Helicobacter pylori eradication therapy on histologic change in the distal esophagus

BACKGROUND: Although cases of reflux esophagitis (RE) developing after treatment to eradicate Helicobacter pylori have been discussed in some detail, no reports are available concerning the histologic examination of RE both before and after eradication therapy. MATERIALS AND METHODS: Sixty-one patients and 111 specimens were investigated using endoscopic and histologic techniques. The histologic findings including basal zone height, papillar height, Ki-67 labeling index, and COX-2 expression before and after treatment for H. pylori infection were compared with those in normal controls and patients with endoscopic RE. RESULTS: Twelve months after eradication therapy, the incidence of newly developed endoscopic RE was 20% (5/25). Basal zone height and papillar height had increased at 1 month, but had returned to pretreatment levels after 12 months of eradication therapy. The Ki-67 labeling index was significantly increased 1 and 12 months after eradication therapy compared to values before treatment. COX-2 expression gradually increased after the treatment. The phenomena linked to esophagitis appeared after eradication therapy. However, the severity and extent of these signs were not so high after the treatment of H. pylori than those in patients with overt reflux esophagitis. Focusing on the patients with hiatal hernia, papillar height and Ki-67 labeling index increased significantly after eradication therapy, values being almost the same as those in the patients with endoscopic RE. CONCLUSIONS: Hiatal hernia plays an important role in the possible occurrence of hidden RE after treatment for a H. pylori infection.