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Liblau RS, Latorre D, Kornum BR, Dauvilliers Y, Mignot EJ. The immunopathogenesis of narcolepsy type 1. Nat Rev Immunol 2024; 24:33-48. [PMID: 37400646 DOI: 10.1038/s41577-023-00902-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2023] [Indexed: 07/05/2023]
Abstract
Narcolepsy type 1 (NT1) is a chronic sleep disorder resulting from the loss of a small population of hypothalamic neurons that produce wake-promoting hypocretin (HCRT; also known as orexin) peptides. An immune-mediated pathology for NT1 has long been suspected given its exceptionally tight association with the MHC class II allele HLA-DQB1*06:02, as well as recent genetic evidence showing associations with polymorphisms of T cell receptor genes and other immune-relevant loci and the increased incidence of NT1 that has been observed after vaccination with the influenza vaccine Pandemrix. The search for both self-antigens and foreign antigens recognized by the pathogenic T cell response in NT1 is ongoing. Increased T cell reactivity against HCRT has been consistently reported in patients with NT1, but data demonstrating a primary role for T cells in neuronal destruction are currently lacking. Animal models are providing clues regarding the roles of autoreactive CD4+ and CD8+ T cells in the disease. Elucidation of the pathogenesis of NT1 will allow for the development of targeted immunotherapies at disease onset and could serve as a model for other immune-mediated neurological diseases.
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Affiliation(s)
- Roland S Liblau
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), University of Toulouse, CNRS, INSERM, Toulouse, France.
- Department of Immunology, Toulouse University Hospitals, Toulouse, France.
| | | | - Birgitte R Kornum
- Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yves Dauvilliers
- National Reference Center for Orphan Diseases, Narcolepsy, Idiopathic Hypersomnia and Kleine-Levin Syndrome, Department of Neurology, Gui-de-Chauliac Hospital, CHU de Montpellier, Montpellier, France
- INSERM Institute for Neurosciences of Montpellier, Montpellier, France
| | - Emmanuel J Mignot
- Stanford University, Center for Narcolepsy, Department of Psychiatry and Behavioral Sciences, Palo Alto, CA, USA.
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Roya Y, Farzaneh B, Mostafa A, Mahsa S, Babak Z. Narcolepsy following COVID-19: A case report and review of potential mechanisms. Clin Case Rep 2023; 11:e7370. [PMID: 37251741 PMCID: PMC10213711 DOI: 10.1002/ccr3.7370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 04/24/2023] [Accepted: 05/08/2023] [Indexed: 05/31/2023] Open
Abstract
Key Clinical Message The immune activation in COVID-19 may trigger narcolepsy in vulnerable patients. We suggest clinicians carefully evaluate patients with post-COVID fatigue and hypersomnia for primary sleep disorders, specifically narcolepsy. Abstract The patient is a 33-year-old Iranian woman without a significant past medical history with the full range of narcolepsy symptoms that started within 2 weeks after her recovery from COVID-19. Sleep studies revealed increased sleep latency and three sleep-onset rapid eye movement events, compatible with a narcolepsy-cataplexy diagnosis.
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Affiliation(s)
- Yazdani Roya
- Firoozgar Hospital, Department of Neurology, School of MedicineIran University of Medical SciencesTehranIran
| | - Barzkar Farzaneh
- Center for Educational Research in Medical Sciences(CERMS), Faculty of MedicineIran University of Medical Sciences IUMSTehranIran
| | - Almasi‐Dooghaee Mostafa
- Firoozgar Hospital, Department of Neurology, School of MedicineIran University of Medical SciencesTehranIran
| | - Shojaie Mahsa
- Firoozgar Hospital, Department of Neurology, School of MedicineIran University of Medical SciencesTehranIran
| | - Zamani Babak
- Firoozgar Hospital, Department of Neurology, School of MedicineIran University of Medical SciencesTehranIran
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Ravel JM, Mignot EJM. [Narcolepsy: From the discovery of a wake promoting peptide to autoimmune T cell biology and molecular mimicry with flu epitopes]. Biol Aujourdhui 2019; 213:87-108. [PMID: 31829930 DOI: 10.1051/jbio/2019026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Indexed: 11/14/2022]
Abstract
Narcolepsy-cataplexy was first described in the late 19th century in Germany and France. Prevalence was established to be 0.05 % and a canine model was discovered in the 1970s. In 1983, a Japanese study found that all patients carried HLA-DR2, suggesting autoimmunity as the cause of the disease. Studies in the canine model established that dopaminergic stimulation underlies anti-narcoleptic action of psychostimulants, while antidepressants were found to suppress cataplexy through adrenergic reuptake inhibition. No HLA association was found in canines. A linkage study initiated in 1988 revealed in hypocretin (orexin) receptor two mutations as the cause of canine narcolepsy in 1999. In 1992, studies on African Americans showed that DQ0602 was a better marker than DR2 across all ethnic groups. In 2000, hypocretin-1/orexin A levels were measured in the cerebrospinal fluid (CSF) and found to be undetectable in most patients, establishing hypocretin deficiency as the cause of narcolepsy. Decreased CSF hypocretin-1 was then found to be secondary to the loss of the 70,000 neurons producing hypocretin in the hypothalamus, suggesting immune destruction of these cells as the cause of the disease. Additional genetic studies, notably genome wide associations (GWAS), found multiple genetic predisposing factors for narcolepsy. These were almost all involved in other autoimmune diseases, although a strong and unique association with T cell receptor (TCR) alpha and beta loci were observed. Nonetheless, all attempts to demonstrate presence of autoantibodies against hypocretin cells in narcolepsy failed, and the presumed autoimmune cause remained unproven. In 2009, association with strep throat infections were found, and narcolepsy onsets were found to occur more frequently in spring and summer, suggesting upper away infections as triggers. Following reports that narcolepsy cases were triggered by vaccinations and infections against influenza A 2009 pH1N1, a new pandemic strain that erupted in 2009, molecular mimicry with influenza A virus was suggested in 2010. This hypothesis was later confirmed by peptide screening showing higher activity of CD4+ T cell reactivity to a specific post-translationally amidated segment of hypocretin (HCRT-NH2) and cross-reactivity of specific TCRs with a pH1N1-specific segment of hemagglutinin that shares homology with HCRT-NH2. Strikingly, the most frequent TCR recognizing these antigens was found to carry sequences containing TRAJ24 or TRVB4-2, segments modulated by narcolepsy-associated genetic polymorphisms. Cross-reactive CD4+ T cells with these cross-reactive TCRs likely subsequently recruit CD8+ T cells that are then involved in hypocretin cell destruction. Additional flu mimics are also likely to be discovered since narcolepsy existed prior to 2009. The work that has been conducted over the years on narcolepsy offers a unique perspective on the conduct of research on the etiopathogeny of a specific disease.
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Affiliation(s)
- Jean-Marie Ravel
- Stanford Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Medicine, Stanford University, 3615 Porter Drive, Palo Alto, CA, USA
| | - Emmanuel J M Mignot
- Stanford Center for Sleep Sciences and Medicine, Department of Psychiatry and Behavioral Medicine, Stanford University, 3615 Porter Drive, Palo Alto, CA, USA
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Spear ET, Mawe GM. Enteric neuroplasticity and dysmotility in inflammatory disease: key players and possible therapeutic targets. Am J Physiol Gastrointest Liver Physiol 2019; 317:G853-G861. [PMID: 31604034 PMCID: PMC6962496 DOI: 10.1152/ajpgi.00206.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Intestinal functions, including motility and secretion, are locally controlled by enteric neural networks housed within the wall of the gut. The fidelity of these functions depends on the precision of intercellular signaling among cellular elements, including enteric neurons, epithelial cells, immune cells, and glia, all of which are vulnerable to disruptive influences during inflammatory events. This review article describes current knowledge regarding inflammation-induced neuroplasticity along key elements of enteric neural circuits, what is known about the causes of these changes, and possible therapeutic targets for protecting and/or repairing the integrity of intrinsic enteric neurotransmission. Changes that have been detected in response to inflammation include increased epithelial serotonin availability, hyperexcitability of intrinsic primary afferent neurons, facilitation of synaptic activity among enteric neurons, and attenuated purinergic neuromuscular transmission. Dysfunctional propulsive motility has been detected in models of colitis, where causes include the changes described above, and in models of multiple sclerosis and other autoimmune conditions, where autoantibodies are thought to mediate dysmotility. Other cells implicated in inflammation-induced neuroplasticity include muscularis macrophages and enteric glia. Targeted treatments that are discussed include 5-hydroxytryptamine receptor 4 agonists, cyclooxygenase inhibitors, antioxidants, B cell depletion therapy, and activation of anti-inflammatory pathways.
