Impact of different hold time before addition of platelet additive solution on the in vitro quality of apheresis platelets.

Background: The quality of platelets (PLTs) stored in PLT additive solution (PAS) is dependent on the type and proportion of the used PAS. No data are available as to whether a different hold time before the addition of PAS to hyperconcentrated PLT suspensions has an impact on PLT quality. The in vitro quality between single-donor PLT concentrates was compared with two different hold times with two PASs.

Study Design And Methods: On two occasions, 6x10(11) PLTs in 150 mL of plasma were collected from 20 blood donors. The units were split into two equal parts, and 140 mL of PAS-II or PAS-IIIM (randomized sequence) was added after 2 or 8 hours resulting in a PAS proportion of 65 percent. On Days 1, 5, and 7, glucose and lactate concentration, pH value, PLTs' P-selectin expression, response to hypotonic shock, and release of transforming growth factor-beta1 were determined.

Results: On all days, the lactate concentrations were higher and pH values were lower in units with an 8-hour hold time, whereas the results of in vitro tests relating to the in vivo viability and activation of PLTs were similar for both groups. PAS-IIIM-stored PLTs showed a lower glycolytic activity and better results in all performed in vitro tests than PAS-II-stored PLTs.

Conclusions: Although the metabolism of glucose was enhanced during hold time, the differences between both hold time groups are not meaningful from a biological viewpoint. Therefore, an 8-hour hold time is feasible. PLT storage in PAS-IIIM results in a PLT in vitro quality superior to that of PLTs stored in PAS-II.