title: Decreased TNF-alpha and NK activity in obsessive-compulsive disorder.
abstract: BACKGROUND
  Accumulating evidence points towards the involvement of autoimmune mechanisms in the pathophysiology of some subgroups of obsessive-compulsive disorder (OCD). This study was carried out to investigate whether obsessive-compulsive disorder is associated with altered activity of the immune system, and whether these changes are related to particular clinical characteristics.
  
  
  METHODS
  Ex vivo production of TNF-alpha, IL-4, IL-6, IL-10, and IFN-gamma in whole blood cultures, and NK-cell activity and peripheral blood NK cell-, monocytes-, T-cell-, and B-cell- percentages were measured in 50 medication-free outpatients with OCD and 25 controls.
  
  
  RESULTS
  In OCD patients, we found a significant decrease in production of TNF-alpha (p < 0.0001) and NK-activity (p = 0.002) in comparison with controls. No significant differences were observed in the other immune variables. Patients with first-degree relatives with OCD had significant lower NK-activity than patients who had no relatives with OCD (p = 0.02), and patients with a childhood onset of OCD had significantly lower number of NK-cells than patients with a late onset (p= 0.003).
  
  
  CONCLUSIONS
  Changes in TNF-alpha and NK activity suggest a potential role of altered immune function in the pathophysiology of obsessive-compulsive disorder.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands. d.a.j.p.denys@azu.nl
authors.forename: Damiaan
authors.initials: D
authors.lastname: Denys
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Fluitman
authors.forename: Annemieke
authors.initials: A
authors.lastname: Kavelaars
authors.forename: Cobi
authors.initials: C
authors.lastname: Heijnen
authors.forename: Herman
authors.initials: H
authors.lastname: Westenberg
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016207:Cytokines / Q000097:blood*; D015536:Down-Regulation; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007371:Interferon-gamma / Q000097:blood; D016753:Interleukin-10 / Q000097:blood; D015847:Interleukin-4 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D007958:Leukocyte Count; D008297:Male; D016555:Matched-Pair Analysis; D009771:Obsessive-Compulsive Disorder / Q000145:classification / Q000235:genetics / Q000276:immunology*; D012016:Reference Values; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
chemical_list: D016207:Cytokines; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma