Richard Davey, M.D., (top left), director of FDA’s Division of Blood Applications, holds a unit of blood that is ready for processing. Jason Liu, Ph.D. (top right), director of FDA’s Laboratory of Molecular Testing and Immunogenetics, transfers blood (bottom left) to 50 ml tubes. See more FDA blood research photos on Flickr.
Every two seconds in the U.S., someone needs a blood transfusion or blood product—people of all ages who are injured, need surgery or who are suffering from illness. The Food and Drug Administration's (FDA) primary responsibility with regard to blood and blood products is to assure the safety of patients who receive these life-saving products. FDA is at the forefront of evaluating and encouraging innovative technologies designed to identify and minimize the risks to people who receive transfusions, such as the transmission of infectious disease, while maintaining a safe and adequate supply.
Richard Davey, M.D., is director of the Division of Blood Applications, Office of Blood Research and Review, at FDA. He discusses advances in the field, contingency plans during disasters and why—and when—to give blood.
Q: There have been many improvements in transfusion practice since the modern era of blood transfusion began in 1900. What's on the horizon?
A: We're excited about many developments, including a new red blood cell testing technology aimed at patients with illnesses that require frequent transfusions, for example sickle cell anemia. These patients sometimes develop antibodies that complicate finding compatible blood for transfusion.
A new FDA laboratory is evaluating this new technology which identifies the genetic characteristics of a patient's red blood cells so they can be more precisely matched to a donor. FDA is encouraging submissions from industry for these molecular test kits. It's an important breakthrough.
Exciting research is also progressing on technologies that will significantly reduce any bacteria, viruses and parasites that may be in blood. These technologies would complement existing tests for these infectious agents, thus making a safe blood supply even safer.
Q: Isn't the blood supply already safe?
A: The United States is recognized as having one of the safest blood supplies in the world, but assuring the safety and availability of blood products still poses challenges. The HIV risk to recipients is now only about 1 in every 2 million units of blood transfused in the USA, but it's still not zero. We test all blood for HIV, hepatitis B and C, West Nile virus and the parasite that causes Chagas disease, among other infectious agents. Blood found to contain any of these pathogens is discarded and, in most cases, the individual is notified and deferred from further donation.
Q: Is artificial blood possible?
A: Companies are working to develop oxygen carriers that could substitute for red blood cells. We're working with these companies and remain hopeful that one or more of these technologies eventually will prove to be safe and effective.
Q: How much blood is needed in the U.S.?
A: About 15 million units of red blood cells are drawn every year for transfusion to about five million recipients. In recent years, the demand for red blood cells has declined, primarily because doctors are learning to transfuse more scientifically and use blood only when necessary. However, challenges remain. In June, for example, the American Red Cross had almost 50,000 fewer donors than expected. Type O negative red cells, which can be transfused to people of all blood types, is the blood type most likely to be in short supply, but there is a need for donors of all blood types, all the time.
The American Red Cross and independent blood centers affiliated with America's Blood Centers each collect about 45% of the blood supply, with the remainder collected by hospital blood banks.
Q: At the Boston Marathon, 264 people were injured, creating an unexpected demand for blood. Did that cause a supply problem?
A: Boston has an excellent triage system so casualties were spread among several hospitals, which also spread the need for blood. In case of a disaster such as the marathon bombing, an interagency task force mobilizes to move blood to where it is needed.
Q: During disasters, many people volunteer to donate blood. Is that helpful?
A: It's a good and noble response, but we need donors every day to meet ongoing requirements for blood. It takes two to three days to fully test and qualify blood for transfusion. Therefore, it is the blood that is fully tested and available for transfusion that is used at the time of an emergency. The people donating today will be the heroes if a disaster occurs next week.
After 9/11, for example, many people donated. However, little of the additional blood was needed, and some of the donated blood expired and had to be discarded. The best response during a major disaster is to have already qualified as a regular blood donor and to have records on file at the blood center. Then the blood center can call you when your blood type is most needed. And, as mentioned above, become a regular blood donor for everyday patient needs and to have your blood available if an emergency occurs.
Q. What are the different components of blood, and how are they used?
A. Whole blood can be divided into several components, each of which can be important to a patient in need. Red blood cells carry oxygen, and are important to correct bleeding or to compensate for inadequate production of these cells. Blood platelets are small particles that are important for normal blood clotting to occur. They are often used in cancer patients, when the disease or the treatment interferes with the normal production of these elements. Blood plasma is the yellow fluid that remains when the red cells and other particles are removed. Plasma is also important for normal blood clotting to occur. It can be transfused without modification, or further processed into important products such as gamma globulin or albumin.
Q: How long does blood last?
A: It's different for each of the blood components. Red blood cells can be stored for six weeks as a liquid. Blood platelets can be stored only for five days. Blood plasma can be frozen for use up to one year. New additives, preservatives and storage techniques are being developed to help extend expiration dates.
Q: Of those eligible to donate, how many do so?
A: We estimate that about 45% of the population is eligible to donate blood. However, only about 4% actually do so, and 75% of those are repeat donors.
Donating blood is extremely safe for donors, with each needle and blood bag used only once. About one pint of whole blood is collected in a standard donation, which is about 10% of an average adult's total blood volume. Alternatively, most blood centers have instruments that allow a donor to specifically donate red cells, platelets and/or plasma, according to current needs. The body replaces the donated blood within a short time. Donors get a "mini-physical" and cookies. Most importantly, they know that their donation can help several patients who require these life-saving products. They truly are giving the "gift of life."