title: Kappa free light chains: diagnostic and prognostic relevance in MS and CIS.
abstract: BACKGROUND
  Quantification of kappa free light chains (KFLC) in cerebrospinal fluid shows high diagnostic sensitivity in multiple sclerosis and clinically isolated syndrome patients. However, a clearly defined threshold value is still missing and a possible prognostic value of the KFLC levels in these patients remains undefined.
  
  
  METHODS
  Results of KFLC quantification in 420 controls were used to set an upper limit of normal KFLC concentration in CSF under different blood-CSF-barrier conditions. Additionally, KFLC values of MS and CIS patients were assessed and results were evaluated with reference to the patients corresponding disease courses.
  
  
  RESULTS
  The calculated upper limit of normal KFLC-concentration covers 98% of these control patients. Using this cut-off, plasma cell activity in CSF can be detected in 97% of MS patients and in 97% of CIS patients. However, there is no evidence that the extent of KFLC elevation provides prognostic value in MS and CIS patients in this study.
  
  
  CONCLUSIONS
  KFLC determination should become a first line screen in the diagnostic algorithms of MS and CIS. The extent of elevation of intrathecal KFLC has no prognostic value on the disease course in MS and CIS patients.
authors.affiliation: Department of Neurology, Wilhelminenspital, Vienna, Austria.
authors.forename: Stefan
authors.initials: S
authors.lastname: Presslauer
authors.affiliation: Department of Laboratory Medicine, Wilhelminenspital, Vienna, Austria.
authors.forename: Dejan
authors.initials: D
authors.lastname: Milosavljevic
authors.affiliation: Department of Laboratory Medicine, Wilhelminenspital, Vienna, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Huebl
authors.affiliation: Department of Neurology, Wilhelminenspital, Vienna, Austria.
authors.forename: Silvia
authors.initials: S
authors.lastname: Parigger
authors.affiliation: Department of Neurology, Wilhelminenspital, Vienna, Austria.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Schneider-Koch
authors.affiliation: Department of Neurology, Wilhelminenspital, Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Bruecke
mesh_terms: D000328:Adult; D003711:Demyelinating Diseases / Q000175:diagnosis* / Q000276:immunology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007145:Immunoglobulin kappa-Chains / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis* / Q000276:immunology; D011379:Prognosis
chemical_list: D007145:Immunoglobulin kappa-Chains