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Affiliation(s)
- Estelle T. Spear
- 1Division of Gastroenterology and Hepatology, Department of Medicine, School of Medicine, Stanford University, Stanford, California
| | - Gary M. Mawe
- 2Department of Neurological Sciences, The University of Vermont, Burlington, Vermont
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Alshehri AM, Mendis T, Jackson MW. A cell-based assay for the detection of pathogenic anti-voltage-gated calcium channel autoantibodies in immunoglobulin G from patients with type 1 diabetes. J Immunol Methods 2018; 460:79-86. [PMID: 29940155 DOI: 10.1016/j.jim.2018.06.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 05/30/2018] [Accepted: 06/19/2018] [Indexed: 10/28/2022]
Abstract
Recent studies have postulated the presence of functional autoantibodies (Abs) against L-type voltage gated calcium channels (VGCCs) in the serum of patients with type 1 diabetes, with various proposed physiological consequences, both islet cell associated and extra-glandular. Arguably, the most potentially damaging effect reported for these Abs is induction of apoptosis in pancreatic beta (β) cells, yet a convincing pathogenic mechanism remains to be demonstrated. In the current study, we report an assay of reactive oxygen species (ROS) stress induction in the rat insulinoma cell line Rin A12, as determined by 2', 7'-Dichlorofluorescein diacetate (DCF-DA) fluorescence detection by flow cytometry. We demonstrate that incubation of Rin A12 cells with immunoglobulin G (IgG) containing anti-VGCC activity from patients with T1D mediates a significant increase in ROS, with subsequent induction of apoptosis, as determined by positivity for annexin V expression. Neither T1D patient-derived IgG lacking anti-VGCC activity or IgG from healthy donors altered ROS or annexin V expression, indicating the new assay is specific for the detection of functional anti-VGCC Abs. Subsequent screening of IgG samples derived from individual patients indicated a prevalence of approximately 75% in a cohort of 20 patients with T1D. The new cell-based assay provides, for the first time, experimental evidence supporting a plausible pathophysiological mechanism underlying anti-VGCC Ab-mediated apoptosis induction in β cells. Additionally, the assay is a considerable advance on previously published methods for detecting and characterising the functional activity of anti-VGCC Abs in patient-derived samples.
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Affiliation(s)
- Ahmed M Alshehri
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre, Flinders University, Bedford Park, 5042, South Australia, Australia
| | - Thilini Mendis
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre, Flinders University, Bedford Park, 5042, South Australia, Australia
| | - Michael W Jackson
- Department of Immunology, Allergy & Arthritis, Flinders Medical Centre, Flinders University, Bedford Park, 5042, South Australia, Australia.
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Perez EE, Orange JS, Bonilla F, Chinen J, Chinn IK, Dorsey M, El-Gamal Y, Harville TO, Hossny E, Mazer B, Nelson R, Secord E, Jordan SC, Stiehm ER, Vo AA, Ballow M. Update on the use of immunoglobulin in human disease: A review of evidence. J Allergy Clin Immunol 2016; 139:S1-S46. [PMID: 28041678 DOI: 10.1016/j.jaci.2016.09.023] [Citation(s) in RCA: 369] [Impact Index Per Article: 46.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 09/12/2016] [Accepted: 09/23/2016] [Indexed: 12/20/2022]
Abstract
Human immunoglobulin preparations for intravenous or subcutaneous administration are the cornerstone of treatment in patients with primary immunodeficiency diseases affecting the humoral immune system. Intravenous preparations have a number of important uses in the treatment of other diseases in humans as well, some for which acceptable treatment alternatives do not exist. We provide an update of the evidence-based guideline on immunoglobulin therapy, last published in 2006. Given the potential risks and inherent scarcity of human immunoglobulin, careful consideration of its indications and administration is warranted.
