title: Helicobacter pylori and cagA gene detected by polymerase chain reaction in gastric biopsies: correlation with histological findings, proliferation and apoptosis.
abstract: OBJECTIVE
  The virulence of Helicobacter pylori (HP) in gastroduodenal disease is related to pathogenicity islands (cagPAI) present in some strains. Infection with cagPAI induces IL-8 secretion, increases epithelial cell proliferation and may be important in carcinogenesis. Our objective was to detect HP and the cagA gene (cagPAI marker) by polymerase chain reaction (PCR) and to correlate these results to histological findings, epithelial cell proliferation and apoptosis.
  
  
  METHODS
  Retrospective, at the Surgical and Molecular Pathology Laboratory, Hospital Sírio-Libanês.
  
  
  METHODS
  DNA samples isolated from 164 gastric biopsies were used for HP detection by PCR. cagPAI+ was identified in HP+ cases by cagA gene amplification. All cases were submitted to immunohistochemistry to evaluate cell proliferation, and TUNEL to detect apoptosis. Statistical analysis was performed to compare results.
  
  
  RESULTS
  HP was detected in 67.7% of the patients, with good correlation between HP infection and moderate to severe gastritis, gastric ulcer and MALT lymphoma. There was a correlation between cagPAI+ strains and severe gastric diseases including cancer. The risk of gastric ulcer, adenocarcinoma and MALT lymphoma was 8.8 times higher for cagPAI+ patients. cagPAI+ infection was related to higher proliferation rates. The proliferation/apoptosis index was significantly higher for cagPAI+ patients.
  
  
  CONCLUSIONS
  Cell growth deregulation in cagPAI+ patients could be demonstrated by the difference in the proliferation index. We believe that this explains the carcinogenic role of Helicobacter pylori.
authors: Surgical and Molecular Pathology Laboratory, Hospital Sírio-Libanês, São Paulo, Brazil. katiaramos@uol.com.br
authors: Katia Ramos Moreira
authors: KR
authors: Leite
authors: Elaine
authors: E
authors: Darini
authors: Flavio Canelas
authors: FC
authors: Canavez
authors: Claudia Muraro de
authors: CM
authors: Carvalho
authors: Cristina Aparecida Troquez da Silveira
authors: CA
authors: Mitteldorf
authors: Luiz Heraldo
authors: LH
authors: Camara-Lopes
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial / Q000235:genetics*; D017209:Apoptosis; D001426:Bacterial Proteins / Q000235:genetics*; D049109:Cell Proliferation; D002648:Child; D004812:Epidemiologic Methods; D005260:Female; D005819:Genetic Markers / Q000235:genetics; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D019394:Ki-67 Antigen / Q000032:analysis; D018442:Lymphoma, B-Cell, Marginal Zone / Q000382:microbiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000382:microbiology / Q000473:pathology; D013276:Stomach Ulcer / Q000382:microbiology / Q000473:pathology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D005819:Genetic Markers; D019394:Ki-67 Antigen; C080866:cagA protein, Helicobacter pylori