Performance Evaluation of the Sysmex XN-1000 Hematology Analyzer in Assessment of the White Blood Cell Count Differential in Pediatric Specimens

Introduction: The automated XN-1000 hematology analyzer enables to perform a blood cell count and a leukocyte differential. When abnormal cells were detected, a flag was generated by the analyzer and a manual microscopic examination of the corresponding blood film was performed.

Methods: We compared the white blood cell differentials provided by the automated hematology analyzer XN-1000 in a pediatric population (n = 765) with those obtained through microscopic examination by cytologists and those obtained using a previous version of this analyzer, the XE-2100. Leukocytes count as well as flags sensitivity and specificity was analyzed.

Results: The leukocytes count provided by the analyzer is in good accordance with the differential obtained by manual count in children older than 3 months. The sensitivity for blast detection is 99% and the detection of reactive cells is 63%. The flag specificity remains low (<35%) for blood samples collected from infants between 8 days and 2 years of age, but increases up to 67% thereafter. The results obtained with the XN-1000 analyzer show an improvement in comparison with those obtained with the XE-2100 analyzer.

Conclusion: The automated WBC differential provided by the XN-1000 analyzer in the pediatric setting is accurate, but a meticulous microscopic examination of blood smears remains necessary for infants up to 3 months of age to validate the analyzer flags.