Real-time PCR assay for Torque Teno Virus detection and quantification to support transplant management

  • TTV viral load monitoring can be used to evaluate the immune status of adult transplant patients and is an aid to assess the immune function
  • TTV monitoring could help optimize immunosuppressive drugs reducing the risk for infections and rejection
  • Part of the EU funded project (TTV GUIDE TX) aims to demonstrate the safety and preliminary efficacy of TTV-guided dosing of immunosuppressive drugs in kidney transplant recipients.

Torque Teno Virus (TTV): a surrogate marker of immune function

Graft rejection due to inadequate immunosuppression is the leading cause for chronic graft dysfunction and infectious disease due to reduced immune function is a major cause of death. Optimization of immunosuppressive drugs is a crucial step to minimize the risk of infection and rejection and thereby prolonging patient and graft survival.

The Torque Teno Virus (TTV) is a non-pathogenic virus carried by nearly everyone and interestingly, research has demonstrated TTV peripheral blood copy number is associated with the grade of the immunosuppression of the host (1,2,3). If the immune system is strong, the TT virus load is low; this indicates a risk for graft rejection (6,8). If the immune system is weak, the TT virus load is high; this indicates a risk of opportunistic infections (4, 10,16).

The quantification of the TT virus load in the blood of transplant recipients might help optimize immunosuppressive drugs and thus reduce risk for infections and rejection.

European Project on Kidney Transplant

A EU funded project - TTV GUIDE TX - aims to demonstrate the safety and preliminary efficacy of TTV-guided dosing of immunosuppressive drugs in kidney transplant recipients. TTV allows for a comprehensive and personalized assessment of the function of the immune system. For the first time, this novel and original approach will be tested in an interventional, randomized and controlled clinical trial including hundreds of kidney transplant recipients from all over Europe.

Coordinated by the Medical University of Vienna (Austria), the TTV GUIDE TX brings together 19 partners from 7 EU countries, including kidney transplant physicians, clinical virologists, project and clinical trial managers, ethicists and bioMérieux, to run a clinical trial with almost 300 patients.

The TTV GUIDE TX project will work closely together with The European Kidney Patients’ Federation (EKPF), the European umbrella organization for 23 national kidney patients’ associations. Once established in routine clinical care, TT virus guidance might reduce thousands of infections and kidney transplant rejections each year.

In the future the TT virus might not only help kidney transplant recipients but also patients with liver, heart and lung transplantation and guide therapy in autoimmune, infectious and oncologic diseases

Find out more about the project at:

Please go to: to see the project video.

List of partners :

TTV R-GENE® kit: a promising biomarker for tailored transplant patients management

The TTV R‑GENE® kit, using the real‑time PCR technology after extraction of the viral DNA, enables the detection and quantification the genome of TTV in whole blood and plasma samples. Results are available in 75 minutes (extraction step not included).

Combined with other biological investigation methods (medical imaging, white blood cell count, lymphocyte phenotyping, etc.), the results obtained with the TTV R‑GENE® kit enable TTV viral load monitoring and are an aid to assess the immune function: TTV viral load monitoring can be used to evaluate the immune status of adult transplant patients.

This kit is intended for in vitro diagnostic use only, in clinical laboratories by laboratory health professionals

TTV R-GENE® (423 414)
Principle of the test Genomic detection and quantification of TTV
Ordering information Reference 423 414 – TTV R-GENE® - Real-Time Detection and Quantification kit
Technology Real-Time PCR / 5‘ nuclease Taqman technology
Gene target TTV 5'-UTR region
Specimen Whole blood, Plasma
Detection limit 250 copies/mL
Dynamic Range of Quantification From 250 to 10^9 copies/mL
Controls included Extraction + Inhibition control, Sensitivity control, Negative control
Results within 75 minutes (extraction step not included)
Reporting unit Copies/mL
Number of tests 90 tests
Storage conditions -15°C/-31°C
Validated Extraction platform
  • EMAG®
  • MagNA Pure 96
  • QIAsymphony SP
Validated Amplification platform
  • ABI 7500 Fast, ABI 7500 Fast Dx
  • LightCycler 480 (System II)
  • QuantStudio 5, QuantStudio 5 Dx
  • CFX96
  • Rotor-Gene Q
Status For in vitro diagnostic use


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