AB0381 Clinical and radiographic characteristics of airway disease in patients with rheumatoid arthritis
Authors: N. Konda, Y. Katsumata, Y. Seto, M. Hasegawa, F. Sakai, H. Katsura, H. Yamanaka
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Airway disease (AD) has drawn attention both clinically and etiologically in rheumatoid arthritis (RA), but is still poorly understood. <h3>Objectives</h3> We aimed to elucidate the clinical and radiographic characteristics of AD in patients with RA. <h3>Methods</h3> We retrospectively reviewed high-resolution computed tomography (HRCT) images and clinical data of 131 consecutive RA patients in whom HRCT were scanned for clinical purposes and screening. Overlap patients with other collagen tissue diseases and patients complicated with active infection or lung cancer were excluded. Patients who had a history of drug-induced lung disease, thoracic radiation, or exposure to dust were also excluded. HRCT images were reviewed independently by a pulmonologist and a radiologist in blind fashions, and cases of disagreement were discussed to reach a final consensus. AD was radiographically sub-categorised into 3 sub-groups: central AD, small AD, and middle lobe and lingular bronchiectasis. The associations between AD and interstitial lung disease (ILD) and each pair of the subtypes of AD were analysed by Fisher's exact test. The risk factors for AD and subtypes of AD were identified by multivariate logistic regression analyses. <h3>Results</h3> The mean age of the patients was 65 years old, the mean disease duration of the patients was 123 months, 69% of the patients were women, and 42% of the patients had past/current histories of smoking. The mean Disease Activity Score 28 (DAS28)-erythrocyte sedimentation rate (ESR) value was 2.87. AD and ILD were observed in 53 (40%) and 36 (27%) patients, respectively, and both in 19 (15%) patients. AD and ILD were not significantly associated (p=0.11). By multivariate logistic regression analyses, rheumatoid factor (RF) was identified as risk factors for whole AD (odds ratio [OR] 2.7; 95% confidence interval [CI], 1.0 to 6.9; p=0.04). Central AD, small AD, and middle lobe and lingular bronchiectasis were observed in 45 (34%), 31 (24%), and 17 (13%) patients, respectively. Each pair of these 3 subtypes were significantly associated with each other (p<i>&lt;</i>0.001 in all comparisons). By multivariate logistic regression analyses without considering the overlaps with multiple subtypes of AD in the same patients, age and RF were identified as risk factors for central AD: the OR for age was 1.04 (95% CI, 1.00 to 1.08; p=0.04); the OR for RF was 3.0 (95% CI, 1.1 to 8.5; p=0.034). In contrast, DAS28-ESR values was identified as a risk factor for small AD: the OR for DAS28-ESR values was 1.5 (95% CI, 1.0 to 2.4; p=0.0498). Lastly, no significant risk factor was identified for middle lobe and lingular bronchiectasis by the multivariate logistic regression analysis, although disease duration tended to be longer in the patients with middle lobe and lingular bronchiectasis than in those without (p=0.12). In contrast, smoking histories was not significantly associated with whole AD or any subtypes of AD. <h3>Conclusions</h3> Radiologically defined AD was frequent comorbidity in RA patients, and multiple subtypes of AD were observed and coexisted. Furthermore, AD may be related to the pathology of RA, and different AD subtypes may have distinct risk factors. Prospective studies with early RA patients were warranted to further clarify these findings and clinical impact of AD. <h3>Disclosure of Interest</h3> None declared