Lung findings on thoracic high-resolution computed tomography in patients with ankylosing spondylitis. Correlations with disease duration, clinical findings and pulmonary function testing

Abstract

The aim of this study was to identify the spectrum of abnormalities revealed on high-resolution computerized tomography (HRCT) in patients with ankylosing spondylitis (AS), to compare findings with those of plain radiography and pulmonary function testing (PFT), and to look for correlations between lung involvement and AS severity. We prospectively studied 55 consecutive patients with a diagnosis of AS according to the modified New York criteria who attended our department over a period of 2 years. All patients had a detailed rheumatological examination and underwent plain chest radiography, chest HRCT and PFT. HRCT revealed abnormalities in 29 patients (52.7%), whereas plain chest radiography was abnormal in only 2. Abnormalities consisted of interstitial lung disease (ILD) ( n=4), apical fibrosis ( n=5), emphysema ( n=5), bronchiectasis ( n=4), ground glass attenuation ( n=2), and non-specific interstitial abnormalities ( n=26). Only apical fibrosis and bronchiectasis were statistically more frequent with increasing disease duration (significant trend chi(2)test, p=0.0029 and 0.028, respectively). PFT showed a restrictive process in 19 patients (34.5%). No correlation was noted between HRCT and PFT, nor with AS symptomatic and structural severity parameters. However, there was a statistically significant correlation between PFT and AS symptomatic and structural severity parameters. In conclusion,: this study confirms that the chest HRCT of patients with AS showed a great number of abnormalities undetectable by standard X-rays. The high incidence of lung abnormalities emphasizes the importance of excluding such a diagnosis in patients with AS even without respiratory symptoms.

Pulmonary abnormalities on high-resolution computed tomography in ankylosing spondylitis: relationship to disease duration and pulmonary function testing

“…Although early pulmonary lesions were also detected in this study group, HRCT abnormalities were more frequent in late AS patients. As it is well demonstrated that HRCT is more sensitive than the chest X-ray in detecting lung parenchyma changes in patients with AS [17,20,21,32,34], we did not compare the plain radiography and HRCT findings in this study.…”

“…Parenchymal nodules were shown in two patients (10%). The frequency of nodules in AS was previously notified in the range of 6-40% [17,20,33,34]. Only one patient had bronchiectasis.…”

“…For the first time, it was stated that although interstitial involvement was previously mentioned, small airway involvement was found as frequently as interstitial lung disease in early AS. Until now, the largest series reported belongs to El Maghraoui et al [20] in which 55 AS patients without respiratory symptoms were investigated. Twenty-nine patients (52.7%) showed abnormalities on HRCT, and similar to the results of the study by Casserly et al, the most common findings were non-specific interstitial changes (47.3%) (pleural thickening, followed by varying rates of subpleural and parenchymal band formations, and bronchial wall thickening).…”

“…Furthermore, it was demonstrated that HRCT of the thorax has a diagnostic superiority over plain radiography in the assessment of early pulmonary lesions [16,17]. To the best of our knowledge, there are only a few studies comparing early and late AS-associated lung findings on HRCT [17][18][19][20][21]. The purpose of this study was to identify the pulmonary abnormalities on HRCT in AS patients without respiratory symptoms and to examine their relationship with the duration of disease and PFT results.…”

Cavitary Pulmonary Disease

“…However, cavitary lung lesions have been reported as being rare consequences of many autoimmune diseases. For example, patients with ankylosing spondylitis frequently (50 to 85%) have pulmonary abnormalities detectable by high-resolution computed tomography (45,99,330,369), although a much smaller proportion have abnormal plain chest radiographs (1.3% in one large series) (319). Relatively common findings among patients with ankylosing spondylitis-associated lung abnormalities are apical fibrosis and bulla formation, both of which may appear radiographically as cavitation.…”