SHORT COMMUNICATION CSF proteome analysis in multiple sclerosis patients by two-dimensional electrophoresis D. Chiasserini a,b , M. Di Filippo a,c , A. Candeliere a , F. Susta b , P. L. Orvietani b , P. Calabresi a,c , L. Binaglia b and P. Sarchielli a a Neurologic Clinic, Department of Medical and Surgical Specialties and Public Health, University of Perugia, Perugia, Italy; b Section of Biochemistry, Department of Internal Medicine, University of Perugia, Perugia, Italy; and c Fondazione Santa Lucia, IRCCS c/o CERC, Rome, Italy Keywords: cerebrospinal fluid, clinically isolated syndrome, multiple sclerosis, proteomics Received 27 January 2008 Accepted 7 May 2008 Background and purpose: In recent years, different approaches have been used to investigate changes of cerebrospinal fluid (CSF) proteome in patients affected by multiple sclerosis (MS) with the aim to identify protein markers with potential diag- nostic or prognostic value. Because of the lack of standardization of current proteomic techniques, contrasting results were achieved until now in different laboratories. In this study, we compare CSF proteome of 10 relapsing–remitting MS (RR-MS) patients, 11 patients with clinically isolated syndrome (CIS), and 10 control subjects without neurological or systemic diseases. Methods: The differential expression of CSF pro- teins amongst these cohorts of patients was investigated by using two-dimensional electrophoresis and mass spectrometry. Results and conclusions: We found an over- expression of IgG free kappa light chain protein in both CIS and RR-MS patients, compared with control subjects and an increased expression of an apolipoprotein E isoform in RR-MS patients, compared with CIS and control groups. Our results confirm the presence of CSF proteome changes in MS patients. Future research should be aimed to investigate the role of these candidate CSF markers in larger cohorts of CIS and MS patients. Introduction In recent years, different proteomic approaches have been used to investigate changes of cerebrospinal fluid (CSF) proteome in patients affected by multiple sclerosis (MS), when compared with that of healthy individuals, in order to identify putative polypeptide markers with po- tential diagnostic or prognostic value [1,2]. The aim of the present report was to analyse CSF proteome changes in patients with MS and in patients presenting with a clinically isolated syndrome sugges- tive of MS (CIS). Materials and methods Cerebrospinal fluid proteomes from 11 CIS patients and 10 relapsing–remitting MS (RR-MS) patients, diagnosed according to McDonald criteria [3], were evaluated. Lumbar puncture (LP) was performed on CIS patients at an average of 13.3 ± 5.8 days from the relapse. Expanded Disability Status Score was calculated according to Kurtzke [4] and ranged between 0.5 and 5 for RR-MS patients. CSF withdrawal from RR-MS patients was performed in a remitting phase of the disease, with an average of 3 months from the last relapse. The control group included 10 subjects who were initially seen with an indication for lumbar puncture, but were ultimately found to have no evidence of acute or chronic neurologic or systemic disease. Subjects were excluded from this reference group if they were found to have clinical or laboratory evidence of any active or past neurologic disorder, e.g. stroke, hydrocephalus, intracranial infection, seizures or epilepsy, encephalo- pathy, head trauma, demyelinating diseases, or dis- orders of the peripheral nerves or muscles. Patients with acute or chronic systemic disease, e.g. cancer, bactere- mia or sepsis, and hematologic or rheumatologic dis- orders, were also excluded. Based on traditional criteria for meningitis, positive evidence of central nervous system infection consisted of an appropriate clinical presentation in combination with CSF pleocytosis or cultures positive for virus or bacteria. CSF was centri- fuged at 4°C for 10 min at 1000 g and stored at )80°C before analysis. CSF from patients and control subjects were precipitated with cold acetone ()20°C) overnight Correspondence: Davide Chiasserini, Clinica Neurologica, Universita` di Perugia, Ospedale S Maria della Misericordia, Via S Andrea delle Fratte, 06156, Perugia, Italy (e-mail: d.chiasserini@gmail.com). 998 Ó 2008 The Author(s) Journal compilation Ó 2008 EFNS European Journal of Neurology 2008, 15: 998–1001 doi:10.1111/j.1468-1331.2008.02239.x