LAUSR

Background Lung involvement has been reported in 10-20% of patients (pts) with primary Sjögren’s syndrome (pSS) and mostly affecting parenchyma and airways. Its occurrence significantly impacts both quality of life and mortality in pSS pts. Objectives To characterize lung involvement in a cohort of pSS pts and present our experience with immunosuppressive drug treatment for pSS-interstitial lung disease (ILD). Methods Retrospective analysis of pSS pts followed in our Rheumatology department until December 2018. Lung involvement was based on imaging and/or histopathological alterations described in the spectrum of pSS-associated lung disease. Patients with and without lung disease were compared using parametric and non-parametric tests. Results In total, 137 pSS pts who fulfilled the European-American consensus criteria 2002 were identified, 130 (94.9%) females, with mean age at pSS diagnosis of 56.1 (±12.2) years; median disease duration 6 [IQR 3-10] years and median follow-up 6 [IQR 3-10.25] years. Antinuclear antibodies were positive in 113 (82.5%) pts, with 95/134 (70.9%) pts presenting positive anti-SSA and 60/128 (46.9%) anti-SSB. Specific immunoassays performed in 82 pts allowed identification of anti-Ro52 antibody in 48 (58.5%) of them. Rheumatoid factor was positive in 48/91 (52.7%). During follow-up 3 pts died, 1 due to ILD progression and 2 due to sepsis (respiratory and abdominal), both under immunosuppression. Lung involvement occurred in 17 (12.4%) pts; median time to lung disease was 2 years [IQR 0-8] after pSS diagnosis. Mean EULAR SS disease activity index (ESSDAI) at the time of lung involvement diagnosis was 13.1 (±5). Differences between pts with and without lung involvement are shown in table 1.Table 1 – Comparison between pts with and without lung involvement Lung involvement (n=17) No-lung involvement (n=120) p-value Female 17 (100%) 113 (94.2%) 0.31 Age at pSS diagnosis (mean±SD) 60.9±8.6 55.4±12.4 0.04 Disease duration (median IQR) 8 [2.5-12] 5 [3.9.75] 0.24 ANA 15 (88.2%) 99 (82.5%) 0.56 Anti-Ro52 7 (63.6%) 41 (57.7%) 0.72 Hypergammaglobulinemia during follow-up 10 (58.8%) 48 (40%) 0.14 Constitutional involvement during follow-up 6 (35.3%) 5 (4.2%) < 0.001 Legend: pSS - primary Sjögren’s syndrome; ANA- antinuclear antibodies Regarding pattern of lung involvement, 9 (52.9%) pts had ILD, 6 (35.3%) isolated bronchiectasis and 2 (11.8%) follicular bronchiolitis. In ILD pts, non-specific interstitial pneumonia (NSIP) was documented in 6 pts, lymphocytic interstitial pneumonia in 2 and 1 pt had unclassifiable ILD pattern with lymphocytic alveolitis in bronchoalveolar lavage. One of the pts with NSIP later developed radiographic characteristics suggestive of usual interstitial pneumonia (UIP). Six ILD pts were treated with immunosuppressive drugs. One received cyclophosphamide (CYC), 2 azathioprine (AZA) and 4 mycophenolate mofetil (MMF). From pts receiving MMF, 1 was previously treated with CYC as induction treatment and the other with AZA, but with inefficacy. Rituximab (RTX) was given to 1 pt with refractory arthritis and new ILD onset. After 11 years on RTX (total 10 cycles) the pt complained of persistent dyspnoea and fatigue on minor exertion (cardiac causes excluded), with onset of subtle honeycombing in high resolution computed tomography. At this point pirfenidone was added to RTX, with clinical improvement. Detailed lung function and imaging evolution of pSS-ILD pts is shown in table 2. Conclusion Lung involvement occurred in 12.4% of our cohort and was associated with older disease at pSS diagnosis and presence of constitutional involvement. Small airways disease and ILD had nearly the same prevalence and in the ILD sub-group, NSIP was the commonest pattern. Despite the small number of ILD pts receiving immunosuppression, these drugs seemed to be associated with disease stabilization in most of them. Only 1 pt with UIP pattern had disease progression and eventually died. Disclosure of Interests None declared