Test ID: LCJC
JC Virus, Molecular Detection, PCR, Spinal Fluid
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
As an aid in diagnosing progressive multifocal leukoencephalopathy due to JC virus
Method Name A short description of the method used to perform the test
Real-Time Polymerase Chain Reaction (PCR)/DNA Probe Hybridization
(PCR is utilized pursuant to a license agreement with Roche Molecular Systems, Inc.)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
JCV Qualitative DNA
John Cunningham Virus (JCV)
Polyomavirus
Progressive multifocal leukoencephalopathy (PML)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Sterile vial
Specimen Volume: 1 mL
Collection Instructions: Do not centrifuge.
Forms: If not ordering electronically, submit a Microbiology Request Form (Supply T244) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | NA |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| CSF | Refrigerated (preferred) | 7 days |
| Frozen | 7 days |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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 >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 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 (BKV), a closely related polyomavirus.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Not applicable
Interpretation Provides information to assist in interpretation of the test results
Detection of JC virus (JCV) DNA supports the clinical diagnosis of progressive multifocal leukoencephalopathy due to JCV
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
A negative result does not rule out the possibility of JC virus (JCV) infection.
This test is not to be used as a diagnostic tool for Creutzfeldt-Jakob disease.
The reference range in cerebrospinal fluid is "negative" for this assay, although JCV DNA may be detectable in the absence of clinical symptoms in certain patient populations.(6,7) 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.
Supportive Data
The following data supports the use of this assay for clinical testing.
Accuracy:
26 negative cerebrospinal fluid (CSF) specimens were spiked with JC virus (JCV) positive-control plasmid at the limit of detection (approximately 10 targets/mcL). The 26 spiked specimens were run in a blinded manner with 14 negative (nonspiked) specimens. 100% of the spiked specimens were positive and 100% of the nonspiked specimens were negative.
Analytical Sensitivity/Limit of Detection (LoD):
The lower LoD of this assay is 10 DNA target copies/mcL in CSF.
Analytical Specificity:
No PCR signal was obtained from the extracts of 15 viral isolates that may cause similar symptoms or be found in the CSF, including herpes simples virus types 1 and 2, Epstein-Barr virus, cytomegalovirus, human herpesvirus (HHV)-6, HHV-7, HHV-8, enterovirus, mumps, adenovirus, BK Virus, and SV-40 (Simian virus).
Precision:
Interassay precision was 100% and intraassay precision was 100%.
Reference Range:
The reference range in CSF is "negative" for this assay.
Reportable Range:
This is a qualitative assay and the results are reported as either negative or positive for targeted JC virus DNA.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Safak M, Khalili K: An overview: human polyomavirus JC virus and its associated disorders. J Neurovirol 2006;9 Suppl 1:3-9
2. Khalili K, White MK: Human demyelinating disease and the polyomavirus JCV. Mult Scler 2006 Apr;12(2):133-142
3. Ahsan N, Shah KV: Polyomaviruses and human diseases. Adv Exp Med Biol 2006;577:1-18
4. Romero JR, Kimberlin DW: Molecular diagnosis of viral infections of the central nervous system. Clin Lab Med 2003 Dec;23(4):843-865
5. Chen Y, Bord E, Tompkins T, et al: Asymptomatic reactivation of JC virus in patients treated with natalizumab. N Engl J Med Sep 10 2009;361(11):1067-1074
6. Egli A, Infanti L, Dumoulin A, et al: Prevalence of polyomavirus BK and JC infection and replication in 400 healthy donors. J Infect Dis Mar 15 2009;199(6):837-846
Method Description Describes how the test is performed and provides a method-specific reference
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 S-40 (other polyomaviruses). The LightCycler instrument (Roche Applied Science) amplifies and monitors the development of target nucleic acid sequences after the annealing step during 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) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
87798
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
| Result ID | Reporting Name | LOINC Code |
|---|---|---|
| SRC95 | Specimen Source | 31208-2 |
| 88909 | Result | 33295-7 |
| 28313 | Special Information | 48767-8 |
| 28314 | Report Status | N/A |
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