title: Serum and CSF N-acetyl aspartate levels differ in multiple sclerosis and neuromyelitis optica.
abstract: BACKGROUND
  The identification of biomarkers able to improve the differential diagnosis between multiple sclerosis (MS) and neuromyelitis optica (NMO) is challenging because of a different prognosis and response to treatment. Growing evidence indicates that brain and CSF N-acetyl aspartate (NAA) concentration is a useful marker for characterising different phases of axonal pathology in demyelinating diseases, and preliminary studies suggest that increased serum NAA levels may be a telltale sign of acute neuronal damage or defective NAA metabolism in oligodendrocytes.
  
  
  OBJECTIVE
  To evaluate whether serum and CSF NAA concentration differs in patients with MS and NMO.
  
  
  METHODS
  Observational, multicentre, prospective, cross sectional study.
  
  
  METHODS
  Serum samples were collected from 48 relapsing-remitting MS, 32 NMO and 76 age matched healthy controls. Coeval CSF samples were available for all MS and for 8/32 NMO patients. NAA was measured in serum and CSF by liquid chromatography-mass spectrometry.
  
  
  RESULTS
  MS patients showed higher serum and CSF NAA levels than NMO patients, and higher serum NAA levels than healthy controls (p<0.001). High serum NAA values, exceeding the 95th percentile of serum NAA values in healthy controls, were found in 100% of patients with MS and in no patient with NMO. No differences in serum NAA levels were found between NMO and healthy controls. In MS, serum and CSF NAA levels correlated with disability score.
  
  
  CONCLUSIONS
  Determination of serum and CSF NAA levels may represent a suitable tool in the diagnostic laboratory workup to differentiate MS and NMO.
authors.affiliation: Department of Neurological and Psychiatric Sciences, University of Bari, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Tortorella
authors.forename: M
authors.initials: M
authors.lastname: Ruggieri
authors.forename: E
authors.initials: E
authors.lastname: Di Monte
authors.forename: E
authors.initials: E
authors.lastname: Ceci
authors.forename: P
authors.initials: P
authors.lastname: Iaffaldano
authors.forename: V
authors.initials: V
authors.lastname: Direnzo
authors.forename: M
authors.initials: M
authors.lastname: Mastrapasqua
authors.forename: A
authors.initials: A
authors.lastname: Frigeri
authors.forename: M P
authors.initials: MP
authors.lastname: Amato
authors.forename: B
authors.initials: B
authors.lastname: Hakiki
authors.forename: A
authors.initials: A
authors.lastname: Ghezzi
authors.forename: A
authors.initials: A
authors.lastname: Lugaresi
authors.forename: G
authors.initials: G
authors.lastname: De Luca
authors.forename: F
authors.initials: F
authors.lastname: Patti
authors.forename: E
authors.initials: E
authors.lastname: D'Amico
authors.forename: P
authors.initials: P
authors.lastname: Sola
authors.forename: A M
authors.initials: AM
authors.lastname: Simone
authors.forename: M
authors.initials: M
authors.lastname: Svelto
authors.forename: P
authors.initials: P
authors.lastname: Livrea
authors.forename: M
authors.initials: M
authors.lastname: Trojano
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000097:blood / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D009471:Neuromyelitis Optica / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*
chemical_list: D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate