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Geng C, Tan L, Zhao B, Chen C. Association between vitamin B12 deficiency and risk of Paediatric narcolepsy: Evidence from cross-sectional study and Mendelian randomization analysis. Eur J Paediatr Neurol 2024; 49:106-112. [PMID: 38484414 DOI: 10.1016/j.ejpn.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/25/2024] [Accepted: 03/02/2024] [Indexed: 05/03/2024]
Abstract
BACKGROUND Narcolepsy, a chronic neurologic sleep disorder, has sparked growing interest in the potential role of vitamin B12 in its pathogenic mechanism. However, research on this association has predominantly focused on adults. Our objective was to delineate the phenotypic and genetic connections between serum vitamin B12 levels and paediatric narcolepsy. METHODS To investigate the causal relationship between vitamin B12 and paediatric narcolepsy, we conducted a retrospective analysis involving 60 narcolepsy patients and a matched control group. Univariate and multivariate logistic regression models were employed to identify independent factors influencing paediatric narcolepsy. Furthermore, a bidirectional two-sample Mendelian randomization (MR) analysis was performed to assess the causal connection between serum vitamin B12 levels and narcolepsy. RESULTS Paediatric narcolepsy patients showed significantly lower serum levels of vitamin B12 and folate compared to the control group (P < 0.05). Multivariate logistic regression analysis identified serum vitamin B12 as the exclusive independent factor influencing paediatric narcolepsy (P < 0.001; OR = 0.96; 95%CI: 0.94-0.98). Additionally, IVW model results provided compelling evidence supporting a potential causal association between serum vitamin B12 levels and paediatric narcolepsy (OR: 0.958, 95% CI = 0.946-0.969, P = 0.001). CONCLUSION This study establishes connections at both phenotypic and genetic levels, associating vitamin B12 deficiency with an increased risk of paediatric narcolepsy. These findings provide innovative perspectives for clinical strategies in the prevention and treatment of narcolepsy.
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Affiliation(s)
- Chaofan Geng
- Department of Neurology & Innovation Center for Neurological Disorders, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Leilei Tan
- Department of Neurology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China
| | - Bo Zhao
- Department of Neurology & Innovation Center for Neurological Disorders, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Chen Chen
- Department of Neurology, Zhengzhou University People's Hospital, Henan Provincial People's Hospital, Zhengzhou, China.
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2
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Vuorela A, Freitag TL, Leskinen K, Pessa H, Härkönen T, Stracenski I, Kirjavainen T, Olsen P, Saarenpää-Heikkilä O, Ilonen J, Knip M, Vaheri A, Partinen M, Saavalainen P, Meri S, Vaarala O. Enhanced influenza A H1N1 T cell epitope recognition and cross-reactivity to protein-O-mannosyltransferase 1 in Pandemrix-associated narcolepsy type 1. Nat Commun 2021; 12:2283. [PMID: 33863907 PMCID: PMC8052463 DOI: 10.1038/s41467-021-22637-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 03/18/2021] [Indexed: 02/06/2023] Open
Abstract
Narcolepsy type 1 (NT1) is a chronic neurological disorder having a strong association with HLA-DQB1*0602, thereby suggesting an immunological origin. Increased risk of NT1 has been reported among children or adolescents vaccinated with AS03 adjuvant-supplemented pandemic H1N1 influenza A vaccine, Pandemrix. Here we show that pediatric Pandemrix-associated NT1 patients have enhanced T-cell immunity against the viral epitopes, neuraminidase 175-189 (NA175-189) and nucleoprotein 214-228 (NP214-228), but also respond to a NA175-189-mimic, brain self-epitope, protein-O-mannosyltransferase 1 (POMT1675-689). A pathogenic role of influenza virus-specific T-cells and T-cell cross-reactivity in NT1 are supported by the up-regulation of IFN-γ, perforin 1 and granzyme B, and by the converging selection of T-cell receptor TRAV10/TRAJ17 and TRAV10/TRAJ24 clonotypes, in response to stimulation either with peptide NA175-189 or POMT1675-689. Moreover, anti-POMT1 serum autoantibodies are increased in Pandemrix-vaccinated children or adolescents. These results thus identify POMT1 as a potential autoantigen recognized by T- and B-cells in NT1.
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Affiliation(s)
- A Vuorela
- Clinicum, University of Helsinki, Helsinki, Finland
| | - T L Freitag
- Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland.
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland.
| | - K Leskinen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - H Pessa
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - T Härkönen
- Clinicum, University of Helsinki, Helsinki, Finland
| | - I Stracenski
- Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
| | - T Kirjavainen
- Children's Hospital, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland
| | - P Olsen
- Department of Child Neurology, Oulu University Hospital, Oulu, Finland
| | | | - J Ilonen
- Immunogenetics Laboratory, Institute of Biomedicine, University of Turku, Turku, Finland
- Clinical Microbiology, Turku University Hospital, Turku, Finland
| | - M Knip
- Clinicum, University of Helsinki, Helsinki, Finland
- Children's Hospital, University of Helsinki, and Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, University of Helsinki, Helsinki, Finland
| | - A Vaheri
- Department of Virology, University of Helsinki, Helsinki, Finland
| | - M Partinen
- Clinicum, University of Helsinki, Helsinki, Finland
- Department of Neurosciences, University of Helsinki, Helsinki, Finland
- Helsinki Sleep Clinic, Vitalmed Research Center, Helsinki, Finland
| | - P Saavalainen
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - S Meri
- Department of Bacteriology and Immunology, University of Helsinki, Helsinki, Finland
- Translational Immunology Research Program, University of Helsinki, Helsinki, Finland
| | - O Vaarala
- Clinicum, University of Helsinki, Helsinki, Finland
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3
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Barateau L, Chenini S, Lotierzo M, Rassu AL, Evangelista E, Lopez R, Gorce Dupuy A, Jaussent I, Dauvilliers Y. CSF and serum ferritin levels in narcolepsy type 1 comorbid with restless legs syndrome. Ann Clin Transl Neurol 2020; 7:924-931. [PMID: 32432412 PMCID: PMC7317640 DOI: 10.1002/acn3.51056] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 04/17/2020] [Accepted: 04/22/2020] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES To investigate whether cerebrospinal fluid (CSF) and serum ferritin levels differ between patients with narcolepsy type 1 (NT1) comorbid with restless legs syndrome (RLS) or periodic leg movements during sleep (PLMS), and patients with NT1 or controls without comorbid RLS or PLMS. METHODS Sixty-six drug-free patients with NT1 (44 males, age 38.5 years [14-81]) were enrolled, including 20 with RLS, 18 with PLMS index ≥15/h (six with both RLS and PLMS). Thirty-eight drug-free patients (12 males, age 22.5 years [12-61]) referred for sleepiness complaint, but without central hypersomnia, RLS, PLMS were included as controls. Clinical, electrophysiological and biological (CSF/serum ferritin, orexin [ORX]) data were quantified. RESULTS NT1 patients with and without RLS did not differ for age, gender, and body mass index (BMI). No between-group differences were found for CSF ferritin, ORX, and serum ferritin levels. No CSF ferritin, ORX, and serum ferritin level differences were found between NT1 patients with and without PLMS, or with RLS or PLMS versus not. CSF-ferritin levels were not different between NT1 and controls in adjusted analyses. CSF-ferritin levels in the whole population correlated positively with age, serum-ferritin, BMI, negatively with ORX, but not with PLMS index. In NT1, CSF-ferritin levels correlated with age and serum-ferritin but not with PLMS. CONCLUSION The absence of CSF ferritin deficiency in NT1 with comorbid RLS or PLMS indicates normal brain iron levels in that condition. This result suggests that the frequent association between RLS, PLMS, and NT1 is not based on alterations in brain iron metabolism, a pathophysiological mechanism involved in primary RLS.
