The increased effectiveness of platelet concentrates prepared in acidified plasma

Platelet concentrates prepared in acidified plasma (pH 6.5-6.7) are superiorto concentrates prepared by standard methods, and are 80-90 per cent aseffective as platelet rich plasma (PRP). The use of excess citric acid to acidifyplasma promotes resuspension of the concentrate by eliminating clumping,which is a major factor in the decreased effectiveness of standard concentrates.Analysis of posttransfusion recovery and survival of platelets reveals no evidence of platelet injury in an acid medium.

Acidification of PRP inhibits the aggregation of platelets by adenosine diphosphate (ADP). The presence of endogenous ADP may be an importantfactor in clumping during standard concentrate preparation.

A method of acidification of PRP using citric acid is described which allowspreparation of an effective concentrate from fresh whole blood without subjecting the red cells to acid pH. Reconstitution of the acidified platelet poorplasma and its native red cells increases the citrate molarity by less than 6 percent and results in minimal decrease in pH of the whole blood.

Submitted on May 6, 1965 Accepted on July 25, 1965