title: Helicobacter pylori colonization of the adenotonsillar tissue: fact or fiction?
abstract: OBJECTIVE
  The transmission of the gastric pathogen Helicobacter pylori involves the oral route. Molecular techniques have allowed the detection of H. pylori DNA in samples of the oral cavity, although culture of H. pylori from these type of samples has been sporadic. Studies have tried to demonstrate the presence of H. pylori in adenotonsillar tissue, with contradictory results. Our aim was to clarify whether the adenotonsillar tissue may constitute an extra gastric reservoir for H. pylori.
  
  
  METHODS
  Sixty-two children proposed for adenoidectomy or tonsillectomy were enrolled. A total of 101 surgical specimens, 55 adenoid and 46 tonsils, were obtained. Patients were characterized for the presence of anti-H. pylori antibodies by serology. On each surgical sample rapid urease test, immunohistochemistry, fluorescence in situ hybridization (FISH) with a peptide nucleic acid probe for H. pylori, and polymerase chain reaction-DNA hybridization assay (PCR-DEIA) directed to the vacA gene of H. pylori were performed.
  
  
  RESULTS
  Thirty-nine percent of the individuals had anti-H. pylori antibodies. Rapid urease test was positive in samples of three patients, all with positive serology. Immunohistochemistry was positive in samples of two patients, all with negative serology. All rapid urease test or immunohistochemistry positive cases were negative by FISH. All samples tested were negative when PCR-DEIA for H. pylori detection was used directly in adenotonsillar specimens.
  
  
  CONCLUSIONS
  The adenotonsillar tissue does not constitute an extra gastric reservoir for H. pylori infection, at least a permanent one, in this population of children. Moreover, techniques currently used for detecting gastric H. pylori colonization are not adequate to evaluate infection of the adenotonsillar tissues.
authors.affiliation: Serviço de Otorrinolaringologia, Hospital de São Marcos, Braga, Portugal.
authors.forename: Sérgio
authors.initials: S
authors.lastname: Vilarinho
authors.forename: Nuno M
authors.initials: NM
authors.lastname: Guimarães
authors.forename: Rui M
authors.initials: RM
authors.lastname: Ferreira
authors.forename: Bárbara
authors.initials: B
authors.lastname: Gomes
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Wen
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Vieira
authors.forename: Fátima
authors.initials: F
authors.lastname: Carneiro
authors.forename: Tiago
authors.initials: T
authors.lastname: Godinho
authors.forename: Ceu
authors.initials: C
authors.lastname: Figueiredo
mesh_terms: D000233:Adenoidectomy; D000234:Adenoids / Q000382:microbiology*; D000907:Antibodies, Bacterial / Q000097:blood; D002648:Child; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D015341:Nucleic Acid Probes; D014066:Palatine Tonsil / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D014068:Tonsillectomy; D014510:Urease / Q000032:analysis
chemical_list: D000907:Antibodies, Bacterial; D004269:DNA, Bacterial; D015341:Nucleic Acid Probes; D014510:Urease