title: [Diagnosis of Helicobacter pylori infection in children based on stool antigen test].
abstract: BACKGROUND
  During infancy, preventive, diagnostic and therapeutic efforts for Helicobacter pylori infection should be made.
  
  
  OBJECTIVE
  To evaluate non-invasive diagnostic methods such as stool antigen test (HpSA) and serum anti-H pylori antibody detection (IgG e IgA), compared to endoscopy-based invasive methods (histology and urease test) for the diagnosis of Helicobacter pylori infection.
  
  
  METHODS
  Thirty nine children (aged 3 to 14 years, 20 males) referred for upper gastrointestinal endoscopy, were studied. The gold standard to diagnose Helicobacter pylori infection was defined as a positive invasive diagnostic test (histology and/or urease test). Sensitivity (S), specificity (E) and positive (PPV) and negative (NPV) predictive values were obtained for HpSA and serum antibodies.
  
  
  RESULTS
  Ten children (26%) were infected with H pylori. S, E, PPV and NPV for HpSA were 90, 100, 100 and 97%, respectively. The figures for serum IgG were 81, 97, 89 and 93%, respectively and for IgA, 90, 76, 36 and 96%, respectively.
  
  
  CONCLUSIONS
  HpSA was sensitive and specific as a clinical and epidemiological tool to evaluate H pylori infection in children. Serology was not as accurate, but IgG had a better performance than IgA.
authors.affiliation: Departamento de Pediatría, Sección de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica, Santiago, Chile.
authors.forename: Carmen Gloria
authors.initials: CG
authors.lastname: González F
authors.forename: Carolina
authors.initials: C
authors.lastname: Serrano H
authors.forename: Paul R
authors.initials: PR
authors.lastname: Harris
mesh_terms: D000293:Adolescent; D000907:Antibodies, Bacterial / Q000032:analysis; D000942:Antigens, Bacterial / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000382:microbiology*; D005260:Female; D016481:Helicobacter Infections / Q000097:blood / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D007118:Immunoassay / Q000379:methods / Q000592:standards*; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007155:Immunologic Factors / Q000032:analysis; D008297:Male; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D014510:Urease / Q000032:analysis
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007155:Immunologic Factors; D011933:Reagent Kits, Diagnostic; D014510:Urease