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

Area of Science:

• Clinical Laboratory Science
• Hematology
• Neuroscience

Background:

• Accurate white blood cell (WBC) counts in cerebrospinal fluid (CSF) are crucial for diagnosing neurological conditions.
• Manual cell counting using a hemocytometer is the traditional method, but it is labor-intensive.
• Automated methods offer potential for faster and more efficient CSF analysis.

Purpose of the Study:

• To compare the accuracy of manual WBC counts with automated counts from the Sysmex XE-5000.
• To evaluate the performance of automated CSF WBC counting across different cell concentration ranges.
• To identify potential discrepancies in automated WBC counts, particularly at low cell levels.

Main Methods:

• Analysis of 200 clear cerebrospinal fluid (CSF) samples from adult and pediatric patients.
• Manual WBC counts performed using a hemocytometer.
• Automated WBC counts performed using the Sysmex XE-5000 automated hematology analyzer.
• Method comparison using descriptive statistics and Spearman rank correlation.

Main Results:

• Manual WBC counts ranged from 0 to 702 cells/μL; Sysmex counts ranged from 0 to 629 cells/μL.
• Overall Spearman rank correlation coefficient was 0.77 (P < .001), indicating good agreement.
• Correlation was notably weaker at lower cell concentrations.
• For manual counts of 0-5 cells/μL, Sysmex 95th percentile was 0-23 cells/μL; for 0-10 cells/μL, Sysmex 95th percentile was 0-27 cells/μL.

Conclusions:

• Automated WBC counting on clear CSF samples demonstrates good overall correlation with manual methods.
• Discrepancies are more pronounced at low cell counts, suggesting limitations for precise quantification in this range.
• Larger studies are required to establish new, validated reference ranges for automated CSF WBC counts.