Platelet counting in platelet concentrates with various automated hematology analyzers.
BACKGROUND
Hematology analyzers use impedance, optical, and/or immunologic techniques for counting platelets (PLTs). PLT counting in whole blood has been validated thoroughly; however, this is not the case for PLT counting in PLT concentrates (PCs), in which red cells (RBCs) are absent. Therefore, this study is focused on PLT counting in PCs to study use of ethylenediaminetetraacetate (EDTA), carryover, and accuracy of the analyzers.


METHODS
In total six hematology analyzers (AcT 8, Beckman Coulter; ADVIA 2,120, Bayer; Cell-Dyn 4,000, Abbott; Onyx, Beckman Coulter; K4,500, Sysmex; and XT 2,000i, Sysmex) were tested for PLT counting. PC samples with various PLT concentrations were made (0-1,700 x 10(9)/L) and measured 10 times. Carryover was determined five times.


RESULTS
PC samples (1,000 x 10(9) PLTs/L) in EDTA tubes showed significantly higher PLT counts than samples in "dry" tubes for all analyzers except for the Cell-Dyn 4,000 with the impedance technique. Carryover was not more than 0.3 percent for all analyzers. The K4,500 showed the most accurate results, whereas the Cell-Dyn 4,000 with the impedance technique had low accuracy due to an overestimation of more than 20 percent.


CONCLUSIONS
Most tested analyzers seemed to be suitable for counting PLTs in PCs. All hematology analyzers should be validated for counting PLTs in absence of RBCs as is the case in PCs, in addition to validation of PLT counting in whole blood.
Dijkstra-Tiekstra
Margriet J
MJ
Sanquin Blood Bank Northeast Region, Groningen, The Netherlands. m.dijkstra@sanquin.nl
Kuipers
Willeke
W
Setroikromo
Airies C
AC
de Wildt-Eggen
Janny
J
D001331:Automation; D001792:Blood Platelets / Q000166:cytology*; D004492:Edetic Acid; D006405:Hematology / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D007201:Indicator Dilution Techniques; D010976:Platelet Count / Q000295:instrumentation* / Q000379:methods*
D004492:Edetic Acid