Background Historically, haematology analyser flags for abnormal white blood cells (WBCs) show good sensitivity but lower specificity, causing unnecessary blood film reviews. While the WBC differential channel on Sysmex XE and XN instruments reports a combined flag for blasts/abnormal lymphocytes, the new white precursor cell channel (WPC) on the XN series has been introduced to separate this into a specific flag for either cell type or, if no abnormality, remove the flag entirely. Aims To compare the efficiency of abnormal WBC flags from the XN WPC to our existing analyser and determine whether WPC can reduce false positive flags and blood films required. Methods Abnormal WBC flags from the Sysmex XE-5000 and XN-1000 were compared to manual differential and blood film morphology on 300 K(2)EDTA samples from infants and children. Results The XN WPC flag for blasts was more sensitive and specific than flags indicating blasts on the XE-5000, with a reduction in false positives from 64% (XE) to 36% (XN). Overall efficiency of the WPC flag for abnormal lymphocytes was 94% vs 79% on the XE. WPC reduced false positive flags for blasts and abnormal lymphocytes on neonatal samples by 50%. Automatic reflex analysis by WPC correctly removed a false positive flag from the white cell differential channel on 46% of samples. Total abnormal WBC flags from XN WPC were less (73) than the XE-5000 (92). Conclusions XN WPC demonstrated superior efficiency of abnormal WBC flags on paediatric samples, compared to the XE-5000, with greater sensitivity and specificity of flagging, reducing blood films for review.
