Comparison of clinical features between patients with anti-synthetase syndrome and dermatomyositis: results from the MYONET registry
Ryan Malcolm Hum, James B Lilleker, Janine A. Lamb, Alexander Oldroyd, Guochun Wang, Lucy R Wedderburn, Louise Pyndt Diederichsen, Jens Schmidt, Maria Giovanna Danieli, Paula Oakley, Zoltán Griger, Thuy Nguyen Thi Phuong, Chanakya Kodishala, Mónica Vázquez-Del Mercado, Helena Andersson, Boél De Paepe, Jan De Bleecker, Britta Maurer, Liza McCann, Nicolò Pipitone, Neil McHugh, Robert P New, William Ollier, Niels Steen Krogh, Jiří Vencovský, Ingrid E. Lundberg, Hector Chinoy, MYONET Registry, Sophie D’hose, Xin Lu, Xiaolan Tian, H. Mann, Olga Kryštůfková, Lenka Pleštilová, Martin Klein, Tereza Barochová, Kateřina Kubínová, Chiara Gelardi, Alberto Paladini, Mario Andrea Piga, Luis J. Jara, Miguel Ángel Saavedra, Claudia Cruz‐Reyes, Olga Vera‐Lastra, Lilia Andrade-Ortega, Gabriel Medrano-Ramírez, Minoru Satoh, Mario Salazar-Páramo, Efrain Chavarría-Ávila, Andrea Aguilar-Vázquez, Jesús-Aureliano Robles-De Anda, Marcelo H. Petri, Øyvind Molberg, Maryam Dastmalchi, Antonella Notarnicola, Karina Gheorghe, Johan Rönnelid, Maria Liden, Balsam Hanna, Awat Jalal, Helena Hellström, Jehns Christian Martineus, Nguyễn Thị Ngọc Lan, Leonid Padyukov, Paul New, Hazel Platt, Simon Rothwell, Yasmeen Ahmed, Raymond Armstrong, Robert Bernstein, Carol M. Black, Simon Bowman, Ian N Bruce, Robin Butler, John Carty, Chandra Chattopadhyay, E G Chelliah, Fiona Clarke, P. T. Dawes, Christopher P. Denton, Joseph Devlin, Christopher Edwards, Paul Emery, J. L. A. Fordham, Alexander Fraser, Hill Gaston, Patrick Gordon, Bridget Griffiths, Harsha Gunawardena, Frances Hall, Michael G. Hanna, Beverley Harrison, Elaine M. Hay, David Hilton‐Jones, Lesley Horden, John D. Isaacs, David Isenberg, Adrian Jones, Sanjeet Kamath, Thomas J. Kennedy
Abstract
OBJECTIVES: To compare clinical characteristics, including the frequency of cutaneous, extramuscular manifestations and malignancy, between adults with anti-synthetase syndrome (ASyS) and DM. METHODS: Using data regarding adults from the MYONET registry, a cohort of DM patients with anti-Mi2/-TIF1γ/-NXP2/-SAE/-MDA5 autoantibodies, and a cohort of ASyS patients with anti-tRNA synthetase autoantibodies (anti-Jo1/-PL7/-PL12/-OJ/-EJ/-Zo/-KS) were identified. Patients with DM sine dermatitis or with discordant dual autoantibody specificities were excluded. Sub-cohorts of patients with ASyS with or without skin involvement were defined based on presence of DM-type rashes (heliotrope rash, Gottron's papules/sign, violaceous rash, shawl sign, V-sign, erythroderma, and/or periorbital rash). RESULTS: In total 1054 patients were included (DM, n = 405; ASyS, n = 649). In the ASyS cohort, 31% (n = 203) had DM-type skin involvement (ASyS-DMskin). A higher frequency of extramuscular manifestations, including Mechanic's hands, Raynaud's phenomenon, arthritis, interstitial lung disease and cardiac involvement differentiated ASyS-DMskin from DM (all P < 0.001), whereas higher frequency of any of four DM-type rashes-heliotrope rash (n = 248, 61% vs n = 90, 44%), violaceous rash (n = 166, 41% vs n = 57, 9%), V-sign (n = 124, 31% vs n = 28, 4%), and shawl sign (n = 133, 33% vs n = 18, 3%)-differentiated DM from ASyS-DMskin (all P < 0.005). Cancer-associated myositis (CAM) was more frequent in DM (n = 67, 17%) compared with ASyS (n = 21, 3%) and ASyS-DMskin (n = 7, 3%) cohorts (both P < 0.001). CONCLUSION: DM-type rashes are frequent in patients with ASyS; however, distinct clinical manifestations differentiate these patients from classical DM. Skin involvement in ASyS does not necessitate increased malignancy surveillance. These findings will inform future ASyS classification criteria and patient management.