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

Abstract

The aim of this study was to identify the pulmonary abnormalities on high-resolution computed tomography (HRCT) in patients with ankylosing spondylitis (AS) and to examine the relationship with the duration of disease and pulmonary function test (PFT) results. Twenty male AS patients with a mean age of 37.1 ± 9.4 years were enrolled in this study. The patients were assigned into 2 groups according to disease duration: patients with disease duration <10 years (n = 10) and ≥ 10 years (n = 10). All patients underwent clinical examination, PFT and HRCT. HRCT revealed abnormalities in 14 patients (70%). The most common findings were apical fibrosis (45%) and emphysema (25%). HRCT findings were more prominent in late AS patients (disease duration ≥ 10 years) (P = 0.015). PFT were considered as abnormal in 4 patients (20%). While 3 patients had a restrictive type pulmonary deficiency, one patient had a mild obstructive pattern. Three of these patients had concomitant HRCT abnormalities. On the other hand, 10 patients with normal PFT had abnormalities on HRCT. These findings suggest that pulmonary involvement in AS patients without respiratory symptoms could be sensitively detected by HRCT. However, the clinical significance of these radiological abnormalities should be examined in further prospective studies.

Pulmonary involvement in ankylosing spondylitis assessed by multidetector computed tomography

“…Similarly to our results, Ozdemir et al [3] showed that HRCT abnormalities could be sensitively detected in patients with normal lung functions in the early and late stages of AS and Senocak et al [17] suggested that the parenchymal changes seen on HRCT begin in the early stages and increase in conjunction with disease duration [17]. Kiris et al [6] also found that 28.6% of their patients with early AS had normal PFT results, but abnormal HRCT examinations.…”

“…Our results varied greatly from the previously mentioned studies as the patients in the Ozdemir et al [3] study had a 40% rate of apical fibrosis and Sampaio-Barros et al [4] had a 19% rate of nonspecific linear parenchymal opacities. Furthermore, bronchiectasis occurred in 15.4% of the subjects in the study by Fenlon et al [5], and mosaic perfusion was found in 64.3% of Kiris et al study participants.…”

“…In our study, 95.1% of patients had abnormal findings on CT, but this percentage has varied in other studies, including Sampaio-Barros et al [4] with 40%, El Maghraoui et al [15] with 57.2%, Kiris et al [6] with 64%, Fenlon et al [5] with 69%, Ozdemir et al [3] with 70%, Turetschek et al [16] with 71%, Senocak et al [17] with 83%, and Souza et al [14] with 98.2%. The higher rates found in our study, along with higher rates from other cohorts in the recent years may be related to the advent of thin section and high-resolution algorithms in CT technology.…”

“…Other studies found similar results. Ozdemir et al [3] reported abnormal PFT results in 40% of their study group and the restrictive form was the most commonly seen pattern. Fenlon et al [5] reported abnormal PFT results in 42% of their study group, with restrictive disorders also being the most common.…”

“…Ankylosing spondylitis can affect tracheobronchial tree, pulmonary parenchyma, and pleura; however its thoracic manifestations are usually asymptomatic [2]. The most common abnormal thoracic radiological findings of AS include apical fibrosis, emphysema, pleural involvement, nonspecific linear parenchymal opacities, lymphadenopathy, bronchiectasis, bronchial wall thickening, tracheal dilatation, mosaic patterns, subpleural nodules and interstitial lung disease [3–6]. …”