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Affiliation(s)
- Lucie Barateau
- Sleep‐Wake Disorders UnitDepartment of NeurologyGui‐de‐Chauliac HospitalCHU MontpellierMontpellierFrance
- National Reference Network for NarcolepsyCHU MontpellierMontpellierFrance
- Neuropsychiatry: Epidemiological and Clinical ResearchINSERMUniversity MontpellierMontpellierFrance
| | - Sofiene Chenini
- Sleep‐Wake Disorders UnitDepartment of NeurologyGui‐de‐Chauliac HospitalCHU MontpellierMontpellierFrance
| | - Manuela Lotierzo
- Department of BiochemistryMontpellier University HospitalMontpellierFrance
- PhyMedExpINSERM U1046CNRS UMR 9214University of MontpellierMontpellierFrance
| | - Anna Laura Rassu
- Sleep‐Wake Disorders UnitDepartment of NeurologyGui‐de‐Chauliac HospitalCHU MontpellierMontpellierFrance
| | - Elisa Evangelista
- Sleep‐Wake Disorders UnitDepartment of NeurologyGui‐de‐Chauliac HospitalCHU MontpellierMontpellierFrance
- National Reference Network for NarcolepsyCHU MontpellierMontpellierFrance
- Neuropsychiatry: Epidemiological and Clinical ResearchINSERMUniversity MontpellierMontpellierFrance
| | - Régis Lopez
- Sleep‐Wake Disorders UnitDepartment of NeurologyGui‐de‐Chauliac HospitalCHU MontpellierMontpellierFrance
- National Reference Network for NarcolepsyCHU MontpellierMontpellierFrance
- Neuropsychiatry: Epidemiological and Clinical ResearchINSERMUniversity MontpellierMontpellierFrance
| | - Anne‐Marie Gorce Dupuy
- Neuropsychiatry: Epidemiological and Clinical ResearchINSERMUniversity MontpellierMontpellierFrance
- Department of BiochemistryMontpellier University HospitalMontpellierFrance
| | - Isabelle Jaussent
- Neuropsychiatry: Epidemiological and Clinical ResearchINSERMUniversity MontpellierMontpellierFrance
| | - Yves Dauvilliers
- Sleep‐Wake Disorders UnitDepartment of NeurologyGui‐de‐Chauliac HospitalCHU MontpellierMontpellierFrance
- National Reference Network for NarcolepsyCHU MontpellierMontpellierFrance
- Neuropsychiatry: Epidemiological and Clinical ResearchINSERMUniversity MontpellierMontpellierFrance
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4
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Bruhn C. [Pitolisant for the treatment of narcolepsy with or without cataplexy]. Med Monatsschr Pharm 2016; 39:324-329. [PMID: 29984945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Since March 2016, a new treatment option for adult patients with narcolepsy – with or without cataplexy – has been granted marketing authorization in Europe. Pitolisant (Wakix®) is an inverse agonst at the histamine-3 (H3) receptor. In clinical studies, tests for measurement of wakefulness and attention, pitolisant showed significantly better results in comparison with placebo and similar results in comparison with modafinil. Pitolisant is well tolerated. Postmarketing analyses have to collect data about the long-term safety of pitolisant when used in a real-life setting.
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Thebault S, Waters P, Snape MD, Cottrell D, Darin N, Hallböök T, Huutoniemi A, Partinen M, Pollard AJ, Vincent A. Neuronal Antibodies in Children with or without Narcolepsy following H1N1-AS03 Vaccination. PLoS One 2015; 10:e0129555. [PMID: 26090827 PMCID: PMC4474558 DOI: 10.1371/journal.pone.0129555] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/11/2015] [Indexed: 01/03/2023] Open
Abstract
Type 1 narcolepsy is caused by deficiency of hypothalamic orexin/hypocretin. An autoimmune basis is suspected, but no specific antibodies, either causative or as biomarkers, have been identified. However, the AS03 adjuvanted split virion H1N1 (H1N1-AS03) vaccine, created to protect against the 2009 Pandemic, has been implicated as a trigger of narcolepsy particularly in children. Sera and CSFs from 13 H1N1-AS03-vaccinated patients (12 children, 1 young adult) with type 1 narcolepsy were tested for autoantibodies to known neuronal antigens including the N-methyl-D-aspartate receptor (NMDAR) and contactin-associated protein 2 (CASPR2), both associated with encephalopathies that include disordered sleep, to rodent brain tissue including the lateral hypothalamus, and to live hippocampal neurons in culture. When sufficient sample was available, CSF levels of melanin-concentrating hormone (MCH) were measured. Sera from 44 H1N1-ASO3-vaccinated children without narcolepsy were also examined. None of these patients' CSFs or sera was positive for NMDAR or CASPR2 antibodies or binding to neurons; 4/13 sera bound to orexin-neurons in rat brain tissue, but also to other neurons. MCH levels were a marginally raised (n = 8; p = 0.054) in orexin-deficient narcolepsy patients compared with orexin-normal children (n = 6). In the 44 H1N1-AS03-vaccinated healthy children, there was no rise in total IgG levels or in CASPR2 or NMDAR antibodies three weeks following vaccination. In conclusion, there were no narcolepsy-specific autoantibodies identified in type 1 narcolepsy sera or CSFs, and no evidence for a general increase in immune reactivity following H1N1-AS03 vaccination in the healthy children. Antibodies to other neuronal specific membrane targets, with their potential for directing use of immunotherapies, are still an important goal for future research.
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Affiliation(s)
- Simon Thebault
- Neuroimmunology Group, Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom
| | - Patrick Waters
- Neuroimmunology Group, Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom
| | - Matthew D. Snape
- Department of Paediatrics, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
- The NIHR Oxford Biomedical Centre, Oxford University Hospitals Trust, Oxford, United Kingdom
| | - Dominic Cottrell
- Imperial College of Medicine, University of London, London, United Kingdom
| | - Niklas Darin
- Department of Paediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Tove Hallböök
- Department of Paediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Anne Huutoniemi
- Helsinki Sleep Clinic, Finnish Narcolepsy Research Centre, Helsinki, Finland
| | - Markku Partinen
- Helsinki Sleep Clinic, Finnish Narcolepsy Research Centre, Helsinki, Finland
- Department of Clinical Neurosciences, University of Helsinki, Helsinki, Finland
| | - Andrew J. Pollard
- Department of Paediatrics, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
- The NIHR Oxford Biomedical Centre, Oxford University Hospitals Trust, Oxford, United Kingdom
| | - Angela Vincent
- Neuroimmunology Group, Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom
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6
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Holm A, Bang-Berthelsen CH, Knudsen S, Kornum BR, Modvig S, Jennum P, Gammeltoft S. miRNA profiles in plasma from patients with sleep disorders reveal dysregulation of miRNAs in narcolepsy and other central hypersomnias. Sleep 2014; 37:1525-33. [PMID: 25142559 DOI: 10.5665/sleep.4004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES MicroRNAs (miRNAs) have been implicated in the pathogenesis of human diseases including neurological disorders. The aim is to address the involvement of miRNAs in the pathophysiology of central hypersomnias including autoimmune narcolepsy with cataplexy and hypocretin deficiency (type 1 narcolepsy), narcolepsy without cataplexy (type 2 narcolepsy), and idiopathic hypersomnia. DESIGN We conducted high-throughput analysis of miRNA in plasma from three groups of patients-with type 1 narcolepsy, type 2 narcolepsy, and idiopathic hypersomnia, respectively-in comparison with healthy controls using quantitative real-time polymerase chain reaction (qPCR) panels. SETTING University hospital based sleep clinic and research laboratories. PATIENTS Twelve patients with type 1 narcolepsy, 12 patients with type 2 narcolepsy, 12 patients with idiopathic hypersomnia, and 12 healthy controls. MEASUREMENTS AND RESULTS By analyzing miRNA in plasma with qPCR we identified 50, 24, and 6 miRNAs that were different in patients with type 1 narcolepsy, type 2 narcolepsy, and idiopathic hypersomnia, respectively, compared with healthy controls. Twenty miRNA candidates who fulfilled the criteria of at least two-fold difference and p-value < 0.05 were selected to validate the miRNA changes in an independent cohort of patients. Four miRNAs differed significantly between type 1 narcolepsy patients and healthy controls. Levels of miR-30c, let-7f, and miR-26a were higher, whereas the level of miR-130a was lower in type 1 narcolepsy than healthy controls. The miRNA differences were not specific for type 1 narcolepsy, since the levels of the four miRNAs were also altered in patients with type 2 narcolepsy and idiopathic hypersomnia compared with healthy controls. CONCLUSION The levels of four miRNAs differed in plasma from patients with type 1 narcolepsy, type 2 narcolepsy and idiopathic hypersomnia suggesting that alterations of miRNAs may be involved in the pathophysiology of central hypersomnias.
