Eosinophilic Esophagitis as a Complex Th2 Inflammatory Disease: Results of a Prospective Long-Term Study in Children.

INTRODUCTION: While the eosinophilic esophagitis (EoE) has become the second most common disease entity causing esophageal dysfunction, there is currently a lack of data reporting on pediatric EoE from Germany. This monocentric longitudinal study seeks to fill this gap by investigating treatment success, atopic co-morbidities, and potential blood parameters in a real-world setting. METHODS: This study analyzed data on children with EoE (n = 50), gastroesophageal reflux disease (GERD, n = 13), and controls (n = 5). Evaluated characteristics included clinical manifestations, atopy, and treatment success during disease progress. We defined the primary endpoint as histological remission in all esophageal locations (proximal, mid, distal). Secondary endpoints were histological-clinical, histological-endoscopic, and histological-clinical-endoscopic remission. RESULTS: Of 50 patients (0.5-16.9 years), 26% (n = 13) responded to proton-pump inhibitors (PPI-R) and 74% (n = 37) needed other forms of treatment (PPI-NR). Atopic co-morbidities were observed in 46% (PPI-NR) and 23% (PPI-R). Primary PPI treatment resulted in histological remission in 13 patients (median: 2 [2;4.5] months); only one (8%) achieved complete endoscopic-clinical-histological remission. Thirty-two PPI-NRs (84%) reached histological remission after a median of 7 [4;11] months, but only eleven (34%) acquired complete histological-clinical-endoscopic remission. Absolute blood eosinophil count (AEC) was increased within active EoE (420 [250;550] cells/µL). It distinguished EoE from controls (cutoff 90 cells/µL, sensitivity/specificity: 95.7%/80%) and from GERD (180 cells/µL, 87.5%/66.7%). Eosinophilic cationic protein (ECP) differed between children with active EoE and controls (10 µg/L, 86.7%/100%). CONCLUSIONS: Patients' characteristics are comparable to those from other European countries. AEC and ECP were increased in EoE patients. Achieving complete remission required an intensified therapy regime.