CSI as a marker for active EoE

Eosinophilic esophagitis (EoE) is a chronic non IgE-mediated eosinophilic inflammation of the esophagus that is triggered by ingestion of food proteins. The current gold standard for the diagnosis and follow-up of EoE is esophagogastroduodenoscopy (EGD) with at least 6 biopsies. During follow up, symptoms are well known not to correlate with histological disease severity and therefore, frequent EGD with biopsies are needed for evaluation of treatment success and/or to tailor treatment. EGD’s in children are not only invasive by nature, but are performed under general anesthetics. A less invasive test for the diagnosis and follow-up of EoE, especially in children, is thus desired. Inflamed mucosa, no matter the origin of inflammation, has a higher permeability and therefore lower resistance to electrical flow, which can be measured using impedance. Recently it was shown, that high resolution impedance manometry (HRIM) can be used for the diagnosis of gastroesophageal reflux disease (GERD), another disease that causes inflammation in the esophagus. The contractile segment impedance (CSI) that was calculated during HRIM, measures impedance at the time of the maximal esophageal contraction to ensure that the esophageal mucosa is measured instead of luminal contents.
In parallel to GERD, CSI could thus be a marker for EoE-state (histological remission or active disease). HRIM parameters are influenced by esophageal length, which significantly correlates with patient’s age. As CSI may especially be of added value in children by potentially reducing the number of invasive EGD’s, it is necessary to perform this study in a pediatric cohort in order to obtain reliable data on CSI for the pediatric population. High resolution impedance manometry (HRIM) is a minimally invasive procedure that is comparable to placing a nasogastric feeding tube and takes 15 minutes to perform. Patients do not require sedation and we have recently shown that this test is very well tolerated in children.

Our hypothesis is that contratile segment impedance is a marker for EoE-disease activity (histological remission or active disease)

Study patients will undergo an esophagogastroduodenoscopy for the evaluation of macroscopical and histological endoscopy results. Directly after the EGD, a short questionnaire regarding the burden of the intervention (endoscopy) will be taken. Within 7 days prior/after the endoscopy, a high resolution impedance manometry will be performed to calculate the CSI. Directly after the manometry, the same questionnaire regarding the burden of the intervention (manometry) will be taken in order to compare burden of endoscopy vs manometry.
Positive predictive value, negative predictive value, sensitivity, specificity and likelihood ratios of CSI as well as inter- and intrarater variablility of CSI, cross-validation and cost-effectiveness will be calculated after all study subjects have been included and all endoscopies, manometries and questionnaires have been completed / performed.

High resolution impedance manometry (HRIM)