Lung findings on high-resolution computed tomography in idiopathic ankylosing spondylitis--correlation with clinical findings, pulmonary function testing and plain radiography

Previous studies on the association of ankylosing spondylitis andabnormalities of the lung parenchyma have been based largely on plainradiography and pulmonary function testing. This study, althoughuncontrolled, is the first to use high-resolution computed tomography toexamine the entire lung parenchyma in ankylosing spondylitis patients, andto correlate the findings with clinical assessment, plain radiography andpulmonary function testing. The study population comprised 26 patientsmeeting the New York criteria for idiopathic ankylosing spondylitis whoattended the out-patient department at our institution. High-resolutioncomputed tomography examination revealed abnormalities in 19 patients(70%): these included interstitial lung disease (n = 4), bronchiectasis (n= 6), emphysema (n = 4), apical fibrosis (n = 2), mycetoma (n = 1) andnon-specific interstitial lung disease (n = 12). Plain radiography wasabnormal in only four patients and failed to identify any patient withinterstitial lung disease. All patients with interstitial lung disease onhigh-resolution computed tomography had respiratory symptoms and three ofthe four had evidence of a restrictive process on pulmonary functiontesting. This study raises, for the first time, the possible associationbetween interstitial lung disease and ankylosing spondylitis, andhighlights the use of high-resolution computed tomography in detecting suchdisease in ankylosing spondylitis patients.