title: Mucosal lymphocyte subsets and HLA-DR antigen expression in paediatric Helicobacter pylori-associated gastritis.
abstract: Paediatric studies may provide important insights into the immunopathology of Helicobacter pylori-associated gastritis, as mucosal changes reflect different stages of the immunoinflammatory response. We characterized, by quantitative immunohistochemistry, gastric mucosal lymphocyte phenotype and HLA-DR antigen expression and evaluated correlation with histopathology, in H. pylori-infected (Hp+ve) and uninfected children (Hp-ve). In the infected group, lamina propria CD3+ and IgA plasmocyte cell numbers were significantly higher and a trend for predominance of CD8+ over CD4+ was observed both in epithelium and lamina propria. A correlation of inflammation score with lamina propria CD3+ and CD4+ cell numbers and of CD45RO+ T lymphocytes with density of colonization was observed. The proportion of epithelial cells expressing HLA-DR antigen was significantly higher in the Hp+ve group and furthermore, glandular HLA-DR expression correlated with lamina propria CD3+ cell numbers, emphasizing the potential role of epithelial cells as antigen-presenting cells at this stage of infection.
authors.affiliation: Paediatric Gastrenterology Unit, Department of Paediatrics, University Hospital Santa Maria, Lisbon, Portugal. anaisalopes@sapo.pt
authors.forename: A I
authors.initials: AI
authors.lastname: Lopes
authors.forename: R M M
authors.initials: RM
authors.lastname: Victorino
authors.forename: A M
authors.initials: AM
authors.lastname: Palha
authors.forename: J
authors.initials: J
authors.lastname: Ruivo
authors.forename: A
authors.initials: A
authors.lastname: Fernandes
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005753:Gastric Mucosa / Q000276:immunology* / Q000473:pathology; D005756:Gastritis / Q000276:immunology* / Q000473:pathology; D006684:HLA-DR Antigens / Q000032:analysis*; D016481:Helicobacter Infections / Q000276:immunology* / Q000473:pathology; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007150:Immunohistochemistry / Q000379:methods; D016130:Immunophenotyping; D007223:Infant; D018655:Lymphocyte Count; D008297:Male; D011706:Pyloric Antrum / Q000276:immunology / Q000473:pathology; D018709:Statistics, Nonparametric; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D006684:HLA-DR Antigens; D007074:Immunoglobulin G