The storage quality of apheresis platelets--analysis of results from seven different cell separators.

Apheresis platelet concentrates (CAP) have been available for more than 20 years. Now, as a result of the use of, and progress in, automatic blood separation techniques, the quality of platelets is continually being improved so that we currently have access to purified concentrates which are not contaminated by red cells and contain only very few white cells. In view of the wide experience available to us, it was useful to monitor a number of qualitative parameters indicating platelet activation during storage. We monitored platelet aggregation, release of beta thromboglobulin, activation of complement and other basic parameters in seven platelet concentrates from seven cell separators (Cobe Spectra, MCS Haemonetics, CS3000+, Baxter, Excel Dideco, Autopheresis C Baxter, and V50 Haemonetics). We found that in the majority of cases aggregation was greatly reduced during storage. Release of beta thromboglobulin and activation of complement increased. pH remained within acceptable limits in some cases. However, in others (MCS, Excel), a decrease in pH < 6.0 was found. To conclude, although CAP, which are from a single donor, reduce the risks of transfusion, they are not protected from physical alteration and therefore from reduction in the clinical effects of transfusion. It is therefore necessary to improve the storage conditions of these cells in the future, for example by designing new plastics, or adding platelet storage media. Basic biological parameters should also be defined, within the framework of quality assurance, to evaluate platelet quality.