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Affiliation(s)
- Elena E Perez
- Allergy Associates of the Palm Beaches, North Palm Beach, Fla.
| | - Jordan S Orange
- Department of Pediatrics, Section of Immunology Allergy and Rheumatology, Center for Human Immunobiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Tex
| | - Francisco Bonilla
- Department of Pediatrics, Clinical Immunology Program, Children's Hospital Boston and Harvard Medical School, Boston, Mass
| | - Javier Chinen
- Department of Pediatrics, Section of Immunology Allergy and Rheumatology, Center for Human Immunobiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Tex
| | - Ivan K Chinn
- Department of Pediatrics, Section of Immunology Allergy and Rheumatology, Center for Human Immunobiology, Texas Children's Hospital and Baylor College of Medicine, Houston, Tex
| | - Morna Dorsey
- Department of Pediatrics, Allergy, Immunology and BMT Division, Benioff Children's Hospital and University of California, San Francisco, Calif
| | - Yehia El-Gamal
- Department of Pediatrics, Pediatric Allergy and Immunology Unit, Children's Hospital and Ain Shams University, Cairo, Egypt
| | - Terry O Harville
- Departments of Pathology and Laboratory Services and Pediatrics, University of Arkansas, Little Rock, Ark
| | - Elham Hossny
- Department of Pediatrics, Pediatric Allergy and Immunology Unit, Children's Hospital and Ain Shams University, Cairo, Egypt
| | - Bruce Mazer
- Department of Pediatrics, Allergy and Immunology, Montreal Children's Hospital and McGill University, Montreal, Quebec, Canada
| | - Robert Nelson
- Department of Medicine and Pediatrics, Division of Hematology and Oncology and Stem Cell Transplantation, Riley Hospital, Indiana University School of Medicine and the IU Melvin and Bren Simon Cancer Center, Indianapolis, Ind
| | - Elizabeth Secord
- Department of Pediatrics, Wayne State University, Children's Hospital of Michigan, Detroit, Mich
| | - Stanley C Jordan
- Nephrology & Transplant Immunology, Kidney Transplant Program, David Geffen School of Medicine at UCLA and Cedars-Sinai Medical Center, Los Angeles, Calif
| | - E Richard Stiehm
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, Calif
| | - Ashley A Vo
- Transplant Immunotherapy Program, Comprehensive Transplant Center, Kidney Transplant Program, Cedars-Sinai Medical Center, Los Angeles, Calif
| | - Mark Ballow
- Department of Pediatrics, Division of Allergy & Immunology, University of South Florida, Morsani College of Medicine, Johns Hopkins All Children's Hospital, St Petersburg, Fla
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A novel cell-based assay for inhibitory anti-muscarinic type 3 receptor antibodies in primary Sjögren’s syndrome. J Immunol Methods 2015; 427:117-21. [DOI: 10.1016/j.jim.2015.11.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/04/2015] [Accepted: 11/11/2015] [Indexed: 11/21/2022]
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Abstract
Although narcolepsy was first described in the late nineteenth century in Germany and France, much of the research on this disorder has been conducted at Stanford University, starting with Drs. William C. Dement and Christian Guilleminault in the 1970s. The prevalence of narcolepsy was established, and a canine model discovered. Following the finding in Japan that almost all patients with narcolepsy carry a specific HLA subtype, HLA-DR2, Hugh Mac Devitt, F. Carl Grumet, and Larry Steinman initiated immunological studies, but results were generally negative. Using the narcoleptic canines, Dr. Nishino and I established that stimulants increased wakefulness by stimulating dopaminergic transmission while antidepressants suppress cataplexy via adrenergic reuptake inhibition. A linkage study was initiated with Dr. Grumet in 1988, and after 10 years of work, the canine narcolepsy gene was cloned by in 1999 and identified as the hypocretin (orexin) receptor 2. In 1992, studying African Americans, we also found that DQ0602 rather than DR2 was a better marker for narcolepsy across all ethnic groups. In 2000, Dr. Nishino and I, in collaboration with Dr. Lammers in the Netherlands, found that hypocretin 1 levels in the cerebrospinal fluid (CSF) were undetectable in most cases, establishing hypocretin deficiency as the cause of narcolepsy. Pursuing this research, our and Dr. Siegel's group, examining postmortem brains, found that the decreased CSF hypocretin 1 was secondary to the loss the 70,000 neurons producing hypocretin in the hypothalamus. This finding revived the autoimmune hypothesis but attempts at demonstrating immune targeting of hypocretin cells failed until 2013. At this date, Dr. Elisabeth Mellins and I discovered that narcolepsy is characterized by the presence of autoreactive CD4(+) T cells to hypocretin fragments when presented by DQ0602. Following reports that narcolepsy cases were triggered by vaccinations and infections against influenza A 2009 pH1N1, a new pandemic strain that erupted in 2009, our groups also established that a small epitope of pH1N1 resembles hypocretin and is likely involved in molecular mimicry. Although much remains to be done, these achievements, establishing hypocretin deficiency as the cause of narcolepsy, demonstrating its autoimmune basis, and showing molecular mimicry between hypocretin and sequences derived from a pandemic strain of influenza, are likely to remain classics in human immunology.
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Affiliation(s)
- Emmanuel J M Mignot
- Stanford University Center for Sleep Sciences, 3165 Porter Drive, #2178, Palo Alto, CA, 94304, USA,
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9
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The inhibitory effects of antimuscarinic autoantibodies in the sera of primary Sjogren syndrome patients on the gastrointestinal motility. Mol Immunol 2013; 56:583-7. [DOI: 10.1016/j.molimm.2013.06.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 05/25/2013] [Accepted: 06/07/2013] [Indexed: 11/19/2022]
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Antibodies interfering with the type 3 muscarinic receptor pathway inhibit gastrointestinal motility and cholinergic neurotransmission in Sjögren's syndrome. ACTA ACUST UNITED AC 2011; 63:1426-34. [DOI: 10.1002/art.30282] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Narcolepsy is a lifelong sleep disorder characterized by a classic tetrad of excessive daytime sleepiness with irresistible sleep attacks, cataplexy (sudden bilateral loss of muscle tone), hypnagogic hallucination, and sleep paralysis. There are two distinct groups of patients, ie, those having narcolepsy with cataplexy and those having narcolepsy without cataplexy. Narcolepsy affects 0.05% of the population. It has a negative effect on the quality of life of its sufferers and can restrict them from certain careers and activities. There have been advances in the understanding of the pathogenesis of narcolepsy. It is thought that narcolepsy with cataplexy is secondary to loss of hypothalamic hypocretin neurons in those genetically predisposed to the disorder by possession of human leukocyte antigen DQB1*0602. The diagnostic criteria for narcolepsy are based on symptoms, laboratory sleep tests, and serum levels of hypocretin. There is no cure for narcolepsy, and the present mainstay of treatment is pharmacological treatment along with lifestyle changes. Some novel treatments are also being developed and tried. This article critically appraises the evidence for diagnosis and treatment of narcolepsy.
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Furthering the understanding of the pathophysiology of narcolepsy. Curr Neurol Neurosci Rep 2010; 11:127-30. [PMID: 21125429 DOI: 10.1007/s11910-010-0165-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Increased immune complexes of hypocretin autoantibodies in narcolepsy. PLoS One 2010; 5:e13320. [PMID: 20967199 PMCID: PMC2954157 DOI: 10.1371/journal.pone.0013320] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 09/16/2010] [Indexed: 01/31/2023] Open
Abstract
Background Hypocretin peptides participate in the regulation of sleep-wake cycle while deficiency in hypocretin signaling and loss of hypocretin neurons are causative for narcolepsy-cataplexy. However, the mechanism responsible for alteration of the hypocretin system in narcolepsy-cataplexy and its relevance to other central hypersomnias remain unknown. Here we studied whether central hypersomnias can be associated with autoantibodies reacting with hypocretin-1 peptide present as immune complexes. Methodology Serum levels of free and dissociated (total) autoantibodies reacting with hypocretin-1 peptide were measured by enzyme-linked immunosorbent assay and analyzed with regard to clinical parameters in 82 subjects with narcolepsy-cataplexy, narcolepsy without cataplexy or idiopathic hypersomnia and were compared to 25 healthy controls. Principal Findings Serum levels of total but not free IgG autoantibodies against hypocretin-1 were increased in narcolepsy-cataplexy. Increased levels of complexed IgG autoantibodies against hypocretin-1 were found in all patients groups with a further increase in narcolepsy-cataplexy. Levels of total IgM hypocretin-1 autoantibodies were also elevated in all groups of patients. Increased levels of anti-idiotypic IgM autoantibodies reacting with hypocretin-1 IgG autoantibodies affinity purified from sera of subjects with narcolepsy-cataplexy were found in all three groups of patients. Disease duration correlated negatively with serum levels of hypocretin-1 IgG and IgM autoantibodies and with anti-idiotypic IgM autoantibodies. Conclusion Central hypersomnias and particularly narcolepsy-cataplexy are characterized by higher serum levels of autoantibodies directed against hypocretin-1 which are present as immune complexes most likely with anti-idiotypic autoantibodies suggesting their relevance to the mechanism of sleep-wake cycle regulation.
