Increase of sCD40L in supernatants. Increase during the storage of SDA platelet components (A,C,E) and pooled platelet component (B,D,F). Day 5 represents the last day of storage for which SDA platelet components and pooled platelet component can be used for transfusion in our study. The production of sCD40L was quantified by Luminex technology. Values shown are deducted from background levels. Data (scatter plot and mean; n as indicated in Table 1) are expressed in picograms per milliliter. Group comparisons were performed by 1-way analysis of the variance followed by the Kruskal-Wallis test with Dunn posttest. The 2-tailed t test and Mann-Whitney test were used to compare 2 groups (*P < .05; **P < .01; ***P < .001).