Duodenal intraepithelial lymphocytosis in Helicobacter pylori gastritis: comparison before and after treatment.

Our aims were to assess performance of duodenal intraepithelial lymphocyte counting for diagnosis of Helicobacter pylori (H. pylori) gastritis, and effects of eradication therapy on intraepithelial lymphocytosis. Paired duodenal and gastric biopsies from subjects with a pathologic diagnosis of H. pylori gastritis were reviewed. Higher duodenal intraepithelial lymphocyte counts were observed in 40 subjects with H. pylori gastritis (26 ± 5 per villus) than 52 subjects negative for H. pylori (12 ± 2 per villus). After successful eradication therapy, duodenal lymphocytes were indistinguishable from H. pylori-negative subjects, whereas they remained elevated after failed eradication therapy. This study confirms previous reports of increased duodenal intraepithelial lymphocytes in patients with concurrent Helicobacter pylori gastritis. Intraepithelial lymphocyte counts of > 15 per villus or > 10 per 100 enterocytes were predictive of infection. Duodenal lymphocytosis decreases significantly after successful eradication therapy but remains elevated when treatment fails.