Experts Debate Cleansing Blood
Experts Debate Cleansing Blood
CDC HIV/STD/TB Prevention News Update
Thursday, August 08, 2002
"Experts Debate Cleansing Blood"
St. Petersburg Times (08.08.02)::Wes Allison
The giants of America's blood-banking world, along with the makers of
medical devices and federal regulators, convened Wednesday at the National
Institutes of Health for a workshop on cleaning blood of HIV, hepatitis C
and a host of viruses, bacteria and parasites. The meeting comes on the
heels of an announcement by Florida Blood Services that HIV-positive blood
went undetected and infected two transfusion recipients.
Since 1999, American blood banks using highly sensitive nucleic acid have
tested for HIV in donated blood, cutting the transfusion transmission risk
to just 1 in 2 million. The
procedure works very well except when a donor gives blood up to ten days
after becoming infected, as is believed to have happened in the Florida
Blood Services case. Within that window there may not be enough virus in the
sample for the test to detect.
Over 100 deaths and hundreds of illnesses each year stem from transfusions
due to a wide array of bacteria, from staphylococcus to streptococcus. Most
susceptible are platelets, the blood's clotting agent. Unlike other blood
products, which are chilled or frozen, platelets must be stored at room
temperature, allowing bacteria to grow.
"This is the most common cause of morbidity and mortality from blood
transfusion, way more than HIV, way more than hepatitis, way more than
anything you've heard of," said Dr. Rosalyn Yomtovian, director of the blood
bank and transfusion medicine at University Hospitals of Cleveland.
Experts are turning to a new procedure called pathogen inactivation. The
process works by infusing blood products with chemicals that make pathogens
vulnerable to destruction. The goal is not to filter the blood, but to
destroy the DNA of any bugs in it, rendering them inert.
Experts from the United States, Europe and Canada, however, have misgivings
about pathogen inactivation. Cleansing could double or triple blood
processing costs. Also, the treatment damages blood cells, meaning more
blood would have to be collected. And it will take years of testing to
determine the procedure's safety.
Cerus Corp.-Baxter Healthcare has cleared the first of several regulatory
hurdles for approval of its Helix pathogen inactivation system in the
European Union. And three companies have submitted early test results to the
FDA. FDA licensing of one system or another will likely lead to its becoming
the de
facto standard of care