title: Allergies and Disease Severity in Childhood Narcolepsy: Preliminary Findings.
abstract: BACKGROUND
  Narcolepsy frequently begins in childhood, and is characterized by excessive daytime sleepiness, with the presence of cataplexy reflecting a more severe phenotype. Narcolepsy may result from genetic predisposition involving deregulation of immune pathways, particularly involving T helper 2 cells (Th2). Increased activation of Th2 cells is usually manifested as allergic conditions such as rhinitis, atopic dermatitis, and asthma. We hypothesized that the presence of allergic conditions indicative of increased Th2 balance may dampen the severity of the phenotype in children with narcolepsy.
  
  
  METHODS
  A retrospective chart review of childhood narcolepsy patients was conducted at three major pediatric sleep centers. Patients were divided into those with narcolepsy without cataplexy (NC-) and narcolepsy with cataplexy (NC+). Demographics, polysomnographic and multiple sleep latency test data, and extraction of information on the presence of allergic diseases such allergic rhinitis, atopic dermatitis, and asthma was performed.
  
  
  RESULTS
  There were 468 children identified, with 193 children in NC- group and 275 patients in the NC+ group. Overall, NC+ children were significantly younger, had higher body mass index, and had shorter mean sleep latencies and increased sleep onset rapid eye movement events. The frequency of allergic conditions, particularly asthma and allergic rhinitis, was markedly lower in NC+ (58/275) compared to NC- patients (94/193; P < 0.0001).
  
  
  CONCLUSIONS
  Involvement of the immune system plays an important role in the pathophysiology of narcolepsy. Current findings further suggest that an increased shift toward T helper 2 cells, as indicated by the presence of allergic conditions, may modulate the severity of the phenotype in childhood narcolepsy, and reduce the prevalence of cataplexy in these patients.
authors.affiliation: Section of Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
authors.forename: Secil
authors.initials: S
authors.lastname: Aydinoz
authors.affiliation: Department of Child Psychiatry and Sleep Center, Chang Gung Memorial Hospital, Gueishan Township, Taoyuan Country, Taiwan.
authors.forename: Yu-Shu
authors.initials: YS
authors.lastname: Huang
authors.affiliation: Section of Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
authors.forename: David
authors.initials: D
authors.lastname: Gozal
authors.affiliation: Unité de Sommeil Pédiatrique & INSERM U1028 Service Epilepsie-Sommeil-Explorations Fonctionnelles Neurologiques Pédiatriques, Hôpital Femme-Mère-Enfant 59, Bron, Lyon, France.
authors.forename: Clara O
authors.initials: CO
authors.lastname: Inocente
authors.affiliation: Unité de Sommeil Pédiatrique & INSERM U1028 Service Epilepsie-Sommeil-Explorations Fonctionnelles Neurologiques Pédiatriques, Hôpital Femme-Mère-Enfant 59, Bron, Lyon, France.
authors.forename: Patricia
authors.initials: P
authors.lastname: Franco
authors.affiliation: Section of Sleep Medicine, Department of Pediatrics, Pritzker School of Medicine, Biological Sciences Division, The University of Chicago, Chicago, IL.
authors.forename: Leila
authors.initials: L
authors.lastname: Kheirandish-Gozal
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D015992:Body Mass Index; D002385:Cataplexy / Q000150:complications / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology; D002641:Chicago / Q000453:epidemiology; D002648:Child; D003876:Dermatitis, Atopic / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D006967:Hypersensitivity / Q000150:complications* / Q000453:epidemiology / Q000276:immunology*; D008297:Male; D009290:Narcolepsy / Q000150:complications* / Q000453:epidemiology / Q000276:immunology / Q000503:physiopathology*; D017286:Polysomnography; D012189:Retrospective Studies; D065631:Rhinitis, Allergic / Q000150:complications / Q000453:epidemiology / Q000276:immunology; D012895:Sleep, REM / Q000502:physiology; D013624:Taiwan / Q000453:epidemiology; D018418:Th2 Cells / Q000276:immunology; D055815:Young Adult
keywords: allergy; asthma; cataplexy; narcolepsy; sleep latency