title: Prevalence of anti-SOX1 reactivity in various neurological disorders.
abstract: OBJECTIVE
  Anti-SOX1 antibodies are associated with small cell lung cancer (SCLC) and predict a paraneoplastic etiology in Lambert-Eaton myasthenic syndrome (LEMS). In 2010, a study described these antibodies in a small cohort of putative non-paraneoplastic, immune-mediated neuropathies. In this respect, we investigated the seroprevalence and specificity of anti-SOX1 antibodies in a large cohort of neurological disorders.
  
  
  METHODS
  Overall, serum samples of 1493 consecutive patients were screened for anti-SOX1 reactivity by an ELISA: 471 with well-defined neurological disorders (multiple sclerosis, motor neuron disease, Guillain-Barré syndrome, and chronic inflammatory demyelinating polyneuropathy), 185 with polyneuropathy (PNP) of unknown origin, and 837 with neurological syndromes of suspicious paraneoplastic etiology. These were compared to eight positive controls with definite paraneoplastic neurological syndromes (PNS) and 92 healthy individuals. We also collected demographic and clinical data, including well-characterized onconeural antibodies in anti-SOX1-positive patients.
  
  
  RESULTS
  Fifteen patients (1.0%) showed anti-SOX1 reactivity: two with multiple sclerosis, two with PNP of unknown origin, and 11 suspicious PNS cases. Remarkably, 9/15 anti-SOX1-positive patients had a PNP. However, antibody concentrations were significantly lower compared to positive controls, and none additionally harbored well-characterized onconeural antibodies. During a follow-up of at least four years, only five patients had cancer: one thyroid, one Hodgkin lymphoma, two breast, and one patient had multiple malignancies - prostate, penis, cecum, liver, and non-small cell lung cancer. However, none had SCLC, typically associated with SOX1 antibodies.
  
  
  CONCLUSIONS
  The seroprevalence of anti-SOX1 antibodies in patients with various neurological disorders is low. These patients predominantly have PNPs, which might represent a group of immune-mediated diseases.
authors.affiliation: Department of Neurology and Neurophysiology, Medical Center - University of Freiburg, Faculty of Medicine, Breisacher Strasse 64, D-79106 Freiburg, Germany. Electronic address: benjamin.berger@uniklinik-freiburg.de.
authors.forename: Benjamin
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: Rick
authors.initials: R
authors.lastname: Dersch
authors.affiliation: Department of Neurology and Neurophysiology, Medical Center - University of Freiburg, Faculty of Medicine, Breisacher Strasse 64, D-79106 Freiburg, Germany.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ruthardt
authors.affiliation: ravo Diagnostika GmbH, Oltmannsstrasse 5, D-79100 Freiburg, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Rasiah
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; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000097:blood* / Q000453:epidemiology*; D012372:ROC Curve; D055757:SOXE Transcription Factors / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G; C527923:SOX10 protein, human; D055757:SOXE Transcription Factors
keywords: Immune-mediated; Neuropathy; Onconeural antibodies; PNS; Paraneoplastic neurological syndromes; SOX1