title: Cerebrospinal fluid interleukin-6 in central nervous system inflammatory diseases.
abstract: BACKGROUND
  Interleukin (IL)-6 is recognised as an important cytokine involved in inflammatory diseases of the central nervous system (CNS).
  
  
  OBJECTIVE
  To perform a large retrospective study designed to test cerebrospinal fluid (CSF) IL-6 levels in the context of neurological diseases, and evaluate its usefulness as a biomarker to help discriminate multiple sclerosis (MS) from other inflammatory neurological diseases (OIND).
  
  
  METHODS
  We analyzed 374 CSF samples for IL-6 using a quantitative enzyme-linked immunosorbent assay. Groups tested were composed of demyelinating diseases of the CNS (DD, n = 117), including relapsing-remitting MS (RRMS, n = 65), primary progressive MS (PPMS, n = 11), clinically isolated syndrome (CIS, n = 11), optic neuritis (ON, n = 30); idiopathic transverse myelitis (ITM, n = 10); other inflammatory neurological diseases (OIND, n = 35); and non-inflammatory neurological diseases (NIND, n = 212). Differences between groups were analysed using Kruskal-Wallis test and Mann-Whitney U-test.
  
  
  RESULTS
  CSF IL-6 levels exceeded the positivity cut-off of 10 pg/ml in 18 (51.4%) of the 35 OIND samples, but in only three (3.9%) of the 76 MS samples collected. CSF IL-6 was negative for all NIND samples tested (0/212). IL-6 cut-off of 10 pg/ml offers 96% sensitivity to exclude MS.
  
  
  CONCLUSIONS
  CSF IL-6 may help to differentiate MS from its major differential diagnosis group, OIND.
authors.affiliation: Department of Clinical Neurosciences, Division of Neurology, University Hospital of Geneva, Geneva, Switzerland.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Wullschleger
authors.forename: Viktoria
authors.initials: V
authors.lastname: Kapina
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molnarfi
authors.forename: Delphine S
authors.initials: DS
authors.lastname: Courvoisier
authors.forename: Jörg D
authors.initials: JD
authors.lastname: Seebach
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Santiago-Raber
authors.forename: Denis F
authors.initials: DF
authors.lastname: Hochstrasser
authors.forename: Patrice H
authors.initials: PH
authors.lastname: Lalive
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003711:Demyelinating Diseases / Q000134:cerebrospinal fluid; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D020528:Multiple Sclerosis, Chronic Progressive / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000134:cerebrospinal fluid* / Q000175:diagnosis; D009188:Myelitis, Transverse / Q000134:cerebrospinal fluid; D009902:Optic Neuritis / Q000134:cerebrospinal fluid; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6