title: Increased serum levels of interleukin-8 in patients with tension-type headache.
abstract: OBJECTIVE
  The pathophysiology of tension-type headache is not well understood. Increased peripheral levels of pro-inflammatory cytokines may act as mediators of several chronic pain disorders. The aim of the present study was to investigate the peripheral levels of chemokines in patients with tension-type headache.
  
  
  METHODS
  This was a cross sectional study evaluating serum levels of chemokines in age and sex-matched tension-type headache patients, ictally and interictally, and control participants. Beck Depression and Anxiety Inventories were recorded. Serum levels of monocyte chemoattractant protein-1, macrophage inflammatory protein 1α, regulated on activation, normal T cell expressed and secreted, eotaxin, eotaxin-2, interleukin-8, interferon gamma induced protein-10 were measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  A total of 96 participants (48 tension-type headache, 48 controls) were included. Interleukin-8 levels were significantly increased in patients with tension-type headache when compared to controls (413.8 (123.4-1756.3) and 329 (107.8-955.6), respectively, P = 0.025). Anxiety and depression scores were higher in patients with tension-type headache but interleukin-8 increase in tension-type headache patients persisted after controlling for anxiety and depression symptoms. Patients with headache at the time of assessment had increased monocyte chemoattractant protein-1 levels when compared with patients without headache (2809.3 (1101-6122.2) and 1630.2 (669.3-31056.8), respectively P = 0.026). Patients with episodic and chronic tension-type headache had no significant differences in serum chemokines levels.
  
  
  CONCLUSIONS
  Interleukin-8 was increased in tension-type headache and monocyte chemoattractant protein-1 was higher in tension-type headache patients with headache, suggesting that pro-inflammatory mechanisms may participate in tension-type headache pathophysiology.
authors.affiliation: Neurosciences Postgraduation Program, Federal University of Minas Gerais (UFMG), Brazil CHRU, Pole Neurologie, Université Lille 2, France contato@renandomingues.med.br.
authors.forename: Renan B
authors.initials: RB
authors.lastname: Domingues
authors.affiliation: Neurosciences Postgraduation Program, Federal University of Minas Gerais (UFMG), Brazil.
authors.forename: Halina
authors.initials: H
authors.lastname: Duarte
authors.affiliation: Interdisciplinar Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais (UFMG), Brazil.
authors.forename: Natália P
authors.initials: NP
authors.lastname: Rocha
authors.affiliation: Neurosciences Postgraduation Program, Federal University of Minas Gerais (UFMG), Brazil Interdisciplinar Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais (UFMG), Brazil.
authors.forename: Antonio L
authors.initials: AL
authors.lastname: Teixeira
mesh_terms: D000328:Adult; D000368:Aged; D018925:Chemokines / Q000097:blood; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D016209:Interleukin-8 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D018781:Tension-Type Headache / Q000097:blood* / Q000503:physiopathology; D055815:Young Adult
chemical_list: C508606:CXCL8 protein, human; D018925:Chemokines; D016209:Interleukin-8
keywords: Tension-type headache; anxiety; chemokines; chronic tension-type headache; depression; episodic tension-type headache; inflammation