Background: Differences in platelet counts are observed by use of automated haematology analyzers making interlaboratory comparison difficult.
Materials and methods: Twenty-eight single-donor platelet concentrates (PCs) were collected. Platelet concentration and markers of platelet destruction were investigated during storage for 11/12 days.
Results: Increasing impedance-immunoplatelet ratio was observed during storage, correlating to platelet fragments, large platelets, platelet density and cell-lysis. High variability was observed for optical-immunoplatelet ratio.
Conclusion: Immunoplatelet count or correction factor calculated by impedance-immunoplatelet ratio should be used to confirm that platelet unit meets platelet count requirements or to compare results from clinical trials. Optical platelet count is not recommended.