The prevalence of and risk factors for bronchiectasis in inflammatory bowel disease: a chest CT-based case-control study.

Background: To identify the prevalence, clinical and imaging characteristics, and the risk factors for bronchiectasis in IBD.

Research design and methods: We retrospectively enrolled IBD patients from 1 January 2020 to 1 July 2022. Chest HRCT was evaluated for the presence and severity of bronchiectasis. The clinical characteristics were compared between the IBD patients with and without bronchiectasis.

Results: Among the 429 IBD patients, 34.5% showed bronchiectasis on chest HRCT. Four main imaging characteristics of bronchiectasis showed in IBD patients: multiple lobe involvement: 72.3% (107/148) of the patients had ≥2 lobes involved; Central predominance (>50%) in distribution; Mostly cylindrical bronchiectasis (>90%); Mild severity in most cases with Smith score <4 and Bhalla score of one point. Multi-factor logistic regression analysis showed that age of IBD onset ≥35 years (OR = 2.05, 95%CI 1.26-3.32), history of immunosuppressant therapy (OR = 3.93, 95%CI 2.12-7.27), ESR > 20 mm/h (OR = 2.01, 95%CI 1.21-3.33) and positive ASCA (OR = 1.37, 95% CI 1.06-1.77) were independently associated with the presence of bronchiectasis in IBD.

Conclusions: More than 1/3 IBD patients in our cohort presented bronchiectasis on chest HRCT, with almost no respiratory symptoms and the mild degree of bronchiectasis, which is easily overlooked. IBD patients may need routine chest HRCT scanning for bronchiectasis.