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HelpTest Code HPRP Helicobacter pylori with Clarithromycin Resistance Prediction, Molecular Detection, PCR, Tissue
Ordering Guidance
If testing directly from feces is desired, order HPFRP / Helicobacter pylori with Clarithromycin Resistance Prediction, Molecular Detection, PCR, Feces.
For more information see Helicobacter pylori Diagnostic Algorithm.
Specimen Required
The high sensitivity of amplification by polymerase chain reaction requires the specimen to be processed in an environment in which contamination of the specimen by Helicobacter pylori DNA is unlikely.
Submit only 1 of the following specimens:
Specimen Type: Fresh tissue or biopsy
Sources: Stomach (or duodenum)
Container/Tube: Sterile container
Specimen Volume: Entire collection or 5 mm (3) approximate size of a pencil eraser
Collection Instructions:
1. Collect fresh tissue specimen.
2. Submit tissue in a sterile container (without adding anything).
3. Refrigerate or freeze the specimen.
Specimen Stability Information: Refrigerated (preferred) 7 days/Frozen 7 days
Preferred:
Supplies: Tissue Block Container (T553)
Specimen Type: Formalin-fixed, paraffin-embedded (FFPE) tissue block
Sources: Stomach (or duodenum)
Container/Tube: Tissue block
Collection Instructions: Submit FFPE tissue block to be cut and returned.
Specimen Stability Information: Ambient (preferred)/Refrigerated
Acceptable:
Specimen Type: Formalin-fixed, paraffin-embedded (FFPE) tissue scroll
Sources: Stomach (or duodenum)
Container/Tube: Sterile container for each individual cut section (scroll)
Collection Instructions: Perform microtomy and prepare five separate 10-micron sections. Each section (scroll) must be placed in a separate sterile container for submission.
Specimen Stability Information: Ambient (preferred)/Refrigerated
Useful For
Aiding in the diagnosis of Helicobacter pylori infection and prediction of clarithromycin resistance or susceptibility directly from gastric biopsies
Reflex Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| TISSR | Tissue Processing | No | No |
Testing Algorithm
When this test is ordered, the reflex test may be performed at an additional charge.
For more information see Helicobacter pylori Diagnostic Algorithm.
Special Instructions
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Reporting Name
H pylori + Clarithro Resist, PCRSpecimen Type
VariesSpecimen Minimum Volume
Fresh tissue or biopsy: 5 mm(3)
Formalin-fixed paraffin-embedded tissue block: One block
Formalin-fixed paraffin-embedded tissue scroll: Two 10-micron sections
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Varies | Varies | ||
Reject Due To
| Tissue in formalin formaldehyde, or acetone FFPE slides |
Reject |
Clinical Information
Helicobacter pylori is a cause of peptic ulcer disease and, when left untreated, a risk factor for gastric cancer. H pylori diagnosis includes noninvasive tests (eg, stool polymerase chain reaction [PCR], urea breath test, stool antigen test) and tests requiring endoscopy to collect specimens for analysis. Several tests can be performed on gastric specimens, including H pylori PCR.
Antimicrobial resistance in H pylori is poorly studied but is rising, challenging its treatment. Assessment of antimicrobial resistance can guide treatment. Endoscopically collected gastric specimens can be cultured for H pylori and the recovered organism tested for phenotypic antimicrobial susceptibility. However, the organism can be difficult to isolate in culture, and even when isolated, may not amenable to phenotypic susceptibility testing due to its fastidious nature.
Clarithromycin resistance is most often associated with 23S ribosomal RNA (rRNA) gene mutations (particularly A2143G, A2142G/C). A systematic review and meta-analysis showed the sensitivity and specificity of detection of the H pylori A2142G/C and/or A2143G combination for prediction of clarithromycin resistance in H pylori in biopsy samples to be 96% each.
This test detects H pylori in gastric and duodenal biopsy specimens and, when detected, assesses for H pylori 23S rRNA gene mutations associated with clarithromycin resistance.
Reference Values
Not detected
Interpretation
A ‘detected’ result indicates the presence of Helicobacter pylori 23S ribosomal RNA gene; also indicated is whether or not one the three most common 23S ribosomal RNA gene mutations (A2143G, A2142G/C) associated with clarithromycin resistance is detected.
A ‘not detected’ result for H pylori indicates the absence of detectable H pylori DNA but does not negate the presence of the organism and may occur due to inhibition of the polymerase chain reaction (PCR), sequence variability underlying primers or probes, or the presence of H pylori DNA in quantities less than the limit of detection of the assay.
Cautions
Testing should be performed at least 4 weeks after completion of antibiotic (including bismuth) therapy and after proton pump inhibitor (PPI) or vonoprazan therapy has been withheld for 2 weeks. False-negative results may occur if testing occurs prior to these recommended timeframes. Histamine 2-receptor antagonists have been shown to slightly decrease the sensitivity of some Helicobacter pylori tests and, if possible, should be discontinued 2 weeks before testing. Antacids do not appear to impair test performance and may be taken until one day before testing.
Test results should be used as an aid in the diagnosis. The single assay should not be used as the only criterion to form a treatment decision; results of this test should be correlated with clinical presentation and results of other laboratory tests. A negative result does not negate the presence of the organism or active disease.
Potential cross-reactivity may occur with the following non-pylori Helicobacter species: Helicobacter acinonychis, Helicobacter cetorum, and Helicobacter mustalae (not been reported to cause disease in humans) and Helicobacter canis, Helicobacter cinaedi, Helicobacter bizzozeronii, and Helicobacter heilmannii (infrequently found in humans).
This assay examines the three most common 23S ribosomal RNA mutations associated with clarithromycin resistance. Other mechanisms of clarithromycin resistance are not assessed, nor are mechanisms of resistance to non-clarithromycin antimicrobial agents.
Day(s) Performed
Monday through Friday
Report Available
4 to 6 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
87798
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| HPRP | H pylori + Clarithro Resist, PCR | 88509-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| HPS3 | Specimen Source | 31208-2 |
| 616027 | Helicobacter pylori Result | 91060-4 |
| 616028 | Clarithromycin Resistance Result | 88509-5 |
Forms
If not ordering electronically, complete, print, and send Gastroenterology and Hepatology Test Request (T728) with the specimen.