Definition
- H. pylori is a bacterium that is found in the stomach of about two thirds of the people in the world, although most infected people will never develop disease. H. pylori infection is a major risk factor for peptic ulcer disease. These bacteria are responsible for the large majority of gastric ulcers and upper duodenal ulcers. Research studies indicate that infection with H. pylori increases the risk of gastric cancer, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and possibly pancreatic cancer. H. pylori infection may be diagnosed by invasive (e.g., histopathology) or noninvasive (e.g., serology, breath urea test, stool antigen) tests. Most tests use an EIA format. Tests using monoclonal antibodies against H. pylori have reported the best accuracy.
Use
- Testing is requested for evaluation of patients with dyspepsia or other upper GI symptoms suggesting H. pylori infection. Stool specimens, collected and transported using standard laboratory methods. Testing may be submitted to monitor effect of treatment for H. pylori infection. Stool antigen become undetectable with effective therapy.
Interpretation
- Expected result: Negative.
- Positive result: Active H. pylori infection. False-positive results may be seen in approximately 5% of tests.
- Negative result: The patient is unlikely to have active infection with H. pylori. False-negative results may be seen in 5 " 7% of patients; repeat testing or testing with other types of assays for infection should be considered in patients with high suspicion for H. pylori infection.
Suggested Reading
1Choi J, Kim CH, Kim D, et al. Prospective evaluation of a new stool antigen test for the detection of Helicobacter pylori, in comparison with histology, rapid urease test, 13C-urea breath test, and serology. J Gastroenterol Hepatol. 2011;26:1053 " 1059.