Isoelectric focusing is superior to immunofixation electrophoresis in diagnosing CNS inflammation.
BACKGROUND
A sensitive method to detect intrathecal IgG production is important in diagnosing inflammatory central nervous system (CNS) diseases, including multiple sclerosis (MS).


OBJECTIVE
To compare cerebrospinal fluid (CSF) electrophoresis with isoelectric focusing (IEF), immunofixation-peroxidase electrophoresis (IFPE) and high-resolution agarose electrophoresis with protein-staining (HRAGE).


METHODS
Paired serum and CSF samples from 307 consecutive patients attending a general neurology clinic were examined with IEF, IFPE and HRAGE. Clinical diagnosis was based on review of the patients' medical records after an average of 4 years.


RESULTS
The sensitivity for detecting any inflammatory (autoimmune or infectious) CNS disease (52 patients) was 67% for IEF, 50% for IFPE and 29% for HRAGE. The sensitivity for detecting MS (14 patients) was 93%, 86% and 29% respectively. The sensitivity for detecting clinically isolated syndrome (eight patients) was 75%, 25% and 13% respectively. The number of oligoclonal bands in IEF was higher in inflammatory than in non-inflammatory neurological diseases or symptoms, but similar in MS and other inflammatory diseases.


CONCLUSIONS
IEF is the method of choice in diagnosing intrathecal IgG synthesis.
Mygland
A
A
Department of Neurology, Sørlandet Sykehus, Kristiansand, Norway. aase.mygland@sshf.no
Trydal
T
T
Vinje
B U
BU
Vedeler
C
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002493:Central Nervous System Diseases / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D015331:Cohort Studies; D004586:Electrophoresis / Q000379:methods*; D004660:Encephalitis / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009187:Myelitis / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D043025:Oligoclonal Bands / Q000097:blood / Q000134:cerebrospinal fluid*; D011237:Predictive Value of Tests; D012189:Retrospective Studies
D043025:Oligoclonal Bands