title: Screening for onconeural antibodies in neuromyelitis optica spectrum disorders.
abstract: BACKGROUND
  Some so-called "non-classical" paraneoplastic neurological syndromes (PNS), namely optic neuritis and myelitis, clinically overlap with neuromyelitis optica spectrum disorders (NMOSD), and conversely, in cancer-associated NMOSD, a paraneoplastic etiology has been suggested in rare cases. Therefore, we retrospectively investigated the prevalence of onconeural antibodies, which are highly predictive for a paraneoplastic etiology, and the prevalence of malignancies in NMOSD patients.
  
  
  METHODS
  We retrospectively screened 23 consecutive patients from our clinic with NMOSD (13 were anti-aquaporin-4 [AQP4] antibody positive, 10 were AQP4 negative) for onconeural antibodies using an immunoblot.
  
  
  RESULTS
  All patients were negative for a broad spectrum of antibodies targeting intracellular onconeural antigens (Hu, Yo, Ri, CV2/CRMP5, Ma1, Ma2, Zic4, SOX1, Tr, and amphiphysin). Notably, only two patients had a malignancy. However, neoplastic entities (astrocytic brain tumor and acute myeloid leukemia) were not typical for PNS.
  
  
  CONCLUSIONS
  Our data suggest that there is no need to routinely screen anti-AQP4 antibody positive NMOSD patients with a typical presentation for onconeural antibodies. Furthermore, absence of these antibodies in NMOSD, which is typically non-paraneoplastic, confirms their high specificity for PNS.
authors.affiliation: Department of Neurology and Neurophysiology, Medical Center-University of Freiburg, Faculty of Medicine, Breisacher Strasse 64, D-79106, Freiburg, Germany. benjamin.berger@uniklinik-freiburg.de.
authors.forename: Benjamin
authors.identifier: http://orcid.org/0000-0001-7680-8880
authors.initials: B
authors.lastname: Berger
authors.affiliation: Department of Neurology and Neurophysiology, Medical Center-University of Freiburg, Faculty of Medicine, Breisacher Strasse 64, D-79106, Freiburg, Germany.
authors.forename: Tilman
authors.initials: T
authors.lastname: Hottenrott
authors.affiliation: Department of Neurology and Neurophysiology, Medical Center-University of Freiburg, Faculty of Medicine, Breisacher Strasse 64, D-79106, Freiburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Rauer
authors.affiliation: Department of Neurology and Neurophysiology, Medical Center-University of Freiburg, Faculty of Medicine, Breisacher Strasse 64, D-79106, Freiburg, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Stich
mesh_terms: D000328:Adult; D000368:Aged; D051401:Aquaporin 4 / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D009419:Nerve Tissue Proteins / Q000276:immunology; D009471:Neuromyelitis Optica / Q000276:immunology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D051401:Aquaporin 4; D001323:Autoantibodies; D009419:Nerve Tissue Proteins; C075637:amphiphysin
keywords: Aquaporin-4; NMOSD; Neuromyelitis optica spectrum disorders; Onconeural antibodies; Paraneoplastic