From the Guidelines
The urea breath test (UBT) is the preferred eradication test for confirming Helicobacter pylori elimination after treatment. This non-invasive test should be performed at least 6 weeks after completing antibiotic therapy and at least 2 weeks after stopping proton pump inhibitors (PPIs) to avoid false-negative results, as recommended by the most recent guidelines 1. During the test, the patient ingests urea labeled with either carbon-13 or carbon-14. If H. pylori is present in the stomach, its urease enzyme breaks down the labeled urea, releasing labeled carbon dioxide that can be detected in the patient's breath. The UBT offers excellent sensitivity and specificity, making it more reliable than stool antigen testing or serology. Stool antigen testing is an acceptable alternative when UBT is unavailable, but serology is not recommended for confirming eradication since antibodies may persist for months after successful treatment 1. Endoscopic tests like rapid urease testing or histology should be reserved for cases requiring direct visualization of the gastric mucosa. Testing for eradication is crucial after treatment, particularly in patients with complicated ulcer disease, persistent symptoms, or MALT lymphoma, as it can induce lymphoma regression and long-term clinical disease control in most patients 1.
Some key points to consider when choosing an eradication test include:
- The test should be performed at least 6 weeks after completing antibiotic therapy and at least 2 weeks after stopping PPIs
- UBT is the preferred test due to its high sensitivity and specificity
- Stool antigen testing is an acceptable alternative when UBT is unavailable
- Serology is not recommended for confirming eradication due to the persistence of antibodies after successful treatment
- Endoscopic tests should be reserved for cases requiring direct visualization of the gastric mucosa
It's also important to note that the choice of therapy should consider effectiveness and cost of various regimens versus side effects, and that the occurrence of resistance, especially to clarithromycin, renders the standard triple therapy used to cure H. pylori infection ineffective 1. Therefore, the UBT is the most reliable and recommended test for confirming H. pylori eradication, and should be used in conjunction with the most effective and appropriate treatment regimen for each patient.
From the Research
Eradication Test of Choice for H. pylori
The eradication test of choice for Helicobacter pylori (H. pylori) is a crucial aspect of managing the infection. Several tests are available, including:
- Urea breath test
- Stool antigen test
- Endoscopy with histologic examination, rapid urease test, and culture
Noninvasive Tests
Noninvasive tests, such as the urea breath test and stool antigen test, are commonly used to confirm eradication of H. pylori. These tests should be performed at least 4 weeks after completion of eradication therapy 2.
- The urea breath test has a sensitivity of 94% and a specificity of 100% 3
- The stool antigen test has a sensitivity of 94% and a specificity of 97% 3
Timing of Tests
The timing of these tests is important, as false-negative results can occur if the tests are performed too soon after completion of therapy.
- The stool antigen test can be predictive of eradication as early as 7 days after completion of therapy, with a positive predictive value of 100% and a negative predictive value of 91% 3
Choice of Test
The choice of test may depend on various factors, including the patient's symptoms, medical history, and the availability of testing facilities.
- The urea breath test is considered a reliable method for assessing H. pylori status 4
- The stool antigen test is also an accurate test, although it may have a lower diagnostic value after eradication treatment 2
Recommendations
Based on the available evidence, the following recommendations can be made: