title: Growth arrest specific gene 6 protein concentration in cerebrospinal fluid correlates with relapse severity in multiple sclerosis.
abstract: BACKGROUND
  Growth arrest specific gene 6 (Gas6) protein enhances survival of oligodendrocytes and neurons, and it is involved in autoimmunity. Therefore, we aimed to verify whether cerebrospinal-fluid (CSF) Gas6 concentration may represent a biomarker of disease activity in multiple sclerosis.
  
  
  METHODS
  Sixty-five patients who underwent a spinal tap during relapse of relapsing/remitting multiple sclerosis (RR-MS)(McDonald-criteria) were studied. Forty patients affected by noninflammatory/nonautoimmune neurological diseases served as controls. Relapse was defined according to Schumacher criteria. Symptoms were grouped according to Kurtzke-Functional System (FS). Clinical characteristics of the relapse, duration, Expanded-Disability-Status Scale (EDSS) change, number of FS involved, completeness of recovery, age, steroid therapy, were categorised. Patients were followed at 6-month intervals to assess relapse rate and EDSS progression. Gas6 was measured (CSF, plasma) by in-house-enzyme-linked immunoassay (ELISA).
  
  
  RESULTS
  Higher CSF Gas6 concentrations were observed in relapses lasting ≤60 days (8.7 ± 3.9 ng/mL) versus >60 days (6.5 ± 2.6) or controls (6.5 ± 2.4; P = 0.05), with ≤2 FS involved (8.5 ± 3.8) versus >2 FS (5.6 ± 2.5) (P < 0.05) and EDSS change ≤2.5 points (8.8 ± 3.7) versus >2.5 (6.5 ± 3.5) (P = 0.04). Conversely, CSF Gas6 was not predictive of the completeness of recovery. Plasma and CSF concentrations were not related (R (2) = 0.0003), and neither were predictive of relapse rate or EDSS progression after first relapse.
  
  
  CONCLUSIONS
  CSF concentration of Gas6 is inversely correlated with the severity of relapse in RR-MS patients but does not predict the subsequent course of the disease.
authors.affiliation: AOU Maggiore della Carità, 28100 Novara, Italy. sainaghi@med.unipmn.it
authors.forename: P P
authors.initials: PP
authors.lastname: Sainaghi
authors.forename: L
authors.initials: L
authors.lastname: Collimedaglia
authors.forename: F
authors.initials: F
authors.lastname: Alciato
authors.forename: R
authors.initials: R
authors.lastname: Molinari
authors.forename: D
authors.initials: D
authors.lastname: Sola
authors.forename: E
authors.initials: E
authors.lastname: Ranza
authors.forename: P
authors.initials: P
authors.lastname: Naldi
authors.forename: F
authors.initials: F
authors.lastname: Monaco
authors.forename: M
authors.initials: M
authors.lastname: Leone
authors.forename: M
authors.initials: M
authors.lastname: Pirisi
authors.forename: G C
authors.initials: GC
authors.lastname: Avanzi
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood* / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood* / Q000378:metabolism / Q000473:pathology*; D012008:Recurrence; D000099255:Growth Arrest-Specific Protein 6
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D000099255:Growth Arrest-Specific Protein 6