AB0626 Epitope profiling of ANTI-RO52 antibodies in patients with systemic sclerosis, systemic sclerosis-associated primary biliary cirrhosis, and primary biliary cirrhosis alone. (15th June 2017)

• Record Type: Journal Article
• Authors: Liaskos, C; Gkoutzourelas, A; Simopoulou, T; Marou, E; Scheper, T; Meyer, W; Sakkas, L; Bogdanos, DP
• Is Part Of: Annals of the rheumatic diseases. Volume 76(2017)Supplement 2
• Page Start: 1271
• Page End: 1271
• Publication Date: 2017-06-15
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2017-eular.5299
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Anti-Ro52 antibodies are detected in patients with Sjogren's syndrome (SjS), systemic sclerosis (SSc) and other autoimmune rheumatic diseases. Epitope mapping studies of anti-Ro52 in autoimmune rheumatic diseases have failed to find any difference on epitope recognition suggesting a common stimulus for the loss of tolerance to Ro52. Such epitope differences, however, were noted between SjS and non-rheumatic diseases and in particular, SjS-associated primary biliary cirrhosis (SjS-PBC) or PBC alone (1). Objectives: To assess whether or not the Ro52 epitope profile in anti-Ro52+ SSc patients differs from that of SSc-associated PBC (SSc-PBC) or PBC. Methods: Serum samples were obtained from 63 anti-Ro52-positive (by ELISA) patients (33 SSc, 10 SSc-PBC, 20 PBC alone). Antibody reactivity to full length recombinant Ro52 and 5 baculovirus expressed Ro52 fragments spanning the whole sequence [Ro52–1 (aa 1–129), Ro52–2 (aa 125–268), Ro52–3 (aa 269–475), Ro52–4 (aa 57–180, partly overlapping with Ro52–1 and Ro52–2), and Ro52–5 (aa 181–320, partly overlapping with Ro52–2 and Ro52–3)] were tested by a line immunoassay. Results: Reactivity was present to: full length Ro52 in all anti-Ro52 positive SSc, PBC-SSc, or PBC patients by line immunoassay; Ro52–1 in 6/33 (18.2%) SSc, 3/10 (30%) SSc-PBC, and 3/20 (15%) PBC; Ro52–2 in 33/33 (100%) SSc, 10/10 (100%) SSc-PBC and 20/20 (100%) PBC; Ro52–3 in 0/33 (0%) SSc, 0/10 (0%) SSc-PBC and 0/20 (0%) PBC; Ro52–4 in 4/33 (12.1%) SSc, 2/10 (20%) SSc-PBC, and 4/20 (20%) PBC and Ro52–5 in 11/33 (33.3%) SSc 4/10 (40%) SSc-PBC, and 9/20 (45%) PBC respectively (p>0.05 for all epitopes amongst the 3 cohorts). No statistically significant correlation was found. Conclusions: The major epitope of anti-Ro52 does not differ among SSc, PBC-SSc and PBC and is localized on aa125–268, the major epitopic region of anti-Ro52 antibodies in SjS and other rheumatic diseases. Our epitope mapping data suggest that the mechanisms responsible for the loss of tolerance to Ro52 is common amongst diseases. References: Mytilinaiou, Maria G.; Meyer Wolfgang; Komorowski, Lars; Probst, Christian; Davies, Edward T.; Vergani, Diego; Bogdanos, Dimitrios P. B-cell epitope mapping of anti-Ro52 responses in patients with primary biliary cirrhosis., Hepatology, Vol. 52 (4), 2010, 489. Disclosure of Interest: C. Liaskos: None declared, A. Gkoutzourelas: None declared, T. Simopoulou: None declared, E. Marou: None declared, T. Scheper Employee of: Euroimmun AG, W. Meyer Employee of: Euroimmun AG, L. Sakkas: None declared, D. Bogdanos: None declared