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At a meeting in March 1990, members of FDA's Blood Products Advisory Committee expressed concerns about reports of severe, unexplained toxicity of artificial red cell oxygen carriers in patients in clinical trials.

Fratantoni and other CBER experts evaluated the committee's recommendations, as well as animal and human studies of the preparations. In the May 1991 issue of Transfusion, FDA published "points to consider" for researchers investigating red cell oxygen carriers. In evaluating risks and benefits of the carriers, the agency recommended "consideration of, and comparison with, the safety profile of approved oxygen carriers, such as red cells [derived from the public blood supply]."

No one knows for sure whether researchers will ever develop an "ideal" artificial oxygen carrier as an alternative to homologous transfusion. But promising possibilities are on the drawing board, and FDA is monitoring those possibilities.

Meanwhile, working alternatives continue in the operating room and the pharmacy.

The Real Scoop on AIDS and Shortages

Two concerns about blood transfusion get a lot of news coverage: AIDS and shortages.

The American blood supply is reasonably safe, and patients who need blood can accept it with confidence, according to Food and Drug Administration experts. But this doesn't mean that blood is entirely risk-free. Blood is human tissue, a biological product, so it carries a degree of risk.

Estimates of the risk of infection with HIV, the virus responsible for AIDS, range from 1 in 61,000 to 1 in 225,000 transfused units — or potentially 90 to 300 infections among some 18 million blood products used each year. The risk from transfusion, however, is far less than the risk of not getting blood when it's needed.

FDA's job is to enforce safeguards, such as questioning potential donors about risk behaviors, testing their blood for infection, quarantining donated blood until tests show it to be safe, and monitoring the blood banking system. Recent steps by FDA to help make the blood supply safer include:

Informing firms making computer software intended for blood product manufacture that the software programs are medical devices

Obtaining a consent degree placing the American Red Cross under court supervision to strengthen its quality control procedures

Proposing guidelines to help prevent recurrent blood center problems by eliminating causes of errors, ensuring integrity of test results, establishing effective controls for manufacture and recordkeeping, and ensuring adequate employee training

Proposing a rule, in conjunction with a Health Care Financing Administration rule, calling for blood centers to provide donor test results to hospitals so that patients who receive units can be notified if the donors later test positive for HIV antibodies.

In other words, FDA regulates blood banking much as it does manufacturers. Blood banks must meet quality control requirements comparable to those of the pharmaceutical industry and must ensure the safety of their commodities.

As for shortages, the blood supply has its ups and downs, like any commodity, but this fluctuation does not mean there's not enough blood for transfusions, says Joseph Fratantoni, M.D., director of hematology at FDA's Center for Biologics Evaluation and Research, which regulates blood banks and blood products. "It's a relative shortage," he says. Last winter, for instance, some 40 U.S. cities reported blood shortages. Contributing circumstances included the Los Angeles earthquake, a severe influenza season, and extremely cold weather over an extended period.

At any one time, Fratantoni says, only 4 to 5 percent of the U.S. population is donating all the blood, with 8 million volunteers donating 12 million units each year. About 20 to 25 percent of Americans, when interviewed, say they want no part of giving blood, he says. Of the rest, a significant percentage are unable to donate because they're anemic — mostly reproductive-age women — leaving about 40 to 50 percent of the total population eligible to donate.

Approved Alternatives

A number of approved drugs and biologicals can lessen the need for or serve as alternatives to blood transfusion:

Kogenate and Recombinate (recombinant factor VIII)--prevent or control bleeding in patients with hemophilia A and prevent bleeding associated with surgery.

Amicar (aminocaproic acid)—stabilizes clotting to control urinary tract bleeding and bleeding related to heart surgery, lung or cervical cancer, and other conditions.

Cyklokapron (tranexamic acid)—controls bleeding in hemophilia and reduces the need for factor VIII replacement after tooth extraction; it is for short-term use (two to eight days).

DDAVP Injection (desmopressin)—increases clotting factor VIII to control bleeding in patients with mild to moderate von Willebrand disease (a bleeding disorder) or hemophilia A, and prevents bleeding associated with surgery.

Trasylol Injection (aprotinin)—decreases the need for transfusion in patients undergoing coronary artery bypass surgery.

Epogen and Procrit (epoetin alfa)—stimulate red blood cell production in patients with anemia related to chronic kidney failure, taking Retrovir (zidovudine) for HIV infection, or receiving cancer chemotherapy.

Leukine and Prokine (sargramostim)—stimulate the bone marrow, where blood cells form, to produce white blood cells; they are used in patients with non-Hodgkin's lymphoma, Hodgkin's disease, and acute lymphoblastic leukemia.

Neupogen (filgrastim)—stimulates white blood cell production in cancer patients undergoing chemotherapy.

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www.fda.gov
FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.