Accuracy of Monoclonal Stool Tests for Determining Cure of Helicobacter pylori Infection After Treatment

• Published in: Helicobacter (Cambridge, Mass.) Mass.), 2010-06, Vol.15 (3), p.201-205
• Main Authors: Calvet, Xavier, Lario, Sergio, Ramírez-Lázaro, María José, Montserrat, Antònia, Quesada, Mariela, Reeves, Lynsey, Masters, Helen, Suárez-Lamas, David, Gallach, Marta, Miquel, Mireia, Martínez-Bauer, Eva, Sanfeliu, Isabel, Segura, Ferran
• Format: Article
• Language: English
• Subjects: Adult; Aged; Antibodies, Bacterial; Antibodies, Monoclonal; Drug Monitoring - methods; False Positive Reactions; Feces; Feces - microbiology; Female; Helicobacter Infections - diagnosis; Helicobacter Infections - drug therapy; Helicobacter pylori; Helicobacter pylori - isolation & purification; Humans; Immunoassay; Language; Male; Middle Aged; Persistent infection; post-eradication follow-up; Predictive Value of Tests; Sensitivity and Specificity
• ISSN: 1083-4389; 1523-5378
• DOI: 10.1111/j.1523-5378.2010.00757.x

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.