Buffy coat platelets stored in apyrase, aprotinin, and ascorbic acid in a suspended bag: combined strategies for reducing platelet activation during storage.

BACKGROUND

Platelet activation is an important factor impeding the clinical effectiveness of platelet transfusions. In this study, platelet concentrates (PCs) were prepared by a novel suspended-bag buffy coat technique that was followed by the addition of a mixture of platelet activation inhibitors to the storage bag.

STUDY DESIGN AND METHODS

In vitro platelet function was evaluated in PCs prepared by the suspended-bag buffy coat technique and stored at 22 degrees C for 5 days in the presence of (n = 12) or absence (n = 12) of apyrase, ascorbic acid, and aprotinin (AAA).

RESULTS

Platelets from AAA-incubated PCs demonstrated mean ATP levels 17 percent (p < 0.004), 13 percent (p < 0.02), and 22 percent (p < 0.003) higher than those measured in parallel control PCs on Days 1, 3, and 5, respectively. Similarly, on Days 3 and 5 of storage, respectively, 45-percent (p < 0.001) and 50-percent (p < 0.001) greater ADP-induced maximum aggregation was observed in AAA-incubated PCs than was seen in control preparations. AAA-incubated PCs demonstrated alpha-granule membrane protein-140 expression 92 percent (p < 0.01), 133 percent (p < 0.003), and 104 percent (p < 0.001) below that in control PCs on Days 1, 3, and 5, respectively. At similar intervals, a significant increase in recovery from hypotonic shock also was observed in AAA-incubated PCs. Further, Day 5 AAA-PCs demonstrated significantly higher morphology scores and O2 consumption than did control preparations.

CONCLUSION

Buffy coat platelets prepared in suspended bags and stored in the presence of AAA demonstrate significantly reduced activation and enhanced functional and metabolic activity.