Evaluation of the monocyte counting by the ABX Vega. Comparison with the manual method and fluoro-flow cytometry

This study allowed evaluation and comparison of the precision (20 samples) and agreement (200 samples) of the relative and absolute values of the mono cyte count using three methods: microscopic, flow cytometry and the automat ed ABX Vega hematology analyzer. Flow cytometry is the most precise method, even if the coefficient of variation of the automated analyzer is very sim ilar. The coefficient of correlation between the ABX Vega and the flow cyto meter is very satisfactory (r = 0.8042). This study of the agreement also m ade it possible to confirm the difficulty that automated hematology analyze rs have in differentiating between some granulocytes and monocytes and thei r propensity to overstimate the latter when the sample includes immature fo rms of granulocytes. This fact stresses the importance of the microscopic m ethod, despite its lack of precision. The observed discrepancies did not le ad to any difficulties in clinical interpretation; however, this finding sh ould be taken into consideration, particularly in myleoproliferative syndro mes and the laboratory monitoring of chemotherapy.