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Huda MSB, Mani H, Durham BH, Dovey TM, Halford JCG, Aditya BS, Pinkney JH, Wilding JP, Hart IK. Plasma obestatin and autonomic function are altered in orexin-deficient narcolepsy, but ghrelin is unchanged. Endocrine 2013. [PMID: 23179778 DOI: 10.1007/s12020-012-9838-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Narcolepsy-cataplexy is characterised by orexin deficiency, sleep disturbance, obesity and dysautonomia. Ghrelin and obestatin affect both energy intake and sleep. Our aim was to investigate ghrelin, obestatin and metabolic/autonomic function in narcolepsy-cataplexy. Eight narcolepsy-cataplexy patients (seven CSF orexin-deficient) and eight matched controls were studied. The subjects had a fixed energy meal with serial blood samples and measurement of heart rate variability (HRV). Fasting plasma obestatin was more than threefold higher in narcolepsy subjects (narcolepsy 89.6 ± 16 pg/ml vs. control 24.9 ± 3 pg/ml, p < 0.001). There was no change in HRV total power, but post-prandial low-frequency (LF) power and high-frequency (HF) power were lower in the narcolepsy group [area under the curve (AUC): HF power narcolepsy 1.4 × 10(5) ± 0.2 × 10(5) vs. control 3.3 × 10(5) ± 0.6 × 10(5 )ms(2)/h, p < 0.001]. On multiple regression analyses, the only significant predictor of plasma obestatin was HF power, which was inversely correlated with obestatin (β = -0.65 R (2) = 38 %, p = 0.009). Fasting and post-prandial plasma ghrelin were similar in both groups (narcolepsy 589.5 ± 88 pg/ml vs. control 686.9 ± 81 pg/ml, p = 0.5; post-prandial AUC-narcolepsy 161.3 ± 22 ng/ml/min vs. control 188.6 ± 62 ng/ml/min, p = 0.4). Only the narcolepsy group had significant suppression of plasma ghrelin after the meal (ANOVA, p = 0.004). In orexin-deficient narcolepsy, fasting plasma ghrelin is unaltered, and post-prandial suppression is preserved. Fasting plasma obestatin is increased and correlates with autonomic dysfunction. As obestatin affects NREM sleep, we suggest that increased plasma levels contribute to the disrupted sleep-state control in narcolepsy.
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Affiliation(s)
- M S B Huda
- University of Liverpool Diabetes and Endocrinology Research Group, Clinical Sciences Centre, University Hospital Aintree, Liverpool, L9 7AL, UK.
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Raveendra B, Hao W, Baccala R, Reddy MM, Schilke J, Bennett JL, Theofilopoulos AN, Kodadek T. Discovery of peptoid ligands for anti-aquaporin 4 antibodies. Chem Biol 2013; 20:351-9. [PMID: 23521793 PMCID: PMC3640264 DOI: 10.1016/j.chembiol.2012.12.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 12/02/2012] [Accepted: 12/08/2012] [Indexed: 10/27/2022]
Abstract
Neuromyelitis optica (NMO) is an autoimmune inflammatory disorder of the central nervous system. In most NMO patients, autoantibodies to the water channel protein Aquaporin 4 (AQP4) are present at high levels and are thought to drive pathology by mediating complement-dependent destruction of astrocytes. Here, we apply recently developed chemical library screening technology to identify a synthetic peptoid that binds anti-AQP4 antibodies in the serum of NMO patients. This finding validates, in a well-defined human disease, that synthetic, unnatural ligands for the antigen-binding site of a disease-linked antibody can be isolated by high-throughput screening.
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Affiliation(s)
- Bindu Raveendra
- Departments of Chemistry & Cancer Biology, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458
| | - Wu Hao
- Departments of Chemistry & Cancer Biology, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458
| | - Roberto Baccala
- Department of Immunology & Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037
| | | | | | - Jeffrey L. Bennett
- Departments of Neurology and Ophthalmology, University of Colorado School of Medicine, 12700 E. 19 Ave., Aurora, CO 80045
| | - Argyrios N. Theofilopoulos
- Department of Immunology & Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037
| | - Thomas Kodadek
- Departments of Chemistry & Cancer Biology, The Scripps Research Institute, 130 Scripps Way, Jupiter, FL 33458
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Abstract
The objective of this study was to perform global gene expression profiling of patients affected by narcolepsy with cataplexy (NRLCP). This enabled identifying new potential biomarkers and relevant molecules possibly involved in the disease pathogenesis. In this study 10 NRLCP patients and 10 healthy controls were compared. Total RNA isolated from blood specimens was analyzed using microarray technology followed by statistical data analysis to detect genome-wide differential gene expression between patients and controls. Functional analysis of the gene list was performed in order to interpret the biological significance of the data. One hundred and seventy-three genes showed significant (p < 0.01) differential expression between the two tested conditions. The biological interpretation allowed categorizing differentially expressed genes involved in neurite outgrowth/extension and brain development, which could be possibly regarded as peripheral markers of the disease. Moreover, the NRLCP-related gene expression profiles indicated a dysregulation of metabolic and immune-related mechanisms. In conclusion, the gene expression profile associated to NRLCP suggested that molecular markers of neurological impairment, dysmetabolic and immune-related mechanisms, can be detected in blood of NRLCP patients.
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Affiliation(s)
- Camilla Bernardini
- Institute of Anatomy and Cell Biology, Catholic University, Rome, Italy.
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Carlander B, Puech-Cathala AM, Jaussent I, Scholz S, Bayard S, Cochen V, Dauvilliers Y. Low vitamin D in narcolepsy with cataplexy. PLoS One 2011; 6:e20433. [PMID: 21633708 PMCID: PMC3102118 DOI: 10.1371/journal.pone.0020433] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Accepted: 04/19/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Narcolepsy with cataplexy (NC) is currently thought to be an autoimmune-mediated disorder in which environmental risk factors make a significant contribution to its development. It was proposed that vitamin D deficiency plays a role in autoimmune diseases. Here we investigated whether NC can be associated with 25-hydroxyvitamin D (25(OH)D) level deficiency in patients with NC compared with gender- and age-matched normal controls. METHODOLOGY Serum level of 25 (OH)D was determined in 51 European patients with typical NC compared to 55 age-, gender-, and ethnicity-matched healthy controls. Demographic and clinical data (age at onset, duration and severity of disease at baseline, and treatment intake at time of study) and season of blood sampling were collected to control for confounding variables. PRINCIPAL FINDINGS Serum 25(OH)D concentration was lower in NC compared to controls (median, 59.45 nmol/l [extreme values 24.05-124.03] vs. 74.73 nmol/l [26.88-167.48] p = 0.0039). Patients with NC had significantly greater vitamin D deficiency (<75 nmol/l) than controls (72.5% vs 50.9%, p = 0.0238). Division into quartiles of the whole sample revealed that the risk of being affected with NC increased with lower 25(OH)D level, with a 5.34 OR [1.65-17.27] for the lowest quartile (p = 0.0051). Further adjustment for BMI did not modify the strength of the association (OR: 3.63, 95% CI = 1.06-12.46, p = 0.0191). No between BMI and 25(OH)D interaction, and no correlation between 25(OH)D level and disease duration or severity or treatment intake were found in NC. CONCLUSION We found a higher frequency of vitamin D deficiency in NC. Further studies are needed to assess the contribution of hypovitaminosis D to the risk of developing narcolepsy, and to focus on the utility of assessing vitamin D status to correct potential deficiency.
