PURPOSE OF THE STUDY.
To assess the prevalence and determine clinical factors, biomarkers, or allergic sensitization that may be predictive of airway hyperresponsiveness (AHR) in children with eosinophilic esophagitis (EoE).
The study group included children ages 7 to 18 years (n = 33), with biopsy-diagnosed EoE, on stable medications (excluding systemic antibiotics or corticosteroids) for at least 4 weeks, and no other lung disease aside from asthma or allergies. Age-matched healthy controls (n = 37) without EoE, asthma, other lung disease, or atopic disease in the preceding year were enrolled from the general population.
Cross-sectional analysis included a retrospective chart review, an assessment of most recent EoE control, and the presence and severity of comorbid asthma and atopic dermatitis. Pulmonary function testing with methacholine challenge and exhaled nitric oxide (eNO) were prospectively measured. AHR was defined as a provocative concentration necessary to affect an FEV1 decrease of 20% (PC20) <8 mg/mL. Peripheral blood was analyzed for complete blood count with differential, total serum IgE, IL-4, IL-5, IL-13, eotaxin, EGF, and FGF-2. Specific IgE to house dust mite, ragweed, Alternaria, timothy grass, Bermuda grass, cedar, and cat were measured by using ELISA (positive >0.70 IU/mL).
Children with EoE had a higher frequency of allergic rhinitis, atopic diagnosis, physician-diagnosed asthma, food allergy, prior wheeze and respiratory symptoms, eczema, total serum IgE, peripheral eosinophilia, and more frequent sensitization to at least 1 aeroallergen compared with healthy controls. While baseline spirometry was normal, EoE subjects had lower PC20 values (indicating greater airway reactivity) and higher eNO (indicating increased lower airway atopic inflammation) in comparison with healthy subjects. Frequency of AHR was significantly greater in EoE (OR = 4.13; 95% CI: 1.16–14.62; P = .0281) and EoE without asthma (OR = 6.60; 95% CI: 1.64–26.58; P = .0079). In particular, AHR was present in 8 of 18 EoE subjects without a prior asthma diagnosis. When history of wheezing was included, 66.7% of EoE subjects were considered to have a definite or likely diagnosis of asthma. An elevated total serum IgE was associated with a greater risk of AHR (OR = 99.643; 95% CI: 1.633–56.925; P = .0124), but eNO and allergen sensitization were not. There were no differences in median serum levels of IL-5, IL-9, eotaxin, EGF, and FGF-2 among EoE subjects with and without AHR and healthy controls.
There is a high frequency of AHR and likely asthma diagnosis in EoE subjects. Elevated total serum IgE was the only marker associated with a greater risk of AHR in EoE children.
As previously reported, EoE subjects had a very high prevalence of associated atopic disorders, and this study suggests that EoE patients in particular are being underdiagnosed for asthma. The cross-sectional design did not account for possible AHR variation over time and possible association with changes in EoE disease activity and lacks a comparison with children with atopic disease without EoE. Longitudinal studies correlating AHR with the treatment of EoE and associated atopic disease would help to determine its significance in EoE.
- Copyright © 2017 by the American Academy of Pediatrics