PURPOSE: To determine the frequency and distribution of pulmonary lesions with high resolution computed tomography (HRCT) in early ankylosing spondylitis (AS) patients, and to compare the HRCT findings with the results of pulmonary function tests (PFT) and respiratory symptoms.
METHODS: Eighty-two patients who met the modified New York Criteria for classification of AS were initially evaluated. Among them; 26 patients (21 male and 5 female, disease duration 3.38±1.65 yrs) met the study inclusion criteria. After a through physical examination, all patients underwent chest radiography, thoracic HRCT and PFT.
RESULTS: All chest radiographs were normal. Thirteen (50%) patients had abnormalities on HRCT. The most frequent of these were emphysema (34.6%), bronchiectasis (30.8%), ground glass opacity (26.9%) and septal thickening (23.1%). HRCT was abnormal in 8 of 21 asymptomatic (38.1%) and in all five symptomatic patients (p<0.05). Eight patients had abnormal PFT and all had a restrictive pattern. Restrictive lung function impairment was seen in four of the 13 patients (30.8%) with abnormal HRCT findings and 4 out of 13 patients (30.8%) with normal HRCT findings. Nine patients with normal PFT had abnormalities on HRCT. There was no correlation between PFT values and HRCT findings.
CONCLUSION: HRCT is more sensitive than chest x-rays or PFTs in detecting pleuropulmonary lesions in patients with early AS. The lung involvement appears to be not only common but also starts in early stage of AS.
CLINICAL IMPLICATIONS: This study brings up a possibility that pleuropulmonary tissue is an independent primary target in AS. The confirmation of this possibility with further studies creates an opportunity of preventing a major morbidity and mortality condition with early initiation of effective treatment in patients with AS in the future.
DISCLOSURE: Sevin Baser, None.