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Affiliation(s)
- Bertrand Carlander
- National Reference Network for Narcolepsy, Department of Neurology, Hôpital Gui-de-Chauliac, CHU Montpellier, Montpellier, France
| | | | | | - Sabine Scholz
- National Reference Network for Narcolepsy, Department of Neurology, Hôpital Gui-de-Chauliac, CHU Montpellier, Montpellier, France
| | - Sophie Bayard
- National Reference Network for Narcolepsy, Department of Neurology, Hôpital Gui-de-Chauliac, CHU Montpellier, Montpellier, France
- Inserm U1061, University of Montpellier 1, Montpellier, France
| | - Valérie Cochen
- National Reference Network for Narcolepsy, Department of Neurology, Hôpital Gui-de-Chauliac, CHU Montpellier, Montpellier, France
| | - Yves Dauvilliers
- National Reference Network for Narcolepsy, Department of Neurology, Hôpital Gui-de-Chauliac, CHU Montpellier, Montpellier, France
- Inserm U1061, University of Montpellier 1, Montpellier, France
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Donjacour CEHM, Aziz NA, Frölich M, Roelfsema F, Overeem S, Lammers GJ, Pijl H. Sodium oxybate increases prolactin secretion in narcolepsy patients and healthy controls. Eur J Endocrinol 2011; 164:363-70. [PMID: 21148631 DOI: 10.1530/eje-10-0913] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Hypocretin deficiency causes narcolepsy and may affect neuroendocrine systems, including TSH, ACTH and LH secretion. Symptoms can be treated effectively with sodium oxybate (SXB) in many patients. This study was performed to compare prolactin (PRL) secretion in patients and matched controls and establish the effect of SXB administration on PRL and sleep in both the groups. DESIGN Open label intervention. Blood was sampled before and after 5 days of SXB treatment. The study was performed at the Leiden University Medical Centre, Leiden, The Netherlands. METHODS Subjects were admitted to the clinical research centre on both occasions. PATIENTS OR PARTICIPANTS Eight male hypocretin-deficient narcolepsy with cataplexy patients and eight controls matched for sex, age, body mass index, waist-to-hip ratio and fat percentage were enrolled. INTERVENTIONS SXB two times 3 g per night for five consecutive nights. RESULTS Patients and controls underwent 24 h blood sampling at 10 min intervals for measurement of PRL concentrations. The PRL concentration time series was analysed with a new deconvolution programme, approximate entropy (ApEn) and Cosinor analysis. Sleep was polygraphically recorded. Basal and pulsatile PRL secretion, as well as pulse regularity and frequency, ApEn and diurnal parameters were similar in patients and controls. SXB treatment caused similar nocturnal increase in PRL secretion, advance of the acrophase and decrease in ApEn in patients and controls. Slow wave sleep was increased to a similar extent in patients and controls. CONCLUSION This detailed study did not demonstrate altered PRL secretion in hypocretin-deficient narcolepsy patients during the basal state or during SXB administration. Therefore, hypocretin signalling is unlikely to be a regulator of the lactotrophic system.
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Affiliation(s)
- Claire E H M Donjacour
- Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, Postal Zone J3-R 151, PO Box 9600, 2300 RC Leiden, The Netherlands.
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12
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Abstract
A patient with narcoleptic attacks and isolated thyrotropin deficiency is presented. Substitution with l-thyroxine did not relieve his narcoleptic attacks. Deficiency, in the central nervous system, of the ergotropic substance thyrotropin-releasing hormone (TRH) might have caused the thyrotropin deficiency and contributed to the narcoleptic attacks. However, prolonged oral medication with TRH, in doses of 120 or 240 g daily, failed to attain any significant relief. Although this does Not exclude TRH unresponsiveness due to absent or defective TRH receptors, the true cause of the disease remains to be elucidated.
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13
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Dahmen N, Manderscheid N, Helfrich J, Musholt PB, Forst T, Pfützner A, Engel A. Elevated peripheral visfatin levels in narcoleptic patients. PLoS One 2008; 3:e2980. [PMID: 18714344 PMCID: PMC2500162 DOI: 10.1371/journal.pone.0002980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Accepted: 07/17/2008] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE Narcolepsy is a severe sleep disorder that is characterized by excessive daytime sleepiness, cataplexies and a tendency towards obesity. Recent discoveries indicate that the major pathophysiology is a loss of hypocretin (orexin) producing neurons due to immunologically mediated degeneration. Visfatin is a recently described proinflammatory adipokine. It is identical to the immune modulating pre-B-cell colony enhancing factor (PBEF). Our study examines the hypothesis that visfatin levels are altered in narcoleptic patients. METHODS For the analysis, a total of n = 54 patients (n = 18 males and n = 36 females) with the diagnosis of narcolepsy according to DSM-IV and the International Classification of Sleep Disorders were examined (BMI mean 30.3+/-5.5, age mean 52.5+/-16.1 years). As a control group 39 unrelated (n = 12 males and n = 27 females) healthy volunteers with no sleep disorder according to DSM-IV were included (BMI mean 28.5+/-4.6, age mean 51.1+/-13.6 years). Peripheral visfatin levels were measured using a commercial enzyme immunoassay kit with a measurement range from 0.1-1000 ng/ml. Narcolepsy symptoms, severity and frequency of symptoms as well as the total duration of various aspects of the symptomatology were assessed by unstructured and structured clinical interviews in including the Stanford Center for Narcolepsy Sleep Inventory. RESULTS Circulating visfatin was found to be significantly increased in HLA DR2 positive narcoleptic patients compared to controls. CONCLUSION Taken together, our results add to the evidence of disturbed immunological regulation in patients with narcolepsy.
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Affiliation(s)
- Norbert Dahmen
- Department of Psychiatry, University of Mainz, Mainz, Germany
| | | | - Jana Helfrich
- Department of Psychiatry, University of Mainz, Mainz, Germany
| | | | | | | | - Alice Engel
- Department of Psychiatry, University of Mainz, Mainz, Germany
- * E-mail:
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14
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Abstract
BACKGROUND Narcolepsy is a severe sleep disorder that in most patients is characterized by the deficiency of central orexin. Clinically, narcolepsy is associated with obesity. Currently, there is a literature controversy about the potential alteration of leptin levels in narcoleptic patients. Theoretically, diminished leptin levels could partially contribute to the observed overweight of patients. Two studies have reported decreased leptin levels, whereas a larger, recent study failed to detect differences between patients and controls. METHODS To help settle the controversy, we have measured peripheral leptin levels in 42 narcoleptic patients and in 31 body mass index-matched controls. RESULTS No significant differences in leptin levels between the groups were observed. Mean leptin levels were 16.0 +/- 14.9 ng/mL in the narcoleptic men and 30.4 +/- 17.8 ng/mL in the narcoleptic women. The corresponding values for the controls were 21.2 +/- 17.0 ng/mL (P = 0.49, men) and 33.9 +/- 16.9 ng/mL (P = 0.31, women). In addition, no correlation was found between leptin levels and clinical symptomatology in the narcoleptic patients. CONCLUSIONS Taken together, the data argue against a major deterioration of leptin secretion in narcoleptic patients.
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Affiliation(s)
- Norbert Dahmen
- Department of Psychiatry, University of Mainz, Mainz, Germany.
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15
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Abstract
Autoimmunity is considered the most likely cause of human narcolepsy-cataplexy, but no specific autoantibodies or antigen(s) have yet been identified. By means of indirect avidin-biotin immunohistochemical method, we searched for antibodies in serum from narcolepsy-cataplexy patients and controls that bind to rat hypocretin neurons. No staining was found in eight out of nine narcolepsy-cataplexy patients or controls. The serum from one narcolepsy-cataplexy patient, however, strongly produced staining of the membrane and superficial cytoplasm of neurons in the lateral hypothalamus. Dual staining revealed that the vast majority of the hypocretin-positive neurons were positive, but nonhypocretin neurons in the same area were binding antibodies from the patient's serum. These results show that antibodies bind to specific hypocretin- and nonhypocretin-containing neurons in the hypothalamus and indicate the presence of autoantibodies in narcolepsy patients.
