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The causal relationship between the urease-producing bacterium, Helicobacter pylori, and chronic active gastritis, duodenal ulcer, and nonulcer dyspepsia is well established. Conventional methods for the diagnosis of active Helicobacter pylori infection include evaluation of biopsied gastric tissue by histopathology and culture. Less invasive assays include testing for the presence of Helicobacter pylori antigen is stool specimens and detection of Helicobacter pylori urease production by the Urea Breath Test (UBT). Serologic testing for the presence of IgM/IgG/IgA class antibodies to Helicobacter pylori is also performed; however, this is not recommended by either the American College of Gastroenterologists nor the American Gastroenterological Association (AGA) as an accurate marker for active disease. These serologic markers can remain elevated despite resolution of active disease and may lead to misdiagnosis and/or inappropriate treatment.
Recommendations for use of the (13)C-Urea Breath Test (Meretek UBT) were recently provided by the Digestive Health Initiative, a joint committee assembled with representatives from the AGA, the American Society for Gastrointestinal Endoscopy (ASGE), and the American Association for the Study of Liver Diseases (AASLD).(1) These recommendations include the following statements: "When endoscopy is not clinically indicated, the primary diagnosis of Helicobacter pylori infection can be made serologically or with the UBT. When endoscopy is clinically indicated, the primary diagnosis should be established by biopsy urease testing and/or histology. Available evidence suggests that confirmation of Helicobacter pylori eradication is not mandatory in most situations because of costs associated with testing. However, for selected patients with complicated ulcer disease, low-grade gastric mucosa-associated lymphoid tissue lymphoma, and following resection of early gastric cancer, it is appropriate to confirm eradication. In other situations, the decision to confirm Helicobacter pylori eradication should be made on a case-by-case basis."
This consensus group further specifies that there is no indication to test asymptomatic people and that testing for Helicobacter pylori is only recommended if treatment is planned.
The (13)C-Urea Breath Test (Meretek UBT) is a highly sensitive and specific noninvasive, nonradioactive test for diagnosing Helicobacter pylori infection prior to antimicrobial treatment and for assessing whether the organism has been successfully eradicated following antimicrobial therapy.
In 2 recent large prospective studies, the (13)C-UBT was shown to be as, or more, sensitive and specific for diagnosing Helicobacter pylori active infection than culture, PCR, stain, rapid urease testing of biopsy tissue, or serology.
When the test is used to assess eradication, it should be performed 4 to 6 weeks after completion of antimicrobial treatment.
See Helicobacter pylori Diagnostic Algorithm in Special Instructions.
Diagnostic testing for Helicobacter pylori infection in patients suspected to have active Helicobacter pylori infection or for monitoring response to therapy
The Helicobacter pylori urea breath test can detect very low levels of Helicobacter pylori and, by assessing the entire gastric mucosa, avoids the risk of sampling errors inherent in biopsy-based methods. In the absence of gastric Helicobacter pylori, the (13)C-urea does not produce (13)CO2 in the stomach.
A negative result does not rule out the possibility of Helicobacter pylori infection. If clinical signs are suggestive of Helicobacter pylori infection, retest with a new specimen or by using an alternative method.
A false-positive test may occur due to urease associated with other gastric spiral organisms observed in humans such as Helicobacter heilmannii.
A false-positive test could occur in patients who have achlorhydria.
This test is not appropriate for asymptomatic people.
Testing for Helicobacter pylori is only recommended if treatment is planned.
For patients with phenylketonuria (PKU), the Pranactin-Citric solution contains phenylalanine (75 mg/dose; for reference, 12 ounces of a typical diet cola contains approximately 80 mg).
Antimicrobials, proton pump inhibitors, and bismuth preparations are known to suppress Helicobacter pylori and ingestion of these within 2 weeks prior to performing the breath test may give false-negative results.
Premature collection time can lead to a false-negative diagnosis for a patient with marginally positive result.
If particulate matter is visible in the reconstituted Pranactin-Citric solution after thorough mixing, the solution should not be used.
The patient should have fasted for at least 1 hour before administering the breath test.
The breath test should not be used until 4 weeks or more after the end of treatment for the eradication of Helicobacter pylori as earlier posttreatment assessment may give false-negative results.
A correlation between the number of Helicobacter pylori organisms in the stomach and the breath test result has not been established.
1. Talley NJ, Vakil NB, Moayyedi P: American gastroenterological association technical review on the evaluation of dyspepsia. Gastroenterology 2005;129:1756-1780