ABSTRACT
We evaluated and compared three automated blood cell counters, Coulter STKS, Sysmex NE 8000 and Technicon H-2. These perform both a complete blood cell count and a full white cell differential count. Carry-over was found to be acceptable, except for the leucocyte count by the Sysmex NE 8000 (1.5%; p < 0.001). Linearity over a wide concentration range for all of the measured parameters, haemoglobin, red blood cells, white blood cells and platelets, was excellent (r > 0.98). Within-run precision was verified with 22 samples covering a wide range of cell counts by repeated analysis (n = 20) of the same sample. Coefficients of variation (CV) were acceptable, < 4% for values within the normal range. The CVs for eosinophils and basophils were less good but without clinical impact. Analysis of 270 samples showed that the Coulter counter indicated the presence of atypical cell populations more frequently (19%; p = 0.02). Message of qualitative abnormalities displayed by the three analysers were often discordant. These three blood cell counters differed in their sensitivity and positive predictive value for detecting abnormal blood cells rather than in their specificity and negative predictive value. Other operating aspects of three instruments that are important in haematological practice are documented.
