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Background: Progression of interstitial lung disease (ILD) reduces long-term survival in patients with systemic sclerosis (SSc), such that aggressive treatment and tight monitoring should be considered in appropriate patients. Conversely, identifying stable SSc-ILD patients over time is important in clinical practice to avoid overtreatment and inclusion into clinical trials.
Objectives: To determine factors associated with stable SSc-ILD, assessing several definitions for ILD progression.
Methods: We included all SSc patients from two expert SSc centers with well characterized SSc cohorts who had ILD on HRCT, consecutive annual lung function assessments including forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) and comprehensive serial clinical and imaging assessments available. Patients were defined as long-term stable ILD if no progression was observed over three years, using the following definitions for ILD progression:
FVC decline ≥5% over 12 months
2022 ATS/ERS/JRS/ALAT guideline progressive pulmonary fibrosis (PPF) criteria with (1) worsening of respiratory symptoms; (2) absolute decline in FVC ≥5% or in DLCO ≥10% and (3) disease progression on HRCT, over 12 months
INBUILD progressive fibrosing ILD (PF-ILD) criteria with (1) relative FVC decline ≥10%, (2) relative FVC decline ≥5-<10% and worsening of respiratory symptoms or an increased extent of fibrosis on HRCT, or (3) worsening of respiratory symptoms and an increased extent of fibrosis, within 24 months.
Logistic regression was applied, adjusting for known risk factors for ILD progression, including treatment, to identify factors predictive of stable ILD.
Results: In total, 231 SSc-ILD patients were included (Table 1). We identified 75 (32%) patients with stable ILD over three years defined by no FVC decline ≥5%, 133 (58%) defined by not fulfilling the PPF guidelines criteria and 105 (45%) not fulfilling the INBUILD PF-ILD criteria. Factors predicting long-term, stable ILD varied in univariable logistic regression depending on which definition was applied and no consistent factor could be identified. Multivariable logistic regression models also varied based on the applied definition. Stable ILD using no FVC ≥5% decline was predicted by lower baseline FVC (Figure 1A). Stable ILD defined by no PPF and no PF-ILD was significantly predicted by the absence of dcSSc and of ground glass opacities on HRCT (Figure 1B and C).
Conclusion: Long-term stable ILD in SSc occurs but the frequency varies based on which definition is applied. Prediction of stable patients is challenging, highlighting the necessity of comprehensive disease assessment and monitoring over time.
Disease characteristics of stable patients fulfilling the different definitions for ILD progression over an observation period of 3 years
REFERENCES: NIL.
Acknowledgements: NIL.
Disclosure of Interests: Anna-Maria Hoffmann-Vold Boehringer Ingelheim, Boehringer Ingelheim, Janssen, Medscape, Merck Sharp & Dohme, Novartis and Roche, ARXX, BMS, Boehringer Ingelheim, Genentech, Janssen, Medscape, Merck Sharp & Dohme and Roche, Boehringer Ingelheim, Janssen, Liubov Petelytska: None declared, Håvard Fretheim Boehringer Ingelheim, Trond M Aaløkken Boehringer Ingelheim, Mike O. Becker Vifor, Amgen, Novartis, MSD, Mepha, Amgen, Vifor, Hilde Jenssen Bjørkekjær Janssen, Cathrine Brunborg: None declared, Cosimo Bruni Eli-Lilly, Boehringer Ingelheim, Novartis Foundation for Bio-medical Research, AbbVie and Wellcome Trust, Christian Clarenbach Boehringer Ingelheim, GSK, Astra Zeneca, Sanofi Advisor, Vifor, Grifols, OM Pharma, Daiichi Synkyo, CSL Behring, Phuong Phuong Diep Boehringer Ingelheim, Boehringer Ingelheim, Rucsandra Dobrota: None declared, Michael T Durheim Boehringer Ingelheim, Roche, Boehringer Ingelheim, Muriel Elhai: None declared, Thomas Frauenfelder Bayer and Bracco, Boehringer Ingelheim, Bayer, Suzana Jordan: None declared, Emily Langballe Boehringer Ingelheim, Øyvind Midtvedt: None declared, Carina Mihai Biotest, Novartis, Mepha, Boehringer-Ingelheim, Janssen Cilag, Øyvind Molberg: None declared, Oliver Distler Boehringer Ingelheim, Janssen, Medscape, CITUS AG, 4P-Pharma, Abbvie, Acceleron, Alcimed, Altavant, Amgen, AnaMar, Argenx, Arxx, AstraZeneca, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galderma, Galapagos, Glenmark, Gossamer, Horizon, Janssen, Kymera, Lupin, Medscape, Merck, Miltenyi Biotec, Mitsubishi Tanabe, Novartis, Orion, Prometheus, Redxpharma, Roivant, Topadur and UCB.