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Affiliation(s)
- Stine Knudsen
- Department of Clinical Neurophysiology, Danish Center for Sleep Medicine, University Hospital of Glostrup, Denmark
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16
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Himmerich H, Beitinger PA, Fulda S, Wehrle R, Linseisen J, Wolfram G, Himmerich S, Gedrich K, Wetter TC, Pollmächer T. Plasma Levels of Tumor Necrosis Factor α and Soluble Tumor Necrosis Factor Receptors in Patients With Narcolepsy. ACTA ACUST UNITED AC 2006; 166:1739-43. [PMID: 16983052 DOI: 10.1001/archinte.166.16.1739] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Narcolepsy is a disabling sleep disorder characterized by excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. Recent studies suggest that the immune system might play a pathogenic role pointing to a possible involvement of inflammatory cytokines. METHODS We investigated a sample of 30 patients with narcolepsy in comparison with 120 sex- and age-matched and 101 sex-, body mass index (BMI)-, and age-matched randomly selected normal controls. In these groups, plasma concentrations of tumor necrosis factor alpha (TNF-alpha) and its soluble receptors p55 and p75 (soluble TNF receptor [sTNF-R] p55 and sTNF-R p75) were measured using commercial enzyme-linked immunosorbent assays. RESULTS The narcoleptic patients showed a significantly higher BMI compared with controls of the same age. Soluble TNF-R p75 levels were consistently elevated in the narcoleptic patients compared with their sex- and age-matched (P = .001) as well as sex-, BMI-, and age-matched counterparts (P = .003). Female narcoleptic patients exhibited higher sTNF-R p55 levels compared with their sex- and age-matched controls (P = .01), but this difference disappeared when comparing patients with sex-, BMI-, and age-matched normal controls. Tumor necrosis factor alpha levels did not differ significantly between groups. CONCLUSION Narcoleptic patients show increased plasma levels of sTNF-R p75, suggesting a functional alteration of the TNF-alpha cytokine system, further corroborating a possible pathogenic role of the immune system in this sleep disorder.
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17
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Bassetti CL, Hersberger M, Baumann CR. CSF prostaglandin D synthase is reduced in excessive daytime sleepiness. J Neurol 2006; 253:1030-3. [PMID: 16598611 DOI: 10.1007/s00415-006-0153-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 01/06/2006] [Accepted: 01/24/2006] [Indexed: 01/12/2023]
Abstract
Lipocalin-type prostaglandin D synthase (L-PGDS) is a brain enzyme, which produces prostaglandin D(2), a substance with endogenous somnogenic effects. Using a standardized protocol for immunonephelometric determination of cerebrospinal fluid (CSF) L-PGDS levels, we show that CSF L-PGDS levels are significantly lower in 34 patients with excessive daytime sleepiness when compared with levels in 22 healthy controls. Thus, L-PGDS may represent the first neurochemical measure of excessive daytime sleepiness.
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Affiliation(s)
- Claudio L Bassetti
- Department of Neurology, Universitätsspital Zürich, Frauenklinikstrasse 26, 8091 Zürich, Switzerland.
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18
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Jordan W, Tumani H, Cohrs S, Rodenbeck A, Rüther E, Bechthold J, Mayer G. Narcolepsy increased L-PGDS (beta-trace) levels correlate with excessive daytime sleepiness but not with cataplexy. J Neurol 2005; 252:1372-8. [PMID: 15944863 DOI: 10.1007/s00415-005-0870-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Revised: 03/10/2005] [Accepted: 03/16/2005] [Indexed: 11/27/2022]
Abstract
OBJECTIVES Alterations in the prostaglandin-D-system have been found in animal sleep experiments and disorders that present with hypersomnia or sleep disturbances. The recently demonstrated involvement of the leptomeningeal lipocalin-type prostaglandin-Dsynthase (L-PGDS) (beta-trace) in human physiological sleep encouraged us to investigate its role in the pathophysiology of narcolepsy. METHODS In a pilot study, serum LPGDS and melatonin concentrations were assessed in 14 narcoleptic patients during undisturbed sleep and total sleep deprivation, compared with those from 14 healthy controls during undisturbed sleep. Excessive daytime sleepiness was measured by a standardized questionnaire (Epworth sleepiness scale, ESS). RESULTS In narcoleptic patients, markedly increased baseline L-PGDS levels were significantly correlated with the ESS score, but not with the degree of cataplexy. Serum L-PGDS concentrations in patients as well as in controls followed a time-dependent fluctuation with evening increases, highest values during the night and in the morning. Compared with controls, patients exhibited significant/increased amplitude of circulating L-PGDS without any suppression by total sleep deprivation. CONCLUSION These findings indicate that the prostaglandin-D-system contributes to the pathophysiology of narcolepsy, e. g. the regulation of excessive daytime sleepiness. Since it has been suggested that L-PGDS is also involved in neurodegenerative disorders, there may be a more specific role of the prostaglandin- D-system in narcoleptic aetiogenesis. Moreover, its linkage with the immune system as well as with human sleep regulation offers a direct access for investigating both systems.
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Affiliation(s)
- Wolfgang Jordan
- Dept. of Psychiatry and Psychotherapy, Georg-August-University of Göttingen, von Sieboldstr. 5, 37075 Göttingen, Germany.
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19
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Kok SW, Roelfsema F, Overeem S, Lammers GJ, Frölich M, Meinders AE, Pijl H. Altered setting of the pituitary-thyroid ensemble in hypocretin-deficient narcoleptic men. Am J Physiol Endocrinol Metab 2005; 288:E892-9. [PMID: 15625087 DOI: 10.1152/ajpendo.00327.2004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Narcolepsy is a sleep disorder caused by disruption of hypocretin (orexin) neurotransmission. Injection of hypocretin-1 acutely suppresses TRH and TSH release in rats. In contrast, subchronic administration does not appear to affect the hypothalamo-pituitary-thyroid ensemble in animals. We explored (in 7 patients and 7 controls) whether hypocretin deficiency impacts circulating TSH levels and circadian timing of TSH release in narcoleptic humans. Plasma TSH concentration profiles (blood samples taken at 10-min intervals during 24 h) and TSH levels in response to TRH injection were analyzed by Cluster, robust regression, approximate entropy (ApEn), and deconvolution. Circulating TSH levels were lower in patients, which was primarily attributable to lower pulse amplitude and nadir concentrations. TSH secretion correlated positively with mean 24-h leptin levels (R2 = 0.46, P = 0.02) and negatively with amount of sleep (R2 = 0.29, P = 0.048). Pattern-synchrony between 24-h leptin and TSH concentrations was demonstrated by significant cross-correlation and cross-ApEn analyses with no differences between controls and patients. Sleep onset was closely associated with a fall in circulating TSH. Features of diurnal rhythmicity of circulating TSH fluctuations were similar in patients and controls, with the acrophase occurring shortly after midnight. Thyroxine and triiodothyronine concentrations were similar in patients and controls and did not display a diurnal rhythm. The response of plasma TSH levels to TRH was also similar in both groups. Sleep patterns in narcoleptics were significantly disorderly compared with controls, as measured by ApEn (P = 0.006). In summary, circulating TSH concentrations are low in hypocretin-deficient narcoleptic men, which could be attributable to their low plasma leptin levels and/or their abnormal sleep-wake cycle.
