Background: Hematology analyzers have been able to make automated counts of cells present in CSF samples in recent years. Most of them cannot provide reliable counts of the low cell levels usually present in CSF.
Methods: Functional sensitivity, precision, analytical measurement range, and method comparisons were deter- mined according to Clinical Laboratory Standards Institute (CLSI) guidelines.
Results: The functional sensitivity for white blood cells (WBC) and red blood cells (RBC) was 18/μL and 725/μL (minimum reported concentration), respectively. The total precision ranged from 6.1% to 16.3% for WBC counts within the concentration of 33-183/μL and from 4.1% to 19.4% for RBC counts within the concentration of 745-11,350/μL. The within-run precision for WBC was 3.1% at 7,592/μL. The analytical measurement range was 18-10,078/μL for WBC and 725-5,222,550/μL for RBC. There was good correlation between WBC and RBC counts determined by the XE5000 and microscopic examination, according to slopes and R2 method comparisons. The correlation of the two methods for mononuclear cell (MN) counts was 0.907 with the WBC count of 50-5,000/μL. The reliability of WBC counts produced by the XE-5000 was 0.7.
Conclusions: The XE-5000 performed satisfactorily in the CSF assay, but it is still necessary to manually confirm the WBC count when it is less than 18/μL.