Pos0953 progressive pulmonary fibrosis in connective tissue disease associated interstitial lung diseases

Background Progressive pulmonary fibrosis (PPF) is characterized by deterioration of respiratory symptoms, lung function decline and progressive fibrosis on high-resolution computed tomography (HRCT). It is associated with poor prognosis. Patients with connective tissue disease-related interstitial lung disease (CTD-ILD) may also develop PPF and need intensified clinical management. However, different criteria for PPF are used in trials (i.e. INBUILD and RELIEF) and the ATS/ERS/JRS/ALAT 2022 guideline. [1-3] This variety in criteria complicates study comparison and clinical implication. Objectives To explore the prognostic relevance for mortality of different PPF criteria in patients with CTD-ILD. Methods This is a single center retrospective cohort study in patients with CTD-ILD or interstitial pneumonia with autoimmune features between 2005 and 2021. The prognostic relevance was compared between the INBUILD criteria [1] , the ATS/ERS/JRS/ALAT 2022 criteria [3] , and the simplified progressive fibrosing (simplified PF) criteria used in a previous cohort (≥10% relative decline in FVC, ≥15% relative decline in DLCO, or progression of fibrosis on HRCT within two years) [4] in the time-dependent receiver operator characteristic model. Results The cohort consisted of 230 patients. The median age was 63 years (IQR 54—69), and 122 (53%) were female. The most prevalent CTD was rheumatoid arthritis (n=77, 33%), followed by 38 (17%) patients with idiopathic inflammatory myopathies and 33 (14%) with primary Sjögren’s syndrome. Various HRCT patterns were observed at baseline: UIP in 63 (27%) patients, fibrotic NSIP in 21 (9%), cellular NSIP in 25 (11%), mixed NSIP in 79 (34%), OP in 34 (15%), two (1%) mixed NSIP/OP, and other patterns in six. The median follow-up period was 6 (3—9) years. Mortality risk was independently associated with age (adjusted HR 1.07, p < 0.001), smoking history (adjusted HR 1.90, p = 0.045), extent of fibrosis on HRCT at baseline (adjusted HR 1.05, p = 0.018) and baseline DLCO % of predicted (adjusted HR 0.97, p = 0.013). PPF was observed in 61 (27%) patients meeting INBUILD criteria, 53 (23%) meeting ATS/ERS/JRS/ALAT 2022 criteria, 136 (59%) meeting simplified PF criteria and 125 (54%) when using simplified PF criteria with a threshold for HRCT ≥ 5% increase in the extent of fibrosis. The prognostic relevance for mortality did not differ between simplified PF criteria, INBUILD and ATS/ERS/JRS/ALAT 2022 criteria; the prognostic relevance improved when the simplified PF criteria defined HRCT progression with a ≥5% increase in fibrosis. (Figure 1) Conclusion Higher age, smoking, increased extent of fibrosis and low baseline DLCO were associated with poor prognosis. The prognostic value was similar between the different PPF criteria and increased during the first three years and achieved a plateau thereafter. References [1]KR Flaherty, AU Wells, V Cottin, et al. N Engl J Med. 2019;381(18):1718-27. [2]J Behr, A Prasse, M Kreuter, et al. Lancet Respir Med. 2021;9(5):476-86. [3]G Raghu, M Remy-Jardin, L Richeldi, et al. Am J Respir Crit Care Med. 2022;205(9):e18-e47. [4]YH Chiu, J Spierings, PA de Jong, et al. Respir Med. 2021;187:106579. Figure 1. Acknowledgements: NIL. Disclosure of Interests Yu-Hsiang Chiu: None declared, Maaike Koops: None declared, Mareye Voortman: None declared, H. Wouter van Es: None declared, Lucianne Langezaal: None declared, Paco Welsing: None declared, Anna Jamnitski: None declared, Anne Wind: None declared, Jacob M. van Laar Grant/research support from: Grant from Boehringer, Astra Zeneca, MSD, Roche, J.C. Grutters: None declared, Julia Spierings Grant/research support from: A grant from Boehringer.