Helicobacter pylori Antigen, Feces
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Helicobacter pylori is well recognized as the cause of chronic active gastritis, duodenal ulcer, and nonulcer dyspepsia.
Currently accepted methods for the diagnosis of Helicobacter pylori infection include, the urea breath test (UBT), and culture or histologic examination or direct urease testing (CLO test) of biopsy specimens obtained at the time of gastroduodenoscopy (ENDO). Each of these tests has its drawbacks, including lack of specificity (serology) or high cost, complexity, and inconvenience for the patient (UBT and ENDO).
See Helicobacter pylori Diagnostic Algorithm in Special Instructions.
As an aid in the diagnosis of Helicobacter pylori
Monitoring the eradication of Helicobacter pylori after therapy (in most situations, confirmation of eradication is not mandatory)
The utility of this test in asymptomatic individuals is not known, but testing for Helicobacter pylori in such individuals is not generally recommended
Positive results indicate the presence of Helicobacter pylori antigen in the stool.
Negative results indicate the absence of detectable antigen but does not eliminate the possibility of infection due to Helicobacter pylori.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Stool must be mixed thoroughly to ensure representative sampling.
This is a qualitative, not a quantitative, test.
Falsely negative results may be obtained within 2 weeks of treatment with antimicrobials, bismuth, or proton pump inhibitors. A negative test result in such a situation should be followed up with a repeat test at least 2 weeks after discontinuing therapy.
Interfering Substances: The following substances that may be present in human stool, DO NOT interfere with positive or negative test results at the stated concentrations per 500 microliters of human stool: TUMS (10 mg), Mylanta (0.84 mg), Pepto Bismol ( 0.35 mg), Tagamet (1 mg), Prilosec OTC (1 mg), barium sulfate (10 mg), whole blood (100 microliters), mucin (6.7 mg), human hemoglobin (ie, dark stool) (15 mg), steric + palmitic acids (ie, fatty stool) (7.9 mg).
Performance characteristics of the test have not been established for watery, diarrheal stools.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. NIH Consensus Development Panel. Helicobacter pylori in peptic ulcer disease. JAMA 1994;272:65-69
2. Report of the Digestive Health Initiative. International Update Conference on H. pylori. Tysons Corner, McLean, VA, Feb 13-16, 1997