title: Replicated evidence of absence of association between serum S100B and (risk of) psychotic disorder.
abstract: BACKGROUND
  S100B is a potential marker of neurological and psychiatric illness. In schizophrenia, increased S100B levels, as well as associations with acute positive and persisting negative symptoms, have been reported. It remains unclear whether S100B elevation, which possibly reflects glial dysfunction, is the consequence of disease or compensatory processes, or whether it is an indicator of familial risk.
  
  
  METHODS
  Serum samples were acquired from two large independent family samples (n = 348 and n = 254) in the Netherlands comprising patients with psychotic disorder (n = 140 and n = 82), non-psychotic siblings of patients with psychotic disorder (n = 125 and n = 94) and controls (n = 83 and n = 78). S100B was analyzed with a Liaison automated chemiluminescence system. Associations between familial risk of psychotic disorder and S100B were examined.
  
  
  RESULTS
  Results showed that S100B levels in patients (P) and siblings (S) were not significantly different from controls (C) (dataset 1: P vs. C: B = 0.004, 95% CI -0.005 to 0.013, p = 0.351; S vs. C: B = 0.000, 95% CI -0.009 to 0.008, p = 0.926; and dataset 2: P vs. C: B = 0.008, 95% CI -0.011 to 0.028, p = 0.410; S vs. C: B = 0.002, 95% CI -0.016 to 0.021, p = 0.797). In patients, negative symptoms were positively associated with S100B (B = 0.001, 95% CI 0.000 to 0.002, p = 0.005) in one of the datasets, however with failure of replication in the other. There was no significant association between S100B and positive symptoms or present use or type of antipsychotic medication.
  
  
  CONCLUSIONS
  S100B is neither an intermediate phenotype, nor a trait marker for psychotic illness.
authors.affiliation: Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, European Graduate School of Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Christine
authors.initials: C
authors.lastname: van der Leeuw
authors.affiliation: Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, European Graduate School of Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Machteld
authors.initials: M
authors.lastname: Marcelis
authors.affiliation: Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, European Graduate School of Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Sanne C T
authors.initials: SC
authors.lastname: Peeters
authors.affiliation: Departments of Neurology and Laboratory Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands ; Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.
authors.forename: Marcel M
authors.initials: MM
authors.lastname: Verbeek
authors.affiliation: Central Diagnostic Laboratory, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Paul P C A
authors.initials: PP
authors.lastname: Menheere
authors.affiliation: Deparment of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Lieuwe
authors.initials: L
authors.lastname: de Haan
authors.affiliation: Department of Psychiatry and Psychology, School for Mental Health and Neuroscience, European Graduate School of Neuroscience, Maastricht University Medical Centre, Maastricht, The Netherlands ; King's College London, King's Health Partners, Department of Psychosis Studies, Institute of Psychiatry, London, United Kingdom.
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.affiliation: Departments of Psychiatry and Neuroscience, Erasmus Medical Centre, Rotterdam, The Netherlands ; Department "Nieuwe Kennis", Delta Centre for Mental Health Care, Rotterdam, The Netherlands.
authors.forename: Nico J M
authors.initials: NJ
authors.lastname: van Beveren
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D012307:Risk Factors; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D015415:Biomarkers; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human