New methods showing in vitro changes of platelets

IntroductionIn vitro methods for assessing stored platelets are time consuming and variably correlate with in vivo survival. We used the ADVIA 120 and the Thromboelastogram (TEG) to assess changes during storage to determine a correlation of the results with those of other commonly used measures.MethodsPlatelet concentrates were tested at 1 and 5 days of storage. In vitro test included platelet count, aggregation response, the hypotonic shock response (HSR), The Kunicki morphology score (KMS) and platelet activation using CD62. The ADVIA® was used to measure the platelet density and the granule content. The TEG measured the kinetics of clot formation.ResultsThe platelet count and HRS did not change during storage. Aggregation decreased 50% by day 5. The KMS dropped from 307 at day 2–170. The MPC fell below 200 g/l. There was slight platelet activation; the rate of clot formation decreased.ConclusionsStandard measures of in vitro platelet function indicated alterations during storage. A MPC of less than 200 corresponded to a Kunicki morphology score of less than 200. The TEG results correlated will with the KMS. These measurements may prove useful in predicting platelet survival and recovery.