Opportunities for Medical Research

Scope of the Problem The field of transfusion medicine began 100 years ago, in 1900, with the discovery by Landsteiner of the ABO blood group system. This discovery demonstrated thatplasmaproteinshavedefined specificities.Theseplasmaproteins, later termedantibodies, recognizeepitopeson red blood cells. These discoveries constituted a starting point for blood banking—collection and storage of blood— and for immunohematology, the serological investigation of blood group antigens (FIGURE 1). During the past 3 to 4 decades, significant advances have been achieved in improving the blood supplywithrespect toavailability, safety, and fractionation intocomponents, such as red blood cells, platelet concentrates, and plasma proteins. Donors currently donate approximately 12 million units of blood annually in the United States. Without these donations, many procedures and treatments, such as hematopoietic stem cell transplantation, complex cardiac and orthopedic surgery, and organ transplantation, would not be possible. A safe and adequate blood supply is a fundamental necessity to support state-ofthe-art medical and surgical therapies. However, resources are now needed to translate advances in the biology of hematopoietic cells into newer cellular therapies and to investigate the unique immunological effects that result from transfusion of blood cells. This article discusses current status and progress in several aspects of transfusion medicine, including adequacy and safety of the blood supply, appropriate use of transfusion therapy, development of novel cellular therapies, and manipulation and prevention of immune responses.