title: Serum cytokine levels in Kleine-Levin syndrome.
abstract: OBJECTIVE
  Kleine-Levin Syndrome (KLS) is a rare sleep disorder causing recurrent symptomatic episodes of severe hypersomnia, cognitive impairment, apathy, and derealization. These episodes are interspersed with long periods of normal sleep, cognition, and behavior. The pathogenesis of KLS is still unknown. The objective of this study was to determine serum cytokine levels in patients with KLS during and between episodes.
  
  
  METHODS
  Fifty-two typical KLS patients were included in the study of whom 17 patients donated blood samples both during and between episodes. Blood samples were collected in USA, France, and Taiwan in a clinical setting. Processing of the samples was performed at the Stanford Center for Sleep Sciences and Medicine.
  
  
  RESULTS
  We did not observe any changes in serum cytokine levels during KLS episodes compared to between episodes. In a small cohort of asymptomatic KLS patients and age- and gender matched healthy controls (n = 8/group) whose blood samples were all collected and processed at the same day; asymptomatic KLS patients had significantly higher levels of serum sVCAM1 cytokine compared to healthy controls.
  
  
  CONCLUSIONS
  These data suggest that KLS episodes are not accompanied by an abnormal systemic immune reaction.
authors.affiliation: Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Studies, Stanford School of Medicine, Palo Alto, CA, USA; Molecular Sleep Laboratory, Department of Diagnostics, Glostrup Hospital, Glostrup, Denmark; Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark. Electronic address: Birgitte.kornum@regionh.dk.
authors.forename: Birgitte Rahbek
authors.initials: BR
authors.lastname: Kornum
authors.affiliation: Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Studies, Stanford School of Medicine, Palo Alto, CA, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Rico
authors.affiliation: Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Studies, Stanford School of Medicine, Palo Alto, CA, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.affiliation: Department of Child Psychiatry and Sleep Center, Chang Gung Memorial Hospital and University, Taoyaung, Taipei, Taiwan.
authors.forename: Yu-Shu
authors.initials: YS
authors.lastname: Huang
authors.affiliation: National Reference Center for Narcolepsy, Idiopathic Hypersomnia and Kleine-Levin Syndrome, Sleep Disorders Unit and Inserm U975, Pitié-Salpêtrière Hospital(APHP), Pierre and Marie Curie University, Paris, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Arnulf
authors.affiliation: Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark.
authors.forename: Poul
authors.initials: P
authors.lastname: Jennum
authors.affiliation: Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Studies, Stanford School of Medicine, Palo Alto, CA, USA.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mignot
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D018925:Chemokines / Q000097:blood; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007378:Interleukins / Q000097:blood; D017593:Kleine-Levin Syndrome / Q000097:blood*; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D018925:Chemokines; D016207:Cytokines; D007378:Interleukins
keywords: Hypersomnia; Kleine–Levin syndrome; Recurrent episodes; Serum cytokines