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* Context.-The new hematology analyzer Sysmex XE2100 (TOA Medical Electronics, Kobe, Japan) has a novel, combined, white blood cell differential technology and a special reagent system to enumerate nucleated red blood cells.
Design.-Performance evaluation of both technologies of the Sysmex XE-2100 according to the H20-A protocol of the National Committee for Clinical and Laboratory Standards and comparison of the results with those for the hematology analyzer Sysmex NE-8000 (TOA Medical Electronics).
Specimens.-Five hundred forty-four blood samples randomly chosen from various inpatient and outpatient departments of the Vienna University hospital.
Results.-Five-part white blood cell differential counts on the XE-2100 revealed excellent correlation with the
manual reference method for neutrophils, lymphocytes, and eosinophils (r = .925, .922, and .877, respectively) and good correlation for monocytes and basophils (r = .756 and .763, respectively). The efficiency rates of flagging for the presence of >=1% abnormal white blood cells were 83% (XE-2100) and 66% (NE-8000). The correlation of automated and microscopic nucleated red blood cell counts was excellent (r = .97).
Conclusions.-From the present evaluation and our former experience with other types of Sysmex analyzers, we conclude that the new white blood cell differential technology of the XE-2100 represents a further development toward more efficient flagging of abnormal white blood cells.
(Arch Pathol Lab Med. 2001;125:391-396)
The white blood cell differential (WBC-diff) technologies of hematology analyzers can be roughly divided into electric and optical methods.1 In the electric impedance method, cells are classified on the basis of a combination of cell size data from direct-current resistance information and intracellular data from alternating-current capacitance information. The optical method discriminates between cells on the basis of forward- and side-scattered light. To optimize the WBC-diff capacities, these technical methods may be combined with chemical alterations of either blood cells and/or reagents. Flow-cytochemical differential instruments classify cells using a combination of the optical method and enzyme cytochemistry.2 The Abbott Cell Dyn 4000 combines the optical method with a special reagent that allows for discrimination of nucleated red blood cells (NRBCs) from WBCs by staining NRBC nuclei with a specific fluorochrome dye.3 The Sysmex hematology analyzer (SE-9000) combines the electric impedance method with special reagents that disrupt the mature WBCs but fix immature WBCs, which are then identified in a special...