Prevalence and characteristics of lung involvement on high resolution computed tomography in patients with ankylosing...

To determine the prevalence of lung involvement and the spectrum of abnormalities revealed on HRCT in patients with AS, a systematic literature review was conducted in the Medline database up to May 2009 and in the abstracts of rheumatology scientific meetings (2006-2008). A hand search of references was also performed. Among the 264 selected articles, 10 articles (303 patients) allowed a calculation of the prevalence of lung abnormalities on thoracic HRCT in AS. A total of 185 patients (61%) had an abnormal thoracic HRCT: upper lobe fibrosis in 21 (6.9%), emphysema in 55 (18.1%), bronchiectasis in 33 (10.8%), and ground glass attenuation in 34 (11.2%). Non specific interstitial abnormalities were observed in 101 (33%) patients. The most common observed abnormalities were pleural thickening (52%), parenchymal bands (45%) and interlobular septal thickening (30%). Only the prevalence of upper lobe fibrosis increased significantly with disease duration (3 studies). Mild and non-specific interstitial abnormalities on thoracic HRCT are common in patients with AS, even in patients with early disease and without respiratory symptoms.