AB0600 Clinical relevance of autoantibody profiles in systemic sclerosis
Authors: A Burlui, A Cardoneanu, E Rezus
Journal: Annals of the Rheumatic Diseases (2017)

<h3>Background</h3> Systemic sclerosis (SSc) is a connective tissue disease accompanied by immune abnormalities. A number of autoantibodies such as anti-centromere, anti-topoisomerase I, anti-RNA polymerase III and anti-U3 (fibrillarin) antibodies were proven to be of great diagnostic and prognostic factors in patients with scleroderma. Certain studies have reported the presence of antinuclear, anti-SSA (Ro) and/or anti-SSB (La), anti-Pm/Scl, anti-endothelial cell and anti-nucleosome antibodies in patients with systemic sclerosis. However, the clinical relevance of these autoantibodies is yet to be fully elucidated. <h3>Objectives</h3> Our aim was to assess clinical features, capillaroscopic abnormalities and autoantibody titers in patients with systemic sclerosis as well as analyze relationships between these parameters. <h3>Methods</h3> We conducted a prospective observational study on 36 adult patients who satisfied ACR/EULAR 2013 criteria for systemic sclerosis.We recorded disease duration. current symptoms and classified patients as limited cutaneous (lc) SSc and diffuse cutaneous (dc) SSc. Skin involvement was assessed using the modified Rodnan skin score (mRSS). We performed nailfold videocapillaroscopy using a FEDMED Digitale 100N at a magnification of 200X. Thoracic Xrays were done to establish the presence of pulmonary fibrosis. Ultrasounds were performed by a single examiner to evaluate pulmonary artery pressure. Blood samples were drawn to measure anti-topoisomerase 1, anti-centromere, anti-SSA (Ro), anti-SSB (La), anti-U1RNP and anti-nucleosome antibody titers (ELISA). Patient characteristics were included in a database and analyzed using IBM SPSS Statistics v20. <h3>Results</h3> Our study group was composed of 20 dc SSc (55.6%) and 16 lc SSc (44.4%) patients. Severity of capillary changes correlated with mRSS values (p,0.01), anti-topoisomerase I (p=0.006), anti-SSA (p=0.01) and anti-nucleosome antibodies (p=0.02). We found positive associations between the presence of dysphagia, anti-centromere (p=0.009) and anti-SSA (p&lt;0.01) titers in patients with lc SSc. Anti-centromere antibody positivity also correlated with pulmonary hypertension (p=0,011) and pulmonary fibrosis (p=0,04) in these patients. Anti-SSA antibodies correlated with pulmonary hypertension (p&lt;0.01) and capillaroscopic changes (p=0.024) in dc SSc. <h3>Conclusions</h3> Our findings support the relationship between autoantibody titers, systemic involvement and microvascular changes in scleroderma patients. Non-specific autoantibodies such as anti-nucleosome and anti-SSA antibodies were associated with microvascular changes in our study group. Further studies in this field may provide new information on SSc pathogenesis and possibly novel targets for treatment in scleroderma patients. <h3>References</h3> Fuschiotti P. Current perspectives on the immunopathogenesis of systemic sclerosis. ImmunoTargets and Therapy. 2016;5:21–35. doi: 10.2147/ITT.S82037. Choi MY, Fritzler MJ. Progress in understanding the diagnostic and pathogenic role of autoantibodies associated with systemic sclerosis. Current Opinion in Rheumatology. 2016;28(6):586–594. doi: 10.1097/BOR.0000000000000325. Rezus E. Reumatologie, “Gr. T. Popa”, UMF. Iasi, 2014, 162–183. Rezus E. Sclerodermia Sistemica in Reumatologie, “Gr. T. Popa”, UMFIasi, 2014, 162–183. ISBN: 978-606-544-255-9. Pattanaik D, Brown M, Postlethwaite BC, Postlethwaite AE. Pathogenesis of Systemic Sclerosis. Frontiers in Immunology. 2015;6:272. doi: 10.3389/fimmu.2015.00272. <h3>Disclosure of Interest</h3> None declared