Ultrasound screening for interstitial lung disease in rheumatoid arthritis

As interstitial lung disease (ILD) in rheumatoid arthritis (RA) patients is associated with increased mortality due to loss of diffusion capacity and pulmonary hypertension, regular screening for structural abnormalities of the lung is advised. In addition to standard radiological examination with computed x-ray tomography, ultrasound of the lung could allow non-invasive and radiation-free structural monitoring of the lung. The objective of this study was to test the frequency of abnormalities in lung sonography in patients with RA who did not have clinical signs or symptoms of lung disease.

In a prospective study of 64 consecutive patients with rheumatoid arthritis and 40 healthy volunteers, we screened the pleura and the pulmonary parenchyma for sonographic abnormalities. All RA patients underwent high resolution computer tomography of the lung.

28% of RA patients showed pleural nodules or B-line phenomena. In these patients, CT scans showed signs of incipient interstitial lung disease. Lung sonography showed sporadic abnormalities in 7% of the healthy controls.

Transthoracic ultrasound of the lung is an inexpensive and safe tool to screen patients with RA for incipient pulmonary structural changes.