RA-ILD: an update Save

Interstitial lung disease (ILD) remains a leading cause of mortality in rheumatoid arthritis (RA). Estimates of involvement of ILD in RA remain relatively imprecise (estimated prevalence 5-20%), though this partly reflects the wide spectrum of ILD and differing ascertainment.

Abstract 1393 attempts to estimate the prevalence of lung involvement (ILD, bronchiolitis and nodules) in early RA. This is an interim analysis of the FIND-RA prospective study, aimed at determining the factors associated with early RA-ILD. Patients were included if they newly diagnosed with RA (ACR/EULAR criteria) with symptoms of RA present for between 1-10 years. ILD was detected in 12% of the 245 patients included. Disease activity was slightly higher in patients with RA-ILD (DAS28-CRP 2.55 vs 2.12, p=0.028). Key to interpretation of these results when fully published will be details including extent of lung involvement, symptoms of ILD and rate of progression. The study remains in recruitment phase, with high numbers allowing a more precise estimate of ILD burden in RA.

Abstract 0245 assessed biologic/targeted synthetic DMARD (b/tsDMARD) selection and outcomes in the Veterans Health Administration between 2006 and 2018. They attempted to evaluate associations between FVC (<60%, 60-80% or >80%) and initial b/tsDMARD selection and treatment outcomes (respiratory hospitalisation & death). Degree of FVC impairment did not appear to influence choice of b/tsDMARD, though factors that did influence b/tsDMARD selection included female gender, more frequent pulmonology/rheumatology visits and higher comorbidity scores. Given data around the treatment of RA-ILD remain frustratingly lacking, this is probably not a surprising result. Unsurprisingly, severity of ILD predicted respiratory hospitalisation (hazard ratio 1.67 for FVC <60%) and death (HR 1.64). Baseline methotrexate use was associated with reduced risk of death, which though encouraging, may be limited by confounding by indication.

RA-ILD remains an understudied complication of RA, with disproportionately high morbidity and mortality. We look forward to further studies to guide screening and management.