Platelet indices as quality markers of platelet concentrates during storage.

The quality of platelet concentrates (PC) is an important issue in transfusion therapy. Recently, platelet indices have been used as markers for the quality control of PCs, as these reflect storage-induced shape changes in platelets. We also analyzed platelet indices such as platelet count, which could be detrimental and influence the rate of pH change during acceptable storage conditions. In the present study, platelet indices (with and without EDTA) were analyzed in stored PC. Forty pooled PRP-PCs were stored for 7 days and various platelet indices were analyzed with and without EDTA incubation. These indices included platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW) and platelet large cell ratio (PLCR). Difference in platelet paramters dPLT, dMPV, dPDW and dPLCR were calculated. Platelet indices correlating with pH changes, as determined by regression analysis, included dMPV and dPDW, while dPLT did not show much correlation (P < 0.05). Mean pH decreased from 7.25 to 6.86 between day 0 and day 7, respectively (P > 0.05). Platelet indices correlating with pH included PDW and MPV, while PLT did not show much correlation with pH. The platelet index dPDW (r = -0.26) and dMPV (r = -0.18) showed maximum, but not perfect, correlation with pH (P < 0.01). The coefficient of determination (R2) was maximum for the platelet indices dPDW and dP-LCR (R2 > 0.6). We conclude that measurements of platelet indices after EDTA incubation have great potential as quality markers of PC, especially when analyzed in combination with pH.