title: Cleavage of cystatin C is not associated with multiple sclerosis.
abstract: Recently, Irani and colleagues proposed a C-terminal cleaved isoform cystatin C (12.5 kDa) in cerebrospinal fluid as a marker of multiple sclerosis. In this study, we demonstrate that the 12.5 kDa product of cystatin C is formed by degradation of the first eight N-terminal residues. Moreover, such a degradation is not specific in the cerebrospinal fluid of multiple sclerosis, but rather is given by an inappropriate sample storage at -20 degrees C. We conclude that the use of the 12.5 kDa product of cystatin C in cerebrospinal fluid might lead to a fallacious diagnosis of multiple sclerosis. Preanalytical validation procedure is mandatory for proteomics investigations.
authors.affiliation: Centro Studi sull'Invecchiamento, Fondazione G. D'Annunzio, Chieti, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Del Boccio
authors.forename: Damiana
authors.initials: D
authors.lastname: Pieragostino
authors.forename: Alessandra
authors.initials: A
authors.lastname: Lugaresi
authors.forename: Maria
authors.initials: M
authors.lastname: Di Ioia
authors.forename: Barbara
authors.initials: B
authors.lastname: Pavone
authors.forename: Daniela
authors.initials: D
authors.lastname: Travaglini
authors.forename: Simona
authors.initials: S
authors.lastname: D'Aguanno
authors.forename: Sergio
authors.initials: S
authors.lastname: Bernardini
authors.forename: Paolo
authors.initials: P
authors.lastname: Sacchetta
authors.forename: Giorgio
authors.initials: G
authors.lastname: Federici
authors.forename: Carmine
authors.initials: C
authors.lastname: Di Ilio
authors.forename: Domenico
authors.initials: D
authors.lastname: Gambi
authors.forename: Andrea
authors.initials: A
authors.lastname: Urbani
mesh_terms: D016477:Artifacts; D055316:Cystatin C; D015891:Cystatins / Q000134:cerebrospinal fluid* / Q000737:chemistry*; D004356:Drug Storage; D005615:Freezing; D006801:Humans; D008970:Molecular Weight; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid*; D010446:Peptide Fragments / Q000134:cerebrospinal fluid / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D010446:Peptide Fragments