Evaluation of a routine hematology analyzer for quality control of leukoreduced plasma

BACKGROUND: Quality control of residual white blood cells (WBCs) and red blood cells (RBCs) in leukoreduced plasma is mandatory. Although technological advances have been made, analysis of quality controls using routine hematology analyzers has not generally been introduced. The aim of this study was to evaluate if the routine hematology analyzer Sysmex XN-10, (Sysmex Nordic ApS) could be used for quality control of residual WBCs and RBCs in leukoreduced plasma. STUDY DESIGN AND METHODS: Linearity, accuracy, and precision were established for two Sysmex XN-10 analyzers using spiked donor plasma. ADAM rWBC (NanoEnTek) and manual counting in the Burker chamber (NanoEnTek) were reference methods for WBCs and RBCs, respectively. Twenty-five consecutive leukoreduced donor plasma samples were also tested. RESULTS: For WBCs, the linearity criteria were met for the ADAM rWBC, but not for the Sysmex XN-10 instruments. Precision on both Sysmex XN-10 instruments was accurate only at 6 cells/μL, and accuracy was consistently acceptable only at 5 to 6 cells/μL. The precision and accuracy of the ADAM rWBC were acceptable at 2 to 6 cells/μL. For RBCs, both Sysmex XN-10 instruments and manual counting in the Burker chamber were linear and fulfilled the precision criteria. Accuracy was acceptable for both Sysmex instruments at 6 to 12 × 109 WBCs/L but fluctuated within the study's measuring range for the Burker chamber. No false-positive results were seen in the 25 consecutive donor plasma samples tested. CONCLUSION: For quality control purposes of leukoreduced plasma, the Sysmex XN-10 analyzer is suitable for the enumeration of residual RBCs but not of residual WBCs.