Asthma is prevalent in children with eosinophilic esophagitis (EoE), previously estimated at 24-42% versus 9% for the general population. However, studies of pulmonary function and airway hyperresponsiveness (AHR) in children with EoE are lacking.
A cross-sectional study was conducted of children aged 6-18 years with EoE and healthy controls. Methacholine challenge (AHR defined as provocative concentration of methacholine <8mg/ml), and exhaled nitric oxide were performed. Peripheral blood was analyzed for total IgE, eosinophil count, eotaxin, and serum cytokines.
Baseline spirometry was normal and not significantly different for EoE subjects (n=33) and healthy controls (n=37). AHR was present in 33% of children with EoE and 10.8% of healthy controls (p=0.04). 20% of EoE subjects with asthma (n=15) had AHR, versus 44% of EoE subjects without asthma (n=18). Overall, 69.7% of EoE subjects had either asthma or AHR. AHR correlated strongly with serum IgE (p<0.0001) and exhaled nitric oxide (p=0.0002).
Epidermal growth factor (EGF) and fibroblastic growth factor 2 (FGF-2) were elevated in subjects with EoE and asthma , compared to healthy controls and those with EoE but no asthma (p<0.05). Subjects with EoE and asthma who were on asthma controller medications had similar levels of EGF and FGF-2 as healthy controls. Th2 cytokines and eotaxin did not differ significantly among any groups.
Asthma and AHR may be more prevalent than previously estimated in children with EoE. Serum elevations of EGF and FGF-2 were seen in EoE subjects with asthma, but not in subjects on asthma controller medications.