Test Code LAB21005 Human Herpesvirus-6 A and B DNA Detection and Quantification, PCR, Plasma
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Lavender top (EDTA)
Submission Container/Tube:
Preferred: Plastic vial
Acceptable: Screw-capped, sterile container
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot plasma into a plastic vial.
Secondary ID
619925Useful For
As an adjunct in the rapid diagnosis of human herpesvirus-6 infection using plasma specimens
This test should not be used to screen asymptomatic patients
Method Name
Real-Time Polymerase Chain Reaction (PCR)
Reporting Name
HHV-6 A and B DNA Quant PCR, PSpecimen Type
Plasma EDTASpecimen Minimum Volume
0.3 mL
Specimen Stability Information
Specimen Type | Temperature | Time |
---|---|---|
Plasma EDTA | Refrigerated (preferred) | 7 days |
Frozen | 7 days | |
Ambient | 24 hours |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Heparin | Reject |
Clinical Information
Human herpesvirus-6 (HHV-6) is a member of the Herpesviridae family. These DNA viruses contain a capsid surrounded by a lipid envelope. Among members of this group, this virus is most closely related to cytomegalovirus (CMV) and HHV-7. As with other members of the herpesvirus group (herpes simplex virus [HSV]-1, HSV-2, varicella-zoster virus, CMV, Epstein-Barr virus, HHV-7, HHV-8), HHV-6 may cause primary and reactivated infections.(1) Infection with HHV-6 occurs early in childhood. Most adults (80%-90%) have been infected with this virus.
Human herpesvirus-6 was first linked with exanthem subitum (roseola infantum) in 1998; since then, the virus has been associated with central nervous system disease almost exclusively in patients who are immunocompromised.(1) HHV-6 is commonly detected in patients post transplantation. Clinical symptoms associated with this viral infection include febrile illness, pneumonitis, hepatitis, and encephalitis. However, most HHV-6 infections are asymptomatic.(2)
Human herpesvirus-6 is designated as variant A (HHV-6A) or variant B (HHV-6B) depending on restriction enzyme digestion patterns and its reaction with monoclonal antibodies. Generally, variant B has been associated with exanthem subitum, whereas variant A has been found in many immunosuppressed patients.(3) Infection with HHV-6 is very common, approaching 100% seroprevalence in developed countries.(4) In about 1% of the population, HHV-6 can integrate into the host genome. Often asymptomatic in immunocompetent hosts, reactivation can cause serious disease in immunocompromised individuals, particularly those with AIDS and transplant recipients, which can cause rejection of the transplanted organ and even death.(1)
This assay will be used to assist with diagnosis and monitoring of HHV-6 disease in patients who are suspected of having disease due to HHV-6 infection. It will also be used as an initial indicator of infection versus chromosomally-integrated HHV-6.
Reference Values
Undetected
Interpretation
The quantification range of this assay is 500 to 5,000,000 copies/mL (2.70 log to 6.70 log copies/mL)
An "Undetected" test result indicates the absence of human herpesvirus-6 (HHV-6) DNA in plasma.
A test result of "<500 copies/mL (<2.70 log copies/mL)" indicates that HHV-6 DNA is detected in the plasma, but the assay cannot accurately quantify the level of HHV-6 DNA.
A test result of ">5,000,000 copies/mL (>6.70 log copies/mL)" indicates that the HHV-6 DNA level present in plasma is above 5,000,000 copies/mL (6.70 log copies/mL), and the assay cannot accurately quantify the level of HHV-6 DNA. A viral load above 5,000,000 copies/mL should raise suspicion for chromosomally-integrated HHV-6 (ciHHV-6), and additional testing to rule out ciHHV-6 may be needed.
An "Inconclusive" result indicates that the presence or absence of HHV-6 DNA in the plasma specimen could not be determined with certainty after repeat testing in the laboratory, possibly due to inhibition or the presence of an interfering substance. If clinically indicated, submission of a new specimen for testing is recommended.
Method Description
The RealStar HHV-6 (human herpesvirus-6) PCR (polymerase chain reaction) Kit 1.0 (Altona Diagnostics) and the Exact Diagnostics HHV6-A/B Verification Panels and controls (Bio-Rad) are utilized for this assay. The assay employs TaqMan hydrolysis probe chemistry, with production of visible amplification curves and associated crossing point (Cp) values; no melting temperature curve is produced. A probe specific for HHV-6A DNA is labeled with the fluorophore FAM and is detected on the 465-510 channel. A probe specific for HHV-6B DNA is labeled with the fluorophore Cy5 and is detected on the 533-580 channel. The probe specific for the Internal Control (IC) is labeled with the fluorophore JOE, is detected on the 618-660 channel, and will be used within the mastermix. Using probes linked to distinguishable dyes enables the parallel detection and differentiation of HHV-6A and HHV-6B DNA as well as the detection of the IC in corresponding detector channels of the LC480 II instrument. The MagNA Pure 96 instrument (Roche Diagnostics) using the MP96 DNA and Viral NA small volume kit with an input of 200 mcL and a final elution volume of 100 mcL is utilized for viral nucleic acid extraction. The Pathogen Universal 200 protocol is used.(Package insert: RealStar HHV-6 Virus PCR Kit 1.0. Altona Diagnostics; Version 09/2018)
Day(s) Performed
Monday through Friday
Report Available
4 to 6 daysPerforming Laboratory

Test 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
87533
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
QHV6P | HHV-6 A and B DNA Quant PCR, P | 49392-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
622169 | HHV6 A DNA Detect/Quant, P | 49392-4 |
622170 | HHV6 B DNA Detect/Quant, P | 49392-4 |
Forms
If not ordering electronically, complete, print, and send an Microbiology Test Request (T244) with the specimen.