Histological Changes of Lower Esophagus Transiently Occur One Month after Helicobacter pylori Eradication, but Will Recover within 12 Months

Purpose: Although the association between newly diagnosed reflux esophagitis and Helicobacter pylori (H. pylori) eradication has been reported, there are few reports that examined esophagitis hisitologically both before and after eradication. This study evaluated the histological changes in lower esophagus before and after eradication therapy. Methods: Histological evaluation of lower esophagus in 55 subjects (25 without endoscopically reflux esophagitis with H. pylori, 13 with mild esophagitis without H. pylori and 17 normal controls without H. pylori) were analyzed before, 1 and 12 months after H. pylori eradication. Basal layer zone thickness, height of papillae, Ki-67 index were used as histological evalution of esophagitis. Results: One month after eradication, basal zone thickness and Ki-67 index significantly increased (p < 0.05, respectively). Papillar height also increased although not significantly. Twelve months after eradication, basal zone thickness and papillar height return to the levels before eradication. The same tendency was found in Ki-67 index, although its recovery was not absolute during 12 months. In H. pylori positive subjects without endoscopically reflux esophagitis, the histological findings were not different from those in H. pylori negative controls, regardless of eradication. In H. pylori negative subjects with esophagitis, all histological parameters showed significantly high levels compared to those in H. pylori positive subjects without esophagitis before and after eradication, and those in normal controls (p < 0.05). Conclusions: H. pylori eradication may cause histological esophagitis during a short observation period. However, its histological change may possibly recover 12 months after eradication.