title: Oligoclonal bands in cerebrospinal fluid: a comparative study of isoelectric focusing, agarose gel electrophoresis and IgG index.
abstract: OBJECTIVE
  To compare the sensitivity and specificity of isoelectric focusing (IEF) with immunofixation, agarose gel electrophoresis (AGE) and the IgG index in detecting intrathecally synthesized IgG in multiple sclerosis (MS) and in other nervous system disorders.
  
  
  METHODS
  Cerebrospinal fluid (CSF) and serum from 147 patients with various nervous system diseases, 20 of whom had MS, were compared with IEF, AGE and the IgG index.
  
  
  RESULTS
  CSF-restricted oligoclonal bands (OCB) were found in 20 of 20 patients with MS using IEF and in 9 of 20 using AGE. OCB were found in 12 patients with other nervous system disorders (OND) using IEF and 4 using AGE. The mean IgG index was 0.50 in OND and 0.96 in MS (P< 0.0001). Of 20 MS patients, 9 had an IgG index above the defined cut-off value of 0.72.
  
  
  CONCLUSIONS
  IEF is about twice as sensitive as AGE in detecting OCB in MS. IEF is also far superior to the IgG index in determining intrathecal IgG synthesis.
authors.affiliation: Department of Neurology, University of Bergen, Norway.
authors.forename: J
authors.initials: J
authors.lastname: Lunding
authors.forename: R
authors.initials: R
authors.lastname: Midgard
authors.forename: C A
authors.initials: CA
authors.lastname: Vedeler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D004587:Electrophoresis, Agar Gel; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000134:cerebrospinal fluid; D007136:Immunoglobulins / Q000097:blood / Q000134:cerebrospinal fluid*; D007525:Isoelectric Focusing; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood / Q000134:cerebrospinal fluid* / Q000175:diagnosis*; D009422:Nervous System Diseases / Q000134:cerebrospinal fluid / Q000175:diagnosis; D043025:Oligoclonal Bands; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D007074:Immunoglobulin G; D007136:Immunoglobulins; D043025:Oligoclonal Bands