Improved alignment of reticulocyte counts between Sysmex XT-2000i instruments

BACKGROUND: Reticulocytes are the most sensitive index available to authorities who seek to sanction athletes for blood doping based on deviations beyond individual reference ranges. Because such data comprise longitudinal results that are generated by different laboratories, the comparability of reticulocyte counts from different instruments is of crucial importance. AIMS: To enhance between-instrument comparability of reticulocyte counts reported by the Sysmex XT-2000i automated haematology analyser. METHODS: We optimised recalibration of instruments towards assigned values of control material (e-CHECK) in tandem with fresh blood verification. RESULTS: In terms of reticulocyte counts reported as a percentage of all cells in a fresh blood sample, it was possible to recalibrate all three test instruments so that the mean of 10 samples was within 0.1% of the comparative instrument's mean value. CONCLUSIONS: This approach provides a straightforward means of reducing between-instrument differences in reticulocyte counts generated by the Sysmex XT-2000i.