In vitro assays used in the evaluation of the quality of stored platelets: Correlation with in vivo assays

There have been reports on platelet storage studies that have demonstrated little or no correlation of in vitro parameters with in vivo parameters of viability such as CCI, and % recovery and survival by radio labeling. However, this does not mean that the in vitro parameters necessarily are poor predictor of in vivo viability, but may be related to the fact that in the vivo parameters, as absolute values, do not precisely reflect the viability of the platelets due to uncertainty in the splenic uptake and inaccuracy of the estimated blood volume of the recipient.A more informative way to examine the predictability of the in vitro parameters is to examine whether processing and storage conditions associated with loss or improvement in vivo viability are also associated with corresponding changes to the in vitro parameters and vice versa.