Molecular Detection by PCR

Molecular detection of Tropheryma whipplei by PCR.

For suspected classic Whipple’s disease (gastroenteritis), acceptable and reliable samples for testing are duodenal, gastric, or colonic biopsy. For suspected neurologic infection, acceptable samples for testing are CSF, brain tissue, and in some rare cases blood. Blood has the potential for positive detection but is NOT considered a reliable specimen for Whipple’s disease. Send tissues in sterile screw top culture bottles/jars. A minimum of 2mL of fluid specimen in a sealed screw top tube. For blood samples, a minimum of 1mL of unspun whole blood in a sealed EDTA collection vial is required. Serum, plasma, saliva and stool are not acceptable samples.

Whole blood unspun in EDTA tubes. Tissues are preferred frozen but formalin fixed/paraffin embedded tissue will also be processed. Blood samples must be received at the NML no longer than 48 hours from the time of collection.

Ship frozen tissue and CSF samples on dry ice and whole blood on ice packs. If any specimens, including CSF, were not frozen after collection, refrigerate and ship on ice packs.

Shipping of specimens shall be done by a TDG certified individual in accordance with TDG regulations. For additional information regarding classification of specimens for the purposes of shipping, consult either Part 2 Appendix 3 of the TDG Regulations or section 3.6.2 of the IATA Dangerous Goods Regulations as applicable.

For detection of classic gastrointestinal Whipple’s disease, the patient should exhibit symptoms of weight loss, mal-adsorption, weakness, fatigue, chronic diarrhea, lymphadenopathy, and abdominal pain. For suspicion of cerebral Whipple’s disease the patient should exhibit symptoms of neurological dysfunction, hemoparesis, cognitive dysfunction, dementia, seizures and ocular abnormalities. Ataxia, myelopathy and meningitis may also be present but are uncommon symptoms.

Completed Special Bacteriology requisition form.

Submit only specimens which are listed as samples ideal for the detection of a particular T. whipplei infection.

Results are based upon a real-time PCR assay of repeat sequences within the T. whipplei genome. Any positive or inconclusive results are repeated for confirmation by conventional PCR assays. A negative result does not eliminate the possibility of a T. whipplei infection but will only rule out a potential infection of the relative area of specimen origin. As with any laboratory test, the results of the test should be interpreted with consideration of all of the laboratory and clinical findings available.

12 calendar days. Please note that during times when large numbers of samples are received or if tests must be repeated the turnaround time may be longer.

1. Fenollar F, Birg ML, Gauduchon V, et al. 2003. Culture of Tropheryma whipplei from human samples: a 3-year experience (1999 to 2002). J. Clin. Micro. 41(8):3816-3822.
2. Fenollar F , Laouira S , Lepidi H , Rolain JM , Raoult D . 2008. Value of Tropheryma whipplei quantitative polymerase chain reaction assay for the diagnosis of Whipple disease: usefulness of saliva and stool specimens for first-line screening. Clin. Infect. Dis. (47):659-67.
3.  Lagier J-C, Lepidi H, Raoult D, et al. Systemic Tropheryma whipplei Clinical Presentation of 142 Patients with Infections (2010). Medicine 89:337-345.
4. Panegyres PK. 2008. Diagnosis and management of Whipple’s disease of the brain. Prac. Neuro. (8):311-317.
5. Rolain JM, Fenollar F, Raoult D. 2007. False positive PCR detection of Tropheryma whipplei in the saliva of healthy people. BMC Microbiology, 7:48.