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33385 - TTV Torque Teno Virus qPCR

Test Code: 33385

TTViWATCH Torque Teno Virus qPCR assay

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Clinical and Procedure
Clinical Utility

TTViWATCH™: Torque Teno Virus qPCR is a rapid, reliable, non-invasive means to monitor for the risk of graft rejection vs. infection in solid organ transplant recipients.

About Test

Torque Teno Virus (TTV) is a small, non-enveloped virus belonging to the Anelloviridae family. This circular, single-stranded DNA virus is highly prevalent in humans and is found in diverse body fluids, including blood, saliva, and semen.

Despite its widespread presence in 90% of normal, healthy adults, TTV has not been linked to any specific diseases, making its clinical significance unclear. A number of studies suggest that TTV may act as a marker of immune status rather than a pathogen, with higher viral loads observed in immunocompromised individuals, such as organ transplant recipients and HIV patients. The prevalence of TTV in solid organ transplant recipients is up to 99% depending on time post-transplant.

TTV viral load monitoring is a promising tool in clinical diagnostics, providing critical information for managing patient health, particularly in those with compromised immune systems, including solid organ transplant recipients.

TTV viral load monitoring is beneficial for both infection and rejection risk monitoring in solid organ transplant recipients. The analyte, viral DNA, is stable, and the method of analysis (qPCR) has excellent precision and a large dynamic range.

TTV viral load in plasma indicates the intensity of host immunosuppression and is associated with the risk of allograft rejection and infectious disease.

  • Higher TTV viral load is associated with a higher risk of Infection and lower risk of Rejection
  • Lower TTV viral load is associated with a higher risk of Rejection and lower risk of Infection

Extraction of genomic acid from plasma specimen followed by PCR amplification of targets using real-time PCR methods. An internal control is added to ensure that extraction was performed correctly and that the PCR reaction was not inhibited.

Turnaround Time

1 - 2 business days

Specimen Information
Specimen Type Test Code CPT Code NY Approved Volume Assay Range Special Instructions
plasma 33385 87799 Yes

0.6 ml minimum, 2.0mL recommended

250 to 5.00E+09 copies/mL

  • Collect 4-5 mL whole blood in EDTA tube.
  • Avoid using gel separator tubes; samples collected in gel separator tubes have increased rate of PCR inhibition.
  • Centrifuge and transfer 2 mL plasma to sterile, screw top tube.
  • Specimens should be shipped within the following parameters;
    • 7 days at ambient temperature (15˚C to 25˚C)
    • >7 days of refrigerated storage (2˚C to 8˚C)
    • 30 days frozen at -20°C (-32˚C to -10˚C)
    • 30 days frozen at -80°C (-90˚C to -64˚C)

Can be shipped at ambient or frozen temperature Monday through Friday.

Causes for Rejection

Specimens beyond their acceptable length of time from collection as listed in the specimen handling.


Specimens are approved for testing in New York only when indicated in the Specimen Information field above. The CPT codes provided are based on Eurofins Viracor’s interpretation of the American Medical Association's Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. Eurofins Viracor assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material.

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