Comparison of Quantitative Cerebrospinal Fluid Cytology Using Manual Counting and the Sysmex XN–1000

Abstract Background Cerebrospinal fluid (CSF) cytology is essential for diagnosing neurological disorders. Automated analysers offer faster results, but their accuracy in cell differentiation remains debated. This study compares CSF cytology using the Sysmex XN–1000 analyser with manual counting in the Fuchs–Rosenthal (F–R) chamber. Methods A total of 89 CSF samples from patients aged 10 days to 80 years were analysed. Manual counting was performed using the F–R chamber, while the Sysmex XN–1000 measured cell counts in body fluid mode. Statistical comparisons in Medcalc software included the Shapiro–Wilk test, Wilcoxon test, Bland–Altman plots, Mann–Whitney test, and Cohen’s kappa coefficient. Results There were no statistically significant differences between the F–R chamber compared to Sysmex in mononuclear cells (MNc). Statistical significance was defined as P < 0.05. Data presented as median [min–max]): 10 [1–724]/µl vs. 9 [0–670]/µl resp. ( P = 0.1286); and in red blood cells (RBC): 36 [0–18,091]/µl – vs. 0 [0–34,000]/µl resp. ( P = 0.5412). However, there were statistically significant changes in polymorphonuclear cells (PMNc) ( P = 0.0002) using the F–R chamber – 0 [0–1,428]/µl in comparison with Sysmex – 1 [0–1,008]/µl. Cohen’s kappa analysis demonstrated a very good strength agreement ( K = 0.89) in the classification of oligocytosis and pleocytosis. Conclusions The Sysmex XN–1000 is a fast and efficient tool for CSF cytology but it has limitations, especially in differentiating PMNc in siderophage–rich neonatal samples. Although it improves workflow, manual verification remains crucial for diagnostic accuracy.