Utilization of automated systems to provide cerebrospinal fluid (CSF) cell counts warrants new reference ranges, according to a study published in the January issue of Clinical Biochemistry. The researchers propose new CSF cell count reference ranges of < 4 cells/μL for lymphocytes, < 3 cells/μL for monocytes, and < 3 cells/μL for granulocytes. They further determined that automated systems’ ability to differentiate mononuclear cells is of limited differential diagnostic utility. CSF cell counts have traditionally been manually performed using a microscope and cell counting chamber. The downsides of this technique are that it is time-consuming, requires trained laboratory personnel to be present, and there can be high variability among trained staff. While the performance of automated systems and manual counts is similar, automated systems reduce turnaround time, lower costs, and can provide more detailed cell differentiation than manual analysis. Cells are usually classified as erythrocytes, granulocytes, and mononuclear cells using manual analysis, while automated systems can further separate mononuclear cells into lymphocytes and monocytes based on size, absorbance, and light-scattering characteristics. The researchers used the Siemens ADVIA 2120i automated counter to establish a reference range from samples in 80 neurologically healthy volunteers (mean age 67 years) undergoing orthopedic surgery, with […]