Automated flow cytometric analysis of blood cells in cerebrospinal fluid: analytic performance

We compared the performance of an automated method for obtaining RBC and WBC counts and WBC differential counts in cerebrospinal fluid (CSF) samples with the reference manual method. Results from 325 samples from 10 worldwide clinical sites were used to demonstrate the accuracy, precision, and linearity of the method. Accuracy statistics for absolute cell counts showed a high correlation between methods, with correlation coefficients for all reportable absolute counts greater than 0.9. Linearity results demonstrated that the method provides accurate results throughout the reportable ranges, including clinical decision points for WBCs of 0 to 10/microL. Interassay precision and intra-assay precision for the ADVIA 120 (Bayer HealthCare, Tarrytown, NY) method were acceptable at all levels. The ADVIA 120 CSF Assay enumerates and differentiates cells via flow cytometry in a minimally diluted sample, improving the analysis of typically hypocellular CSF samples. Study results demonstrate that the automated ADVIA 120 CSF Assay is an acceptable alternative to the labor-intensive manual method.