Interruption of agitation of platelet concentrates: a multicenter in vitro study by the BEST Collaborative on the effects of shipping platelets

BACKGROUND: Transported platelets (PLTs) are not under continuous agitation. The aim of this study was to determine whether PLTs shipped between 24 and 48 hours would be able to maintain a pH(22 degrees C) value of 6.5 at the end of 7 days of storage. STUDY DESIGN AND METHODS: Six laboratories prepared leukoreduced PLTs. PLT pools were divided into low and high PLT concentration with paired shipped (20-43 hr) and unshipped controls. Units were under continuous agitation at 22 +/- 2 degrees C when not being transported. In vitro measures including pH, pO(2), and pCO(2) were determined over 7 days. RESULTS: Ninety-two PLT components from 24 pools were eligible for analysis. One unshipped control and three shipped products failed to maintain a pH(22 degrees C) value of 6.5 through 7 days. In vitro characteristics were maintained slightly better over 7 days of storage in the unshipped control arms. PLT concentration, shipping time, and their interaction were significant determinants of the final pH at the end of storage (p < 0.05). Lactate generation rate increased by 35 +/- 2 (mean +/- SE) micromol per 10(12) PLTs per hour over baseline during shipping (p < 0.0001). After restoration of standard blood banking conditions with agitation, this rate dropped 24 +/- 2 micromol per 10(12) PLTs per hour (p < 0.0001). CONCLUSION: PLTs in plasma shipped for at least 20 to 24 hours maintain a pH(22 degrees C) value of 6.5 for 7 days. A longer shipping time may result in a pH(22 degrees C) value of 6.5. During shipping, glycolysis was up regulated in these PLTs resulting in increased lactic acid production. After restoration of agitation, shipped products down regulated glycolysis. These effects should be accounted for in the development of PLT storage and transportation systems.