Measurement of mucosal conductivity by MII is a potential marker of mucosal integrity restored in infants on acid-suppression therapy.

Esophageal multichannel intraluminal impedance (MII) allows measurement of the conductivity of adjacent contents. During esophageal rest, raw impedance levels may represent mucosal integrity. We assessed the influence of proton pump inhibitors (PPIs) on presumed mucosal integrity by reanalyzing raw MII levels of 21 pH-MII tracings from infants with gastroesophageal reflux (GER) disease before and after esomeprazole treatment. Median (interquartile range) esophageal MII increased during treatment, 938 (652-1304) versus 1885 (1360-2183) Ohm, P < 0.0001. Patients with lower MII levels demonstrated a larger increase on therapy: Spearman r2 = 0.28, P = 0.014. No correlation with standard GER parameters was observed. In conclusion, PPI therapy increases MII levels in infants with symptomatic GER disease.