Chronic interstitial lung disease associated with systemic lupus erythematosus: A multicentric study of 89 cases

Abstract Background and Objective Chronic interstitial lung disease (ILD) occurs rarely with systemic lupus erythematosus (SLE) as compared with other connective tissue diseases. This multicentric retrospective study of patients with SLE‐ILD from the OrphaLung and French SLE networks during 2005–2020 aimed to describe the characteristics of patients with SLE‐ILD and analyse factors associated with prognosis. Methods We analysed data for 89 patients with SLE‐ILD (82 women, 92.1%) (median age at SLE diagnosis: 35 years interquartile range 27–47). All patients met the 2019 EULAR/ACR criteria for the diagnosis of SLE. Results Forty two (47.2%) patients were positive for anti‐ribonuclear protein antibodies and 45 (50.6%) for anti SSA/Ro antibodies. A total of 58 (65.2%) patients had another connective tissue disease: Sjögren's syndrome ( n = 33, 37.1%), systemic sclerosis ( n = 14, 15.7%), inflammatory myopathy ( n = 6, 6.7%), or rheumatoid arthritis ( n = 6, 6.7%). ILD was diagnosed along with SLE in 25 (28.1%) patients and at a median of 6 (0–14) years after the SLE diagnosis. The most frequent CT pattern was suggestive of non‐specific interstitial pneumonia ( n = 41, 46.0%) with or without superimposed organizing pneumonia. After a median follow‐up of 86.5 39.5–161.2 months, 18 (20.2%) patients had died and 6 (6.7%) underwent lung transplantation. The median 5‐year and 10‐year transplantation‐free survival were 96% (92–100) and 87% (78–97). In total, 44 (49.4%) patients showed ILD progression. Cutaneous manifestations and Raynaud's phenomenon were associated with better survival. Only forced vital capacity was significantly associated with survival and ILD progression. Conclusion ILD is a rare manifestation of SLE with good overall prognosis but with possible risk of ILD progression. Patients with SLE‐ILD frequently have another connective tissue disease.