Platelet-Rich Plasma: Autologous Transfusion
Platelets are small (2–3 μm diameter), anucleate megakaryocyte cell fragments containing secretory granules and a glycoprotein-rich membrane with multiple adhesion receptors. Platelets are one of the most challenging blood products to manage. Because of the high cost, short shelf life and higher risk for transfusion complications such as bacterial contamination, transfusion-related acute lung injury (TRALI), allergic transfusion reactions, and febrile nonhemolytic transfusion reactions, interest in reducing platelet transfusions has evolved in recent years Prophylactic platelet transfusion is routinely performed for interventional procedures for which a low platelet count is perceived as an increased risk of bleeding; however, the validity of this practice is unknown. aPRP is prepared from autologous anticoagulated whole blood. Different technologies are available for aPRP isolation, including small volume tube centrifugation methods and larger apheresis machines. The different systems concentrate the platelet fraction by two-fold to five-fold , although claims of seven-fold to ten-fold are sometimes advertised. ABO compatibility of blood products is a fundamental of blood banking. The need to provide compatible blood products for red blood cell and large volume plasma transfusions to avoid hemolytic transfusion reactions is undisputed. Using an autologous product with a good safety profile has led many clinicians to use aPRP to treat injuries, skin ulcers, cartilage defects, and other orthopedic applications. Introducing aPRP into wounds, joints or tendons can create an imbalance in growth factors and cytokines, which may tilt the body toward healing, or toward chronic injury. Basic science explorations may help us understand how the mix of factors found in aPRP can be harnessed to help rather than harm the patient.