Organ transplantation is an important medical procedure which saves lives in cases where a patient has organ failure or disablement, and it is now possible to transplant many organs including heart, lungs, kidney, and liver.  In some cases, the transplanted organ is rejected by the recipient patient, which creates a life-threatening situation.  Monitoring the patient for rejection is difficult and expensive, often requiring invasive procedures.  Furthermore, current surveillance methods lack adequate sensitivity. 
The present invention resolves these problems by providing non-invasive methods of monitoring organ transplant patients for rejection that are sensitive, rapid and inexpensive.