title: Helicobacter pylori (H. pylori) in gastric mucosa of children with abdominal complaints: immunohistochemistry detects antigen-reactive corpus mucosa cells.
abstract: BACKGROUND
  Previous morphological and serological studies of gastric Helicobacter pylori (H. pylori) colonization among Estonian children with abdominal complaints, as well as among populations of schoolchildren, have shown a high prevalence of H. pylori (49-60%). Based on published data concerning the high specificity and sensitivity of immunohistochemical detection of H. pylori, we examined the prevalence of H. pylori in gastric biopsy specimens of Estonian children by different localization and morphological type of gastritis comparing Giemsa staining with immunohistochemistry.
  
  
  METHODS
  Formalin-fixed biopsies (107 antral, 108 corpus mucosa) of 112 children (41 boys, 71 girls, age range 1-16 years, median age 12 years) with abdominal complaints were stained with hematoxylin & eosin and Giemsa stains, as well as examined using the peroxidase antiperoxidase (PAP) method with polyclonal antibodies to H. pylori.
  
  
  RESULTS
  Gastritis of any degree and localization was found in 84/112 (75%) children. Using Giemsa staining H. pylori were detected in 83/112 (74%) of all children, and by use of the PAP method in 55/112 (49%) (p = .001). Concordance of the results of immunohistochemical and Giemsa methods in antrum biopsies was 70%, in corpus biopsies 73%. In 12 out of 108 (11%) corpus mucosa specimens a positive staining with anti-H. pylori IgG was localized in the cytoplasma of corpus mucosal cells in the neck part of the glands.
  
  
  CONCLUSIONS
  The prevalence of H. pylori was higher when employing the Giemsa stain in comparison with immunohistochemistry. Antibody reactivity of cells in the neck part of the corpus glands may either be due to cross-reactivity of anti-H. pylori IgG with epithelial cell epitopes, or to internalization of H. pylori by these cells, suggesting a pathogenic role of neck cells in an anti-H. pylori immune response.
authors.affiliation: Department of Immunology, University of Tartu, Estonia.
authors.forename: T
authors.initials: T
authors.lastname: Vorobjova
authors.forename: H I
authors.initials: HI
authors.lastname: Maaroos
authors.forename: T
authors.initials: T
authors.lastname: Rägo
authors.forename: A
authors.initials: A
authors.lastname: Zimmermann
authors.forename: R
authors.initials: R
authors.lastname: Uibo
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004396:Coloring Agents; D004957:Estonia; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology / Q000382:microbiology* / Q000473:pathology; D016481:Helicobacter Infections / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007223:Infant; D008297:Male; D011706:Pyloric Antrum / Q000382:microbiology / Q000473:pathology; D012189:Retrospective Studies
chemical_list: D000907:Antibodies, Bacterial; D004396:Coloring Agents