Tropheryma whipplei, PCR (TWRP)

Marshfield Lab Public WebSite

Marshfield Clinic Public WebSite

Test Code: WHIPPSO

Overview
Ordering
Specimen
Performing
Clinical/Interpretive
Contacts
Coding

Synonyms/Keywords

Whipple's Disease

Useful For

As an aid in diagnosis of Whipple disease, especially for identifying inconclusive or suspicious cases, using tissue or fluid specimens

Specimen Requirements

Specimen Type	Preferred Container/Tube	Acceptable Container/Tube	Specimen Volume	Specimen Minimum Volume (allows for 1 repeat)
Submit only 1 of the following specimens:
Fresh tissue or Biopsy collected from: Small intestine tissue (duodenum, ileum, or jejunum), lymph node, bone, joint, synovial, liver, pancreas, spleen, lung, heart valve (and other heart tissues), or brain	Sterile container		Entire collection	5 mm (approximately the size of a pencil eraser)
Fluid: Cerebrospinal or ocular (eg, vitreous humor)	Sterile vial		0.5 mL	0.5 mL
Synovial Fluid	EDTA Lavender Top Tube (LTT)	Pink Top Tube (PTT), Royal Blue Top EDTA Tube (RBTT), Sterile vial containing and EDTA-derived aliquot, red clot tube (no anticoagulant), or sterile container	0.5 mL	0.5 mL
Paraffin-embedded Tissue Block prepared from: Small intestine (duodenum, ileum or jejunum), lymph node, bone, joint, synovial, liver, pancreas, spleen, lung, heart valve (and other heart tissues) or brain	Submit a FFPE tissue block to be cut and returned	Perform microtomy and prepare five separate 10-micron sections. Each section (scroll) must be placed in a separate sterile container for submission.

Collection Processing Instructions

Fresh tissue or biopsy:

1. Collect fresh tissue specimen.

2. Submit tissue only, do not add fluid to tissue.

3. Refrigerate or freeze specimen.

Synovial Fluid:

Send specimen in original tube (preferred).

Specimen Stability Information

Specimen Type	Temperature	Time
Fresh Tissue or Biopsy	Refrigerated (preferred)	< 7 days
Fresh Tissue or Biopsy	Frozen	< 7 days
Cerebrospinal, Ocular or Synovial Fluid	Refrigerated (preferred)	< 7 days
Cerebrospinal, Ocular or Synovial Fluid	Frozen	< 7 days
FFPE	Ambient (preferred)
FFPE	Refrigerated

Rejection Criteria

Slides, Bone Marrow

Interference

Test results should be used as an aid in diagnosis and not be considered diagnostic in themselves. The single assay should not be used as the only criteria to form a clinical conclusion, but results should be correlated with patient symptoms and clinical presentation. A negative result does not negate the presence of the organism or active disease.

Performing Laboratory Information

Performing Location	Day(s) Test Performed	Report Available	Methodology/Instrumentation
Mayo Clinic Laboratories	Monday, Wednesday, Friday	2-7 days	Real-Time Polymerase Chain Reaction (PCR)

Reference Lab

Mayo Clinic Laboratories

Test 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, 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 Tropheryma whipplei DNA in quantities less than the limit of detection of the assay.

Outreach CPTs

CPT	Modifier (if needed)	Quantity	Description	Comments
87798

Synonyms/Keywords

Whipple's Disease

Ordering Applications

Ordering Application	Description
COM	Tropheryma whipplei, PCR (TWRP)
Cerner	Tropheyma whipplei, PCR (TWRP)

If the ordering application you are looking for is not listed, contact your local laboratory for assistance.