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Progressive Decline of Lung Function in Rheumatoid Arthritis–Associated Interstitial Lung Disease
Author(s) -
ZamoraLegoff Jorge A.,
Krause Megan L.,
Crowson Cynthia S.,
Ryu Jay H.,
Matteson Eric L.
Publication year - 2017
Publication title -
arthritis and rheumatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.106
H-Index - 314
eISSN - 2326-5205
pISSN - 2326-5191
DOI - 10.1002/art.39971
Subject(s) - medicine , interstitial lung disease , vital capacity , rheumatoid arthritis , hazard ratio , pulmonary function testing , cohort , diffusing capacity , gastroenterology , usual interstitial pneumonia , rheumatoid factor , confidence interval , lung , lung function
Objective Interstitial lung disease (ILD) is associated with substantial morbidity in rheumatoid arthritis (RA), but very little is known about its long‐term progression. This study was undertaken to investigate the progression of pulmonary disease using a large single‐center cohort of patients with RA‐associated ILD. Methods Records of all patients with RA‐associated ILD seen at Mayo Clinic between 1998 and 2014, with at least 4 weeks follow‐up and at least 1 pulmonary function test, were identified and manually screened for study inclusion. Progression was defined as a diffusing capacity for carbon monoxide (DL co ) <40% predicted (or patients whose illness was too advanced to undergo screening) or a forced vital capacity (FVC) <50% predicted. Time to progression was analyzed using the Kaplan‐Meier method. Results Of the 167 patients included in the study, 81 (49%) were female, with a mean ± SD age of 67 ± 10 years at diagnosis of ILD. Median follow‐up time from diagnosis of ILD was 3.3 years (range 0.01–14.8). One‐third of the patients required supplemental oxygen, 40% developed DL co <40% predicted, and 22% developed FVC <50% predicted within 5 years after ILD diagnosis. Usual interstitial pneumonia (UIP) versus nonspecific interstitial pneumonia (NSIP) was a risk factor for DL co progression (hazard ratio 3.29 [95% confidence interval 1.28–8.41]). Lower DL co and FVC at baseline increased the risk for progression to DL co <40% predicted and FVC <50% predicted, and higher rates of change in the first 6 months also increased the risk of progression. Conclusion Progressive loss of pulmonary function is common in RA‐associated ILD and is worse in patients with UIP than in those with NSIP. Predictors of progression in patients with RA‐associated ILD may aid clinicians in identifying patients at highest risk for progression of ILD.