Automated cerebrospinal fluid cell counts using the Sysmex XE-5000: is it time for new reference ranges?

The main objectives of the study were to compare manual and automated WBC counts on clear cerebrospinal fluid (CSF) samples. Clear CSF samples from 200 adults and children were studied. Cell counts were performed manually using a hemocytometer and then analyzed on the Sysmex XE-5000. Descriptive statistics and Spearman correlation for nonparametric data were used for method comparison. Manual WBC counts ranged from 0 to 702 cells/μL, and Sysmex counts ranged from 0 to 629 cells/μL. The Spearman rank correlation coefficient for the entire range of data was 0.77 (P < .001); however, the correlation was weaker at the low end of the data spectrum. For manual WBC ranges of 0 to 5 cells/μL and 0 to 10 cells/μL, the corresponding Sysmex 0 to 95th percentile ranges were 0 to 23 cells/μL and 0 to 27 cells/μL, respectively. The results suggest that larger studies are necessary to determine new reference ranges for automated CSF WBC counts.