Immunohistochemical detection of Helicobacter pylori infection in gastric biopsies of urea breath test-positive and -negative pediatric patients.

Helicobacter pylori (H. pylori) is a common cause of gastritis in both children and adults, and its incidence increases every year. The aims of this study were to evaluate the histopathologic features of H. pylori gastritis and to compare immunohistochemical with histochemical [hematoxylin-eosin (HE) and Giemsa] staining of gastric biopsy specimens for the detection of H. pylori infection from urea breath test (UBT) (-) and UBT (+) children. Seventy-eight gastric biopsies from pediatric patients who were administered UBT were included in this study. Gastric biopsy specimens were evaluated histopathologically and graded according to the Sydney system. HE, Giemsa and immunohistochemical staining was performed for the identification of H. pylori. The frequency of H. pylori gastritis was higher in the antrum than corpus. All biopsies with H. pylori colonization showed chronic inflammation with activity. By using immunohistochemical method, coccoid forms of H. pylori and spiral bacteria with low density were observed easily. With histochemical staining, 1/10 (10%) UBT (-) biopsies were H. pylori (+), while with immunohistochemical staining, 3 of the biopsies from UBT (-) patients were found to be H. pylori (+). Biopsies from 65 of 78 (83.3%) UBT (+) patients were H. pylori (+) with histochemical staining, but only 53 of these biopsies were found to be H. pylori (+) immunohistochemically. We conclude that immunohistochemical staining is more specific than histochemical staining and UBT for the detection of H. pylori infection.