A simple morphological score for the quality control of platelet concentrates

The percentage of platelets that retain discoid form correlate with their post-transfusion viability and therefore they may act as a simple indicator for the quality of the stored platelet concentrates (PCs). The morphological score (MS) of platelets, given by Kunicki, requires the index of different forms of platelets: discoid, spherical, starlike and bizarre. In the present study, we intended to clarify whether the morphological score of discoid platelets alone could serve as a method for the estimation of PCs quality. During the first five days after preparation, samples of standard platelet concentrates (SPCs) and of leucodepleted platelet concentrates (LDPCs) were analyzed morphologically by immersion light microscopy using smears stained by the May-Grünwald-Giemsa method. In addition to the MS, an original Modified Morphological Score (MMS), for a population of 200 platelets, was used to count platelets with the discoid shape. The mean MMS ranged (first to fifth day) from 192.6 to 166.6 with SPCs and from 197.2 to 185.4 with LDPCs. There is a significant difference (ANOVA) between: (a) PCs prepared by different techniques (p < 0.01); (b) the quality of the same PCs during the storage (p < 0.0001).