Verax Biomedical receives FDA clearance for Platelet PGD test

Sep 23 2011

A $30 test that takes fewer than 30 minutes to perform can prevent potentially deadly transfusions of bacterial contamination in platelets, according to a new study published in the peer-reviewed journal Transfusion. An early view of the study can be found at the journal's web site.

Following the study, the U.S. Food and Drug Administration on September 8, 2011, cleared a new indication for the test, known as the Verax Platelet PGD^® test, Verax Biomedical and Fenwal Inc. announced today. The FDA said the test can now be labeled and marketed as a "safety measure" for leukoreduced apheresis platelets. This is the first time the agency has used the "safety measure" designation for a test to detect bacterial contamination in platelets. The test's label and packaging have been revised to include this new safety indication.

The test was developed by Verax Biomedical of Worcester, Mass., and is marketed and sold globally by Fenwal Inc. of Lake Zurich, Ill. The Verax Platelet PGD^® test is the only rapid test for the detection of bacteria in platelets that is cleared by the FDA and CE Marked in Europe.

Published studies demonstrate that bacterial contamination in platelets is the most important infectious threat to transfusion safety. Hospitals in the U.S. and Europe, particularly those that specialize in treating cancer, are starting to adopt the Verax Platelet PGD^® test as an additional safety measure for their platelet inventory.

Blood centers perform culture tests for bacteria in apheresis platelets 24 hours after donation, analyze results and dispose of contaminated units. But platelets have a five-day shelf life and bacteria levels just 24 hours after donation may be too low for detection by culture. Studies show that early culture testing misses an estimated three of every four bacterially contaminated units, which are then released to hospitals for transfusion.

The Verax Platelet PGD^® test is meant to be used as a safety measure following culture testing of apheresis platelets. It is performed within 24 hours of transfusion, when bacteria populations (if present) may have grown to more detectable levels.

The study published in Transfusion examined more than 27,000 platelet transfusions. Eighteen hospitals participated in the study. The study confirmed the ability of the Verax Platelet PGD^® test to detect bacteria missed by culture testing and enabled clinicians to prevent potentially deadly infections in patients. The study's lead investigator is Michael R. Jacobs, M.D., Ph.D., of the Case Western Reserve University and University Hospitals Case Medical Center in Cleveland, Ohio.

"Experts in transfusion medicine have known for some time that early culture testing has limitations," said Dr. Jacobs. "What our study shows is that testing platelets within 24 hours of transfusion allows hospitals to prevent many contaminated units from reaching patients. It's a potentially life-saving safety measure that should be considered for implementation as an infection-prevention practice for hospitals and other sites of care."

Platelet transfusions are typically needed to prevent or treat bleeding in individuals undergoing chemotherapy for cancer, following major trauma, during or after surgery, and in patients who are not able to produce platelets.

More than 5 million platelet doses are transfused annually worldwide and an estimated 1 in 2,000 doses are contaminated by bacteria. Bacteria-contaminated platelets can cause sepsis, a life-threatening infection in the bloodstream that can spread to multiple organs.

According to the FDA in a November 2009 news release, "bacterial contamination of platelets is the leading infectious cause of patient fatalities associated with platelet transfusion."

Because patients who receive platelet transfusions are often very sick, instances of transfusion-related reactions and deaths can be difficult to confirm. Experts agree such reactions are under-reported.

The Verax Platelet PGD^® test targets antigens found on the surface of a wide spectrum of bacteria known to be harmful in high concentrations. The test was originally cleared by U.S. regulators in 2007 for apheresis platelets and CE Marked for distribution in Europe in 2009.

According to the study in Transfusion, use of the test on the day of transfusion "can interdict contaminated units and prevent transfusion reactions." Transfusion is published by AABB, an international organization that accredits blood centers and hospital-based blood banks.