BRISBANE, Calif., Jan. 22 /PRNewswire/ -- For many Americans living
with a heart transplant, invasive heart-muscle biopsies that check for
organ rejection are a fact of life. However, a simple blood test that
analyzes a patient's genes, introduced in 2005, has been evaluated by
leading transplant centers and their experience verifies it can
accurately detect the absence of heart transplant rejection, according
to data reported in a new study authored by a consensus team of
international heart transplant experts and published in the December
2006 edition of the Journal of Heart and Lung Transplantation (JHLT).
In 2006, results from the CARGO (Cardiac Allograft Rejection Gene
Expression Observational) study were published and reported on the
utility of a gene expression profiling (GEP) test, called AlloMap(R)
molecular expression testing, which had been commercially available for
nearly a year. Developed by XDx, a molecular diagnostics company in
Brisbane, Calif., the test is currently offered at 40 transplant
centers in the United States.
"AlloMap testing is not only less
invasive and less risky than biopsy, it also monitors the absence of
organ rejection and raises the suspicion of damage before any damage to
the heart happens. Biopsy records damage that has already occurred,"
says Dr. Mario Deng, the article's corresponding author. Dr. Deng is
director of cardiac transplantation research and associate professor of
clinical medicine at Columbia University College of Physicians and
Surgeons, and a practicing cardiologist at New
York-Presbyterian/Columbia University Medical Center.
Approximately 30 percent of all heart transplant patients reject their
new heart at least once in the first year after transplantation. When
testing reveals organ rejection, a patient's immunosuppressive regimen
"The Cleveland Clinic was the first transplant
center in the United States to use the AlloMap test to follow patients
after cardiac transplant," said Dr. Randall C. Starling, the
editorial's first author and vice chairman of cardiovascular medicine
and section head of heart failure and cardiac transplant medicine at
Cleveland Clinic. "There is clearly a need for new methods to determine
the best way to manage heart transplant patients. Gene expression
profiling appears to be the future, and holds the potential to improve
accuracy of diagnosis, reduce the need for invasive procedures and
reduce cost. Additional research is necessary, but we are encouraged
that gene expression profiling will improve the care of our patients."
Based on the new data published as an invited editorial, in more
than 99 percent of cases, the AlloMap test successfully predicted the
absence of moderate or severe acute cellular organ-transplant
rejection. These results confirm the findings of the CARGO study.
The AlloMap test was developed to rule out rejection, meaning that a
low test score very reliably identifies transplant patients who are not
rejecting their transplanted heart. The primary advantage of the test
is to identify low-risk patients who can be monitored and managed using
noninvasive methods and who may benefit from being more aggressively
weaned off intensive immunosuppressive regimens that are associated
with serious side effects.
"Many of the premier transplant
centers in the United States have incorporated AlloMap testing into
their treatment protocol and physicians are relying on the test to
accurately manage the care of heart transplant recipients," said Pierre
Cassigneul, president and chief executive officer of XDx. "The invited
editorial in JHLT further validates the usefulness and accuracy of
AlloMap testing. We are pleased to see continued confirmation of the
test's abilities from real-world use."
The AlloMap test was
developed by XDx in partnership with eight major U.S. research
universities and presents current immune activity of the transplanted
heart recipient. The test uses real-time polymerase chain reaction
(PCR) and an algorithm to analyze the patient's gene expression. The
AlloMap test is currently being developed for use in lung
Before the availability of AlloMap testing,
heart-muscle biopsy was the only method available for detecting
rejection of the transplanted heart. Invasive heart biopsies are
performed frequently in the first year post-transplant and periodically
thereafter, often for the patient's lifetime.
Currently, the AlloMap test is available to heart transplant patients, ages 15 and older, two months post-transplantation.