title: Assessment of p21, p53 expression, and Ki-67 proliferative activities in the gastric mucosa of children with Helicobacter pylori gastritis.
abstract: BACKGROUND
  Helicobacter pylori that is generally acquired in childhood and infects the gastric mucosa is considered to be responsible for many pathobiological changes that are linked to the pathogenesis of gastric cancer. Although the majority of studies on the subject have been carried out in adults, there are a limited number of studies on children that reflect the early period of infection and may be of greater significance.
  
  
  OBJECTIVE
  We aimed to determine the role of H. pylori infection and/or gastritis in several histopathological changes, p53, p21, and cell proliferation-associated Ki-67 antigen expression in the gastric mucosa.
  
  
  METHODS
  We studied 60 patients with a mean age of 7.5 ± 4.5 years at referral. On the basis of endoscopic appearance and the evaluation of the gastric antral specimens, the patients were divided into three groups: patients without gastritis, patients with H. pylori-positive gastritis, and patients with H. pylori-negative gastritis. To determine the expression of p53, Ki-67, and p21 in gastric biopsy specimens, immunohistochemical stains were performed.
  
  
  RESULTS
  The incidence of neutrophil activity, which was one of our histopathologic parameters, was significantly higher in the H. pylori-positive gastritis group than the other two groups. The presence of lymphoid aggregate was more frequent in H. pylori ± gastritis groups than the nongastritis group. p53 expression was found to be significantly higher in the H. pylori-positive gastritis group than the nongastritis group. Ki-67 and p21 expressions were significantly more frequent in the H. pylori-positive gastritis group than the other two groups. When we evaluated the density of H. pylori, as the density of bacteria increases, we found that the expressions of p53, p21, and Ki-67 increased significantly.
  
  
  CONCLUSIONS
  Expression of the studied precancerous markers in significant amounts indicates the importance of childhood H. pylori infection in the constitution of gastric cancer in adulthood.
authors.affiliation: aKastamonu Dr. Munif İslamoglu State Hospital, Department of Pediatrics, Kastamonu bDepartment of Pediatric Gastroenterology and Hepatology, Acibadem University cDepartment of Pathology, Yeditepe University, Istanbul, Turkey dDepartment of Pediatrics, Yeditepe University, Istanbul, Turkey.
authors.forename: Coskun
authors.initials: C
authors.lastname: Saf
authors.forename: Enver Mahir
authors.initials: EM
authors.lastname: Gulcan
authors.forename: Ferda
authors.initials: F
authors.lastname: Ozkan
authors.forename: Seyhan Perihan
authors.initials: SP
authors.lastname: Cobanoglu Saf
authors.forename: Ayca
authors.initials: A
authors.lastname: Vitrinel
mesh_terms: D001706:Biopsy; D049109:Cell Proliferation; D002648:Child; D002675:Child, Preschool; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D005260:Female; D005753:Gastric Mucosa / Q000378:metabolism / Q000473:pathology; D005756:Gastritis / Q000378:metabolism / Q000382:microbiology* / Q000473:pathology; D016481:Helicobacter Infections / Q000378:metabolism* / Q000473:pathology; D016480:Helicobacter pylori; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D011230:Precancerous Conditions / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D013274:Stomach Neoplasms / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53