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Test ID: WHIPB Tropheryma whipplei, Molecular Detection, PCR, Blood

Reporting Name

Tropheryma whipplei PCR, B

Useful For

Aiding in the diagnosis of Whipple disease, especially for identifying inconclusive or suspicious cases, using whole blood specimens

Clinical Information

Whipple disease is a chronic, systemic illness that in the majority of cases involves the small intestine and its lymphatic drainage. The disease primarily affects middle-aged individuals, with a peak incidence in the third and fourth decades. Clinical findings may include malabsorption, chronic diarrhea, abdominal pain, arthralgia, fever, and central nervous system symptoms.

 

Pathologic changes associated with Whipple disease are distinctive, with diagnosis dependent on histologic examination of biopsy specimens from involved tissues. Electron microscopic or special high-resolution light microscopic examination of the lamina propria of the small intestine of patients with untreated Whipple disease reveals many rod-shaped bacillary organisms. These tiny bacilli, referred to as Whipple bacilli, measure about 0.25 micrometer long and are seen as periodic acid-Schiff-positive granules within macrophages. These inclusions represent fragments of the cell walls from degenerating bacilli.

 

Culture of Whipple bacilli from biopsy material is laborious and the organism is very slow growing. Definitive identification of the Whipple-associated bacillus has been difficult because of these limitations. Recently, molecular techniques using PCR and nucleotide sequencing allowed classification of this bacillus as an actinomycete not closely related to any other known species, which has been named Tropheryma whipplei.

Interpretation

A positive result indicates the presence of Tropheryma whipplei DNA.

 

A negative result indicates the absence of detectable T whipplei DNA, but does not negate the presence of the organism and may occur due to inhibition of PCR, sequence variability underlying primers or probes, or the presence of T whipplei DNA in quantities less than the limit of detection of the assay.

Analytic Time

2 days

Day(s) and Time(s) Performed

Monday, Wednesday, Friday

Clinical Reference

1. Ramzan NN, Loftus E Jr, Burgart LJ, et al: Diagnosis and monitoring of Whipple disease by polymerase chain reaction. Ann Intern Med 1997;126:520-527

2. Morgenegg S, Dutly F, Altwegg M: Cloning and sequencing of a part of the heat shock protein 65 gene (hsp65) of "Tropheryma whippleii" and its use for detection of "T whipplei" in clinical specimens by PCR. J Clin Microbiol 2000;38:2248-2253

3. von Herbay A, Ditton HJ, Schuhmacher F, et al: Whipple's disease: staging and monitoring by cytology and polymerase chain reaction analysis of cerebrospinal fluid. Gastroenterology 1997;113(2):434-441

4. Dolmans RA, Boel CH, Lacle MM, Kusters JG: Clinical manifestations, treatment, and diagnosis of Tropheryma whipplei infections. Clin Microbiol Rev. 2017 Apr;30(2):529-555. doi: 10.1128/CMR.00033-16

Method Name

Real-Time Polymerase Chain Reaction (PCR)

Specimen Type

Whole Blood EDTA


Specimen Required


The high sensitivity of amplification by PCR requires the specimen to be processed in an environment in which contamination of the specimen by Tropheryma whipplei DNA is unlikely.

 

Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Royal blue top (EDTA), pink top (EDTA), or sterile vial containing EDTA-derived aliquot

Specimen Volume: 1 mL

Collection Instructions: Send specimen in original tube (preferred).


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated (preferred) 7 days
  Ambient  7 days
  Frozen  7 days

Reference Values

Not applicable

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

87798

LOINC Code Information

Test ID Test Order Name Order LOINC Value
WHIPB Tropheryma whipplei PCR, B 42602-3

 

Result ID Test Result Name Result LOINC Value
SRC89 Specimen Source 31208-2
56064 Result 42602-3

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Microbiology Test Request (T244)

-Gastroenterology and Hepatology Client Test Request (T728)

Mayo Clinic Laboratories | Neurology Catalog Additional Information:

mml-Behavioral, mml-Movement-Disorders, mml-CNS-Infections, mml-Pediatric