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Viracor TRAC® Liver dd-cfDNA

Test Code: 33036

Viracor TRAC® Kidney dd-cfDNA

Transplant Rejection Allograft Check (TRAC®),  donor-derived cell-free DNA (dd-cfDNA)

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Clinical and Procedure
Clinical Utility

The Viracor Transplant Rejection Allograft Check (TRAC®) donor-derived cell-free DNA (dd-cfDNA) assay is designed to be a noninvasive liquid biopsy to monitor the percent of dd-cfDNA by next generation sequencing (NGS) in the transplant recipient’s plasma post- transplant.

About Liver Transplant
Liver transplants are performed to replace diseased livers with healthy ones. Transplantation of the whole liver is not always necessary, depending on liver transplant indications. There are some instances where only a section of the liver is needed for pediatric transplant patients. Because of this, family members who are genetically compatible can donate part of their livers (living donor transplantation or live donor transplantation). Otherwise, the majority of livers come from unrelated deceased organ donors.

About Transplant Rejection and dd-cfDNA
The current standard method of allograft rejection diagnosis and surveillance is by organ biopsy, which is an invasive technique that suffers from high cost and multiple potential serious complications for the patient. Biopsies may also be inconclusive and lead to adverse treatment decisions. Recently, quantification of dd-cfDNA (by NGS methods) in a transplant recipient’s plasma has been developed to non-invasively monitor and diagnose organ rejection in transplant recipients.

Research has shown that donor-derived cell-free DNA (dd-cfDNA) found in a patient’s plasma may be used as a liquid biopsy marker for identifying solid organ transplant rejection. Donor-derived cell-free DNA is released when the donated organ is attacked by either antibody or cell-mediated rejection processes. While the exact mechanism of action resulting in the circulating dd-cfDNA is not known, some researchers have speculated it could be produced by apoptosis, necrosis or active secretion. Regarded as a potential universal molecular biomarker, the concept of dd-cfDNA is being applied to several different solid organ transplant recipient populations. Not only is the method noninvasive, but the method has the ability quantify the percentage of cell-free DNA post organ transplant.

About Viracor TRAC® dd-cfDNA
Viracor licensed dd-cfDNA technology from Stanford, who has developed a genotyping and bioinformatics pipeline utilizing NGS for organ transplant rejection. Utilizing a blood sample evaluated by this genotyping and bioinformatics pipeline (with a large dynamic range) the Viracor TRAC® dd-cfDNA test help providers evaluate solid organ transplant rejection when the donated organ came from closely related individuals, e.g. sibling kidney donors. The licensed algorithm accurately quantifies the donor derived fraction of cell-free DNA, even when the donor genotype is unknown. This method can provide essential information, in a non-invasive way, which may be useful in the determination of organ rejection.


The Transplant Rejection Allograft Check (TRAC®) assay determines the percentage of circulating cell free DNA (cfDNA) in transplant recipients derived from donor grafts.  cfDNA is extracted from plasma isolated from whole blood collected in Streck BCL tubes.  The cfDNA is quantified, DNA libraries are prepared and analyzed with whole genome next generation sequencing (NGS) (2 x 75 paired end sequencing).  NGS sequence data are mapped to a human reference genome and, along with donor genotype data generated using genomic DNA isolated from donor white cells and analyzed with the Illumina Infinium Omni2.5-8 beadchip arrays on the iScan instrument, final calculation of the donor and recipient fractions of the cfDNA are analyzed using a bioinformatics pipeline to calculate the percentage of donor derived cfDNA present.

Turnaround Time

4-6 days business days from receipt of specimen.

Specimen Information
Specimen Type Order Code CPT Code NY Approved Volume Assay Range Special Instructions
whole blood 33036 0118U Yes

10 mL Streck (or) 6 mL HemaSure-OMIC

0.5% - 60%

  • Collect EITHER 10 mL whole blood in a Streck cell-free DNA BCT (OR) 6 mL whole blood in a HemaSure-OMICs Whole Blood Collection Tube. Streck tubes must be completely full to maintain proper ratio of blood to anticoagulant. HemaSure-OMICs tubes should be completely filled to the 6 mL indicator to ensure proper ratio of blood to stabilizing reagent.
  • For best results when using HemaSure-OMICs whole blood collection tubes, a 21G or 22G winged needle with an extension tube (butterfly) is advised.
  • For best results when using a Streck cell-free DNA BCT, a 21G or 22G needle is advised. Slower fill times may be observed when using a smaller gauge needle.
  • Regarding order of draw: HemaSure-OMICs tubes can be drawn in any order. Streck cell-Free DNA BCT can be drawn after EDTA tubes (purple top) and before the Glycolytic inhibitor tubes (grey top). If a Streck tube immediately follows a heparin tube, collect an EDTA tube first as a waste tube prior to collection in Cell-Free DNA BCT. When using a winged (butterfly) collection set for venipuncture and the Cell-Free DNA BCT is the first tube drawn, a non-additive or EDTA discard tube should be partially drawn first in order to eliminate air or 'dead space' from tubing.
  • After venipuncture, it is critical to mix tubes thoroughly by inverting the tube 8-10 times end-over-end immediately after collection.
  • Ship the HemaSure-OMICs or Streck tube via ambient shipping. Samples must be received and processed no more than 7 days after collection.
  • Please call Client Services at 1-800-305-5198 to order either Streck cell-free DNA BCT or HemaSure-OMICs whole blood collection tubes for your lab.

Ship Monday through Friday. Friday shipments must be labeled for Saturday delivery. All specimens must be labeled with patient's name, collection date and time. A Eurofins Viracor test requisition form must accompany each specimen. Multiple tests can be run on one specimen. Ship specimens FedEx Priority Overnight® to: Eurofins Viracor, 18000 W 99th St.ive, Lenexa, KS 66219

Causes for Rejection

Whole blood frozen, specimens beyond their acceptable length of time from collection as listed in the specimen handling, or specimen types or containers other than those listed.


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.


Bromberg JS, Brennan DC, et. al. Biological Variation of Donor-Derived Cell-Free DNA in Renal Transplant Recipients: Clinical Implications. Journal of Applied Laboratory Medicine (2017, September); 2:02, 1-13.

Gielis EM, Ledeganck KJ, De Winter BY, et. al. Cell-Free DNA: An Upcoming Biomarker in Transplantation. American Journal of Transplantation (2015); 15: 2541-2551.

De Vlaminick I, Martin L, Kertesz M, et. al. Noninvasive monitoring of infection and rejection after lung transplantation. Proceedings of the National Academy of Sciences (2015, October 27); 112:43, 13336-13341.

Grskovic M, Hiller DJ, Eubank LA, et. al. Validation of a Clinical-Grade Assay to Measure Donor-Derived Cell-Free DNA in Solid Organ Transplant Recipients. The Journal of Molecular Diagnosics (2016, November); 18:6, 890-902.

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