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Affiliation(s)
- Simon W Kok
- Department of General Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
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20
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Abstract
Excessive daytime sleepiness (EDS) has recognized detrimental consequences such as road traffic accidents, impaired psychological functioning and reduced work performance. EDS can result from multiple causes such as sleep deprivation, sleep fragmentation, neurological, psychiatric and circadian rhythm disorders. Treating the underlying cause of EDS remains the mainstay of therapy but in those who continue to be excessively sleepy, further treatment may be warranted. Traditionally, the amphetamine derivatives, methylphenidate and pemoline (collectively sympathomimetic) psychostimulants were the commonest form of therapy for EDS, particularly in conditions such as narcolepsy. More recently, the advent of modafinil has broadened the range of therapeutic options. Modafinil has a safer side-effect profile and as a result, interest in this drug for the management of EDS in other disorders, as well as narcolepsy, has increased considerably. There is a growing school of thought that modafinil may have a role to play in other indications such as obstructive sleep apnea/hypopnea syndrome already treated by nasal continuous positive airway pressure but persisting EDS, shift work sleep disorders, neurological causes of sleepiness, and healthy adults performing sustained operations, particularly those in the military. However, until adequately powered randomised-controlled trials confirm long-term efficacy and safety, the recommendation of wakefulness promoters in healthy adults cannot be justified.
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Affiliation(s)
- Dev Banerjee
- Sleep and Ventilation Unit, Department of Respiratory Medicine, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK
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21
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Okun ML, Giese S, Lin L, Einen M, Mignot E, Coussons-Read ME. Exploring the cytokine and endocrine involvement in narcolepsy. Brain Behav Immun 2004; 18:326-32. [PMID: 15157949 DOI: 10.1016/j.bbi.2003.11.002] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2003] [Revised: 11/04/2003] [Accepted: 11/05/2003] [Indexed: 01/22/2023] Open
Abstract
Narcolepsy is a disabling neurological sleep disorder characterized by excessive daytime sleepiness and abnormal REM sleep manifestations. Recently, the role of cytokines and growth hormone in the regulation of sleep and narcolepsy has been considered, and data suggest that proinflammatory cytokines may be involved in sleep and narcoleptic symptoms. Serum and clinical data were obtained from the Stanford Center for Narcolepsy Research for 39 Narcoleptics (22 Females, 17 Males, age 39+/-14.9) and 40 controls (13 Females, 27 Males, age 46+/-17.9). Plasma levels of TNF-alpha, IL-6, and human growth hormone (hGH) were measured by ELISA. TNF-alpha and IL-6 were significantly increased in narcoleptic subjects compared to controls (p=.001). Interestingly, hGH was significantly increased in narcoleptic subjects (p <.0001). There was also a significant difference in the epworth sleepiness scale (ESS) (17.7+/-4.6 vs. 5.5+/-3.2, p <.0001). These data indicate that narcoleptics, relative to controls, had higher serum levels of TNF-alpha, IL-6, and hGH. These data suggest that the dysregulation of sleep observed in narcoleptics correlates with the immune and endocrine dysregulation seen in these subjects, and the observed changes may in fact contribute to the higher likelihood of disturbed sleep and/or increased incidence of infection. Additional work is required to fully characterize connections between cytokines and narcoleptic symptomatology.
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Affiliation(s)
- M L Okun
- Department of Psychology, University of Colorado at Denver, CB 173, POB 173364, Denver, CO 80217-3364, USA
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Kok SW, Overeem S, Visscher TLS, Lammers GJ, Seidell JC, Pijl H, Meinders AE. Hypocretin deficiency in narcoleptic humans is associated with abdominal obesity. Obes Res 2003; 11:1147-54. [PMID: 12972686 DOI: 10.1038/oby.2003.156] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To determine the prevalence of obesity among patients with narcolepsy, to estimate associated long-term health risks on the basis of waist circumference, and to distinguish the impact of hypocretin deficiency from that of increased daytime sleepiness (i.e., reduced physical activity) on these anthropometric measures. RESEARCH METHODS AND PROCEDURES A cross-sectional, case-control study was conducted. Patients with narcolepsy (n = 138) or idiopathic hypersomnia (IH) (n = 33) were included. Age-matched, healthy members of the Dutch population (Monitoring Project on Risk Factors for Chronic Diseases and Doetinchem Project; n = 10,526) were used as controls. BMI and waist circumference were determined. RESULTS Obesity (BMI > or = 30 kg/m(2)) and overweight (BMI 25 to 30 kg/m(2)) occurred more often among narcolepsy patients [prevalence: 33% (narcoleptics) vs. 12.5% (controls) and 43% (narcoleptics) vs. 36% (controls), respectively; both p < 0.05]. Narcoleptics had a larger waist circumference (mean difference 5 +/- 1.4 cm, p < 0.001). The BMI of patients with IH was significantly lower than that of narcolepsy patients (25.6 +/- 3.6 vs. 28.5 +/- 5.4 kg/m(2); p = 0.004). DISCUSSION Overweight and obesity occur frequently in patients with narcolepsy. Moreover, these patients have an increased waist circumference, indicating excess fat storage in abdominal depots. The fact that patients with IH had a lower BMI than narcoleptics supports the notion that excessive daytime sleepiness (i.e., inactivity) cannot account for excess body fat in narcoleptic patients.
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Affiliation(s)
- Simon W Kok
- Department of General Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
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23
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Overeem S, Geleijns K, Garssen MPJ, Jacobs BC, van Doorn PA, Lammers GJ. Screening for anti-ganglioside antibodies in hypocretin-deficient human narcolepsy. Neurosci Lett 2003; 341:13-6. [PMID: 12676332 DOI: 10.1016/s0304-3940(03)00085-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Narcolepsy is a sleep disorder caused by defective hypocretin (orexin) neurotransmission. It is thought to result from an autoimmune destruction of hypocretin producing neurons. Recently, low hypocretin levels were found in patients with Guillain-Barré syndrome, a post-infectious immune-mediated disorder in which a variety of circulating antibodies against neuronal gangliosides are found. We therefore considered gangliosides to be candidate antigens in narcolepsy as well, and screened for the presence of a panel of serum anti-ganglioside antibodies in a group of 28 well-characterized narcoleptic patients. We did not find a correlation between increased titers of anti-ganglioside antibodies and hypocretin-deficient narcolepsy. This study does not support the hypothesis that an autoimmune response is involved in narcolepsy. However, as an autoimmune attack may be selective and/or transient, future studies are needed to ultimately refute or confirm the autoimmune hypothesis.
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Affiliation(s)
- Sebastiaan Overeem
- Department of Neurology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands.
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Kok SW, Meinders AE, Overeem S, Lammers GJ, Roelfsema F, Frölich M, Pijl H. Reduction of plasma leptin levels and loss of its circadian rhythmicity in hypocretin (orexin)-deficient narcoleptic humans. J Clin Endocrinol Metab 2002; 87:805-9. [PMID: 11836325 DOI: 10.1210/jcem.87.2.8246] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recent observations have implicated hypocretin deficiency in the pathogenesis of narcolepsy. Hypocretin neurotransmission also affects energy balance, and narcoleptic patients tend to become obese. Because hypocretins appear to have important neuroendocrine effects, we hypothesized that the neuroendocrine systems that regulate energy balance might be distinctly set in narcolepsy. As leptin is a pivotal part of these systems, we explored the 24-h plasma leptin (20-min sampling interval) concentration profile in six narcoleptic males and six normal controls, matched for age, sex, body mass index, waist/hip ratio, and fat mass. We thus demonstrated a reduction of the mean 24-h leptin concentration in narcoleptics to 52% of that in controls (5.9 microg/liter in narcolepsy vs. 11.4 microg/liter in controls; P < 0.05). Further, a nocturnal acrophase (clock time of the highest concentration), which is typical of normal leptin secretion, was observed in controls (mean, 2335 h; 95% confidence interval, 2105-0205 h), but not in narcoleptic patients. The mechanisms that potentially disturb the circadian rhythm of leptin levels in hypocretin-deficient narcoleptic humans include anomalies of the sleep-wake cycle and/or disruption of the circadian distribution of autonomic activity. As leptin deficiency clearly leads to morbid obesity in experimental animals and humans, we infer that the observed reduction of plasma leptin levels may predispose narcoleptic humans to weight gain.
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Affiliation(s)
- S W Kok
- Department of General Internal Medicine, Leiden University Medical Center, 2300 RC Leiden, The Netherlands.