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A novel impedance-based cellular assay for the detection of anti-calcium channel autoantibodies in type 1 diabetes. J Immunol Methods 2010; 361:31-6. [PMID: 20655919 DOI: 10.1016/j.jim.2010.07.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 07/13/2010] [Indexed: 12/13/2022]
Abstract
We have recently postulated that functional autoantibodies (Abs) against L-type voltage-gated calcium channels (VGCCs) contribute to autonomic dysfunction in type 1 diabetes (T1D). Previous studies based on whole-organ assays have proven valuable in establishing the mechanism of anti-VGCC Ab activity, but are complex and unsuitable for screening large patient cohorts. In the current study, we used real-time dynamic monitoring of cell impedance to demonstrate that anti-VGCC Abs from patients with T1D inhibit the adherence of Rin A12 cells. The functional effect of the anti-VGCC Abs was mimicked by the dihydropyridine agonist, Bay K8644, and reversed by the antagonist, nicardipine, providing a pharmacological link to the whole-organ studies. IVIg neutralized the effect on cell adhesion of the anti-VGCC Abs, consistent with the presence of anti-idiotypic Abs in IVIg that may prevent the emergence of pathogenic Abs in healthy individuals. The cell impedance assay can be performed in a 96 well plate format, and represents a simple method for detecting the presence of anti-VGCC activity in patient immunoglobulin (IgG). The new cell assay should prove useful for further studies to determine the prevalence of the Ab and its association with symptoms of autonomic dysfunction in patients with T1D.
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Fontana A, Gast H, Reith W, Recher M, Birchler T, Bassetti CL. Narcolepsy: autoimmunity, effector T cell activation due to infection, or T cell independent, major histocompatibility complex class II induced neuronal loss? ACTA ACUST UNITED AC 2010; 133:1300-11. [PMID: 20403960 DOI: 10.1093/brain/awq086] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Human narcolepsy with cataplexy is a neurological disorder, which develops due to a deficiency in hypocretin producing neurons in the hypothalamus. There is a strong association with human leucocyte antigens HLA-DR2 and HLA-DQB1*0602. The disease typically starts in adolescence. Recent developments in narcolepsy research support the hypothesis of narcolepsy being an immune-mediated disease. Narcolepsy is associated with polymorphisms of the genes encoding T cell receptor alpha chain, tumour necrosis factor alpha and tumour necrosis factor receptor II. Moreover the rate of streptococcal infection is increased at onset of narcolepsy. The hallmarks of anti-self reactions in the tissue--namely upregulation of major histocompatibility antigens and lymphocyte infiltrates--are missing in the hypothalamus. These findings are questionable because they were obtained by analyses performed many years after onset of disease. In some patients with narcolepsy autoantibodies to Tribbles homolog 2, which is expressed by hypocretin neurons, have been detected recently. Immune-mediated destruction of hypocretin producing neurons may be mediated by microglia/macrophages that become activated either by autoantigen specific CD4(+) T cells or superantigen stimulated CD8(+) T cells, or independent of T cells by activation of DQB1*0602 signalling. Activation of microglia and macrophages may lead to the release of neurotoxic molecules such as quinolinic acid, which has been shown to cause selective destruction of hypocretin neurons in the hypothalamus.
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Affiliation(s)
- Adriano Fontana
- Institute of Experimental Immunology, University Hospital Zurich, Haeldeliweg 4, CH 8044 Zurich, Switzerland.
