The U.S. Food and Drug Administration has approved a noninvasive test that allows physicians to identify heart transplant receivers who are rejecting the new muscular organ.

Called AlloMap, the test examines specific types of genetic data which is included in the white blood cells. Also knows as leukocytes, these cells defend the body against infectious diseases and foreign materials. However, they can also turn against a transplanted organ, triggering disastrous effects. After an individual’s blood sample is analyzed in the laboratory, the test produces a score that indicates what the chances of the human body to reject a donated heart are.

"AlloMap can help contribute to an appropriate treatment plan by identifying those patients not experiencing postoperative heart transplant rejection," asserted Daniel G. Schultz, Director of FDAs Center for Devices and Radiological Health.

According to Dr. James Yee, chief medical officer of XDx, Inc., the molecular diagnostics company based in Brisbane, Calif, which developed AlloMap, the test "requires only a simple blood sample." It is particularly helpful in tracking down a "silent rejection," (the rejection which doesn’t imply obvious symptoms), the Associated Press reported.

The test, which costs $2,950, was clinically validated by employing data from nine top heart-transplant centers taking which took part in the Cardiac Allograft Rejection Gene Expression Observational study. 

50 percent of the rejections happen in the first month and a half after the moving of the heart from the donor to the patient's body, and an estimated 25 percent of the recipients reject the transplant in the first year following the transfer.

AlloMap is the third in vitro diagnostic multivariate index assay (IVDMIA) approved by the Food and Drug Administration.