Test Code JCPCR JC Virus, Molecular Detection, PCR, Spinal Fluid
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Preferred: 12 x 75-mm screw cap vial
Acceptable: Sterile screw cap vial
Container/Tube: Sterile vial
Specimen Volume: 0.5 mL
Collection Instructions: Do not centrifuge.
Useful For
Aiding in diagnosing progressive multifocal leukoencephalopathy due to JC virus
This test is not to be used as a diagnostic tool for Creutzfeldt-Jakob disease
This test is not recommended for screening asymptomatic patients
Testing Algorithm
For more information see Meningitis/Encephalitis Panel Algorithm.
Special Instructions
Method Name
Real-Time Polymerase Chain Reaction (PCR)/DNA Probe Hybridization
Reporting Name
JC Virus, PCR, CSFSpecimen Type
CSFSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
CSF | Refrigerated (preferred) | 7 days | |
Frozen | 7 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitabilityClinical Information
JC virus (JCV), a member of the genus Polyomavirus, is a small nonenveloped DNA-containing virus. Primary infection occurs in early childhood, with a prevalence of greater than 80%.(1) The virus is latent but can reactivate in immunosuppressed patients, especially those with AIDS.
JCV is recognized as the etiologic agent of progressive multifocal leukoencephalopathy (PML), a fatal demyelinating disease of the central nervous system.(2,3) Histologic examination of brain biopsy tissue may reveal characteristic pathologic changes localized mainly in oligodendrocytes and astrocytes. Detection of JCV DNA by polymerase chain reaction (PCR) (target gene, large T antigen) in the cerebrospinal fluid specimens of patients with suspected PML infection has replaced the need for biopsy tissue for laboratory diagnosis.(4) Importantly, the PCR test is specific with no cross-reaction with BK virus, a closely related polyomavirus.
Reference Values
Negative
Interpretation
Detection of JC virus (JCV) DNA supports the clinical diagnosis of progressive multifocal leukoencephalopathy due to JCV.
Cautions
A negative result does not rule out the possibility of JC virus (JCV) infection.
The reference value in cerebrospinal fluid is "negative" for this assay, although JCV DNA may be detectable in the absence of clinical symptoms in certain patient populations.(5,6) However, this assay is only to be used for patients with appropriate neurological and neuroradiological features of progressive multifocal leukoencephalopathy and is not indicated for screening asymptomatic patients.
Method Description
Viral nucleic acid is extracted from the specimen using the MagNA Pure automated instrument (Roche Applied Science). Primers are directed to the large T antigen gene, which is a conserved sequence specific for JC virus (JCV). This assay detects only JCV; it does not detect BK virus or Simian virus 40 (SV40) (other polyomaviruses). The LightCycler instrument (Roche Applied Science) amplifies and monitors the development of target nucleic acid sequences after the annealing step during polymerase chain reaction (PCR) cycling. This automated PCR system can rapidly detect amplicon development through stringent air-controlled temperature cycling in capillary cuvettes. The detection of amplified products is based on the fluorescence resonance energy transfer (FRET) principle. For FRET product detection, a hybridization probe with a donor fluorophore, fluorescein, on the 3'-end is excited by an external light source and emits light that is absorbed by a second hybridization probe with an acceptor fluorophore, LC-Red 640, at the 5'-end. The acceptor fluorophore then emits a light of a different wavelength that can be measured with a signal that is proportional to the amount of specific PCR product.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
Same day/ 1 to 4 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest 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 |
---|---|---|
JCPCR | JC Virus, PCR, CSF | 33295-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
618305 | JC Virus, PCR, CSF | 33295-7 |