title: Automated cerebrospinal fluid cell count--new reference ranges and evaluation of its clinical use in central nervous system infections.
abstract: OBJECTIVE
  The purposes of this study were to establish new reference ranges for leukocytes in the CSF and to examine if the separation of mononuclear cells into lymphocytes and monocytes could be used to differentiate between various CNS infections that present with a similar picture in manual CSF cell counts.
  
  
  METHODS
  The automated cell counter Siemens ADVIA 2120 i was used. For the reference range section, we analyzed CSF from 80 neurologically healthy volunteers. For the differential diagnosis section we analyzed cell counts and hospital records from 175 patients with CSF mononuclear pleocytosis.
  
  
  RESULTS
  Correlation was good between automated and manual leukocyte counts for samples with erythrocyte counts <250 cells/μL. For the neurologically healthy volunteers studied in the reference range section, the 95th percentile was 3.0 cells/μL for lymphocytes, 1.0 cell/μL for monocytes and 1.0 cell/μL for granulocytes. In the differential diagnosis section, comparisons were done between the groups Lyme neuroborreliosis and viral CNS infection. There were no significant differences between these two groups regarding cell counts; neither for lymphocytes, median 58 cells/μL vs. 72 cells/μL (P = n.s.); nor for monocytes, median 13 cells/μL vs. 16 cells/μL (P = n.s.); nor for granulocytes, median 1 cell/μL vs. 2 cells/μL (P = n.s.)
  
  
  CONCLUSIONS
  We suggest new CSF cell count reference ranges of <4 cells/μL for lymphocytes, <3 cells/μL for monocytes and <3 cells/μL for granulocytes. The separation of mononuclear cells into lymphocytes and monocytes did not facilitate the discrimination between Lyme neuroborreliosis and viral CNS infection.
authors.affiliation: Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy at the University of Gothenburg, 416 45 Gothenburg, Sweden. Electronic address: daniel.bremell@infect.gu.se.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bremell
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, 413 45 Gothenburg, Sweden. Electronic address: niklas.mattsson@neuro.gu.se.
authors.forename: Niklas
authors.initials: N
authors.lastname: Mattsson
authors.affiliation: Department of Anaesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden. Electronic address: fredrik.wallin@vgregion.se.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Wallin
authors.affiliation: Department of Anaesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg 413 45, Sweden. Electronic address: john.henriksson@vgregion.se.
authors.forename: John
authors.initials: J
authors.lastname: Henriksson
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, 413 45 Gothenburg, Sweden. Electronic address: mariann.wall@vgregion.se.
authors.forename: Mariann
authors.initials: M
authors.lastname: Wall
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, 413 45 Gothenburg, Sweden. Electronic address: kaj.blennow@neuro.gu.se.
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.affiliation: Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at the University of Gothenburg, 413 45 Gothenburg, Sweden; UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom. Electronic address: henrik.zetterberg@clinchem.gu.se.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.affiliation: Department of Infectious Diseases, Institute of Biomedicine, The Sahlgrenska Academy at the University of Gothenburg, 416 45 Gothenburg, Sweden. Electronic address: lars.hagberg@medfak.gu.se.
authors.forename: Lars
authors.initials: L
authors.lastname: Hagberg
mesh_terms: D001331:Automation; D002452:Cell Count; D002494:Central Nervous System Infections / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D002555:Cerebrospinal Fluid / Q000166:cytology*; D003937:Diagnosis, Differential; D006801:Humans; D012015:Reference Standards
keywords: Cell count; Cerebrospinal fluid; Lyme neuroborreliosis; Reference ranges; Viral encephalitis; Viral meningitis