Role of Intraluminal Esophageal Impedance Baseline in the Diagnosis of Esophagitis in Children.

 Low values of esophageal impedance baseline (EIB) have been related to esophagitis. The aim of this study was to evaluate the diagnostic performance of EIB for erosive esophagitis (ErE) and histological esophagitis (HiE) in children studied for gastroesophageal reflux.  Children who underwent esophageal multichannel intraluminal impedance-pH monitoring (MII-pH) and upper-endoscopy with esophageal biopsies were studied retrospectively. EIB values were obtained by MII-pH. ErE was assessed by endoscopy following the Hetzel-Dent classification; HiE was defined by basal zone hyperplasia, papillary lengthening, or inflammatory infiltration. EIB was compared between groups. Receiver operating characteristic (ROC) curves were obtained to calculate the global diagnostic performance of EIB and to find cut-off values for sensitivity and specificity. Logistic regression was used for age adjustment.  Fifty-one patients were studied: 11 had ErE and 23 had HiE. EIB median values were 1,159 in ErE versus 2,583 in non-ErE (U = 80,  < 0.01). The adjusted ROC curve analysis for ErE was 0.85 (95% CI = 0.74-0.96); the EIB cut-off value = 2,379 determined sensitivity = 100% and specificity = 52.6% in children < 4 years old. and sensitivity = 100% and specificity = 63.2% in children > 4 years old. EIB median values were 1,666 in HiE versus 2,669 in non-HiE ( = 80,  < 0.01). The adjusted ROC curve analysis for HiE was 0.75 (95% CI = 0.59-0.90); the EIB cut-off value = 2,296 determined sensitivity = 71.2% and specificity = 83.1% in children < 4 years old, and sensitivity = 75.1% and specificity = 80.1% in children > 4 years old.  EIB provides statistically significant diagnostic performances for ErE and HiE. It could become a useful tool, especially to discriminate between ErE and non-ErE, avoiding other invasive tests.