Características da gastrite crônica associada a Helicobacter pylori: Aspectos topográficos, doenças associadas e correlação com o status cagA

Abstract

Aims: We aimed to investigate the topographical pattern of H. pylori gastritis in relation to cagA status and association with duodenal ulcer (DU) and early gastric carcinoma (EGCa). Materials and method: We studied chronic gastritis (CG) in 160 patients submitted to upper endoscopy and in 40 patients with EGCa submitted to gastrectomy. Samples were taken from the antrum and corpus in the lesser and greater curvatures, incisura and from the tumour and were processed routinely for histology and histochemistry for intestinal metaplasia (IM) characterisation. H. pylori was evaluated by histology, immunohistochemistry, culture, and PCR; cagA status was evaluated by polymerase chain reaction (PCR). CG was analyzed according to the updated Sydney System. In 130 patients a topographic study was conducted by the comparative analysis of the gastritis parameters among the areas and according to cagA status. Results: CG was observed in 121 patients, 24 had UD and 14 were normal. cagA-positive strains were detected in 59 patients with GC, 17 DU and 24 EGCa. All gastritis parameters were significantly more intense in the cagA-positive group than in cagA-negative one. Infection by cagA-positive strains was associated with atrophy and IM. IM was significantly more intense in the middle portion of the lesser curvature in the antral mucosa. In CG or EGCa patients infected with cagA-positive strains, inflammation and activity compromised equally the antrum and distal corpus, whereas atrophy and IM were more frequently found in the antral mucosa. In DU, CG was antral-predominant irrespectively of cagA status. Conclusions: According to our data the topographical pattern of H. pylori-associated gastritis seems to be associated with cagA status. Precancerous lesions were significantly more intense in the antral lesser curvature, where most gastric carcinomas arise.