title: Circulating interleukin-10 and interleukin-12 in Parkinson's disease.
abstract: BACKGROUND
  Interleukin (IL)-12 is a heterodimeric cytokine produced by activated blood monocytes, macrophages and glial cells. It enhances differentiation and proliferation of T cells and increases production of proinflammatory cytokines. IL-10 is a pleiotropic cytokine produced by both lymphocytes and mononuclear phagocytes including microglia. Recent studies demonstrated the neuroprotective effect of IL-10. There is little information about the involvement of IL-12 or IL-10 in the pathophysiology of Parkinson's disease (PD).
  
  
  OBJECTIVE
  The objective of our study was to assess the role of IL-12 as a potential marker of immune reactions in patients with PD and to investigate whether IL-10, an immunosuppressive cytokine, may have a neuroprotective effect in the pathogenesis of PD.
  
  
  METHODS
  We measured using immunoassay serum IL-12 and IL-10 levels in 41 patients with PD in comparison with serum levels in 19 healthy subjects (controls) age and sex matched. IL-12 and IL-10 levels were tested for correlation with sex, age, disease duration, Hoehn and Yahr stage and the UPDRS III score.
  
  
  RESULTS
  The PD group presented with significantly increased IL-10 levels when compared with the control group (P = 0.02). The increase observed was not affected by the treatment status. A strong and significant correlation between IL-10 and IL-12 levels was observed in patients with PD (R(S) = 0.7, P < 0.000001).
  
  
  CONCLUSIONS
  Our findings suggest that IL-10 may be involved in the pathogenetic mechanisms of PD. The elevation of IL-10 and the significant correlation between IL-10 and IL-12, a proinflammatory cytokine, may suggest that immunological disturbances and neuroprotective mechanisms are involved in patients with PD.
authors.affiliation: Department of Neurology, School of Medicine, Athens National University, Athens, Greece. mrentzos@med.uoa.gr
authors.forename: M
authors.initials: M
authors.lastname: Rentzos
authors.forename: C
authors.initials: C
authors.lastname: Nikolaou
authors.forename: E
authors.initials: E
authors.lastname: Andreadou
authors.forename: G P
authors.initials: GP
authors.lastname: Paraskevas
authors.forename: A
authors.initials: A
authors.lastname: Rombos
authors.forename: M
authors.initials: M
authors.lastname: Zoga
authors.forename: A
authors.initials: A
authors.lastname: Tsoutsou
authors.forename: F
authors.initials: F
authors.lastname: Boufidou
authors.forename: E
authors.initials: E
authors.lastname: Kapaki
authors.forename: D
authors.initials: D
authors.lastname: Vassilopoulos
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002634:Chemotaxis, Leukocyte / Q000276:immunology; D019610:Cytoprotection / Q000276:immunology*; D004660:Encephalitis / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D005260:Female; D005911:Gliosis / Q000097:blood / Q000276:immunology / Q000503:physiopathology; D006801:Humans; D007108:Immune Tolerance / Q000276:immunology*; D016753:Interleukin-10 / Q000032:analysis / Q000097:blood*; D018664:Interleukin-12 / Q000032:analysis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000097:blood* / Q000276:immunology* / Q000503:physiopathology; D010586:Phagocytes / Q000276:immunology; D011237:Predictive Value of Tests; D015854:Up-Regulation / Q000276:immunology
chemical_list: D015415:Biomarkers; D016753:Interleukin-10; D018664:Interleukin-12