Distinctive Clinical Characteristics and Outcome of ILD-Onset Rheumatoid Arthritis and ACPA-Positive ILD: a Longitudinal Cohort of 282 Cases.

The aim of this study is to investigate the clinical features and outcome of interstitial lung disease (ILD)-onset rheumatoid arthritis (RA) and anti-citrullinated protein antibody (ACPA)-positive ILD-only patients. Arthritis-onset and ILD-onset RA-ILD and ACPA-positive ILD-only patients consecutively admitted to Peking Union Medical College Hospital from January 2008 to December 2017 were enrolled and followed-up. Their demographic, clinical, and laboratory features as well as outcome were collected and analyzed. Compared with arthritis-onset RA-ILD (n = 166, median arthritis-to-ILD interval: 60 months), the ILD-onset RA-ILD (n = 75, median ILD-to-arthritis interval: 2 months) had less rheumatoid nodules and higher titer of ACPA, and manifested more stable ILD (median estimated progression-free survival: 120 vs. 100 months, p = 0.019). Elder age (≥ 65 years) at ILD diagnosis and UIP pattern were associated with ILD progression by both univariate and Cox hazards modeling analysis (p < 0.05). In ACPA-positive ILD-only patients (n = 41), arthritis developed in 7 (17.1%) female patients after a median interval of 24 months. ACPA-positive ILD who subsequently developed arthritis exhibited higher frequency of rheumatoid factor (RF), higher titer of ACPA, and higher levels of ESR and CRP (p < 0.05). Multivariate regression analysis showed that positive RF (OR 12.55, 95% CI 1.31 to 120.48) was the independent risk factor for arthritis development in ACPA-positive ILD-only patients. ILD-onset RA-ILD had more stable ILD compared with arthritis-onset RA-ILD. ACPA-positive ILD patients with positive RF are at increased risk of developing RA.

[Chest High-resolution Computed Tomography Imaging Features of Lung Involvement in Rheumatoid Arthritis].

Objective To explore the chest high-resolution computed tomography (HRCT) features in patients with rheumatoid arthritis (RA) complicated with pulmonary involvement. Methods Totally 161 patients with RA with lung involvement were collected from June 2014 to May 2018. The chest HRCT findings were retrospectively analyzed. According to the imaging features as well as the results of history taking,pulmonary function test,pathology,and bronchoalveolar lavage fluid test,RA-related lung diseases (RA-LD) were classified and their clinical characteristics were compared. Results These 161 RA-LD patients (56 males and 105 females) whose mean age at diagnosis was (60.7±12.8) years (14-85 years) included 87 cases of usual interstitial pneumonia (UIP) (including 16 cases of possible UIP),44 cases of non-specific interstitial pneumonia (NSIP),10 cases of organizing pneumonia,7 cases of lymphocytic interstitial pneumonia,9 cases of small airway disease (SAD) (including 8 cases of bronchiolitis obliterans and 1 case of follicular bronchiolitis),and 4 other lung manifestations (including 3 cases of diffuse alveolar hemorrhage and 1 case of rheumatoid nodules). The UIP group had the oldest average age [(63.3±12.1) years old] and the highest smoking rate (41.4%). The SAD group had the youngest average age [(54.7±15.1) years old] and there was no smoking history. There were significant differences between these two groups (P=0.020,P<0.001). Seventy patients (43.5%) with RA-LD were complicated with pleural lesions. Conclusions RA involving the lung is common and has varied imaging manifestations,with interstitial lung diseases (mainly UIP and NSIP) being the most important manifestations. RA patients should undergo lung HRCT as early as possible to identify the lung involvement and related types.