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25
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Higuchi S, Usui A, Murasaki M, Matsushita S, Nishioka N, Yoshino A, Matsui T, Muraoka H, Ishizuka Y, Kanba S, Sakurai T. Plasma orexin-A is lower in patients with narcolepsy. Neurosci Lett 2002; 318:61-4. [PMID: 11796186 DOI: 10.1016/s0304-3940(01)02476-4] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Recently identified hypothalamic peptides called orexins (or hypocretins) have been implicated in the sleep-wake cycle and in sleep disorder narcolepsy. Neuropathological studies have shown that in patients with narcolepsy, global reduction in the expression of orexins occurs due to the loss of orexin neurons in the hypothalamus. Cerebrospinal fluid analysis has confirmed a reduced or undetectable level of orexin-A in most narcolepsy patients. In this study, measurement of plasma orexin showed significantly lower concentrations in patients with narcolepsy than in age- and gender-matched normal controls. These data suggest that low levels of orexin-A in plasma could serve as a biological marker for narcolepsy.
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Affiliation(s)
- S Higuchi
- Institute of Clinical Research, National Alcoholism Center, Kurihama Hospital, 5-3-1 Nobi, Yokosuka, Kanagawa, 239-0841, Japan.
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26
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Dalal MA, Schuld A, Haack M, Uhr M, Geisler P, Eisensehr I, Noachtar S, Pollmächer T. Normal plasma levels of orexin A (hypocretin-1) in narcoleptic patients. Neurology 2001; 56:1749-51. [PMID: 11425946 DOI: 10.1212/wnl.56.12.1749] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Deficient orexin signaling has been shown to cause narcolepsy-like conditions in animals. In human narcolepsy, CSF levels of orexin A (hypocretin-1) were reported to be low in most cases. The authors measured CSF and plasma orexin A levels in patients with narcolepsy and in controls. Confirming earlier studies, they found CSF orexin A levels to be extremely low in patients with narcolepsy. However, plasma orexin A levels did not differ from those observed in controls. These results suggest that orexin deficiency in patients with narcolepsy is a phenomena restricted to the CNS.
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Affiliation(s)
- M A Dalal
- Max Planck Institute of Psychiatry, Munich, Germany
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Abstract
Familial and sporadic forms of narcolepsy exist in both humans and canines. Mutations in the hypocretin receptor 2 gene (Hcrtr 2) cause canine familial narcolepsy. In humans, mutations in hypocretin-related genes are rare, but cerebrospinal fluid (CSF) hypocretin-1 is undetectable in most sporadic cases. Using the canine model, we investigated ( 1 ) whether hypocretin deficiency is involved in sporadic cases and ( 2 ) whether alterations in hypocretin neurons or ligand levels also contribute to the phenotype in Hcrtr 2 mutants. We found that hypocretins were undetectable in the brains of three of three and the CSF of two of two sporadic narcoleptic dogs tested. In contrast, hypocretin levels were not altered in brains and CSF of genetically narcoleptic Dobermans, and hypocretin-containing neurons were of normal appearance. Therefore, multiple hypocretin-related etiologies are likely to be involved in canine narcolepsy. The presence of hypocretin peptides in Hcrtr 2-mutated animals suggests that neurotransmission through Hcrtr 1 may be intact, arguing for a preferential importance of Hcrtr 2-mediated function in narcolepsy.
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Affiliation(s)
- B Ripley
- Center for Narcolepsy, Stanford Sleep Center, Stanford University School of Medicine, Palo Alto, California 94304, USA
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28
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Abstract
OBJECTIVE To validate use of high-performance liquid chromatography (HPLC) in determining imipramine concentrations in equine serum and to determine pharmacokinetics of imipramine in narcoleptic horses. ANIMALS 5 horses with adult-onset narcolepsy. PROCEDURE Blood samples were collected before (time 0) and 3, 5, 10, 15, 20, 30, and 45 minutes and 1, 2, 3, 4, 6, 8, 12, and 24 hours after IV administration of imipramine hydrochloride (2 or 4 mg/kg of body weight). Serum was analyzed, using HPLC, to determine imipramine concentration. The serum concentration-versus-time curve for each horse was analyzed separately to estimate pharmacokinetic values. RESULTS Adverse effects (muscle fasciculations, tachycardia, hyperresponsiveness to sound, and hemolysis) were detected in most horses when serum imipramine concentrations were high, and these effects were most severe in horses receiving 4 mg of imipramine/kg. Residual adverse effects were not apparent. Value (mean +/- SD) for area under the curve was 3.9 +/- 0.7 h X microg/ml, whereas volume of distribution was 584 +/- 161.7 ml/kg, total body clearance was 522 +/- 102 ml/kg/h, and mean residence time was 1.8 +/- 0.6 hours. One horse had signs of narcolepsy 6 and 12 hours after imipramine administration; corrresponding serum imipramine concentrations were less than the therapeutic range. CONCLUSIONS AND CLINICAL RELEVANCE Potentially serious adverse effects may be seen in horses administered doses of imipramine that exceed a dosage of 2 mg/kg. Total body clearance of imipramine in horses is slower than that in humans; thus, the interval between subsequent doses should be longer in horses.
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Affiliation(s)
- K E Peck
- Texas A&M Veterinary Medical Diagnostic Laboratory, Texas A&M University, College Station 77843, USA
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29
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Abstract
Recently, hypocretins have been implicated in the pathophysiology of narcolepsy, a sleep disorder characterized particularly by the occurrence of excessive daytime sleepiness and cataplexy. Hypocretins, which stimulate food intake, have been reported to be absent in the cerebrospinal fluid (CSF) of the majority of patients suffering from narcolepsy. Because these patients also display an increased body mass index (BMI), it has been suggested that disturbances in metabolism and food intake regulation may be present. To further investigate these presumed alterations, we studied the production of leptin, a fat-cell-derived hormone signaling to the brain the size of the adipose tissue. We measured the levels of leptin in serum and CSF from 15 narcoleptic patients and compared the results to those from age-, sex- and BMI-matched control groups of depressive patients and patients suffering from a noninflammatory neurological disorder. Compared to both control groups, leptin levels in serum, but not in the CSF, were significantly reduced in narcoleptic patients by more than 50%. These results support the hypothesis that human narcolepsy is accompanied by complex alterations of the regulation of food intake and metabolism. The significance of these alterations for the core symptomatology of narcolepsy should be a target of future research.
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Affiliation(s)
- A Schuld
- Max Planck Institute of Psychiatry Munich, Germany.
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30
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Ramos L, Bakhtiar R, Tse FL. Liquid-liquid extraction using 96-well plate format in conjunction with liquid chromatography/tandem mass spectrometry for quantitative determination of methylphenidate (Ritalin) in human plasma. Rapid Commun Mass Spectrom 2000; 14:740-745. [PMID: 10825011 DOI: 10.1002/(sici)1097-0231(20000515)14:9<740::aid-rcm938>3.0.co;2-c] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Methylphenidate (MPH; Ritalin: methyl-alpha-phenyl-2-piperidinacetate hydrochloride) is utilized for the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. Recently, we described a rapid enantioselective liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the determination of the enantiomers of MPH (Rapid Commun. Mass Spectrom. 1999; 13: 2054). A lower limit of quantification (LLOQ) of 87 pg/mL was attained for the human plasma assay. The present paper describes a high-throughput sample preparation procedure in conjunction with racemic LC/MS/MS analysis for MPH with a LLOQ of 50 pg/mL. A semi-automated robotics method using liquid-liquid extraction (LLE) in a 96-well plate format was developed and validated. The correlation coefficients were > or =0.998 for MPH indicating good fits of the regression models over the range of the calibration curve. The accuracy and precision of the semi-automated approach were comparable to those obtained using the manual sample preparation technique reported previously (vide supra). The current method can easily be adapted to the enantioselective LC/MS/MS assay of MPH. The assay was simple, fast, specific, and exhibited excellent ruggedness.
