Proliferação epitelial gástrica em crianças infectadas por Helicobacter pylori

• Ano de defesa: 2006
• Autor(a) principal: Christiane Teixeira Cartelle
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Patologia; Neoplasias gástricas/complicações; Divisão celular; Gastrite/patologia; Infecções por helicobacter/patologia; Imunoistoquímica; Infecções por helicobacter/complicações; Contagem de células; Adolescente; Proteínas de bactérias; Células epiteliais; Pré-escolar; Antígeno nuclear de célula em proliferação; Mucosa gástrica; Úlcera duodenal/patologia; Crianças; Helicobacter pylori/patogenicidade
• Link de acesso: http://hdl.handle.net/1843/BUOS-9C3HXT

Backgroud: Epithelial proliferation stimulated by Helicobacter pylori may have a role on gastric carcinogenesis. Most studies on gastric epithelial proliferation have been performed in adults. Aims: To analyze gastric epithelial proliferation in children infected by cagA+ strains. Material and methods: We studied 54 children: 28 boys, 26 girls, age 10±3.7 years, 45 H. pylori-positive (Hp+) (34 cagA+), 15 with duodenal ulcer (DU),and 30 with H. pylori gastritis. H. pylori and cagA status were determined by polymerase chain reaction (PCR). Epithelial proliferation was studied by immunohistochemistry (sABC) by counting Ki-67 nuclei in the antral neck zone; the percentage of Ki-67 nuclei was determined by case and by neck zone in each diagnostic group and related to H. pylori infection, cagA status, and the intensity of gastritis. Results: The percentage ofKi-67 nuclei was higher in Hp+ (40%) than in H. pylori negative (Hp-) (14.3%) patients (p=10-3), in DU (47.7%) compared to Hp+ gastritis (40%; p= .075, and in cagA+ (42.1) compared to cagA- patients (30.8%) (p=10-3); among H. pylori gastritis, epithelial proliferation was significantly higher in cagA+ (42.9% Ki-67+ nuclei) compared to cagApatients (30.8% Ki-67+ nuclei) (p=10-3); among cagA+ patients, no difference was observed the percentage of Ki-67+ nuclei in DU (41.7%) compared to gastritis patients (42.9%) (p=.45). However, the number of Ki-67+ nuclei/neck zone was significantly higher in DU than in gastritis (p=.001). The degree of inflammation and activity correlated directly in H.pylori infection (p=.05 and p=.001), cagA+ status (p=.04 andp=.003) and DU (p=0.01 and p=.04). Na relationship was observed in the gastritis group (p>.1).Conclusion: In children, infection by cagA positive strains was significantly associated with high epithelial proliferation. Proliferation was significantly higher in DU patients and correlated directly with inflammation and activity. Our results do not corroborate a major role for proliferation in gastric carcinogenesis and suggest that inflammatory reaction may modulated the process. Differently from adults, higher proliferative activity was observed in DU compared to patients with non-ulcer gastritis