy Galindo-Feria: None declared, Begum Horuluoglu: Jessica Day: Catia Cerqueira: Susanna Proudman: Ingrid E. Lundberg Consultant of: Consulting fees Corbus Pharmaceuticals, Inc, Grant/research support from: Research grants Bristol Myers Squibb Astra Zeneca, Vidya Limaye Scientific adviser Actelion Boehringer-Ingelheim, PI clinical trials Bayer, Corbus, CSL