Reporting Sysmex XN Absolute Neutrophil Count in Samples with Leukocyte Analyzer Flagging

Abstract

Objective: To provide faster laboratory data reporting, we evaluated the accuracy of Sysmex XN (Sysmex Inc, Kobe, Japan) absolute neutrophil count (ANC) in the presence of analyzer flagging. Methods: Sysmex XN and manual microscopy ANC were compared with 80 autovalidated control specimens and with 280 study specimens with analyzer flagging regarding immature granulocytes (IG) >3% or other leukocyte abnormalities. Specimens with ambiguous neutrophil clusters were excluded. Results: A slight positive overall method bias was seen for Sysmex XN compared to manual microscopy (n = 280), 0.025 (95% confidence interval [CI], -0.023 to 0.069) × 109/L. With IG > 10% (n = 123) the bias was larger, but not clinically significant, 0.17 (95% CI, 0.060-0.25) × 109/L. No clinically significant difference was seen in neutropenic (ANC < 1.5 × 109/L) specimens (n = 91), 0.070 (95% CI, -0.013 to 0.14) × 109/L. Conclusion: These data indicate that Sysmex XN ANC can be reported in the presence of certain analyzer flagging to improve patient care.