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

Abstract

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. 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. 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. 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.