ABSTRACT
BACKGROUND: Active gastritis, gastric mucosal atrophy and intestinal metaplasia are lesions associated with Helicobacter pylori infection. Atrophy and intestinal metaplasia are only seen in adults. OBJECTIVES: We describe pediatric patients with atrophy and metaplasia, and compare the inflammatory response in these patients to controls. METHODS: As part of a multicenter study of pediatric H. pylori infection, gastric biopsy specimens obtained during diagnostic upper endoscopy of 19 H. pylori-infected children and 45 uninfected controls were reviewed and graded by using the updated Sydney system. The inflammatory response was characterized using immunohistochemistry for T lymphocytes, B lymphocytes, and macrophages, and TUNEL assay for apoptosis. RESULTS: Histology of H. pylori-infected and control biopsy specimens showed active gastritis in 32% and 2% respectively (P = 0.002). Mild intestinal metaplasia was found in 4 H. pylori-infected children, in two of whom it appeared to be accompanied by atrophy. Specimens from patients with H. pylori infection contained increased numbers of B lymphocytes in lymphoid nodules, and apoptosis in the superficial epithelium and inflammatory cells. T lymphocytes and macrophages appeared in similar numbers in specimens from controls and infected patients. CONCLUSIONS: We describe intestinal metaplasia associated with H. pylori infection in children. Since atrophy usually precedes intestinal metaplasia in adults, we suggest that atrophy exists in children. High numbers of B lymphocytes and apoptosis in the surface epithelium are seen in patients with H. pylori infection and may be related to the development of atrophy and intestinal metaplasia.