Accuracy of monoclonal stool tests for determining cure of Helicobacter pylori infection after treatment

Helicobacter. 2010 Jun;15(3):201-5. doi: 10.1111/j.1523-5378.2010.00757.x.

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.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antibodies, Bacterial*
  • Antibodies, Monoclonal*
  • Drug Monitoring / methods*
  • False Positive Reactions
  • Feces / microbiology*
  • Female
  • Helicobacter Infections / diagnosis*
  • Helicobacter Infections / drug therapy
  • Helicobacter pylori / isolation & purification*
  • Humans
  • Immunoassay
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Sensitivity and Specificity

Substances

  • Antibodies, Bacterial
  • Antibodies, Monoclonal