title: Oligoclonal free light chains in cerebrospinal fluid as markers of intrathecal inflammation. Comparison with oligoclonal IgG.
abstract: OBJECTIVE
  To compare the sensitivity and specificity of CSF-restricted oligoclonal IgG and free light chains as markers of multiple sclerosis and other inflammatory neurological diseases.
  
  
  METHODS
  196 paired CSF and serum samples were examined for oligoclonal IgG and oligoclonal free light chains. The sensitivity and specificity of the tests were calculated and optimal cut-offs for the number of CSF-restricted oligoclonal bands were then determined by analysis of receiver operating characteristic curves.
  
  
  RESULTS
  Optimal cut-off values were ≥5 IgG bands for multiple sclerosis, ≥4 IgG bands for inflammatory neurological disease, ≥6 free κ, and ≥2 free λ bands for both purposes. Using these cut-off values, sensitivities and specificities for multiple sclerosis were 83.8% and 91.3% for IgG, 83.8% and 81.0% for free κ, and 67.6% and 75.4% for free λ. For inflammatory neurological disease, sensitivities and specificities were 60.8% and 95.7% for IgG, 69.6% and 92.6% for free κ, and 64.8% and 86.2% for free λ.
  
  
  CONCLUSIONS
  Although exact cut-off values may vary according to method, reporting borderline results as positive, may compromise the specificity of the test and should be avoided.. The detection of intrathecal free light chain synthesis may be of value especially when the oligoclonal IgG test is negative or borderline, even though its specificity is slightly lower.
authors.affiliation: Department of Biomedical Sciences, Faculty of Medicine, University of Ostrava, Czech Republic.
authors.forename: David
authors.initials: D
authors.lastname: Zeman
authors.forename: Pavel
authors.initials: P
authors.lastname: Hradilek
authors.forename: Pavlina
authors.initials: P
authors.lastname: Kusnierova
authors.forename: Radim
authors.initials: R
authors.lastname: Piza
authors.forename: Katarina
authors.initials: K
authors.lastname: Reguliova
authors.forename: Ivana
authors.initials: I
authors.lastname: Woznicova
authors.forename: Olga
authors.initials: O
authors.lastname: Zapletalova
mesh_terms: D015415:Biomarkers / Q000134:cerebrospinal fluid*; D006801:Humans; D007074:Immunoglobulin G / Q000134:cerebrospinal fluid*; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid*; D043025:Oligoclonal Bands / Q000134:cerebrospinal fluid*; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers; D007074:Immunoglobulin G; D043025:Oligoclonal Bands