Aim: To evaluate the Helicobacter pylori stool antigen (HpSA) test in the assessment of H. pylori infection and the effect of omeprazole treatment on its accuracy. Methods: Study 1: 140 dyspeptic patients were enrolled in the study and defined as H. pylori positive if histology and rapid urease test, or culture alone were positive. HpSA was performed on all patients and 13C‐urea breath test (UBT) on 87. Study 2: 75 patients testing positive using both UBT and HpSA, were given omeprazole 20 mg for 2 weeks (Group A) or omeprazole 40 mg for 2 weeks (Group B), or OAC for 1 week (group C). A Helicobacter pylori stool antigen test was performed on all patients on days 3, 5, 7 and 14 during treatment, and also on days 7 and 14 post‐treatment in groups A and B. UBT was performed in groups A and B on days 7 and 14 during treatment, and days 7 and 14 post‐treatment. Results: 80/140 patients were H. pylori positive. The sensitivity and specificity of HpSA were 93.8 and 90%, similar to UBT (93.9 and 92.1%). Omeprazole significantly reduced both HpSA and UBT values, resulting in a decreased accuracy. Of 25 patients receiving 20 mg omeprazole, HpSA gave 5 and 6 false negatives after 7 and 14 days treatment respectively, while UBT gave 4 and 7 false negatives after 7 and 14 days treatment. Of 25 patients receiving 40 mg omeprazole, HpSA gave 7 and 9 false negatives after 7 and 14 days of treatment, while UBT gave 8 and 9 false negatives after 7 and 14 days of treatment. Two weeks after stopping omeprazole treatment, the HpSA and UBT were positive in all cases. Conclusions: The Helicobacter pylori stool antigen test is valuable in the assessment of H. pylori infection. Short‐term omeprazole treatment decreases the accuracy of both HpSA and UBT in a similar manner.

No abstract

No abstract

Noninvasive tests for Helicobacter pylori are increasingly used. Recently, an enzyme immunoassay for H. pylori detection in feces has been put on the market. Aim of this multicenter study was to evaluate the usefulness of this novel test as a predictor of H. pylori status in the pretreatment setting. Three hundred consecutive patients were enrolled. None of the patients had received any eradicating treatment in the last 12 months, and all underwent gastroscopy with biopsies of the antrum and body for histology (H) and rapid urease test (RUT). H. pylori status was defined positive (or negative) if both H and RUT were positive (or negative). When H and RUT gave conflicting results, the patients were classified as H. pylori-indeterminate. A stool specimen was collected for each patient and tested by using a novel enzyme immunoassay for H. pylori detection (HpSAT). Sensitivity, specificity, and diagnostic accuracy of the test were calculated, as was the cost of each assay. H. pylori status was positive in 159 patients, negative in 131, and indeterminate in 10. HpSAT gave evaluable results (positive or negative) in 293 patients, and doubtful results in 7 (2.3%). Sensitivity, specificity, and diagnostic accuracy of HpSAT were 96.8%, 89.7%, and 93.6% respectively. Considering the H. pylori-indeterminate patients as positive, the percentages were 95.8%, 98.7%, and 93.2% respectively. The cost for each assay was about US $27. These results suggest that HpSAT is a noninvasive, simple, reliable, fast, and cheap method for evaluating H. pylori status in the pretreatment setting.

No abstract