From the Guidelines
To confirm eradication of Helicobacter pylori after completion of bismuth quadruple therapy, a urea breath test (UBT) or stool antigen test should be ordered at least 4 weeks after completion of therapy. These non-invasive tests are the preferred methods for post-treatment confirmation, as recommended by the Maastricht IV/Florence Consensus Report 1. It's crucial to wait at least 4 weeks after completing antibiotics and to stop proton pump inhibitors (PPIs) at least 2 weeks before testing to avoid false-negative results, as suggested by a study in the Annual Review of Medicine 1. The urea breath test works by detecting the presence of urease, an enzyme produced by H. pylori that breaks down urea into carbon dioxide, which can be measured in exhaled breath when using labeled carbon isotopes. The stool antigen test directly detects H. pylori antigens in fecal samples. Both tests have high sensitivity and specificity (>95%) for detecting active infection, as reported in a study in Gut 1. If the patient has alarm symptoms or is at high risk for gastric cancer, endoscopy with biopsy for histology, rapid urease testing, or culture might be considered instead, as recommended by the European Helicobacter study group 1. Confirmation of eradication is important because H. pylori eradication rates with bismuth quadruple therapy are typically 80-90%, meaning a significant number of patients may require retreatment with an alternative regimen. The most recent and highest quality study, published in the Annual Review of Medicine in 2022 1, supports the use of UBT or stool antigen test for post-treatment confirmation, making these tests the preferred choice for confirming eradication of H. pylori. Key points to consider when choosing a test include:
- The test should be non-invasive, such as UBT or stool antigen test
- The test should be performed at least 4 weeks after completion of therapy
- PPIs should be stopped at least 2 weeks before testing to avoid false-negative results
- The test should have high sensitivity and specificity (>95%) for detecting active infection.
From the Research
Test Options for Confirming Eradication of Helicobacter pylori
- A. Urea breath test
- B. Tissue biopsy
- C. Stool Helicobacter pylori antigen
- D. Helicobacter pylori serum antibody
Recommended Test
The recommended test for confirming eradication of Helicobacter pylori after completion of bismuth quadruple therapy is the urea breath test (UBT) 2, 3.
Rationale
The UBT is a non-invasive and accurate test for detecting H. pylori infection. Studies have shown that the UBT can be used to confirm eradication of H. pylori as early as 14 days after completion of therapy 3. The test has high sensitivity and specificity, making it a reliable option for monitoring treatment outcomes 2.
Alternative Tests
While tissue biopsy and stool antigen tests can also be used to detect H. pylori infection, they are not as convenient or non-invasive as the UBT. Serum antibody tests are not recommended for confirming eradication, as they can remain positive for months after treatment 2.
Timing of Test
The test should be performed at least 4 weeks after completion of therapy to ensure accurate results 2, 4. However, studies have shown that the UBT can be performed as early as 14 days after completion of therapy, with high sensitivity and specificity 3.