title: The association between antibodies to neurotropic pathogens and schizophrenia: a case-control study.
abstract: BACKGROUND
  Exposure to neurotropic pathogens has been proposed as an environmental risk factor for schizophrenia and can be evaluated by measuring pathogen-specific immunoglobulin G (IgG). Seroprevalence of pathogen-specific IgG reflects prior exposure, whereas IgG levels are associated with reactivity or reinfection. Several studies have examined these parameters in schizophrenia. However, results still remain inconclusive, as several previous studies did not correct for important confounding factors.
  
  
  OBJECTIVE
  To investigate whether schizophrenia is associated with prior exposure to neurotropic pathogens, or with their reactivation.
  
  
  METHODS
  We examined the seroprevalence and titer of IgG antibodies against herpes simplex virus-1 and -2 (HSV-1/HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), and Toxoplasma gondii (TG) in plasma of 368 adult patients with a schizophrenia spectrum disorder and 282 controls using ELISA.
  
  
  RESULTS
  We did not find evidence for an increased exposure to HSV-1, HSV-2, EBV, and TG in patients. There was a significantly higher seroprevalence of VZV (98.9% vs. 95.6%, P<0.05) and CMV (40.4% vs. 27.7%, P<0.001) in controls as compared with patients, which did not remain statistically significant after adjustment for various potential confounders. We did not find significant differences in antibody titers of seropositive patients and controls for any of the six pathogens.
  
  
  CONCLUSIONS
  Our results do not support the hypothesis that increased exposure to neurotropic pathogens after birth is associated with schizophrenia.
authors.affiliation: Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht , Utrecht, The Netherlands.
authors.forename: Lot D
authors.initials: LD
authors.lastname: de Witte
authors.affiliation: Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht , Utrecht, The Netherlands.
authors.forename: Hans C
authors.initials: HC
authors.lastname: van Mierlo
authors.affiliation: Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center Utrecht , Utrecht, The Netherlands.
authors.forename: Manja
authors.initials: M
authors.lastname: Litjens
authors.affiliation: Department of Psychiatry, University of Groningen , Groningen, The Netherlands.
authors.forename: Hans C
authors.initials: HC
authors.lastname: Klein
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge , Cambridge, UK.
authors.forename: Sabine
authors.initials: S
authors.lastname: Bahn
authors.affiliation: Department of Viroscience, Erasmus University Medical Center , Rotterdam, The Netherlands.
authors.forename: Ab D
authors.initials: AD
authors.lastname: Osterhaus