Automated vs. manual cerebrospinal fluid cell counts: a work and cost analysis comparing the Sysmex XE-5000 and the Fuchs-Rosenthal manual counting chamber.

INTRODUCTION

Cerebrospinal fluid (CSF) cell counts are traditionally performed by manual microscopy using the Fuchs-Rosenthal counting chamber. This procedure is time-, labour- and cost-intensive and requires experienced laboratory staff.

METHODS

The Sysmex XE-5000 haematology analyzer offers a channel to quantify the total cell count of body fluids. We compared technical sensitivity and specificity, intra-assay variability, turn-around time (TAT) and costs for the determination of CSF cell counts between both methods.

RESULTS

The mean coefficients of variation (CV) for total cell counts in CSF of the Fuchs-Rosenthal chamber and the XE-5000 were 15.2% (range: 2.8-47.5%) and 12.5% (range: 1.9-50.6%). Setting the Fuchs-Rosenthal chamber as 'gold standard', our results revealed a sensitivity of 100% and a specificity of 75% for the XE-5000 to detect a pathological cell count (≥ 6 cells/μL), whereas the sensitivity and specificity to detect a severely pathological cell count (≥ 20 cells/μL) were 100% for both. Bland and Altman analysis revealed slightly higher cell counts with the XE-5000. The approximate duration of a single CSF cell count analysis was 635 s for the manual vs. 85 s for the automated method. Total analytical performance costs for the counting chamber were 6.74 EUR per mean analysis and 1.22 EUR for the XE-5000.

CONCLUSION

Our study revealed a lower mean CV for the total cell count for the XE-5000 method. The fully automated CSF cell count results in a 7.5-fold reduction in TAT and leads to a significant decrease in total analytical performance costs.