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Tanaka S, Honda M. IgG abnormality in narcolepsy and idiopathic hypersomnia. PLoS One 2010; 5:e9555. [PMID: 20221267 PMCID: PMC2832686 DOI: 10.1371/journal.pone.0009555] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 02/13/2010] [Indexed: 12/02/2022] Open
Abstract
Background A close association between narcolepsy and the Human Leukocyte Antigen (HLA)-DQB1*0602 allele suggests the involvement of the immune system, or possibly an autoimmune process. We investigated serum IgG levels in narcolepsy. Methodology/Principal Findings We measured the serum total IgG levels in 159 Japanese narcolepsy-cataplexy patients positive for the HLA-DQB1*0602 allele, 28 idiopathic hypersomnia patients with long sleep time, and 123 healthy controls (the HLA-DQB1*0602 allele present in 45 subjects). The serum levels of each IgG subclass were subsequently measured. The distribution of serum IgG was significantly different among healthy controls negative for the HLA-DQB1*0602 allele (11.66±3.55 mg/ml), healthy controls positive for the HLA-DQB1*0602 allele (11.45±3.43), narcolepsy patients (9.67±3.38), and idiopathic hypersomnia patients (13.81±3.80). None of the following clinical variables, age, disease duration, Epworth Sleepiness Scale, smoking habit and BMI at the time of blood sampling, were associated with IgG levels in narcolepsy or idiopathic hypersomnia. Furthermore we found the decrease in IgG1 and IgG2 levels, stable expression of IgG3, and the increase in the proportion of IgG4 in narcolepsy patients with abnormally low IgG levels. The increase in the proportion of IgG4 levels was also found in narcolepsy patients with normal serum total IgG levels. Idiopathic hypersomnia patients showed a different pattern of IgG subclass distribution with high IgG3 and IgG4 level, low IgG2 level, and IgG1/IgG2 imbalance. Conclusions/Significance Our study is the first to determine IgG abnormalities in narcolepsy and idiopathic hypersomnia by measuring the serum IgG levels in a large number of hypersomnia patients. The observed IgG abnormalities indicate humoral immune alterations in narcolepsy and idiopathic hypersomnia. Different IgG profiles suggest immunological differences between narcolepsy and idiopathic hypersomnia.
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Affiliation(s)
- Susumu Tanaka
- Research on the Cause and Treatment of Sleep Disorders, Tokyo Institute of Psychiatry, Tokyo, Japan.
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Cvetkovic-Lopes V, Bayer L, Dorsaz S, Maret S, Pradervand S, Dauvilliers Y, Lecendreux M, Lammers GJ, Donjacour CEHM, Du Pasquier RA, Pfister C, Petit B, Hor H, Mühlethaler M, Tafti M. Elevated Tribbles homolog 2-specific antibody levels in narcolepsy patients. J Clin Invest 2010; 120:713-9. [PMID: 20160349 DOI: 10.1172/jci41366] [Citation(s) in RCA: 205] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 01/06/2010] [Indexed: 11/17/2022] Open
Abstract
Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and attacks of muscle atonia triggered by strong emotions (cataplexy). Narcolepsy is caused by hypocretin (orexin) deficiency, paralleled by a dramatic loss in hypothalamic hypocretin-producing neurons. It is believed that narcolepsy is an autoimmune disorder, although definitive proof of this, such as the presence of autoantibodies, is still lacking. We engineered a transgenic mouse model to identify peptides enriched within hypocretin-producing neurons that could serve as potential autoimmune targets. Initial analysis indicated that the transcript encoding Tribbles homolog 2 (Trib2), previously identified as an autoantigen in autoimmune uveitis, was enriched in hypocretin neurons in these mice. ELISA analysis showed that sera from narcolepsy patients with cataplexy had higher Trib2-specific antibody titers compared with either normal controls or patients with idiopathic hypersomnia, multiple sclerosis, or other inflammatory neurological disorders. Trib2-specific antibody titers were highest early after narcolepsy onset, sharply decreased within 2-3 years, and then stabilized at levels substantially higher than that of controls for up to 30 years. High Trib2-specific antibody titers correlated with the severity of cataplexy. Serum of a patient showed specific immunoreactivity with over 86% of hypocretin neurons in the mouse hypothalamus. Thus, we have identified reactive autoantibodies in human narcolepsy, providing evidence that narcolepsy is an autoimmune disorder.
