RESUMO
Neuroblastoma is a lethal childhood solid tumor of developing peripheral nerves. Two percent of children with neuroblastoma develop opsoclonus myoclonus ataxia syndrome (OMAS), a paraneoplastic disease characterized by cerebellar and brainstem-directed autoimmunity but typically with outstanding cancer-related outcomes. We compared tumor transcriptomes and tumor-infiltrating T and B cell repertoires from 38 OMAS subjects with neuroblastoma to 26 non-OMAS-associated neuroblastomas. We found greater B and T cell infiltration in OMAS-associated tumors compared to controls and showed that both were polyclonal expansions. Tertiary lymphoid structures (TLSs) were enriched in OMAS-associated tumors. We identified significant enrichment of the major histocompatibility complex (MHC) class II allele HLA-DOB∗01:01 in OMAS patients. OMAS severity scores were associated with the expression of several candidate autoimmune genes. We propose a model in which polyclonal auto-reactive B lymphocytes act as antigen-presenting cells and drive TLS formation, thereby supporting both sustained polyclonal T cell-mediated anti-tumor immunity and paraneoplastic OMAS neuropathology.
Assuntos
Neuroblastoma , Síndrome de Opsoclonia-Mioclonia , Criança , Humanos , Autoimunidade , Neuroblastoma/complicações , Neuroblastoma/metabolismo , Síndrome de Opsoclonia-Mioclonia/complicações , Síndrome de Opsoclonia-Mioclonia/patologia , Autoanticorpos , Genes MHC da Classe II , AtaxiaRESUMO
OBJECTIVE: To determine whether there is an association between nonencephalitic herpes simplex virus 1 (HSV-1) infection and anti-NMDA receptor encephalitis (anti-NMDARE). METHODS: Antibody testing was performed using samples from 2 cohorts in a case-control observational study. The cohort "Philadelphia" included 16 serum samples of pediatric anti-NMDARE cases and 42 age-matched controls with other neuroinflammatory disorders studied at the Children's Hospital of Philadelphia and University of Pennsylvania. The cohort "Barcelona" contained 23 anti-NMDARE patient samples and 26 age-matched participants with other neuroinflammatory disorders studied at IDIBAPS-Hospital Clinic, University of Barcelona. The presence of HSV-1 IgG antibodies was examined by ELISA. As an additional control, IgG antibodies to cytomegalovirus (CMV) and Epstein-Barr virus viral capsid antigen (EBV-VCA) were determined. RESULTS: In each cohort, more participants with anti-NMDARE than controls had anti-HSV-1 IgG antibodies. In the Philadelphia cohort (58 participants), 44% of anti-NMDARE cases had antibodies to HSV-1 compared with 14% controls (OR 4.67, 95% CI 1.3-17.3, p = 0.031). In the Barcelona cohort (49 participants), 52% of participants with anti-NMDARE had antibodies to HSV-1 compared with 31% of controls (OR 2.45, 95% CI 0.7-7.9, p = 0.155). Overall, 49% of anti-NMDARE cases have antibodies to HSV-1 in these 2 combined cohorts compared with 21% of controls (Mantel-Haenszel OR 3.21, 95% CI 1.3-7.7, p = 0.007). CONCLUSION: Past HSV-1 infection was found in significantly more anti-NMDARE cases than controls. This suggests a meaningful association between nonencephalitic HSV-1 infection and development of anti-NMDARE.
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In slightly more than 10 years, anti-NMDA receptor (NMDAR) encephalitis has changed from a rare paraneoplastic syndrome to the most common cause of nonviral encephalitis. It presents fulminantly with progressive psychosis, seizures, and autonomic dysfunction, leading to death if untreated. However, rapid recognition and treatment can lead to survival and a return to baseline levels of functioning in many patients. While initially associated with ovarian teratomas, it is now associated with other tumors and can reflect a postviral event. The antibodies to the NMDAR made in this syndrome are pathogenic and are directed at the extracellular domain of the GluN1 subunit. Such antibodies lead to internalization of NMDARs in model systems, leading to a physiological state characterized by NMDAR hypofunction. Analogous disorders, characterized by antibodies to other synaptic receptors, present with neurological and psychiatric dysfunction and also appear to reflect antibody-induced internalization of receptors. However, this simple pathophysiology may be too simplistic to reflect the complexity of events in anti-NMDAR encephalitis. Future scientific investigations may allow a more complete understanding of this disorder and improve treatment of anti-NMDAR encephalitis.
Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato/patologia , Animais , Encefalite Antirreceptor de N-Metil-D-Aspartato/fisiopatologia , Humanos , Modelos Biológicos , Receptores de N-Metil-D-Aspartato/metabolismoRESUMO
Certain mutations can cause proteins to accumulate in neurons, leading to neurodegeneration. We recently showed, however, that upregulation of a wild-type protein, Ataxin1, caused by haploinsufficiency of its repressor, the RNA-binding protein Pumilio1 (PUM1), also causes neurodegeneration in mice. We therefore searched for human patients with PUM1 mutations. We identified eleven individuals with either PUM1 deletions or de novo missense variants who suffer a developmental syndrome (Pumilio1-associated developmental disability, ataxia, and seizure; PADDAS). We also identified a milder missense mutation in a family with adult-onset ataxia with incomplete penetrance (Pumilio1-related cerebellar ataxia, PRCA). Studies in patient-derived cells revealed that the missense mutations reduced PUM1 protein levels by â¼25% in the adult-onset cases and by â¼50% in the infantile-onset cases; levels of known PUM1 targets increased accordingly. Changes in protein levels thus track with phenotypic severity, and identifying posttranscriptional modulators of protein expression should identify new candidate disease genes.
Assuntos
Deficiências do Desenvolvimento/genética , Predisposição Genética para Doença , Haploinsuficiência/genética , Mutação/genética , Proteínas de Ligação a RNA/genética , Convulsões/genética , Adolescente , Adulto , Idade de Início , Idoso de 80 Anos ou mais , Animais , Sequência de Bases , Criança , Pré-Escolar , Deficiências do Desenvolvimento/diagnóstico por imagem , Evolução Molecular , Feminino , Deleção de Genes , Células HEK293 , Humanos , Lactente , Masculino , Camundongos , Pessoa de Meia-Idade , Mutação de Sentido Incorreto/genética , Neurônios/metabolismo , Neurônios/patologia , Linhagem , Estabilidade Proteica , Convulsões/diagnóstico por imagemRESUMO
Purpose: No previous clinical trial has been conducted for patients with neuroblastoma associated opsoclonus myoclonus ataxia syndrome (OMA), and current treatment is based on case reports. To evaluate the OMA response to prednisone and risk-adapted chemotherapy and determine if the addition of intravenous gammaglobulin (IVIG) further improves response, the Children's Oncology Group designed a randomized therapeutic trial. Patient and Methods: Eligible subjects were randomized to receive twelve cycles of IVIG (IVIG+) or no IVIG (NO-IVIG) in addition to prednisone and neuroblastoma risk-adapted chemotherapy. All low-risk patients were treated with cyclophosphamide. The severity of OMA symptoms was evaluated at 2, 6, and 12 months using a scale developed by Mitchell and Pike and baseline versus best response scores were compared. A single patient who did not undergo neurologic assessment was excluded from OMA response analysis. This study is registered with Clinical Trials.gov (identifier NCT00033293). Results: Of the 53 patients enrolled in the study, 62% (33/53) were female. There were 44 low-risk, 7 intermediate-risk, and 2 high-risk neuroblastoma patients. Twenty-six subjects were randomized to receive IVIG+ and 27 were randomized to NO-IVIG. The neuroblastoma 3-year event-free survival (95% confidence interval (CI)) was 94.1% (87.3%, 100%) and overall survival was 98.0% (94.1%, 100%). Significantly higher rates of OMA response were observed in patients randomized to IVIG+ compared to NO-IVIG [21/26=80.8% for IVIG+; 11/27=40.7% for NO-IVIG (odds ratio=6.1; 95% CI: (1.5, 25.9), p=0.0029)]. For the majority of patients, the IVIG+ OMA regimen combined with cytoxan or other risk-based chemotherapy was well tolerated, although there was one toxic death in a high-risk subject. Conclusion: This is the only randomized prospective therapeutic clinical trial in children with neuroblastoma-associated OMA. The addition of IVIG to prednisone and risk-adapted chemotherapy significantly improves OMA response rate. IVIG+ constitutes a back-bone upon which to build additional therapy.
