Identificação da infecção pelo Helicobacter pylori através do teste do antígeno fecal

Abstract

Introduction: The diagnosis of Helicobacter pylori (H. pylori) infection can be performed by non-invasive and invasive methods. The identification through test of fecal antigen (FAT) method is a non-invasive, simple, and relatively inexpensive. The aim of this study was to determine the diagnostic performance of immunoassay FAT in the identification of H. pylori infection. Methods: H. pylori antigens were identified in the stools of dyspeptic patients undergoing upper gastrointestinal endoscopy (UGE). The identification of H. pylori antigens was carried out through the ImmunoCard STAT! HpSA. Histopathology and urease test were the gold standard. Results: We studied 100 patients, 80% women and 20% men, with mean age of 52.7±11.8 years. The prevalence of H. pylori infection was 48%. The FAT immunoassay showed the following measures of diagnostic performance: specificity of 96% (95%CI 89.1-98.9); sensitivity of 65% (95%C I 56.9-67.6); positive predictive value of 94% (95%CI 82.8-98.3) and negative predictive value of 75% (95%CI 69.1-76.8). The accuracy was 80% (95%CI 74-84) and the prevalence odds ratio was 45,6 (95%CI 10,7-188,5). Conclusion: The FAT immunoassay presented high specificity and high positive predictive value. However, due to low sensitivity it would be appropriate to test it in a post-treatment period to assess the eradication of H. pylori.