Comorbidity of Narcolepsy Type 1 With Autoimmune Diseases and Other Immunopathological Disorders: A Case-Control Study.
BACKGROUND
Several evidences suggest that autoimmune diseases (ADs) tend to co-occur in an individual and within the same family. Narcolepsy type 1 (NT1) is a chronic sleep disorder caused by a selective loss of hypocretin-producing neurons due to a mechanism of neural destruction that indicates an autoimmune pathogenesis, although no evidence is available. We report on the comorbidity of ADs and other immunopathological diseases (including allergy diseases) in narcolepsy.


METHODS
We studied 158 Caucasian NT1 patients (60.7% male; mean age 49.4 ± 19.7 years), in whom the diagnosis was confirmed by polysomnography followed by a multiple sleep latency test, or by hypocretin-1 levels measurements.


RESULTS
Thirty out of 158 patients (18.99%; 53.3% female; 29 sporadic and one familial cases) had one or more immunopathological diseases associated. A control group of 151 subjects were matched by gender and age with the narcolepsy patients. Results demonstrated that there was a higher frequency of ADs in our series of narcolepsy patients compared to the sample of general population (odds ratio: 3.17; 95% confidence interval: 1.01 - 10.07; P = 0.040). A temporal relationship with the age at onset of the diseases was found.


CONCLUSIONS
Cataplexy was significantly more severe in NT1 patients with immunopathological diseases, and immunopathological diseases are a risk factor for severe forms of cataplexy in our series (odds ratio: 23.6; 95% confidence interval: 5.5 - 100.1).
Sleep Unit, Clinical Neurophysiology Service, San Carlos University Hospital, Madrid, Spain.
Francisco Javier
FJ
Martinez-Orozco
Histocompatibility, Blood Center of the Community of Madrid, Madrid, Spain.
Jose Luis
JL
Vicario
Neurology Service, Gregorio Maranon University Hospital, Madrid, Spain.
Clara
C
De Andres
Immunology Service, San Carlos University Hospital, Madrid, Spain.
Miguel
M
Fernandez-Arquero
Sleep and Epilepsy Unit, Clinical Neurophysiology Service, Gregorio Maranon University Hospital, Madrid, Spain.
Rosa
R
Peraita-Adrados
Autoimmune diseases; Comorbidity; Epidemiology; Immunopathological diseases; Narcolepsy type 1; Narcolepsy with cataplexy