Effect of additive solutions on platelet biochemistry.

Use of a synthetic medium for resuspension and storage of platelets has several advantages. In addition to the opportunity to save plasma, the use of a synthetic medium offers better possibilities for obtaining platelet products by automatic component processing in a more cost-effective and convenient manner. A synthetic medium also has the potential to avoid transfusion reactions caused by noncompatible plasma proteins and to improve platelet quality, which will lessen the number of units needed in transfusion. Platelets produce a substantial amount of lactic acid by metabolism of glucose. Thus, risk of pH fall is a major problem which platelet additive solutions must address. Two approaches have been used: (1) use of a glucose-free medium, and (2) use of a glucose-containing medium with a buffer system to neutralize the production of lactic acid. Using various synthetic media described in the literature, studies described in this paper suggest that some glucose is needed in the final suspending medium in order to obtain satisfactory maintenance of platelet quality during 5 days of storage. With the presence of acetate in the additive solution, platelet respiration is increased and glycolysis substantially decreased; therefore, with 10-20% of CPD-plasma carryover, sufficient glucose may be present in the final suspending medium to last for 5 days of storage. In addition, phosphate in the additive solution markedly enhances platelet glycolysis, and inhibitors of platelet activation reduce platelet metabolic activity and improve platelet viability and function.