POS1428 GIANT CELL ARTERITIS SIGNS AND SYMPTOMS LEXICON: AN INTERNATIONAL EXPERT CONSENSUS

Background: The lack of standardized definitions for clinical manifestations of giant cell arteritis (GCA) leads to variable interpretations in clinical practice and research settings. An international task force developing response criteria for GCA filled this gap by developing a glossary for signs and symptoms of GCA. Objectives: To create a consensus-based definition of signs and symptoms of GCA to be used by health care professionals, primarily in research settings. Methods: Core definitions or descriptors of signs and symptoms of GCA were extracted from 11 randomized controlled trials. These trials were part of a systematic literature review [1] published by the task force working on developing response criteria for GCA. This information was supplemented by definitions or descriptors from rheumatology textbooks, the 2022 ACR/EULAR Classification Criteria for GCA, the ACR 1990 Classification Criteria of GCA and a Delphi exercise conducted as part of the response criteria for a GCA project. The scientific committee identified general principles deemed important for the interpretation and application of definitions. A 2-round Delphi exercise was conducted. The first round aimed to obtain consensus on the descriptive terms to define each sign or symptom obtained from the literature review; >70% agreement=the descriptor was accepted; <30% agreement=the descriptor was excluded; 30-70% agreement=the descriptor was reassessed in the 2nd round. Round 2 of the Delphi exercise rated the importance of each descriptor: not important, important, or critically important. Those descriptors rated critically important were incorporated into the definitions. Those descriptors without consensus ratings were discussed via virtual meetings. Based on the Delphi, preliminary definitions of the signs and symptoms of GCA were developed. Three virtual meetings were then conducted during which the results of the Delphi and the preliminary definitions of the signs/symptoms of GCA were discussed. Through an online live voting process among task force members, consensus was reached on the definition of each term if >75% agreed on the refined definition. A similar voting process was established if a definition was not necessary. Results: 29 task force members from 11 countries participated in the two Delphi rounds and three virtual meetings. Two overarching principles were formulated by consensus (Table 1). 27 signs and symptoms of GCA were reviewed, with 24 retained for defining. 12/24 signs for symptoms of GCA were not included in the glossary because they were considered either self-explanatory, rare occurrences, or not indicative of a highly specific sign or symptom related to GCA. A high level of consensus was reached on the definition of 12 signs and symptoms of GCA (Table 1). Conclusion: A glossary of definitions for 12 signs and symptoms of GCA was developed through a consensus process among international experts. These definitions were designed for use in research. Applying these definitions should facilitate uniform characterization of GCA features and harmonize enrollment of patients into clinical trials in GCA. Table 1. Overarching principles and definitions of signs and symptoms of giant cell arteritis Numbers in the columns ‘LoA’ indicate the mean and SD (in parenthesis) of the LoA (assessed on a scale from 0=no agreement to 10=full agreement), and the proportion of task force members with a score of at least 8/10. REFERENCES: [1] Sanchez-Alvarez C et al. Measuring treatment outcomes and change in disease activity in giant cell arteritis: A systematic literature review informing the development of the EULAR-ACR response criteria on behalf of the EULAR-ACR response criteria in giant cell arteritis task force. RMD Open. 2023;9(2). Acknowledgements: Dr. Alfred Mahr, Dr. Bhaskar Dasgupta. Disclosure of Interests: Medha Soowamber: None declared, Milena Bond: None declared, Zahi Touma GSK, AstraZeneca, Merck, AbbVie, Eli Lilly and UCB., Sofia Ramiro AbbVie, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, UCB, Sanofi., AbbVie, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, UCB, Sanofi., Carol Langford Bristol-Myers Squibb, GlaxoSmithKline, AstraZeneca, Catalina Sanchez-Alvarez: None declared, Andy Abril: None declared, Sibel Aydin: None declared, Frank Buttgereit: None declared, Dario Camellino speaker and/or advisor fees from Astra-Zeneca, Boehringer Ingelheim, GSK, and Janssen, Maria C. Cid Lecturing fees from GSK, AbbVie, and CSL-Vifor, Consulting fees from GSK, AbbVie, CSL- Vifor, and AstraZeneca, Kiniksa Pharmaceuticals Corp., Peter Grayson: None declared, Bernhard Hellmich: None declared, Tanaz Kermani: None declared, Nader Khalidi: None declared, William Lichliter: None declared, Sarah Mackie Roche/Chugai, Vifor, Pfizer, UCB, Novartis and AbbVie, Roche/Chugai, Sanofi, AbbVie, AstraZeneca, Pfizer, Eric Matteson Boehringer-Ingelheim, GmbH, Boehringer-Ingelheim, GmbH, Mehrdad Maz: None declared, Peter A. Merkel ArGenx, Cabaletta, CSL Behring, Dynacure, HiBio, Janssen, Kyverna, Novartis, NS Pharma, Q32, Regeneron, Sparrow, Vistera, AbbVie, Amgen, AstraZeneca, Boeringher-Ingelheim, Bristol-Myers Squibb, GlaxoSmithKline, InflaRx, Takeda., Eicos, Electra, Forbius, Genentech/Roche, Genzyme/Sanofi, Neutrolis, AbbVie, Amgen, AstraZeneca, Boeringher-Ingelheim, Bristol-Myers Squibb, GlaxoSmithKline, InflaRx, Takeda., Paul A Monach HI-Bio, Lorna Neill: None declared, Cristina Ponte: None declared, Carlo Salvarani: None declared, Wolfgang A. Schmidt: None declared, Peter Villiger: None declared, Kenneth J Warrington Amgen and Sanofi, Madeline Whitlock: None declared, Christian Dejaco Abbvie, Eli Lilly, Janssen, Galapagos, Novartis, Pfizer, Sparrow, Roche and Sanofi, AbbVie.