title: Inflammation and schizophrenia: alterations in cytokine levels and perturbation in antioxidative defense systems.
abstract: OBJECTIVE
  Although several theories have been proposed including developmental/neurodegenerative processes, neurotransmitter abnormalities, viral infection, and immune dysfunction, the exact causative factor of schizophrenia is unclear. A relationship between inflammation and schizophrenia has been supported by abnormal cytokine production and altered antioxidant status. This study was aimed to examine the alterations in serum oxidative-antioxidative status and cytokine levels of schizophrenic patients.
  
  
  METHODS
  A total of 91 schizophrenic patients from Saudi Arabia and 50 age- and sex-matched healthy controls were enrolled in the present study. Fresh blood samples were collected to measure the levels of cytokines and markers of oxidative stress by spectrophotometric assays simultaneously.
  
  
  RESULTS
  We observed that there was a significant increase in the levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 and a decrease in the levels of interferon-γ. Lipid peroxides are elevated in serum, while total-sulfhydryl levels were decreased. Also, the activities of superoxide dismutase and glutathione peroxidase were decreased, while the activities of catalase, glutathione reductase, and myeloperoxidase were found to be elevated in serum.
  
  
  CONCLUSIONS
  We conclude that inflammation resulting from dysregulation of cytokines and altered antioxidant systems may play a critical role in the etiology of schizophrenia.
authors.affiliation: 1Research Centre, Riyadh Military Hospital, Riyadh, Kingdom of Saudi Arabia.
authors.forename: A K
authors.initials: AK
authors.lastname: Al-Asmari
authors.forename: Md W
authors.initials: MW
authors.lastname: Khan
mesh_terms: D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism*; D015415:Biomarkers; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D012559:Schizophrenia / Q000473:pathology*; D055815:Young Adult
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D016207:Cytokines
keywords: Schizophrenia; antioxidants; inflammation; inflammatory cytokines; oxidative stress