Assuntos
Anti-Inflamatórios , Imunoglobulinas Intravenosas , Neuroblastoma , Síndrome de Opsoclonia-Mioclonia , Prednisona , Anti-Inflamatórios/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ataxia/tratamento farmacológico , Ataxia/etnologia , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Lactente , Masculino , Neuroblastoma/complicações , Exame Neurológico , Síndrome de Opsoclonia-Mioclonia/tratamento farmacológico , Síndrome de Opsoclonia-Mioclonia/etiologia , Prednisona/uso terapêutico , Índice de Gravidade de DoençaRESUMO
Opsoclonus myoclonus ataxia syndrome (OMAS) is an autoimmune disorder characterized by rapid, random, conjugate eye movements (opsoclonus), myoclonus, and ataxia. Given these symptoms, autoantibodies targeting the cerebellum or brainstem could mediate the disease or be markers of autoimmunity. In a subset of patients with OMAS, we identified such autoantibodies, which bind to non-synaptic puncta on the surface of live cultured cerebellar and brainstem neuronal dendrites. These findings implicate autoimmunity to a neuronal surface antigen in the pathophysiology of OMAS. Identification of the targeted antigen(s) could elucidate the mechanisms underlying OMAS and provide a biomarker for diagnosis and response to therapy.
Assuntos
Antígenos de Superfície/imunologia , Dendritos/metabolismo , Neurônios/citologia , Síndrome de Opsoclonia-Mioclonia/imunologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Autoanticorpos/sangue , Autoanticorpos/líquido cefalorraquidiano , Tronco Encefálico/citologia , Células Cultivadas , Cerebelo/citologia , Criança , Pré-Escolar , Dendritos/efeitos dos fármacos , Proteína 4 Homóloga a Disks-Large , Proteínas ELAV/metabolismo , Embrião de Mamíferos , Guanilato Quinases/metabolismo , Humanos , Lactente , Proteínas de Membrana/metabolismo , Camundongos , Pessoa de Meia-Idade , Neurônios/efeitos dos fármacos , Síndrome de Opsoclonia-Mioclonia/sangue , Síndrome de Opsoclonia-Mioclonia/líquido cefalorraquidiano , Ratos , Adulto JovemRESUMO
In the majority of pediatric anti-N-methyl-d-aspartate receptor encephalitis (NMDARe) cases, the underlying cause of antibody production and subsequent disease remains unknown. We aimed to characterize this poorly understood population, investigating epidemiological factors potentially related to disease etiology, particularly season of onset. In this retrospective case review study, we analyzed data from the 29 pediatric subjects with anti-NMDAR antibodies and found that symptoms were first reported in the warm months of April-September in 78% of non-tumor-related NMDARe (NT-NMDARe) cases. These findings support further investigation into a possible seasonal trigger of NT-NMDARe.
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OBJECTIVE: To retrospectively determine the frequency of N-Methyl-D-Aspartate (NMDA) receptor (NMDAR) autoantibodies in patients with different forms of dementia. METHODS: Clinical characterization of 660 patients with dementia, neurodegenerative disease without dementia, other neurological disorders and age-matched healthy controls combined with retrospective analysis of serum or cerebrospinal fluid (CSF) for the presence of NMDAR antibodies. Antibody binding to receptor mutants and the effect of immunotherapy were determined in a subgroup of patients. RESULTS: Serum NMDAR antibodies of IgM, IgA, or IgG subtypes were detected in 16.1% of 286 dementia patients (9.5% IgM, 4.9% IgA, and 1.7% IgG) and in 2.8% of 217 cognitively healthy controls (1.9% IgM and 0.9% IgA). Antibodies were rarely found in CSF. The highest prevalence of serum antibodies was detected in patients with "unclassified dementia" followed by progressive supranuclear palsy, corticobasal syndrome, Parkinson's disease-related dementia, and primary progressive aphasia. Among the unclassified dementia group, 60% of 20 patients had NMDAR antibodies, accompanied by higher frequency of CSF abnormalities, and subacute or fluctuating disease progression. Immunotherapy in selected prospective cases resulted in clinical stabilization, loss of antibodies, and improvement of functional imaging parameters. Epitope mapping showed varied determinants in patients with NMDAR IgA-associated cognitive decline. INTERPRETATION: Serum IgA/IgM NMDAR antibodies occur in a significant number of patients with dementia. Whether these antibodies result from or contribute to the neurodegenerative disorder remains unknown, but our findings reveal a subgroup of patients with high antibody levels who can potentially benefit from immunotherapy.
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Despite the introduction of almost 20 new antiseizure drugs in the last several decades, approximately 30% of patients with epilepsy have pharmacoresistant seizures. Although many genetic disorders and cerebral structural lesions are known causes of difficult-to-treat epilepsy, some refractory patients do not fall into these categories. In the search for other etiologic factors, the multiple and close interactions between the immune system and epilepsy have gained substantial interest.(1.)
