Progressive loss of pulmonary function is common in rheumatoid arthritis-interstitial lung disease (RA-ILD) and worse in patients with usual interstitial pneumonia (UIP) than nonspecific interstitial pneumonia (NSIP), a recent study found. All patients with RA-ILD seen at Mayo Clinic in 1998-2014 with at least 4 weeks follow-up and at least 1 pulmonary function test (PFT) were identified and manually screened for study inclusion. Of 167 included patients, 81 (49%) were female with mean age of 67 years at ILD diagnosis; median follow-up time from ILD diagnosis was 3.3 years. Researchers found:

• A third of patients required supplemental oxygen, 40% developed diffusing capacity for carbon monoxide (DLCO) <40% predicted, and 22% developed forced vital capacity (FVC) <50% predicted by 5 years after ILD diagnosis.
• Risk factors for DLCO progression were UIP vs NSIP.