Predicting outcomes in rheumatoid arthritis related interstitial lung disease

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.

Interstitial Lung Disease in Rheumatoid Arthritis Remains a Challenge for Clinicians

“…Previous studies have reported UIP as the predominant radiological pattern and predictor of mortality [14,42]; however, recent studies report a UIP proportion of 40%-54% [40,47]. A recent study showed that radiology-based prediction models in RA-ILD can identify patients with a progressive fibrosis phenotype [112], and that the visual extent of ILD in combination with FVC values, as previously seen in scleroderma [113], predicts outcome in RA-ILD. Morisset et al [47] showed that the addition of HRCT patterns to the ILD-GAP prediction model did not improve its performance.…”

Presentation, diagnosis and clinical course of the spectrum of progressive-fibrosing interstitial lung diseases

“…Most RA-ILD patients with UIP have a similar slightly improved prognosis compared with IPF, with acute exacerbations having a major impact on survival [57,[65][66][67][68]. Conversely, recently published data suggest the existence of a subset of RA-ILD patients with UIP in whom the disease stabilises in the long term, differentiating these patients from those with IPF [69].…”

Impact of radiological honeycombing in rheumatoid arthritis-associated interstitial lung disease

“…In IPF, it is controversial whether having honeycomb is a poor prognostic factor [11,15]. However, recent reports indicated that the development of honeycombing in RA-ILD was a poorer prognostic factor than CT pattern (e.g., UIP, NSIP) [9,11]. Similarly, our recent study also showed having honeycomb to be a poor prognostic factor in RA-ILD [10].…”

“…However, an unclassifiable pattern on HRCT is present to some extent in the RA-ILD population because RA-ILD exhibits a diversity of patterns [6,8]. Recent reports including our study showed that the major HRCT pattern in RA-ILD was mixed nonspecific interstitial pneumonia (NSIP) and UIP [9,10]. However, radiological honeycomb pattern is a poorer prognostic factor than a UIP pattern on HRCT [10].…”