Assuntos
Epilepsia/imunologia , Epilepsia/terapia , Imunoterapia/métodos , HumanosRESUMO
OBJECTIVE: Anti-AMPAR encephalitis is a recently discovered disorder characterized by the presence of antibodies in serum or cerebrospinal fluid against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor. Here, we examine the antigenic specificity of anti-AMPAR antibodies, screen for new patients, and evaluate functional effects of antibody treatment of neurons. METHODS: We developed a fusion protein-based western blotting test for anti-AMPAR encephalitis antibodies. Antibody specificity was also evaluated using immunocytochemistry of HEK293 cells expressing deletion mutants of AMPAR subunits. Purified patient IgG or AMPAR antibody-depleted IgG was applied to live neuronal cultures; amplitude and frequency of miniature excitatory postsynaptic currents (mEPSCs) were measured to evaluate functional effects of antibodies. RESULTS: Using both immunocytochemistry and fusion protein western blots, we defined an antigenic region of the receptor in the bottom lobe of the amino terminal domain. Additionally, we used fusion proteins to screen 70 individuals with neurologic symptoms of unknown cause and 44 patients with no neurologic symptoms or symptoms of known neuroimmunological origin for anti-AMPAR antibodies. Fifteen of the 70 individuals had anti-AMPAR antibodies, with broader antigenic reactivity patterns. Using purified IgG from an individual of the original cohort of anti-AMPAR encephalitis patients and a newly discovered patient, we found that application of IgG from either patient cohort caused an AMPAR antibody-dependent decrease in the amplitude and frequency of mEPSCs in cultured neurons. INTERPRETATION: These results indicate that anti-AMPAR antibodies are widespread and functionally relevant; given the robust response of patients to immunomodulation, this represents a significant treatable patient population.
RESUMO
Autoimmune responses targeting synaptic proteins are associated with a wide range of neurologic symptoms. Among these disorders are those associated with antibodies to ionotropic glutamate receptors, including the NMDAR (N-methyl-D-aspartate receptor) and AMPAR (α-amino-3-hydrozy-5-methyl-4-isoxazolepropionic acid receptor). Patients with anti-NMDAR encephalitis present with psychiatric symptoms, seizures, movement disorders, impaired consciousness, and autonomic derangements; half of patients have an associated ovarian teratoma, and most patients respond to immunosuppressive therapies. Patients' antibodies bind to the amino terminal domain of the NMDAR, and result in loss of NMDARs from synapses with subsequent NMDAR hypofunction. Anti-NMDAR antibodies have now been reported in other neuropsychiatric conditions, including psychosis, dementia, and HSV encephalitis. The pathophysiologic relevance of anti-NMDAR antibodies in these disorders is not yet clear, but their presence may indicate a role for immunotherapy in some patients. Although considerable work remains to be done, our understanding of disorders associated with anti-glutamate receptor antibodies has grown exponentially since they were first described just over 7 years ago, revolutionizing neurology. These antibodies, by interfering with synaptic function, readily link basic science and clinical medicine, and have revealed the impact of sudden but sustained loss of specific neurotransmitter receptors in humans. Improved understanding of their pathophysiology will lead to better treatments for these diseases while providing novel insights regarding the roles of glutamate receptors in learning, memory, and neuropsychiatric disease.
Assuntos
Encefalite Antirreceptor de N-Metil-D-Aspartato/fisiopatologia , Encefalopatias/fisiopatologia , Doença de Hashimoto/fisiopatologia , Receptores de AMPA/imunologia , Animais , Encefalite Antirreceptor de N-Metil-D-Aspartato/tratamento farmacológico , Encefalopatias/tratamento farmacológico , Encefalite , Ácido Glutâmico/metabolismo , Doença de Hashimoto/tratamento farmacológico , HumanosRESUMO
Status epilepticus (SE) describes persistent or recurring seizures without a return to baseline mental status and is a common neurologic emergency. SE can occur in the context of epilepsy or may be symptomatic of a wide range of underlying etiologies. The clinician's aim is to rapidly institute care that simultaneously stabilizes the patient medically, identifies and manages any precipitant conditions, and terminates seizures. Seizure management involves "emergent" treatment with benzodiazepines followed by "urgent" therapy with other antiseizure medications. If seizures persist, then refractory SE is diagnosed and management options include additional antiseizure medications or infusions of midazolam or pentobarbital. This article reviews the management of pediatric SE and refractory SE.
