Objectives: A minimally invasive biomarker to monitor disease activity is one of the greatest unmet clinical needs of the pediatric eosinophilic esophagitis (EoE) population. We aimed to determine whether circulating eosinophil progenitors (EoPs) could be used as a biomarker to identify pediatric patients with active EoE. Methods: In a prospective observational study, peripheral blood samples, symptom history, and laboratory data were collected from pediatric patients undergoing endoscopy for evaluation of EoE on dietary therapy at Cincinnati Children's Hospital. Peripheral blood EoP level was determined by flow cytometry. Results: Thirty-four children with active (n = 16) and inactive (n = 18) EoE were included in the analysis. EoP levels in the peripheral blood were 3-fold higher in patients with active EoE than inactive EoE (P < 0.0025). Blood absolute eosinophil count did not distinguish between active and inactive EoE (P = 0.16). A cut-off EoP level ≥17 accurately detected active disease in 79% of patients with 94.4% specificity and 62.5% sensitivity (area under the curve 0.81; P < 0.0024). Antihistamine use lowered the threshold EoP level to detect active EoE. Conclusions: This study suggests that blood EoP levels may be used as a biomarker to detect active EoE disease in patients undergoing food trials and potentially reduce the need for repeated endoscopies. Larger prospective studies are needed to investigate the effects of antihistamines and swallowed steroids on EoP mobilization into the peripheral blood and longitudinal studies to assess the performance of the assay in individual patients over time.

Objectives: The aim of the study was to determine whether patients with eosinophilic esophagitis (EoE) have lower bone mineral density (BMD) than expected and if bone deficits are more pronounced in subgroups of patients according to comorbidities (atopic disease and joint hypermobility) or treatments (dietary restriction, medication exposure). Study Design: Retrospective chart review was performed to obtain clinical data, including length of diagnosis, comorbidities, and methods of treatment for patients with EoE ages 3 to 21 years who had a lumbar spine dual-energy x-ray absorptiometry scan performed between 2014 and 2017. BMD was standardized by calculation of age, sex, and race-specific z scores. Results: A total of 269 patients met study criteria. The mean BMD z score (−0.55, 95% confidence interval: −0.68, −0.42) was lower than expected (P  < 0.0001), and the prevalence of low BMD z score (≤−2.0) was higher than expected (8.5%, 95% confidence interval: 5.2%–11.9%, P < 0.0001). In multivariable regression models, BMD z scores were −0.27 lower among those following an elimination diet and −0.65 lower among those with any lifetime use of a proton pump inhibitor (93% of the sample). There was no association with swallowed steroid use. Conclusions: In our sample, pediatric patients with EoE had a slightly lower BMD z score compared to peers, and the prevalence of low BMD was higher than expected. Taken cautiously given the limitations of our sample, risk factors for bone deficits included any lifetime use of proton pump inhibitor and a restrictive elimination diet, but not swallowed steroid use. Larger prospective studies are needed to better characterize risk factors for low BMD to help inform screening, selection of therapies, and provide appropriate anticipatory guidance for patients with EoE.