Developments in component therapy: novel components and new uses for familiar preparations.

Over the years, the significant role of blood components in treating certain diseases or conditions has been recognized. The use of these components has expanded as patients undergo chemotherapy for bone marrow ablation and require short-term component support. On the other hand, these transfusions can cause reactions ranging from mild to severe. Despite advances in serological testing for infectious disease agents, the risk of infectious complications from transfusion still remains. In addition, newly identified agents that may be transmitted via transfusion are constantly identified. The cellular components most people are familiar with include packed red blood cells (PRBC), washed PRBC, leukoreduced PRBC, and pooled or apheresis platelets. Plasma products such as fresh frozen plasma (FFP) or crytoprecipitated anti-hemophiliac factor (CRYO), on the other hand, may not be as familiar. As our understanding of how the immune system functions and as technology has progressed, specialized components or manufactured products such as blood substitutes have been advanced as remedies to some of the complications with component transfusion or to meet the ever-increasing need for these products. In this article we will focus on some of the new uses of common components and uncommonly used or newly developing components. We will discuss their origins, composition, and the conditions or diseases they are used to treat. These components include: donor leukocyte infusions, dendritic cell vaccines, blood substitutes, novel platelet products and substitutes, intravenous immunoglobulin (IVIG), fresh frozen plasma and cryosupernatant in therapeutic plasma exchange. The variety of products and conditions reflect the ever-expanding role of immunohematology in the treatment of disease.