Preliminary Evaluation of Cell Population Data Parameters in Different Blood Collection Tubes on Sysmex XN-Series Analysers

Cell population data (CPD) parameters generated by Sysmex XN-series analysers are promising biomarkers for a variety of disease states. Routine use of CPD parameters, however, will require extensive evaluation of potential pre-analytical variables that may affect reliability. At present, no information on the comparability of CPD parameters generated using different blood collection tubes is available. In this preliminary study, we evaluated the impact of four commonly used blood collection tubes—dipotassium (K2) EDTA, tripotassium (K3) EDTA, trisodium citrate, and lithium heparin—on the generation of CPD parameters in whole blood from a cohort of 10 healthy donors. We also evaluated the stability of the CPD parameters generated at 4 h post-collection. Statistically significant differences in the CPD were observed across all blood collection tubes: whole blood anticoagulated with K3EDTA induced minimal biases and was comparable to whole blood anticoagulated with K2EDTA at collection; however, whole blood anticoagulated with citrate and heparin were associated with more substantial and more widespread biases in several parameters with potential clinical relevance. Notably, the biases observed in whole blood anticoagulated with K3EDTA increased in both number and magnitude at 4 h post-collection, whilst the CPD parameters generated with whole blood anticoagulated with K2EDTA remained stable. Although further confirmatory investigations are required, these findings highlight the importance of anticoagulant selection, as well as the need for further pre-analytical research, to support the integration of CPD parameters generated by Sysmex XN-series analysers into routine diagnostic workflows.