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Affiliation(s)
- Vesna Cvetkovic-Lopes
- Département de Neurosciences Fondamentales, Centre Médical Universitaire, Genève, Switzerland
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Potentiation of a functional autoantibody in narcolepsy by a cholinesterase inhibitor. J Transl Med 2009; 89:1332-9. [PMID: 19806080 DOI: 10.1038/labinvest.2009.108] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
We have recently reported the presence of an immunoglobulin G (IgG) autoantibody (Ab) in patients with narcolepsy with cataplexy that abolishes spontaneous colonic migrating motor complexes (CMMCs) and increases smooth muscle tension and atropine-sensitive phasic contractions in a physiological assay of an isolated colon. In this study, we used the cholinesterase inhibitor, neostigmine, to explore the mechanism of the narcoleptic IgG-mediated disruption of enteric motor function in four patients with narcolepsy with cataplexy and to identify a pharmacological mimic of the Ab. Neostigmine potentiated the narcoleptic IgG-mediated increase in smooth muscle resting tension and phasic smooth muscle contractions by an atropine-sensitive mechanism but exerted no effect on resting tension in the presence of control IgG. Decreased frequency of CMMCs mediated by IgG with anti-M3R activity was reversed by neostigmine. Therefore, a challenge with a cholinesterase inhibitor improves the specificity of the CMMC assay for narcoleptic IgG. Tetrodotoxin (TTX), a neuronal sodium channel blocker, also abolished CMMCs and increased resting tone, and a similar potentiation was observed with neostigmine; thus, TTX is a mimic of the functional effects of the narcoleptic IgG in this bioassay. These findings provide a link to pharmacological studies of canine narcolepsy and are consistent with a functional blockade of both excitatory and inhibitory motor neurons by the narcoleptic Ab, similar to the TTX mimic, presumably by binding to an autoantigenic target expressed in both populations of neurons.
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Mignot E, Aran A. The immune system, the brain and narcolepsy. FUTURE NEUROLOGY 2009. [DOI: 10.2217/fnl.09.57] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Emmanuel Mignot
- Department of Psychiatry & Behavioral Sciences, 701 Welch Road, B basement, room 145 Palo Alto, CA 94304–5742, USA
| | - Adi Aran
- Department of Psychiatry & Behavioral Sciences, 701 Welch Road, B basement, room 145 Palo Alto, CA 94304–5742, USA
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Aran A, Lin L, Nevsimalova S, Plazzi G, Hong SC, Weiner K, Zeitzer J, Mignot E. Elevated anti-streptococcal antibodies in patients with recent narcolepsy onset. Sleep 2009; 32:979-83. [PMID: 19725248 DOI: 10.1093/sleep/32.8.979] [Citation(s) in RCA: 229] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
STUDY OBJECTIVES Narcolepsy-cataplexy has long been thought to have an autoimmune origin. Although susceptibility to narcolepsy, like many autoimmune conditions, is largely genetically determined, environmental factors are involved based on the high discordance rate (approximately 75%) of monozygotic twins. This study evaluated whether Streptococcus pyogenes and Helicobacter pylori infections are triggers for narcolepsy. DESIGN Retrospective, case-control. SETTING Sleep centers of general hospitals. PARTICIPANTS 200 patients with narcolepsy/hypocretin deficiency, with a primary focus on recent onset cases and 200 age-matched healthy controls. All patients were DQB1*0602 positive with low CSF hypocretin-1 or had clear-cut cataplexy. MEASUREMENTS AND RESULTS Participants were tested for markers of immune response to beta hemolytic streptococcus (anti-streptolysin O [ASO]; anti DNAse B [ADB]) and Helicobacter pylori [Anti Hp IgG], two bacterial infections known to trigger autoimmunity. A general inflammatory marker, C-reactive protein (CRP), was also studied. When compared to controls, ASO and ADB titers were highest close to narcolepsy onset, and decreased with disease duration. For example, ASO > or = 200 IU (ADB > or = 480 IU) were found in 51% (45%) of 67 patients within 3 years of onset, compared to 19% (17%) of 67 age matched controls (OR = 4.3 [OR = 4.1], P < 0.0005) or 20% (15%) of 69 patients with long-standing disease (OR = 4.0 [OR = 4.8], P < 0.0005]. CRP (mean values) and Anti Hp IgG (% positive) did not differ from controls. CONCLUSIONS Streptococcal infections are probably a significant environmental trigger for narcolepsy.
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Affiliation(s)
- Adi Aran
- Center for Sleep Sciences and Department of Psychiatry, Stanford University School of Medicine, Palo Alto, CA 94304, USA
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