By Turna Ray
Quest Diagnostics has launched a renal transplant rejection test that the company claims can help doctors figure out if their patients are rejecting their new kidneys "weeks before" clinical symptoms or other standard tests can detect such events.
Kidney transplant rejection is a costly and common occurrence. Quest believes that its blood-based, non-invasive Renal Transplant Monitoring test, if widely adopted, can save the healthcare system money by obviating the need for the more expensive tests currently in use.
Quest developed the laboratory test in collaboration with Beth Israel Deaconess Medical Center and Weill Cornell Medical College. The company claims that it is the first commercial molecular diagnostic for kidney transplant rejection.
The real-time PCR-based test gauges several RNA markers, including FoxP3, GZMB, and PRF1, which Quest exclusively licensed from Beth Israel and Weill.
Terry Strom, co-director of The Transplant Institute at Beth Israel, along with Manikkam Suthanthiran, chairman of the Department of Transplantation Medicine at Weill, have published data showing that biomarkers such as FoxP3 and others are useful in detecting acute cellular rejection of renal transplants.
Researchers from Weill Cornell and elsewhere have published studies in several peer-reviewed journals demonstrating an association between the RNA markers in Quest's panel and renal transplant rejection. Rises in blood RNA levels "often occur before a rise in blood levels of serum creatinine," Quest said in a statement. As such, the Renal Transplant Monitoring test may allow doctors to predict earlier that their patients are at risk of transplant rejection and take action to prevent this from happening.
Wendy Bost, director of media relations at Quest, told PGx Reporter that the company "validated the test in the performing laboratory prior to release."
In 2009, there were nearly 17,000 renal transplant procedures performed, making the kidney the most routinely transplanted organ. However, based on 2010 figures from the US Organ Procurement and Transplantation Network and the Scientific Registry of Transplant Recipients, 70 percent of kidney transplants from a deceased donor fail within five years.
Current standard procedures for assessing whether a patient is rejecting a kidney transplant involve checking serum creatinine levels to gauge renal function and performing biopsies of the kidney, which can result in bleeding, graft injury, or loss.
According to 2007 estimates from the Government Accountability Office, the median annual cost for a Medicare beneficiary to experience transplant failure is more than $50,000. Comparatively, the median Medicare cost for someone who has a successful transplant is around $8,500.
The patient list price for the Renal Transplant Monitoring test is $700, according to Quest. "We believe that if our test is able to help reduce the incidence of even a small fraction of failed grafts, its benefits in healthcare cost savings could be significant," Bost said.
Because Quest's molecular diagnostic is less invasive and has been shown to harbor fewer adverse risks associated with the procedure, the company believes that the test can help lower healthcare costs associated with standard methods of assessing kidney transplant rejection.
Simultaneous with the announcement of the test's launch, Quest said that it had inked research and development collaborations around renal transplantation with the two institutions. Quest did not provide further details about the broader collaboration.
"Molecular diagnostics to noninvasively detect and predict renal-transplant rejection and monitor the efficacy and safety of pharmaceutical drug therapy and treatment withdrawal have the potential to significantly improve treatment and outcomes for renal transplant patients,” said Beth Israel's Strom said in a statement.
Transplant rejection is a growing area of investment for molecular diagnostic development, given the invasiveness of standard rejection testing methods and the costly adverse events associated with these procedures.
XDx markets the AlloMap test, a multi-gene expression test that assists doctors in determining whether heart transplant patients are at low risk of rejection and therefore can avoid invasive cardiac biopsies. XDx and Cedars-Sinai Heart Institute are conducting a clinical trial designed to show the usefulness of the AlloMap test in gauging heart transplantation patients' risk of rejection in the critical months immediately following surgery (PGx Reporter 2/8/2012).
AlloMap is cleared by the US Food and Drug Administration.
Quest, meantime, will continue to offer the Renal Transplant Monitoring test as an LDT through its CLIA-certified lab, and is not planning to seek FDA approval for the assay.
"We serve about half of all physicians and hospitals in the US," Bost said. "So, the renal transplant monitoring testing service is broadly available through Quest Diagnostics' laboratories."
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