Usefulness of extended nitric oxide analysis in children with allergic rhinitis

Abstract

Objective

Evaluation of airway inflammation and dysfunction is important in management of allergic rhinitis (AR) since AR is a risk factor for developing asthma. Theoretical nonlinear modeling of exhaled nitric oxide (NO) has revealed extended flow-independent NO parameters that could explain where or how NO metabolism was altered. We aimed to evaluate the association between extended NO parameters and bronchial hyperresponsiveness (BHR) in children with AR.

Methods

Exhaled NO was measured in 74 children with AR on the same day they underwent the provocholine challenge test (PCT). Extended NO was measured in three different exhaled flow rates (30, 100, 200 mL/s) and calculated using the Högman–Meriläinen model. We compared the extended NO parameters including bronchial NO (JawNO), airway tissue NO (CawNO), alveolar tissue NO (CaNO), and diffusing capacity of NO (DawNO) between AR with and without BHR groups, and analyzed the correlation between extended NO parameters and the response–dose ratio (RDR) of the PCT. We additionally evaluated 49 respiratory healthy controls.

Results

Among the 74 children with AR, nine showed BHR. JawNO increased more in children with AR than the control group. In children with AR, JawNO was higher in the AR with BHR than without BHR group, and was correlated positively with log RDR (r = 0.373, p = .001).

Conclusions

Extended NO analysis including JawNO can be a useful tool for assessing BHR in AR.

Keywords:

• Allergic rhinitis
• bronchial hyperresponsiveness
• children
• nitric oxide

Declaration of interest

The authors have no financial relationships relevant to this article to disclosure, and indicate no potential conflict of interests.

Additional information

Funding

This research was supported by Ilsung Research Award from Korea Academy of Pediatric Allergy and Respiratory Disease Annual Congress at 2013.