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Test Code LAB123896 Helicobacter pylori with Clarithromycin Resistance Prediction, Molecular Detection, PCR, Feces

Important Note

Mayo's test code: HPFRP


Ordering Guidance


Confirmation of eradication testing should not be ordered until 4 or more weeks after cessation of treatment.



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.

 

Patient Preparation:

1. For 4 weeks prior to testing, patient should not take antibiotics.

2. For 2 weeks prior to testing, patient should not take proton pump inhibitors or bismuth compounds.

Supplies: Culture and Sensitivity Stool Transport Vial (T058)

Specimen Type: Preserved feces

Submission Container/Tube: Commercially available transport system specific for recovery of enteric pathogens from fecal specimens (15 mL of nonnutritive transport medium containing phenol red as a pH indicator, either Cary-Blair or Para-Pak C and S)

Specimen Volume: 5 mL

Collection Instructions:

1. Collect fresh fecal specimen and submit 1 gram or 5 mL in container with transport medium.

2. Place feces in preservative within 2 hours of collection.

3. Place vial in a sealed plastic bag and send ambient or refrigerated. Specimens sent frozen will be rejected.


Useful For

Aiding in the diagnosis of Helicobacter pylori infection and prediction of clarithromycin resistance or susceptibility directly from stool

Testing Algorithm

For more information see Helicobacter pylori Diagnostic Algorithm.

Reporting Name

H pylori + Clarithro Resist, PCR, F

Specimen Type

Fecal

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fecal Ambient (preferred) 7 days
  Refrigerated  7 days

Reject Due To

Fecal swab
ESwab transport medium
Feces in gel transport medium
ECOFIX preservative formalin
PVA fixative
Unpreserved stool		 Reject

Reference Values

Not detected

Supportive Data

During laboratory verification studies, 745 fecal samples previously tested with the Meridian Premier Platinum HpSA Plus fecal antigen test were assayed with this test. The assay detected Helicobacter pylori DNA in 306/335 antigen positive fecal samples (91% sensitivity [87.5-93.9%, 95% CI]). The H pylori with Clarithromycin Resistance Prediction (HPFRP) assay also detected H pylori DNA in 12/410 antigen negative fecal samples (97.1% specificity [94.9%-98.5%, 95% CI]). Positive and negative predictive values were 96.2% (93.5-98.0%, 95% CI) and 93.0% (90.1-95.2%, 95% CI), respectively. Simple Kappa Coefficient measurement of the performance of the assay against that of the antigen test was 0.89 (0.85-0.92, 95%CI), an almost perfect correlation.(3)

 

Assessment of clarithromycin resistance prediction was made by performing bidirectional Sanger sequencing on all HPFRP positive samples. All 76 samples with predicted clarithromycin susceptible H pylori, demonstrated wildtype 23S ribosomal RNA gene sequence at positions 2142 and 2143. All 37 samples with predicted clarithromycin resistant, pylori demonstrated single nucleotide polymorphisms of A2143G, A2142G, or A2142C in the detected H pylori 23S ribosomal RNA gene.

Specimen Retention Time

7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

87798

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HPFRP H pylori + Clarithro Resist, PCR, F 88509-5

 

Result ID Test Result Name Result LOINC Value
HPSRC Specimen Source 31208-2
608002 Helicobacter pylori Result 91061-2
608003 Clarithromycin Resistance Result 88509-5

Day(s) Performed

Monday, Wednesday, Friday

Report Available

4 to 6 days

Forms

If not ordering electronically, complete, print, and send one of the following with the specimen:

1. Microbiology Test Request (T244)

2. Gastroenterology and Hepatology Test Request (T728)