Blood, 1966, Vol. 27, No. 4, pp. 449-459.
© 1966 American Society of Hematology, Inc.
The Increased Effectiveness of Platelet Concentrates
Prepared in Acidified Plasma
FREDERICK A. FLATOW JR. 1 and
EMIL J. FREIREICH 1
1 Leukemia Service, Medicine Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland.
Platelet concentrates prepared in acidified plasma (pH 6.5-6.7) are superior
to concentrates prepared by standard methods, and are 80-90 per cent as
effective as platelet rich plasma (PRP). The use of excess citric acid to acidify
plasma 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 important
factor in clumping during standard concentrate preparation.
A method of acidification of PRP using citric acid is described which allows
preparation of an effective concentrate from fresh whole blood without subjecting the red cells to acid pH. Reconstitution of the acidified platelet poor
plasma and its native red cells increases the citrate molarity by less than 6 per
cent and results in minimal decrease in pH of the whole blood.
Submitted on May 6, 1965
Accepted on July 25, 1965
