Abstract
The aim of this study was to compare radiology-based prediction models in rheumatoid arthritis-related interstitial lung disease (RAILD) to identify patients with a progressive fibrosis phenotype.RAILD patients had computed tomography (CT) scans scored visually and using CALIPER and forced vital capacity (FVC) measurements. Outcomes were evaluated using three techniques, as follows. 1) Scleroderma system evaluating visual interstitial lung disease extent and FVC values; 2) Fleischner Society idiopathic pulmonary fibrosis (IPF) diagnostic guidelines applied to RAILD; and 3) CALIPER scores of vessel-related structures (VRS). Outcomes were compared to IPF patients.On univariable Cox analysis, all three staging systems strongly predicted outcome (scleroderma system hazard ratio (HR) 3.78, p=9×10−5; Fleischner system HR 1.98, p=2×10−3; and 4.4% VRS threshold HR 3.10, p=4×10−4). When the scleroderma and Fleischner systems were combined, termed the progressive fibrotic system (C-statistic 0.71), they identified a patient subset (n=36) with a progressive fibrotic phenotype and similar 4-year survival to IPF. On multivariable analysis, with adjustment for patient age, sex and smoking status, when analysed alongside the progressive fibrotic system, the VRS threshold of 4.4% independently predicted outcome (model C-statistic 0.77).The combination of two visual CT-based staging systems identified 23% of an RAILD cohort with an IPF-like progressive fibrotic phenotype. The addition of a computer-derived VRS threshold further improved outcome prediction and model fit, beyond that encompassed by RAILD measures of disease severity and extent.
Highlights
The development of lung fibrosis in rheumatoid arthritis is recognised in 2–8% of patients [1, 2], but is associated with a three-fold increased risk of mortality [2]
Baseline data The final rheumatoid arthritis study population comprised 90 patients presenting to the Royal Brompton Hospital and 67 patients presenting to Edinburgh Royal Infirmary with a multidisciplinary team diagnosis of related interstitial lung disease (RAILD)
Interobserver variation scores are shown in online supplementary table S2 and baseline differences between the RAILD and idiopathic pulmonary fibrosis (IPF) populations are shown in online supplementary table S3
Summary
The development of lung fibrosis in rheumatoid arthritis is recognised in 2–8% of patients [1, 2], but is associated with a three-fold increased risk of mortality [2]. Several studies have analysed CT scans in RAILD patients using the idiopathic pulmonary fibrosis (IPF) CT diagnostic guidelines [3] and demonstrated the poor outcome in RAILD associated with a usual interstitial pneumonia (UIP) pattern [4,5,6,7,8,9,10,11]. A potential limitation when extrapolating IPF patterns on CT to RAILD is that the distribution of disease in RAILD may not be basal-predominant, as honeycomb cysts and reticulation may be concentrated peripherally in the middle or upper zones of the lungs [12]. An IPF-like definite UIP pattern with basal predominance on CT may only capture a proportion of RAILD patients with true honeycombing. As highlighted in a recent perspective [15], there is growing recognition within the interstitial lung disease (ILD) community that a predominant focus on IPF may have curtailed the identification of rapidly progressive fibrotic phenotypes in non-idiopathic conditions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
