title: Performance evaluation of the Sysmex haematology XN modular system.
abstract: BACKGROUND
  The Sysmex XN haematology instrument performs automatic reflex testing, depending on sample results. A nucleated red blood cell (NRBC) count is provided on all samples. The instrument has a smaller footprint (34%) than previous Sysmex XE analysers.
  
  
  METHODS
  An evaluation comparing all results to the Sysmex XE-2100 and manual microscopic differential and morphology (n=390) was performed followed by a workflow study of 1000 samples to compare speed of operation and number of blood films reviews required from both systems.
  
  
  RESULTS
  The new features on the instrument are: (1) white cell and NRBC channel, all samples include the NRBC count; (2) white cell precursor channel: false positive flags for blasts, abnormal lymphocytes and atypical lymphocytes are reduced significantly without a statistical increase of false negatives; (3) low white cell count mode: suggested setting of <0.5×10(9)/l. An extended count is more precise and provides an accurate differential. Fluorescent platelet count is performed in a dedicated channel. If the red cell or platelet size histograms are abnormal or if the platelet count is low, then a fluorescent platelet count is automatically performed. Good correlation with the XE-2100 and manual differential was found and the improved results compared to the reference flow cytometric analysis for platelet counts, especially below 30×10(9)/l (XE-2100, R(2)=0.500; XN, R(2)=0.875).
  
  
  CONCLUSIONS
  The XN showed reduced sample turnaround time of 10% and reduced number of blood films for examination, 49% less than the XE-2100 without loss of sensitivity with more precise and accurate results on low cell counts.
authors.affiliation: Department of Haematology, University College London Hospital, London, UK. carolbriggs@hotmail.com
authors.forename: Carol
authors.initials: C
authors.lastname: Briggs
authors.forename: Ian
authors.initials: I
authors.lastname: Longair
authors.forename: Punamar
authors.initials: P
authors.lastname: Kumar
authors.forename: Deepak
authors.initials: D
authors.lastname: Singh
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Machin
mesh_terms: D001772:Blood Cell Count / Q000295:instrumentation*; D004867:Equipment Design; D004900:Erythroblasts / Q000166:cytology; D006402:Hematologic Diseases / Q000175:diagnosis*; D006405:Hematology / Q000295:instrumentation* / Q000379:methods; D057166:High-Throughput Screening Assays / Q000295:instrumentation*; D006801:Humans; D007753:Laboratories / Q000592:standards; D013997:Time Factors