Storing platelets in an additive solution containing magnesium and potassium improves the functionality of the platelets, as measured by in vitro testing, and may allow a reduction of the amount of plasma required to be carried over to the final unit.

PLTs stored at 4 degrees C without agitation maintain metabolic and cellular characteristics to a great extent during 21 days of storage. These studies confirm the view that PLTs lose their discoid shape and that this loss with storage at 4 degrees C is associated with reductions in metabolic rate and in their release of alpha-granule content.

Platelets stored at 4 degrees C retain their in vitro characteristics better than those stored at 22 degrees C, except for parameters that reflect changes in shape. Storage at 4 degrees C is not associated with an increased expression of glycoprotein (GpIb, GpIIb/IIIa) and platelet activation markers (CD62p and CD63) as compared with storage at 22 degrees C.

Our study fills an important knowledge gap in how acid treatment affects PLT function and interactions with immune cells, paving the way for controlled clinical trials to evaluate acid-treated PLTs as an alternative to HLA-matched donors in PLT refractoriness.

In vitro characteristics of platelets stored in PAS with addition of potassium and magnesium indicated higher quality, but this could not be verified by the in vivo parameters by means of recovery and survival.