Pos1453 progressive pulmonary fibrosis according to the new ats definition is not uncommon in the context of sjögren’s syndrome-associated interstitial lung disease

Background Interstitial Lung Disease is relatively frequent in Primary Sjögren’s Syndrome patients (SS-ILD), however, data on its prognosis are heterogenous. The American Thoracic Society (ATS) recently provided clinical-instrumental criteria for the definition of Progressive Pulmonary Fibrosis (PPF) (1), based on the assumption that this clinical phenotype is associated with worse prognosis and may benefit from treatment with the novel antifibrotic agents. Frequency and characteristics of PPF, defined according to ATS, have not been investigated in the context of SS-ILD. Objectives 1. To describe the outcome of SS-ILD in terms of ILD progression according to the recent definition of PPF in our cohort. 2. To identify specific factors associated to PPF in well characterized SS-ILD patients. Methods Demographic, clinical, biological and imaging data of SS patients attending our center were retrospectively analyzed. SS-ILD was defined based on clinical history, pulmonary function tests (PFT) and HRCT assessed by an expert thoracic radiologist for all patients. She also defined ILD pattern, extension (by Warrick score) and progression on HRCT. The new ATS definition of PPF was applied to all SS-ILD patients in follow-up in the last 4 years, who presented at least 2 clinical-instrumental evaluations at 1 year of distance. PPF was defined in the presence of 2/3 among: worsening symptoms, significant functional decline (FVC ≥5% or DLCO ≥10%) and radiological progression, within 1 year. PPF and non-PPF SS-ILD patients, with complete imaging and functional follow-up data available, were then compared in terms of clinical, biological, functional and imaging features. For statistical analysis, we used the Fisher test for categorical data and the ANOVA t-test or Mann-Whitney test for continuous data. Results Out of 620 primary SS patients attending our center, 52 (8.4%) were diagnosed with SS-ILD (F:M=46:6). Mean age at diagnosis was 61 (±13) years, positive SSA were present in 44/52 (84.6%), and the mean follow-up time was 8 (±7) years. ILD was the first manifestation of SS in 32/52 (61.5%) and followed SS diagnosis in 20/52 (38.5%) cases, with a mean latency of 8.5 (±6) years. The distribution of ILD patterns was in line with recent literature, with 24/52 (46.2%) patients presenting NSIP, 9/52 (17.3%) UIP, 7/52 (13.5%) LIP, 8/52 (15.4%) NSIP+OP, 2/52 (3.8%) OP, and 2/52 (3.8%) an unclassifiable pattern. Out of 46 SS-ILD patients with available follow-up data: 13/46 (28.3%) presented worsening clinical symptoms; 13/42 (31%) experimented significant decline of FVC (≥5%) and/or DLCO (≥10%), while 4 patients were unable to perform PFT due to desaturation; 3/46 (6.5%) patients died because of ILD progression. Complete seriate evaluations including HRCT at 1-year distance were available for 17 patients: 8/17 (47.1%) were defined as PPF and 10/17 (58.8%) as non-PPF according to the ATS definition. The former group exhibited older age at diagnosis (p=.001) and a UIP pattern in 5/8 vs 0/9 cases (p=.06). Standard of care immunosuppressive treatment did not differ significantly between the two groups, while no patients were treated with antifibrotics. Conclusion The clinical phenotype of PPF is relatively common among SS-ILD patients and is associated with older age at diagnosis and a UIP pattern on HRCT. These characteristics may aid in the selection of patients eligible for antifibrotic therapy. Reference [1]Raghu G, Remy-Jardin M, Richeldi L, Thomson CC, Inoue Y, Johkoh T, et al. Idiopathic Pulmonary Fibrosis (an Update) and Progressive Pulmonary Fibrosis in Adults: An Official ATS/ERS/JRS/ALAT Clinical Practice Guideline. Am J Respir Crit Care Med. 2022;205(9):e18-e47. Acknowledgements: NIL. Disclosure of Interests None Declared.