RESUMO
The clinical outcome of Helicobacter pylori infection may be associated with the cagA bacterial genotype. To investigate the cagA status of H. pylori-infected patients and the relationship between cagA and peptic ulcer disease, gastric biopsy specimens from 103 Caucasian patients in Brazil were analyzed by PCR. Since allelic variation in cagA exists and distinct H. pylori subgenotypes may circulate in different regions, PCR using primers for a variable 3' region of the cagA gene according to a Japanese methodology and for a consensus cagA 3' region used in Western methods was used for cagA detection. cagA was present in 53 (71%) of 75 H. pylori-positive cases when analyzed by the consensus region method and was associated with duodenal ulcer disease (P = 0.02), but not with gastric ulcer (P = 0.26), when compared to patients with duodenitis or gastritis. The variable region PCR method was able to detect 43 (57%) cagA-positive cases within the same group of H. pylori-positive patients and showed three subtypes of cagA (A, B/D, and C) that were not associated with clinical outcome. However, in 8 (18%) of the cases, more than one subtype was present, and an association between patients with multiple subtypes and disease outcome was observed when compared to patients with isolated subtypes (P = 0.048). cagA was a marker of H. pylori strains for duodenal ulcer disease in our population, and in spite of the differences in the 3' region of the cagA gene, the Japanese methodology was able to detect the cagA status in most cases. The presence of multiple subgenotypes of cagA was associated with gastric ulcer.
Assuntos
Antígenos de Bactérias , Proteínas de Bactérias/genética , Variação Genética , Infecções por Helicobacter/diagnóstico , Helicobacter pylori/genética , Úlcera Péptica/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Feminino , Infecções por Helicobacter/complicações , Infecções por Helicobacter/microbiologia , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 16S/genética , Reprodutibilidade dos Testes , Fumar , População BrancaRESUMO
OBJECTIVE: The term Barrett's esophagus refers to a premalignant condition that is characterized by the replacement of the esophageal squamous mucosa by a columnar-lined one. Preliminary studies have demonstrated reversal of Barrett's mucosa after endoscopic coagulation with different techniques associated with acid inhibition. However, most of these studies have shown that residual Barrett's glands are found underneath the new squamous epithelium in up to 40% of patients. The goal of our study is to verify whether complete restoration of Barrett's mucosa can be achieved by the combination of high power setting argon plasma coagulation and omeprazole. METHODS: A total of 33 patients (mean age: 55.2 yr, range: 21-84 yr; 21 men and 12 women) with histologically demonstrated Barrett's esophagus (mean length: 4.05 cm, range: 0.5-7 cm) were treated. Fourteen cases presented with low-grade dysplasia and one with high-grade dysplasia. All of the extent, or until a maximum of 4 cm, of the Barrett's mucosa was cauterized in each session using argon beam coagulation at a power setting of 65-70 W. All patients received 60 mg omeprazole during the treatment period. RESULTS: Complete restoration of squamous mucosa was obtained in all 33 cases after a mean of 1.96 sessions (range, 1-4). Endoscopic results were histologically confirmed. Nineteen (57.5%) patients experienced moderate to severe chest pain and odyno-dysphagia lasting for 3-10 days after the procedure. Five of these cases experienced high fever and a small volume of pleural effusion, and three patients developed esophageal strictures that needed to be dilated. Another patient developed pneumomediastinum and subcutaneous emphysema without evidences of perforation. After a mean follow-up of 10.6 months there was one endoscopic, as well as histological, recurrence of Barrett's mucosa in a patient with an ineffective laparoscopic fundoplication. CONCLUSIONS: High power setting argon plasma coagulation combined with intensive acid suppression is an effective treatment for the total endoscopic ablation of Barrett's esophagus, at least in the short term. Long-term follow-up of treated patients in whom gastroesophageal reflux is surgically or medically alleviated seems mandatory before drawing definitive conclusions about this therapy.