How does the test work?
First, a blood sampling is taken in a special tube and sent to the laboratory. There, the plasma is recovered, and the concentration of the transplant DNA is determined therein. This analysis takes two days for the first determination, and one working day for each additional sample of an already known patient.
The highly sensitive TheraSure-TRANSPLANT MONITOR already detects a rejection reaction in the early stages and thus allows therapeutic intervention before possible irreversible damage or even an entirely pronounced rejection can occur.
What is cell-free DNA?
DNA is the genetic substance stored in each cell, which is unique for every human being. Nevertheless, all cells of the body have an identical copy of this DNA, which is inherited in half from your father and mother. Cells in the bloodstream and in organs release this DNA to the environment within the scope of normal cell death. Thus, such DNA enters the liquid portion of the bloodstream called blood plasma. Although the concentration is low, this free DNA can be detected with today’s technology.
How can cell-free DNA be used in transplant monitoring?
A transplant places a second DNA from the transplanted organ into the body and, that DNA is clearly distinguishable from patient’s DNA. Even in a transplant, cells always naturally die, and are then replicated. Therefore, cell-free DNA from the transplanted organ can always be detected in the blood plasma. In case of damage to the graft, e.g. by a rejection reaction, many more cells die off, leading to a significant increase in the DNA from the transplanted organ in the plasma. This provides a new value which is entirely specific to the transplanted organ and which can be measured with high sensitivity and accuracy.
What is the advantage of the TheraSure-Transplant Monitor?
The advantage of the test is that it is absolutely specific for the transplanted organ and that it has a very high sensitivity. The latter means that, e.g. the suspicion of rejection can be remarked at a very early stage. Several studies, by us and other scientific working groups, have shown for cardiac transplants in the chronic phase (> 3 months) that a continuous increase in cell-free transplant DNA can precede the subsequent clinical rejection diagnosis by weeks. The advantage for the patient is thus the detection of early warning signs, which allow for a therapeutic intervention before possible irreversible damage occurs due to a full blown rejection of the organ.
Should you have any further questions, please do not hesitate to contact us.