Lymphoid interstitial pneumonia in Sjögren disease: clinical course and comparison with other interstitial lung disease patterns
Gaetano La Rocca, Francesco Ferro, Vincenzo Uggenti, Beatrice Dei, Giovanni Fulvio, Michele Moretti, Riccardo Morganti, Gianluca Sambataro, Marta Mosca, Chiara Romei, Chiara BaldiniAbstract
Objectives
Lymphoid interstitial pneumonia (LIP) is a rare form of Interstitial Lung Disease (ILD), often associated with Sjögren Disease (SjD). However, the clinical-serologic characteristics of SjD-LIP remain poorly characterized. Our objective was to describe the clinical course and outcome of SjD-associated LIP and to compare this subgroup with other SjD-ILD patterns.
Methods
SjD patients with HRCT-confirmed ILD followed in Pisa Rheumatology Unit (January 2019–November 2024) were retrospectively enrolled. ILD patterns were classified through multidisciplinary discussion. Clinical and laboratory data were collected according to ESSDAI definitions, along with pulmonary symptoms and function tests (PFTs).
Results
Fifty-five SjD-ILD patients were included (M: F = 9:46), of whom 11 were diagnosed with LIP (F: M = 11:0). LIP patients showed thin-walled parenchymal cysts as the predominant HRCT finding, and largely preserved pulmonary function (median FVC 101% [IQR 98–105]; DLCO 76% [IQR 75–81]). After a median 5-years follow-up (IQR 2–7) all LIP patients were alive with stable PFTs. Compared with the remaining 44 non-LIP, LIP patients were younger at SjD diagnosis (p<0.001) and more frequently presented purpura (p=0.012), constitutional symptoms (p=0.001), lymphadenopathy (p=0.023), hypergammaglobulinemia (p<0.001), triple anti-Ro60/52/La positivity (p=0.035) and C3 hypocomplementemia (p=0.009).
ILD preceded SjD diagnosis in 30/44 non-LIP vs 1/11 LIP patients (p<0.001), with lower FVC% (p=0.049) and DLCO% (p=0.036) in non-LIP.
Conclusion
LIP defines a distinct, immunologically active phenotype within the spectrum of SjD-ILD, characterized by greater extrapulmonary systemic involvement and serologic markers of B cell hyperactivity, but limited pulmonary functional impact. These findings support long-term lymphoma surveillance and a potential role for B cell targeted therapies in selected patients.