Lab

Helicobacter pylori Stool Antigen

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Helicobacter pylori Stool Antigen, H. pylori Stool Antigen, HpSA

  • Indications
  1. Dyspepsia evaluation
  2. Confirmation of cure after H. pylori management
  • Mechanism
  1. Measures H. pylori antigen present in stool sample
  • Efficacy
  1. Stool monoclonal antigen tests (enzyme immunoassay)
    1. Test Sensitivity: 92%
    2. Test Specificity: 94%
    3. Most accurate, but more expensive than immunochromatography
  2. Stool monoclonal antigen tests (Immunochromatography)
    1. Test Sensitivity: 69-87%
    2. Test Specificity: 87-93%
    3. Variable reliability, but available for office based testing
  3. Accurate for confirmation of cure at 7 days
    1. Antigen levels significantly suppressed with cure
    2. Vaira (2002) Ann Intern Med 136:280-7 [PubMed]
  • Protocol
  • Patient stops medications 2 weeks before test
  1. Stop Proton Pump Inhibitors (but less affected than Urea Breath Test)
  2. Stop all antibiotics
  3. Stop bismuth compounds (e.g. Pepto Bismol)
  • Advantages
  1. Excellent first line non-invasive test for diagnosis
  2. Noninvasive test of H. pylori cure
  3. Inexpensive