ABSTRACT
BACKGROUND: Studies comparing new monoclonal fecal tests for evaluating cure of Helicobacter pylori infection after treatment are scarce. The objective was to compare the diagnostic accuracy of three monoclonal stool tests: two rapid in-office tools -RAPID Hp StAR and ImmunoCard STAT! HpSA - and an EIA test - Amplified IDEIA Hp StAR. MATERIALS AND METHODS: Diagnostic reliability of the three tests was evaluated in 88 patients at least 8 weeks after H. pylori treatment. Readings of immunochromatographic tests were performed by two different observers. Sensitivity, specificity, positive and negative predictive values and 95% confidence intervals were calculated. RESULTS: All tests presented similar performance for post-eradication testing. Sensitivity for detecting persistent infection was 100% for both Amplified IDEIA and RAPID Hp StAR and 90% for ImmunoCard STAT! HpSA. Respective specificities were 94.9%, 92.3-93.6% and 94.9%. Negative predictive values were very high (100%, 100% and 98.7% respectively). But positive predictive values were lower, ranging from 62.5 to 71.4%. CONCLUSION: All monoclonal fecal tests in this series presented similar performance in the post-treatment setting. A negative test after treatment adequately predicted cure of the infection. However, nearly a third of tests were false positive, showing a poor predictive yield for persistent infection.
Subject(s)
Antibodies, Bacterial , Antibodies, Monoclonal , Drug Monitoring/methods , Feces/microbiology , Helicobacter Infections/diagnosis , Helicobacter pylori/isolation & purification , Adult , Aged , False Positive Reactions , Female , Helicobacter Infections/drug therapy , Humans , Immunoassay , Male , Middle Aged , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
BACKGROUND: Well-devised studies comparing new but different monoclonal fecal tests for diagnosing Helicobacter pylori infection are scarce. The objective of this study was to compare the diagnostic accuracy of 3 monoclonal stool tests: 2 rapid in-office tools-RAPID Hp StAR and ImmunoCard STAT! HpSA-and an enzyme immunoassay test-Amplified IDEIA Hp StAR-for diagnosing H. pylori infection prior to eradication treatment. METHODS: Diagnostic reliability was evaluated in 199 untreated consecutive patients with dyspeptic symptoms. The gold standard for diagnosing H. pylori infection was defined as the concordance of the rapid urease test, histopathology, and urea breath test. Readings of immunochromatographic tests were performed by 2 different observers. Sensitivity, specificity, positive and negative predictive values, and 95% confidence intervals were calculated. Sensitivity and specificity were compared using the McNemar test. RESULTS: The sensitivity and specificity of Amplified IDEIA Hp StAR were 90% and 89%, respectively. This enzyme immunoassay test was significantly more sensitive than ImmunoCard STAT! HpSA and more specific than RAPID Hp StAR. The sensitivity and specificity of RAPID Hp StAR were 91% and 80%, respectively, according to observer 1, and 92% and 76%, respectively, according to observer 2. It was significantly more sensitive and less specific than ImmunoCard STAT! HpSA. The sensitivity and specificity of ImmunoCard STAT! HpSA were 69% and 90%, respectively, according to observer 1, and 74% and 89%, respectively, according to observer 2. CONCLUSIONS: Amplified IDEIA Hp StAR seems to be the most accurate stool test for diagnosing H. pylori for patients with dyspeptic symptoms. The currently available in-office tests obtain slightly less reliable results.
