Ab0824 Pulmonary Involvement Secondary to Primary Sjögren’s Syndrome: Monocentric Experience From a Tertiary Care Referral Hospital

Background: Pulmonary involvement (PI) is the second most common extra-glandular manifestation of primary Sjogren Syndrome (pSS) with a prevalence ranging between 10% to 20% significantly impacting patients' prognosis. According to the EULAR Sjogren's Syndrome Disease Activity Index (ESSDAI), PI encompasses both airways involvement (AD) and interstitial lung involvement (ILD). The clinical, functional, and radiological heterogeneity of pSS-PI, along with the absence of specific recommended treatments, has led to controversial results in literature, particularly related to the outcomes and management of this complication. Objectives: To assess PI prevalence in a tertiary care referral hospital's pSS cohort and to characterize patients clinically, functionally, and radiologically. Additionally, to establish relationships between pSS-PI symptoms, radiological patterns, pulmonary function tests (PFTs) abnormalities, therapeutic strategies, and outcomes. Methods: pSS patients meeting ACR/EULAR 2016 criteria with concomitant PI defined by ESSDAI pulmonary criteria, observed from 2000 to 2022, were included. Data collected encompassed the duration of lung disease, reported symptoms, PFTs, radiological patterns, and medications. Mortality and pSS-PI progression, accordingly INBUILD trial criteria, were evaluated and any associations between categorical variables were analyzed using the Fisher exact test. Results: 23/345 pSS patients exhibit PI (6,6%) with a mean onset age of 53,2±11,6 years. The mean follow-up time from diagnosis of pSS-PI to last assessment is 6,2±6,9 years. 19/23 patients (82,6%) display ILD; 4/23 (17,4%) exhibit AD, demonstrated by air trapping on HRCT. Clinically, at pSS-PI diagnosis, ILDs showed significantly more dyspnea and less persistent cough than ADs (p=0.04; p=0.01, respectively). PFTs at diagnosis, showed in 1/19 ILDs a FVC<80% while none of ADs presented FVC abnormalities; of note, in 10/19 ILDs (52%) and in 4/4 ADs (100%) a DLCO<70% was observed, without a significant difference between the two groups (p=1; p=0.12). Focusing on ILD patterns, NSIP was the most prevalent followed by ground glass opacities, LIP, UIP and OP. Mixed patterns were also observed (i.e., NSIP+OP). Regarding treatment employed: in 0/4 ADs no systemic treatment was used while in ILD an immunosuppression was used in 13/19 (68,4%) patients being azathioprine the preferred drug (6/13; 46%). Examining the outcomes of pSS-ILD patients, no death was registered while a progressive phenotype characterized 2/19 pSS-ILD both with NSIP pattern. No difference in dyspnea (p=0.54), cough (p=0.46), FVC<80% (p=1), DLCO<70% (p=0.47), radiological pattern (NSIP; p=0.21) or therapeutic strategy (immunosuppression vs wait-and-see; p=0.54) was noted in comparison to non-progressive ILDs; no progression or death was seen in AD patients. Conclusion: Pulmonary complications in pSS are extremely heterogeneous involving both interstitium and bronchi, the latter probably underrecognized. Although patients with pSS-ILD are characterized by significant dyspnea, substantial abnormalities in PFTs appear to be rare and are comparable between ILD and non-ILD patients, with reduced DLCO the first functional sign. The broad clinical, functional and radiological variability explains the absence of a common treatment strategy, which is still based on the clinician judgment. Nevertheless, a relatively benign prognosis seems to emerge independently from pSS-PI characteristics and therapeutic strategy used. A better phenotyping will enhance pSS-PI risk stratification guiding optimal and shared therapeutic strategies. REFERENCES: [1] Berardicurti O et al. J Clin Med. 2023;12(7):2586. doi:10.3390/jcm12072586 [2] La Rocca G et al. J Clin Med. 2023;12(10):3428. doi:10.3390/jcm12103428 Acknowledgements: NIL. Disclosure of Interests: None declared.