Bronchial reactivity and fractional exhaled NO in Crohn's disease in the era of immunomodulating treatment
Our aim was to determine bronchial hyper-responsiveness (BHR) and fractional exhaled NO (FeNO) in a cohort followed and treated for Crohn's disease (CD) in a Pediatric Gastroenterology Unit. Consecutive children with CD were referred to the Pediatric Pulmonary Unit. Each patient completed a questionnaire, followed by spirometry, methacholine challenge test (MCT) and determination of FeNO. The control group included patients evaluated for functional cough who had negative MCT. Twenty-three children and young adults (mean age, 17.39 ± 2.96 years) with CD were compared to 24 healthy controls. 20/23 patients received immunomodulating treatment. Forced expiratory volume in 1 sec (FEV1) was significantly lower prior to (93.74 ± 10.81%, p = 0.009) and at the end of (78.91 ± 18.39%, p = 0.001) the MCT in the CD group compared with the control group (102.2 ± 10.477% and 95.33 ± 11.075%, respectively). Bronchial hyper-responsiveness was observed in 30.4% of patients with CD. FeNO levels were 15.37 ± 24.17 in CD and 11.38 ± 5.42 in the control group (p = 0.21). Neither the response to MCT nor FeNO levels were affected by the disease duration or activity index. In our series, BHR is less frequent than previously described in children with CD. We hypothesize that our finding could result from immunomodulating treatments or lower disease activity.