Mucosal Impedance Measurements Differentiate Pediatric Patients With Active Versus Inactive Eosinophilic Esophagitis

Abstract

Background and aims: Eosinophilic esophagitis (EoE) is a chronic disorder in children that requires continued assessment of disease activity, involving repeated sedation, endoscopy, and biopsy analysis. We investigated whether mucosal impedance measurements can be used to monitor disease activity in pediatric patients with EoE.

Methods: We measured mucosal impedance at 3 locations in the esophagus in pediatric patients (1-18 years old; 32 with active EoE, 10 with inactive EoE, 32 with nonerosive reflux disease [NERD]) and 53 children with symptoms but normal findings from histologic analyses (controls) undergoing routine esophagogastroduodenoscopy at the Vanderbilt Pediatric Gastroenterology Clinic. Pathologists reviewed biopsies per routine protocol, determined eosinophilic density, and graded spongiosis on an ordinal visual scale. Mucosal impedance measurements were compared within patient groups. The primary outcome was correlation of mucosal impedance measurements with disease activity, based on severity of spongiosis and eosinophil counts.

Results: Mucosal impedance measurements were significantly lower in patients with active EoE at 2, 5, and 10 cm above the squamo-columnar junction (median values of 1069, 1368, and 1707, respectively) compared to patients with inactive EoE (median values of 3663, 3657, and 4494, respectively), NERD (median values of 2754, 3243, and 4387), and controls (median values of 3091, 3760, and 4509) (P < 0.001 for all comparisons to patients with active EoE). We found inverse correlations between mucosal impedance measurements and eosinophil count (P < 0.001), and spongiosis severity (P < 0.001).

Conclusions: Mucosal impedance measurements may provide immediate information about mucosal inflammation in children. Patients with active EoE have significantly lower mucosal impedance values than patients with inactive EoE, NERD, or controls; mucosal impedance measurements correlate inversely with eosinophil counts and spongiosis severity. Mucosal impedance is a promising rapid and less-invasive method to monitor EoE activity in pediatric patients with EoE; it could reduce costs and risks of disease monitoring.

Figure 1

Median (IQR) MI measurements at (A) 2 cm, (B) 5 cm, and (C) 10 cm above the squamocolumnar junctions (SCJ) for the 4 study groups. (D) Median MI measurements distributed axially for each esophageal location. MI measurements were significantly lower for active-EoE compared to inactive-EoE, NERD and controls (P < .001). NERD group demonstrated non-significant lower MI pattern than inactive-EoE and controls.

Figure 2

Total MI measurements by eosinophil counts. MI measurements inversely correlate with the number of eosinophils (P < .001).

Figure 3

Total MI measurements by spongiosis severity grade. MI measurements inversely correlate with the severity of spongiosis (P < .001).

Figure 4

Predictive probability of active-EoE for MI measurements at 2 cm, 5 cm, and 10 cm above the squamocolumnar junction (SCJ).