Necessity of Reticulocyte Calibration for More Accurate and Precise Results

Dear Editor, Reticulocyte count and immature reticulocyte fraction (IRF) are known to be accurate indices of erythropoietic activity [1]. Apart from clinical utility, these parameters are also useful for detecting blood doping in the athletic field [2, 3]. Recently, the XN system (Sysmex, Kobe, Japan) was introduced to the market [4]. Although this new instrument uses the same analytical method for reticulocyte counting as the previous version of the XE system, the number of red blood cells (RBCs) that could be counted during reticulocyte counting was increased to improve the precision; in addition, the XN system introduced a new calibrator (XN CAL, Sysmex) to harmonize the reticulocyte count among different analyzers. Increase in the number of RBCs that can be counted and calibration of the reticulocyte count could contribute to the interchangeability of the results, not only among hospitals but also among anti-doping laboratories. The aim of this study was to demonstrate and quantify the improvement in the performance of reticulocyte parameters in the XN series with calibration. KCI Citation Count: 0