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Anticonvulsivantes/uso terapêutico , Estado Epiléptico/tratamento farmacológico , Criança , HumanosRESUMO
Congenital disorder of glycosylation type IIc (CDG IIc) is characterized by mental retardation, slowed growth and severe immunodeficiency, attributed to the lack of fucosylated glycoproteins. While impaired Notch signaling has been implicated in some aspects of CDG IIc pathogenesis, the molecular and cellular mechanisms remain poorly understood. We have identified a zebrafish mutant slytherin (srn), which harbors a missense point mutation in GDP-mannose 4,6 dehydratase (GMDS), the rate-limiting enzyme in protein fucosylation, including that of Notch. Here we report that some of the mechanisms underlying the neural phenotypes in srn and in CGD IIc are Notch-dependent, while others are Notch-independent. We show, for the first time in a vertebrate in vivo, that defects in protein fucosylation leads to defects in neuronal differentiation, maintenance, axon branching, and synapse formation. Srn is thus a useful and important vertebrate model for human CDG IIc that has provided new insights into the neural phenotypes that are hallmarks of the human disorder and has also highlighted the role of protein fucosylation in neural development.
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Defeitos Congênitos da Glicosilação/genética , Modelos Animais de Doenças , Hidroliases/genética , Sistema Nervoso/metabolismo , Sinapses/metabolismo , Sequência de Aminoácidos , Animais , Glicosilação , Humanos , Hibridização In Situ , Dados de Sequência Molecular , Mutação de Sentido Incorreto , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Peixe-ZebraRESUMO
In humans, mutations in electron transfer flavoprotein (ETF) or electron transfer flavoprotein dehydrogenase (ETFDH) lead to MADD/glutaric aciduria type II, an autosomal recessively inherited disorder characterized by a broad spectrum of devastating neurological, systemic and metabolic symptoms. We show that a zebrafish mutant in ETFDH, xavier, and fibroblast cells from MADD patients demonstrate similar mitochondrial and metabolic abnormalities, including reduced oxidative phosphorylation, increased aerobic glycolysis, and upregulation of the PPARG-ERK pathway. This metabolic dysfunction is associated with aberrant neural proliferation in xav, in addition to other neural phenotypes and paralysis. Strikingly, a PPARG antagonist attenuates aberrant neural proliferation and alleviates paralysis in xav, while PPARG agonists increase neural proliferation in wild type embryos. These results show that mitochondrial dysfunction, leading to an increase in aerobic glycolysis, affects neurogenesis through the PPARG-ERK pathway, a potential target for therapeutic intervention.
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Deficiência Múltipla de Acil Coenzima A Desidrogenase/metabolismo , Deficiência Múltipla de Acil Coenzima A Desidrogenase/patologia , Sistema Nervoso/metabolismo , Sistema Nervoso/patologia , Peixe-Zebra/metabolismo , Animais , Ácidos Carboxílicos/metabolismo , Carnitina/análogos & derivados , Carnitina/sangue , Proliferação de Células/efeitos dos fármacos , Clonagem Molecular , Flavoproteínas Transferidoras de Elétrons/genética , Ativação Enzimática/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Glicólise/efeitos dos fármacos , Humanos , Lactente , Recém-Nascido , Proteínas Ferro-Enxofre/genética , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Mutação/genética , Sistema Nervoso/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/enzimologia , Neurônios/patologia , Oligonucleotídeos Antissenso/farmacologia , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , FenótipoAssuntos
Junção Neuromuscular/fisiologia , Plasticidade Neuronal/fisiologia , Sinapses/fisiologia , Agrina/fisiologia , Animais , Axônios/fisiologia , Regulação da Expressão Gênica , Humanos , Neurônios Motores/fisiologia , Proteínas Musculares/fisiologia , Receptores Proteína Tirosina Quinases/fisiologia , Receptores Colinérgicos/genética , Receptores Colinérgicos/fisiologiaRESUMO
Little is known about the spatial and temporal dynamics of presynaptic and postsynaptic specializations that culminate in synaptogenesis. Here, we imaged presynaptic vesicle clusters in motor axons and postsynaptic acetylcholine receptor (AChR) clusters in embryonic zebrafish to study the earliest events in synaptogenesis in vivo. Prepatterned AChR clusters are present on muscle fibers in advance of motor axon outgrowth from the spinal cord. Motor axon growth cones and filopodia are selectively extended toward and contact prepatterned AChR clusters, followed by the rapid clustering of presynaptic vesicles and insertion of additional AChRs, hallmarks of synaptogenesis. All initially formed neuromuscular synapses contain AChRs that were inserted into the membrane at the time the prepattern is present. Examination of embryos in which AChRs were blocked or clustering is absent showed that neither receptor activity or receptor protein is required for these events to occur. Thus, during initial synaptogenesis, postsynaptic differentiation precedes presynaptic differentiation, and prepatterned neurotransmitter clusters mark sites destined for synapse formation.