evaluation of diagnostic value of helicobacter pylori stool antigen test before and after eradication

aim : to evaluate the diagnostic value of helicobacter pylori stool antigen test before and after eradication background : there are different methods for diagnosis and follow up of helicobacter pylori infection, including invasive methods done with endoscopy and non invasive ones such as ubt and urine analysis antibody. one of non invasive new methods is analysis of helicobacter pylori stool antigen, used for primary diagnosis and post eradication follow up. patients and methods : a total of 54 patients with epigastric discomfort referred to taleghani hospital for upper gastrointestinal endoscopy were enrolled in this study. helicobacter infection was confirmed with rapid urease test, culture and histological methods. gold standards for positive infection were positive culture or positive rut and histology. patients with positive infection (26 patients) were treated with omeprazol, tetracycline, metronidazol, bismuth subsalsylate, for 2 weeks, and then 1 and 3 month later were reevaluated with gold standard tests and helicobacter pylori stool antigen test. results : sensitivity, specificity and accuracy of helicobacter pylori stool antigen test were 78.6%, 92.3%, and 85.2% respectively before eradication, 100% and 56.5% and 61.5% 1 month after eradication and 85.7%, 89.5% and 88.5%, 3 months after treatment. conclusion : helicobacter pylori stool antigen test is an excellent method for pretreatment diagnosis of helicobacter pylori infection, and also in 3-month follow up of eradication, but the specificity and accuracy were low in early period follow up.