To compare the presence and extent of several high-resolution computed tomography (HRCT) observations in different subtypes of rheumatoid arthritis-related interstitial lung disease (RA-ILD) and to examine associations between radiological findings, hospitalization, age, RA duration, pulmonary function tests (PFT) and survival.
HRCTs from 60 RA-ILD patients were independently evaluated and re-categorized into usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), diffuse alveolar damage (DAD) and unclassified subtypes by two radiologists. The presence and extent, which was reported using a semi-quantitative scoring system, of e.g. reticulation, ground-glass opacity, honeycombing, emphysema, traction bronchiectasis and architectural distortion were further evaluated and compared between the subtypes. Associations between radiological findings and survival were identified with the Kaplan-Meier method and Cox's univariate model. The correlations between radiological findings, hospitalization, age, pack years, RA duration and PFT were calculated using Spearman's correlation coefficient.
The extents of reticulation (HR 1.144, p = 0.041), traction bronchiectasis (HR 1.184, p = 0.030), architectural distortion (HR 1.094, p = 0.044) and the presence of pleural fluid (HR 14.969, p < 0.001) were associated with decreased survival. A negative correlation was observed between ground-glass opacity (GGO) and the duration of RA (r = -0.308, p = 0.023). The extents of honeycombing (r = 0.266, p = 0.046), traction bronchiectasis (r = 0.333, p = 0.012) and architectural distortion (r = 0.353, p = 0.007) correlated with hospitalizations due to respiratory reasons.
Many radiological findings associate with the course of the disease of RA-ILD and could potentially be useful when planning the RA treatment or evaluating the risk of death in these patients.