ABSTRACT
The platelet counts documented in most of the studies using the fully automated hematology analyzer XE-5000 are values measured by impedance technology (PLT-I). If blood specimens showing an anomalous particle-size distribution curve in the area where platelet counts are low are used (exceptionally low platelet count samples), the counting method is automatically switched over to an optical method (PLT-O). In the present study, we examined the usefulness of the XE-5000 by comparing PLT-I with PLT-O, using blood samples with low platelet counts collected from patients who visited our hospital between January 1 and March 31, 2012. Dilution linearity left nothing to be desired in either of the two, but simultaneous reproducibility was higher in PLT-O than in PLT-I. The correlations of PLT-I and PLT-O with visual counts were high, working out at r＝0.889～0.984. In the exceptionally low platelet count samples, the correlation coefficient was high in PLT-O than in PLT-I. The cases showing low platelet counts frequently presented giant platelets and/or red cell fragments. Therefore, measuring the samples with low platelet counts requires a high degree of precision. In the samples with exceptionally low platelet counts, PLT-O exceeded PLT-I in simultaneous reproducibility and correlation with visual counts. Thus, our study demonstrated the usefulness of the XE-5000 that could enumerate PLT-O automatically and speedily.