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Agency to test value of treated blood

Published Sep. 4, 2005

Four months after two Tampa Bay area residents contracted HIV from blood transfusions, Florida Blood Services is planning to test a system for removing HIV and other viruses and bacteria from donated blood.

Dr. German F. Leparc, the medical director at FBS, said the blood center is talking with two area hospitals about participating in the clinical trials, and it hopes to begin recruiting patients by April.

One of the two studies would measure the effectiveness and safety of treated platelets, routinely given to cancer patients undergoing chemotherapy to help rebuild their damaged blood.

The other would measure how well treated red blood cells perform when they're transfused into patients undergoing open-heart surgery.

"Is the blood as effective as it is without the treatment?" Leparc said. "Secondly, are the side-effects worse than the benefits? And (thirdly), is the process feasible? Is this something that would work in the real world?"

In July, Florida Blood Services, the Tampa Bay area's main blood bank, announced its tests had failed to detect HIV-positive blood, and two unidentified transfusion recipients were infected.

A three-week investigation by the U.S. Food and Drug Administration found the center's procedures for handling, testing and storing blood met government standards, the agency said. It issued no orders for corrective action.

The Florida Department of Health also investigated and determined FBS was "in compliance with the provisions of the applicable federal and state regulations," the health inspector wrote in a letter to the center.

The cases marked the second and third known transmission of HIV through transfusion since 1999, when blood banks began using an extremely sensitive test _ called nucleic acid testing, or NAT _ to look for the virus.

But if the donor gives blood up to 10 days after becoming infected, as is believed to have happened in this case, there may not be enough virus in the sample for the test to detect.

Currently, samples of blood from 16 to 24 donors are pooled, then tested for HIV and hepatitis C. If a virus is detected, technicians retest each sample until they find the infected one.

Blood banks would like to test each sample individually. That would increase the likelihood of finding HIV and reduce the risk of contracting it to an estimated 1 in 3-million. But experts say they lack the technology to do it, with some 14-million units of blood processed each year in the United States.

"That is the best way of testing, but it's just not feasible at this moment," said Dr. James P. Aubuchon, medical director of the blood bank and transfusion service at Dartmouth Medical School. "It's going to take a few more steps, analytical equipment steps, before we can implement single donor testing routinely."

At this point, cleansing the blood appears more likely. In August, Leparc participated in a national conference, sponsored by the U.S. Food and Drug Administration, exploring blood-cleansing systems, called "pathogen reduction."

Two main systems are being tested: One uses ultraviolet light to kill viruses and bacteria, while the other kills them with chemicals.

Leparc said Florida Blood Services hopes to recruit cancer patients and open-heart surgery patients from two area hospitals to try the treated blood.

Although such improvements were being considered well before the two patients were infected this summer, the St. Petersburg incident jarred the blood-banking community and the public and heightened the sense of urgency.

"What everybody expects is zero risk. Nobody wants to accept anything but zero risk," Leparc said. "I don't think there's anything in life that's zero risk, but we work (toward it). It's not the fact of whether it's possible or not, but trying to get there."