title: Antibodies to microtubule-associated protein-2 in the cerebrospinal fluid are a useful diagnostic biomarker for neuropsychiatric systemic lupus erythematosus.
abstract: OBJECTIVE
  Previous reports indicate that serum anti-microtubule-associated protein 2 (MAP-2) antibodies are common in sera from patients with neuropsychiatric systemic lupus erythematosus (NPSLE). Differential diagnosis of NPSLE is occasionally difficult because of differential diagnosis which can mimic NPSLE. Therefore, specific biomarkers for NPSLE are needed. We conducted this study to clarify whether cerebrospinal fluid (CSF) anti-MAP-2 antibodies are a useful diagnostic biomarker for NPSLE.
  
  
  METHODS
  Enzyme-linked immunosorbent assay was conducted to measure CSF concentrations of anti-MAP-2 and anti-ribosomal P antibodies and of IL-6 in NPSLE patients (n = 24) and non-NPSLE controls (n = 17). The non-NPSLE controls consisted of systemic lupus erythematosus patients with neuropsychiatric symptoms caused by non-NPSLE conditions (n = 10) and patients with other connective tissue diseases (n = 7).
  
  
  RESULTS
  Significantly higher anti-MAP-2 antibody titers were found in the CSF of patients with NPSLE versus non-NPSLE controls. The prevalence of anti-MAP-2 antibodies was 33.3% (8/24) in NPSLE patients when a positive cutoff value was 3 standard deviations above the mean optical density of non-NPSLE controls. None of the controls had anti-MAP-2 antibodies in their CSF. Both anti-ribosomal P antibody titers and concentration of IL-6 in the CSF were significantly higher in patients with NPSLE having anti-MAP-2 antibodies than in patients with non-NPSLE controls.
  
  
  CONCLUSIONS
  Anti-MAP-2 antibodies could be detected in the CSF of 33.3% of patients with NPSLE, and its presence was highly specific for NPSLE. We propose that CSF anti-MAP-2 antibodies are a novel and useful diagnostic biomarker for NPSLE.
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Nozawa
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Soichiro
authors.initials: S
authors.lastname: Nakano
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Mitsuo
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Kaori
authors.initials: K
authors.lastname: Hiruma
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Kentaro
authors.initials: K
authors.lastname: Doe
authors.affiliation: b Institute for Environment and Gender Specific Medicine, Juntendo University Graduate School of Medicine , Chiba , Japan .|c Department of Internal Medicine and Rheumatology , Juntendo University Urayasu Hospital , Chiba , Japan , and.
authors.forename: Iwao
authors.initials: I
authors.lastname: Sekigawa
authors.affiliation: d Department of Rheumatology, Rheumatology and Internal Medicine , Sasaki Institute, Kyoundo Hospital , Tokyo , Japan.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Yamanaka
authors.affiliation: a Department of Rheumatology , Juntendo University Faculty of Medicine , Tokyo , Japan .
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Takasaki
mesh_terms: D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000032:analysis / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000032:analysis / Q000134:cerebrospinal fluid; D003221:Confusion / Q000175:diagnosis / Q000209:etiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000032:analysis / Q000134:cerebrospinal fluid; D020945:Lupus Vasculitis, Central Nervous System / Q000134:cerebrospinal fluid / Q000150:complications / Q000175:diagnosis; D008297:Male; D008869:Microtubule-Associated Proteins / Q000276:immunology*; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012269:Ribosomal Proteins / Q000276:immunology*; D013223:Statistics as Topic
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D015850:Interleukin-6; D008869:Microtubule-Associated Proteins; D012269:Ribosomal Proteins
keywords: Autoantibodies; Autoantigen; Biomarker; Microtubule-associated protein-2; Neuropsychiatric systemic lupus erythematosus