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Lab Dept:
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Microbiology/Virology
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Test Name:
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HELICOBACTER PYLORI ANTIGEN IN STOOL
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General Information
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Lab Order Codes:
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HPA
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Synonyms:
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H. pylori antigen; Stool for H. Pylori antigen; Feces for H. pylori antigen
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CPT Codes:
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87338 - Infectious agent antigen detection by enzyme immunoassay technique. Qualitative or semiquantitative multiple step method; Helicobacter pylori, stool
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Test Includes:
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Screening for the presence of Helicobacter pylori antigen.
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Logistics
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Lab Testing Sections:
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Microbiology
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Phone Numbers:
Minneapolis:
Saint Paul:
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612-813-5866
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651-220-6555
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Test Availability:
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Daily, 24 hours
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Turnaround Time:
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1 day
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Special Instructions:
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Specimen site and date/time of collection are required for processing.
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Specimen
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Specimen Type:
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Fresh, random stool
Note: Watery, diarrheal stools are inappropriate for testing.
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Container:
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Plastic, leakproof container
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Volume:
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1 gram stool
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Collection:
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1. Collect stool in a clean, dry bedpan or on a newspaper over the toilet. Avoid urine and toilet water in specimens, which may cause a dilution factor.
2. Transfer specimen to a plastic, leakproof container. Do not overfill or contaminate the outside of the container.
3. Transport to the laboratory within 2 hours of collection.
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Transport/Storage:
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● Transport to the Microbiology Laboratory immediately at room temperature.
● If a delay >2 hours is anticipated, refrigerate specimen at 2 - 8ºC up to 72 hours.
● If testing cannot be performed within 72 hours, freeze specimen immediately upon receipt and store at -20º to -80ºC. Frozen specimens may be thawed twice.
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Patient Preparation:
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False-negative results may occur on patients receiving antimicrobials, proton pump inhibitors, and bismuth preparations. If a negative result is obtained on a patient receiving these compounds, the test should be repeated on a new specimen obtained two weeks after discontinued treatment.
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Sample Rejection:
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Specimen with a transit time exceeding 2 hours after collection; watery, diarrheal stool; specimen not submitted in appropriate transport container; improperly labeled specimen; insufficient volume; external contamination. If an unacceptable specimen is received, the physician or nursing station will be notified and another specimen will be requested before the specimen is discarded.
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Interpretive
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Reference Range:
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No Helicobacter pylori antigen detected
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Limitations:
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● Test results should be used in conjunction with information available from the patient clinical evaluation and other diagnostic procedures.
● Antimicrobials, proton pump inhibitors, and bismuth preparations are know to suppress H. pylori, and ingestion of these prior to testing may give false-negative results. A positive result from patients receiving these compounds should be considered accurate.
● Performance characteristics have not been established for watery, diarrheal stools.
● H2 Blockers do not interfere with positive results.
● Laxatives should not adversely affect test results because by the time they pass through the patient they are very dilute.
● Urine does not have an adverse affect, but can dilute the specimen causing a false negative reaction.
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Methodology:
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EIA (enzyme immunoassay) antigen capture
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Additional Information:
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Helicobacter pylori infection has been linked to gastritis, duodenal ulcer, gastric cancer, and mucosa-associated lymphoid tissue lymphoma. Most H. pylori infections are acquired during childhood or adolescence in developing countries and developed countries. H. pylori infection was found in 90% of children with gastric ulcers. Acquisition of H. pylori at an early stage might increase the risk of the development of gastric cancer. The route of transmission is unclear; however, the presence of H. pylori in saliva, dental plaque and feces is suggests both oral to oral and fecal to oral transmission.
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References:
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Cook, JH, and M Pezzlo (1992). Specimen receipt and accessioning. Section 1. Aerobic bacteriology, 1.2.1-4. In HD Isenberg (ed) Clinical Microbiology Procedures Handbook. American Society for Microbiology, Washington DC
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Miller, J Michael (1999) A Guide To Specimen Management in Clinical Microbiology, American Society for Microbiology, Washington DC
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Miller, J Michael, and HT Holmes (1999) Specimen Collection, Transport, and Storage In PR Murray et al, (ed), Manual of Clinical Microbiology, 7th edition, American Society for Microbiology, Washington DC, pp 33-104
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