Increase of plasma concentration to 10% improves a number of in vitro storage parameters of apheresis platelets suspended in a bicarbonate-containing additive solution and stored with a 24-hour interruption of agitation

Abstract

Background. A previous study demonstrated several pH failures during 7-day storage of platelets suspended in 5% plasma/95% PAS-5 following a 24-hour interruption of agitation. The aim of this study was to investigate whether pH control improves in platelets stored in PAS-5 with 10% plasma following interruption of agitation.
Materials and methods. Four aliquots were prepared from a single unit of apheresis platelets: two each with 5% and 10% plasma. After resting for 1 hour, the aliquots were placed on an agitator. On day 2, agitation of one aliquot with 5% plasma and another with 10% plasma was interrupted for 24 hours before the aliquots were returned to agitator. The two control aliquots remained on the agitator. An array of platelet parameters was measured on days 2, 5 and 7.
Results. On day 7, aliquots containing 10% plasma and subjected to interruption of agitation had a significantly higher mean pH compared to those of similarly treated aliquots containing 5% plasma (6.80±0.54 vs 6.41±0.57, p≤0.05). Platelets containing 10% plasma/95% PAS-5 subjected to interruption of agitation had a greater hypotonic stress response, greater shape change, higher mitochondrial membrane potential, decreased glucose utilisation and lower CD62P levels compared to those of similarly treated platelets suspended in 5% plasma.
Discussion. Increasing plasma concentration to 10% improves pH control and some in vitro platelet properties during 7 days of storage of platelets suspended in PAS-5 after a 24-hour interruption of agitation compared to those of similarly treated platelets suspended in 5% plasma/95% PAS-5.