As an adjunct in the rapid diagnosis of human herpesvirus-6 infection in cerebrospinal fluid specimens
Real-Time Polymerase Chain Reaction (PCR)/DNA Probe Hybridization
Exanthem Subitum
Herpes Virus-6
HHV-6 (Human Herpes Virus-6)
Human Herpes Virus-6 (HHV-6)
Roseola Infantum
CSF
Question ID | Description | Answers |
---|---|---|
SS012 | Specimen Source |
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Container/Tube:
Preferred: Aliquot Tube
Acceptable: Sterile vial
Specimen Volume: 0.5 mL
Collection Instructions: Do not centrifuge.
If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.
0.3 mL
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability. |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
CSF | Refrigerated (preferred) | 7 days | |
Frozen | 7 days |
As an adjunct in the rapid diagnosis of human herpesvirus-6 infection in cerebrospinal fluid specimens
Human herpesvirus-6 (HHV-6) is a member of the Herpesviridae family.
HHV-6 was first linked with exanthem subitum (roseola infantum) in
HHV-6 is designated as variant A (HHV-6A) or variant B
Negative
The sensitivity of the assay is very dependent upon the quality of the specimen submitted.
A negative test does not exclude infection with human herpesvirus-6 virus. Therefore, the results obtained should be used in conjunction with clinical findings to make an accurate diagnosis.
This assay detects nucleic acid, and therefore, cannot distinguish between viable and nonviable virus. Test performance depends on viral load in the specimen and may not correlate with cell culture performed on the same specimen.
A total of 32 plasma samples and 30 cerebrospinal fluid (CSF) samples were spiked with human herpesvirus-6 (HHV-6) plasmid control at the limit of detection (LoD) (25-50 copies/mcL). The 62piked specimens were run in a blinded manner along with 28 negative (nonspiked) plasma and 30 negative (nonspiked) CSF specimens. Of the spiked specimens, 100% were positive; of the nonspiked specimens, 100% were negative.
Analytical Sensitivity/LoD:
The lower LoD of this assay is 25 to 50 DNA target copies per mcL (in plasma).
Analytical Specificity:
No PCR signal was obtained from extracts of 25 viral, bacterial and fungal isolates that can cause similar symptoms as HHV-6 infection.
Precision:
Interassay precision was 100% and intra-assay precision was 100%.
Reference Range:
Although the reference range is typically "negative" for this assay, this assay may detect viremia in asymptomatic individuals. However, this assay is only to be used for patients with a clinical history and symptoms consistent with HHV-6 infection, and must be interpreted in the context of the clinical picture. This test should not be used to screen asymptomatic patients.
Reportable Range:
This is a qualitative assay and results are reported either as negative or positive for targeted HHV-6 DNA.
1. De Bolle L, Naesens L, De Clercq E: Update on human herpesvirus
2. Dockrell DH, Paya CV: Human herpesvirus-6 and -7 in transplantation. Rev
3. Abdel-Haq NM, Asmar BI: Human herpesvirus
4. Dockrell DH, Smith TF, Paya CV: Human herpesvirus 6. Mayo Clin Proc
Viral nucleic acid is extracted by the MagNA Pure automated instrument (Roche Applied Science) from clinical specimens. Primers directed to the immediate early gene of human herpesvirus-6 (HHV-6), produce a 195 bp amplicon. 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 (1 hour) detect amplicon development through stringent air-controlled temperature cycling and 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 light of a different wavelength that can be measured with a signal that is proportional to the amount of specific PCR product. LightCycler hybridization probes are designed for exact homology to HHV-6.(Cockerill FR III, Uhl JR: Applications and challenges of real-time PCR for the clinical microbiology laboratory. In Rapid Cycle Real-Time PCR Methods and Applications. Edited by U Reischel, C Wittwer, F Cockerill. Berlin, Germany, Springer-Verlag, 2002 pp 3-30)
Monday, Wednesday, Friday
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 US Food and Drug Administration.
87532
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
HHV6V | HHV-6 PCR, Varies | 33942-4 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
SS012 | Specimen Source | 31208-2 |
56092 | HHV-6 PCR, Varies | 33942-4 |