The aim of the study was to compare the platelet counts obtained by impedance methods and optical florescence methods with the international flow reference method in thrombocytopenic blood samples with count<50,000/µl
A total of 118 consecutive blood samples with platelet count of <50,000/µl were selectedPlatelet counts were evaluated in parallel within 6hrs of collection by five methods:
XE2100(Sysmex)-optical[Sysmex-O]
XE2100(Sysmex)-impedance[Sysmex-I]
XE2100(Sysmex)-Reported,based on switching algorithm[Sysmex-R]
LH750(Beckman Coulter)based on impedance with curve correction[LH750]
International flowcytometric reference method on the FACS CantoII(Becton Dickinson)[IRM]
conclusion: Sysmex-R had the least Bias and 95%LA range and thus correlated best with IRM values. In five cases, where Sysmex-R values were based on the underlying Sysmex-I values,correlation with IRM was closest.
LH-750 had a higher Bias compared to Sysmex-O and Sysmex-R but a strikingly similar 95%LA ensures similar results in all three methods. Infact, in the oncology subset, it had the narrowest 95%LA which made it the best performer in this subgroup. Of the three Sysmex results, Sysmex-I had the highest Bias, widest 95%LA, and highest potential risk of overtransfusion. Hence Sysmex-R was found to be a reliable tool for estimation of platelet count in thrombocytopenic patients.