title: Serum levels of IL-6, IL-10 and TNF-α in patients with bipolar disorder and schizophrenia: differences in pro- and anti-inflammatory balance.
abstract: OBJECTIVE
  Previous reports suggest that cytokines act as potential mediators of the interaction between the immune and neuroendocrine systems, and that a proinflammatory state may be associated with bipolar disorder and schizophrenia. The aim is to compare cytokine levels in both disorders.
  
  
  METHODS
  Twenty euthymic bipolar disorder patients, 53 chronic stabilized schizophrenia patients and 80 healthy controls were recruited. Subjects were all non-smokers and non-obese. Cytokines TNF-α, IL-6, and IL-10 were examined by sandwich ELISA.
  
  
  RESULTS
  IL-6 levels were increased in schizophrenia patients when compared to controls (p < 0.0001) and euthymic bipolar disorder patients (p < 0.0001). IL-6 levels were no different in controls compared to euthymic bipolar disorder patients (p = 0.357). IL-10 was lower in controls compared to schizophrenia patients (p = 0.001) or to bipolar disorder patients (p = 0.004). There was no significant difference in TNF-α serum levels among the groups (p = 0.284). Gender-based classification did not significantly alter these findings, and no correlation was found between the antipsychotic dose administered and cytokine levels in patients with schizophrenia.
  
  
  CONCLUSIONS
  These findings evidence a chronic immune activation in schizophrenia. Bipolar disorder seems to present an episode-related inflammatory syndrome. Increased anti-inflammatory factor IL-10 in bipolar disorder and schizophrenia suggests different patterns of inflammatory balance between these two disorders. Results further support the need to investigate cytokines as possible biomarkers of disease activity or treatment response.
authors.affiliation: Bipolar Disorder Program, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Kunz
authors.forename: Keila Maria
authors.initials: KM
authors.lastname: Ceresér
authors.forename: Pedro Domingues
authors.initials: PD
authors.lastname: Goi
authors.forename: Gabriel Rodrigo
authors.initials: GR
authors.lastname: Fries
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Teixeira
authors.forename: Brisa Simões
authors.initials: BS
authors.lastname: Fernandes
authors.forename: Paulo Silva
authors.initials: PS
authors.lastname: Belmonte-de-Abreu
authors.forename: Márcia
authors.initials: M
authors.lastname: Kauer-Sant'Anna
authors.forename: Flavio
authors.initials: F
authors.lastname: Kapczinski
authors.forename: Clarissa Severino
authors.initials: CS
authors.lastname: Gama
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000097:blood* / Q000276:immunology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood; D018836:Inflammation Mediators / Q000097:blood*; D016753:Interleukin-10 / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D012559:Schizophrenia / Q000097:blood* / Q000276:immunology; D013577:Syndrome; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D018836:Inflammation Mediators; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10