Cystatin C in cerebrospinal fluid and multiple sclerosis.
OBJECTIVE
A recent study using surface-enhanced laser desorption/ionization time-of-flight analysis of cerebrospinal fluid identified a 12.5 kDa truncated isoform of cystatin C (CysC) as a specific biomarker for multiple sclerosis (MS).


METHODS
Surface-enhanced laser desorption/ionization time-of-flight analysis of cerebrospinal fluid samples from 43 MS patients and 46 healthy control subjects.


RESULTS
Full-length CysC (13.4 kDa) concentration was similar in MS and control samples. The 12.5 kDa CysC protein was produced from full-length CysC by N-terminal cleavage during storage at -20 degrees C.


CONCLUSIONS
The 12.5 kDa CysC isoform is a storage-related artifact and is not useful as a diagnostic marker for MS.
Hansson
Sara F
SF
Department of Clinical Neuroscience, University of Göteborg, Sahlgrenska University Hospital/Mölndal, Mölndal, Sweden.
Simonsen
Anja Hviid
AH
Zetterberg
Henrik
H
Andersen
Oluf
O
Haghighi
Sara
S
Fagerberg
Inger
I
Andréasson
Ulf
U
Westman-Brinkmalm
Ann
A
Wallin
Anders
A
Rüetschi
Ulla
U
Blennow
Kaj
K
D000595:Amino Acid Sequence; D016477:Artifacts; D015415:Biomarkers / Q000134:cerebrospinal fluid; D055316:Cystatin C; D015891:Cystatins / Q000134:cerebrospinal fluid* / Q000737:chemistry / Q000235:genetics; D004356:Drug Storage; D005615:Freezing; D006801:Humans; D008970:Molecular Weight; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid*; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000134:cerebrospinal fluid / Q000737:chemistry / Q000235:genetics; D020033:Protein Isoforms / Q000134:cerebrospinal fluid / Q000737:chemistry / Q000235:genetics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D010446:Peptide Fragments; D020033:Protein Isoforms