Platelet storage performance is consistent by donor: a pilot study comparing "good" and "poor" storing platelets

BACKGROUNDIn retrospective studies, it has been shown that differences in storage variables of platelet (PLT) concentrates (PCs) are partially donor dependent. It was our aim to prospectively determine the donor effect on PLT quality. STUDY DESIGN AND METHODSBased on quality control data of outdated apheresis PCs, male donors were selected with at least one PC with a pH value of more than 7.0 (good, n=6) or one PC with a pH value of less than 6.7 (poor, n=6) on Day 8. These donors donated a PC (Trima Accel, Terumo) and completed a short questionnaire about their health and lifestyle. PCs were stored for 12 days and analyzed at regular intervals for in vitro quality. RESULTSDonor characteristics were comparable, except that zero of six good and four of six poor donors reported high blood pressure and/or high cholesterol/fat and/or use of medicines. Lactate production in good PCs was lower than that in poor PCs (0.090.03 mmol/day/10(11) PLTs vs. 0.13 +/- 0.04 mmol/day/10(11) PLTs, p<0.05) resulting in a higher pH from Day 5 onward. At the end of storage, the good PCs showed lower CD62P expression, lower phosphatidylserine exposure, and higher mitochondrial membrane potential. PLT functional properties were only slightly different. Despite having lower pH, the poor PCs also fulfilled European Guidelines during 7-day storage. CONCLUSIONPlatelet storage performance is consistent when donors are dichotomized as having good or poor storing PLTs. Metabolic differences are perhaps due to different functionality of the mitochondria. More research is needed to establish the underlying causes and the implications for donors and blood products.