Purpose of review: Subsequent to the ATS/ERS consensus classification of idiopathic interstitial pneumonia, non-specific interstitial pneumonia pattern was the dominant pattern in many collagen vascular diseases, which may explain the better prognosis of interstitial pneumonia associated with collagen disease than idiopathic pulmonary fibrosis. Recent papers on rheumatoid arthritis suggest that this is not the same in all collagen diseases, and this paper will review previous data and discuss recent papers.
Recent findings: In contrast to other collagen diseases, the usual interstitial pneumonia pattern seems to be more common, or at least as common in rheumatoid arthritis. This pathological observation was supported by high-resolution computed tomography findings. In addition to the usual interstitial pneumonia pattern, several types of small airway involvements were frequently observed in rheumatoid arthritis-associated interstitial pneumonia, the prognosis of which is also variable.
Summary: Because the usual interstitial pneumonia pattern may be more frequent in rheumatoid arthritis and some data suggest a poor prognosis for rheumatoid arthritis-associated interstitial pneumonia, further studies are required on the prognosis of collagen vascular disease-associated interstitial pneumonia, especially in relation to the pathological pattern. Drug-related interstitial pneumonia should also be considered in rheumatoid arthritis patients on methotrexate or newer drugs such as leflunomide.