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Affiliation(s)
- L Ramos
- Drug Metabolism and Pharmacokinetics Department, Novartis Institute for Biomedical Research, East Hanover, NJ 07936, USA
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31
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Vgontzas AN, Papanicolaou DA, Bixler EO, Kales A, Tyson K, Chrousos GP. Elevation of plasma cytokines in disorders of excessive daytime sleepiness: role of sleep disturbance and obesity. J Clin Endocrinol Metab 1997; 82:1313-6. [PMID: 9141509 DOI: 10.1210/jcem.82.5.3950] [Citation(s) in RCA: 502] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Excessive daytime sleepiness (EDS) and fatigue are frequent symptoms in the general population and the chief complaint of the majority of patients at Sleep Disorders Centers. There is evidence that the inflammatory cytokines tumor necrosis factor-alpha (TNF alpha), interleukin-1beta (IL-1beta), and IL-6 are involved in physiological sleep regulation and that their administration to humans is associated with sleepiness and fatigue. To explore whether plasma levels of TNF alpha, IL-1beta, and IL-6 are elevated in patients with EDS, we measured morning plasma levels of TNF alpha, IL-1beta, and IL-6 in 12 sleep apneics, 11 narcoleptics, 8 idiopathic hypersomniacs, and 10 normal controls. TNF alpha was significantly elevated in sleep apneics and narcoleptics compared to that in normal controls (P < 0.001 and P = 0.001, respectively). Plasma IL-1beta concentrations were not different between sleep disorder patients and controls, whereas IL-6 was markedly and significantly elevated in sleep apneics compared to that in normal controls (P = 0.028). The primary factor influencing TNF alpha values was the degree of nocturnal sleep disturbance, whereas the primary determinant for IL-6 levels was the body mass index. Our findings suggest that TNF alpha and IL-6 might play a significant role in mediating sleepiness and fatigue in disorders of EDS in humans.
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Affiliation(s)
- A N Vgontzas
- Department of Psychiatry, Pennsylvania State University, Hershey 17033, USA
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32
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Abstract
We measured morning plasma concentrations of delta sleep-inducing-peptide-like-immunoreactivity (DSIP-LI) in 9 sleep apnea patients, 10 narcolepsy patients, and 11 normal controls. Comparisons between the three groups showed no significant differences, although there was a trend toward association with low levels of DSIP-LI in the narcoleptic group, particularly in patients not using medications. No differences were found in the morning or evening plasma DSIP-LI levels in a second group of 11 normal controls and 8 sleep apneics. Our findings do not appear to support a biological marker role of disease activity for single measures of plasma DSIP in sleep apnea.
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Affiliation(s)
- A N Vgontzas
- Department of Psychiatry, Pennsylvania State University, Hershey 17033, USA
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Nishino S, Arrigoni J, Sharp LH, Shelton JD, Dement WC, Mignot E. Serum prolactin response to a D2 antagonist in narcoleptic and control canines. Sleep 1992; 15:474-5. [PMID: 1455131 DOI: 10.1093/sleep/15.5.474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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35
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Godbout R, Montplaisir J. The effect of zimelidine, a serotonin-reuptake blocker, on cataplexy and daytime sleepiness of narcoleptic patients. Clin Neuropharmacol 1986; 9:46-51. [PMID: 2950994 DOI: 10.1097/00002826-198602000-00004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Narcolepsy is a neurological syndrome characterized by two major symptoms: excessive daytime sleepiness and cataplexy. Pharmacological and biochemical evidence support the hypothesis that dopaminergic mechanisms are involved in excessive daytime sleepiness. The pathophysiology of cataplexy and the action mechanisms of anticataplectic agents remain controversial issues. Cataplexy is usually controlled by tricyclic antidepressants, but these drugs interact with several central monoamine systems and also exert an anticholinergic effect. In the present study, zimelidine, a selective serotonin reuptake inhibitor without anticholinergic activity, was administered to 11 narcoleptic patients for 1-16 months. Cataplexy improved markedly in all patients, while no changes could be documented on excessive daytime sleepiness, either by self-report or polysomnographic nap recording. These results confirm the hypothesis that hypersomnolence and cataplexy are subject to different control mechanisms; support a serotoninergic, but not a cholinergic, theory of cataplexy; and suggest that selective serotonin reuptake inhibitors may be the treatment of choice for cataplexy.
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36
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Montplaisir J, de Champlain J, Young SN, Missala K, Sourkes TL, Walsh J, Rémillard G. Narcolepsy and idiopthic hypersomnia: biogenic amines and related compounds in CSF. Neurology 1982; 32:1299-302. [PMID: 6890168 DOI: 10.1212/wnl.32.11.1299] [Citation(s) in RCA: 78] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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37
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Abstract
Growth hormone (GH) and prolactin (PR) secretion were evaluated in 28 patients who had sleep apnea or narcolepsy but no other primary neurologic or endocrine disorders. Eighty-one percent of subjects with impaired alertness failed to demonstrate serum GH concentrations in excess of 5 ng per milliliter following oral administration of L-DOPA, 500 mg. Diminished GH responses to sleep and intravenous arginine were observed in 57 percent and 44 percent, respectively, of patients tested. Sleep-related PRL release was less than normal in women with narcolepsy, with or without sleep apnea. All patients had at least one abnormality in GH or PRL secretion.
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38
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Besset A, Bonardet A, Billiard M, Descomps B, de Paulet AC, Passouant P. Circadian patterns of growth hormone and cortisol secretions in narcoleptic patients. Chronobiologia 1979; 6:19-31. [PMID: 467171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Narcolepsy, a disorder which is clinically characterized by recurring episodes of sleep during the day, frequently associated with nocturnal disrupted sleep and polygraphically by sleep onset REM periods, has been studied in regard to the relationships between GH, cortisol secretion and sleep. Ten narcoleptics were polygraphically recorded during 24 h after one night's adaptation. Blood samples were taken every 20 min for GH and cortisol immuno-assays. Three narcoleptics were recorded twice 2 months later and 2 normal subjects served as controls. The following results were obtained: GH secretory pattern was different in narcoleptics and controls; two groups were identified: the first one showed a very low basal GH secretion with rare and small secretory peaks not clearly linked with sleep. One subject of this group recorded twice showed a similar pattern. The second group exhibited a higher basal secretion with many peaks without any well-defined relationship to sleep stages. The pattern was again consistent in two recordings of 2 subjects in this group. Furthermore GH secretion rose significantly (p less than 0.01) between 2100 and 0000 with no apparent relationship to sleep stages. The cortisol secretory pattern showed a significant rise (p less than 0.01) between 0400 and 1000 and was not different in narcoleptics and controls. In narcolepsy the monophasic sleep-wakefulness cycle is disrupted. The GH secretion pattern is modified whereas the circadian pattern of cortisol secretion is normal and independent of the sleep-wakefulness cycle of the narcoleptic patient.
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Abstract
1 Plasma amphetamine and growth hormone levels have been measured in eight normal and twenty-six narcoleptic subjects following a single dose of (+)-amphetamine (20 mg) or (-)-amphetamine (20 mg) by mouth. 2 Peak plasma levels and the shape of the plasma amphetamine-time curve were similar with both isomers in normal and narcoleptic subjects. 3 In most normal subjects both (+)-and (-)-amphetamine (20 mg) caused an increase in the plasma concentration of growth hormone. The two isomers were approximately equipotent in this respect. Neither (+)- nor (-)-amphetamine (20 mg) caused an increase in plasma growth hormone concentration in narcoleptics. 4 Following amphetamine (30 mg), two of six narcoleptic subjects had an increase in plasma growth hormone concentration. 5 Levodopa (250 mg) with (-)-alpha-methyldopa hydrazine 25 mg (Sinemet) by mouth, caused a rise in plasma growth hormone concentration in most normal subjects. The magnitude of the Sinemet-induced rise in plasma growth hormone concentration in narcoleptics was less than in normal subjects.
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40
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Takahashi K, Takahashi S, Azumi K, Honda Y, Utena H. [Changes of plasma growth hormone level in normal and hypersomnic patients during nocturnal sleep]. Shinkei Kenkyu No Shimpo 1971; 14:743-54. [PMID: 4326646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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