978 resultados para Síndrome de Guillain-Barré


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OBJECTIVE: CNS or peripheral nervous system dysfunction sometimes occurs in Henoch-Schönlein patients. METHODS: We review all Henoch-Schönlein cases published after 1969 with CNS dysfunction without severe hypertension and neuroimaging studies (n = 35), cranial or peripheral neuropathy (n = 15), both CNS and peripheral nervous system dysfunction without severe hypertension (n = 2) or nervous system dysfunction with severe hypertension (n = 2). Forty-four of the 54 patients were <20 years of age. RESULTS: In patients with CNS dysfunction without or with severe hypertension the following presentations were observed in decreasing order of frequency: altered level of consciousness, convulsions, focal neurological deficits, visual abnormalities and verbal disability. Imaging studies disclosed the following lesions: vascular lesions almost always involving two or more vessels, intracerebral haemorrhage, posterior subcortical oedema, diffuse brain oedema and thrombosis of the superior sagittal sinus. Following lesions were noted in the subjects with cranial or peripheral neuropathy without severe hypertension: peroneal neuropathy, peripheral facial palsy, Guillain-Barré syndrome, brachial plexopathy, posterior tibial nerve neuropathy, femoral neuropathy, ulnar neuropathy and mononeuritis multiplex. Persisting signs of either CNS (n = 9) or peripheral (n = 1) nervous system dysfunction were sometimes reported. CONCLUSIONS: In Henoch-Schönlein syndrome, signs of nervous system dysfunction are uncommon but clinically relevant. This review helps clinicians managing Henoch-Schönlein syndrome with nervous system dysfunction.

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Anti-GM1 antibodies are present in some patients with autoimmune neurological disorders. These antibodies are most frequently associated with acute immune neuropathy called Guillain-Barré syndrome (GBS). Some clinical studies associate the presence of these antibodies with poor recovery in GBS. The patients with incomplete recovery have failure of nerve repair, particularly axon regeneration. Our previous work indicates that monoclonal antibodies can inhibit axon regeneration by engaging cell surface gangliosides (Lehmann et al., 2007). We asked whether passive transfer of human anti-GM1 antibodies from patients with GBS modulate axon regeneration in an animal model. Human anti-GM1 antibodies were compared with other GM1 ligands, cholera toxin B subunit and a monoclonal anti-GM1 antibody. Our results show that patient derived anti-GM1 antibodies and cholera toxin beta subunit impair axon regeneration/repair after PNS injury in mice. Comparative studies indicated that the antibody/ligand-mediated inhibition of axon regeneration is dependent on antibody/ligand characteristics such as affinity-avidity and fine specificity. These data indicate that circulating immune effectors such as human autoantibodies, which are exogenous to the nervous system, can modulate axon regeneration/nerve repair in autoimmune neurological disorders such as GBS.

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Die Polyneuropathien sind Komplikationen der Infektion mit dem Human- Immunodeficiency-Virus (HIV). Dazu gehören Polyradikulopathien, distale (sensible) Polyneuropathien, Mono- und Oligoneuropathien und brachiale Neuritiden. Selten gibt es Formen, die sich nicht kategorisieren lassen. In dieser Dissertation präsentieren wir einen aussergewöhnlichen Fall einer bilateralen Neuritis des Nervus vestibulo-cochlearis (N. vestibulocochlearis). In einer ausgedehnten Literaturrecherche ist das erst der dritte beschriebene Fall. Gleichzeitig wurde die Literaturrecherche genutzt, um epidemiologische, klinische und laborchemische Parameter der HIV-assoziierten Polyneuropathien zu analysieren. Dazu wurden Daten von 539 Patientinnen aus 67 Publikationen extrahiert und ausgewertet. Die Daten wurden bezüglich ihrer Qualität gewertet, um den Schlussfolgerungen eine Gewichtung zu geben. Die Literaturanalyse ergab, dass die meisten Daten zu HIVassoziierten – und bezüglich antiretroviraler Therapie (ART) naiven – Polyneuropathien von afrikanischen Patienten stammen. Die meisten europäischen und nordamerikanischen Studien zu diesem Thema wurden vor 1996 publiziert. Polyradikulopathien präsentieren sich typischerweise früh und distale (sensible) Polyneuropathien spät in der HIV-Krankheit. Das Guillain-Barré-Syndrom war das häufigste Krankheitsbild der Polyradikulopathien. Die häufigste Präsentation distaler Polyneuropathien sind Sensibilitätsausfälle an den unteren Extremitäten. Bei den Mono- und Oligoneuropathien hat ein Grossteil der Personen Mononeuropathien, wobei der N. facialis am häufigsten betroffen ist. Die Rolle der ART zur Erholung der Neuropathien konnte nicht beurteilt werden. Unter den HIV-assoziierten Polyneuropathien haben die distalen (sensiblen) Polyneuropathien die schlechtere und die Polyradikulopathien und Mono- oder Oligoneuropathien die bessere Prognose bezüglich Erholung

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The consumption of immunoglobulins (Ig) is increasing due to better recognition of antibody deficiencies, an aging population, and new indications. This review aims to examine the various dosing regimens and research developments in the established and in some of the relevant off-label indications in Europe. The background to the current regulatory settings in Europe is provided as a backdrop for the latest developments in primary and secondary immunodeficiencies and in immunomodulatory indications. In these heterogeneous areas, clinical trials encompassing different routes of administration, varying intervals, and infusion rates are paving the way toward more individualized therapy regimens. In primary antibody deficiencies, adjustments in dosing and intervals will depend on the clinical presentation, effective IgG trough levels and IgG metabolism. Ideally, individual pharmacokinetic profiles in conjunction with the clinical phenotype could lead to highly tailored treatment. In practice, incremental dosage increases are necessary to titrate the optimal dose for more severely ill patients. Higher intravenous doses in these patients also have beneficial immunomodulatory effects beyond mere IgG replacement. Better understanding of the pharmacokinetics of Ig therapy is leading to a move away from simplistic "per kg" dosing. Defective antibody production is common in many secondary immunodeficiencies irrespective of whether the causative factor was lymphoid malignancies (established indications), certain autoimmune disorders, immunosuppressive agents, or biologics. This antibody failure, as shown by test immunization, may be amenable to treatment with replacement Ig therapy. In certain immunomodulatory settings [e.g., idiopathic thrombocytopenic purpura (ITP)], selection of patients for Ig therapy may be enhanced by relevant biomarkers in order to exclude non-responders and thus obtain higher response rates. In this review, the developments in dosing of therapeutic immunoglobulins have been limited to high and some medium priority indications such as ITP, Kawasaki' disease, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, myasthenia gravis, multifocal motor neuropathy, fetal alloimmune thrombocytopenia, fetal hemolytic anemia, and dermatological diseases.

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Multiple sclerosis (MS) is the most common autoimmune disease of the central nerve system and Guillain Barré Syndrome (GBS) is an inflammatory neuropathy involving the peripheral nerves. Anti-myelin immunoglobins may play a role in the demyelination processes of the both diseases. Sulfatide is an abundant glycolipid on myelin and is a candidate target antigen for disease related autoantibodies. The objective of this study was to characterize anti-sulfatide antibodies and compare antibodies from GBS and MS patients with fetal antibodies. Our hypothesis is that some B cells producing disease-associated autoantibodies are derived from or related to B cells of the fetal repertoire. Here we report that reactivity of plasma IgM against sulfatide was elevated in twelve MS patients compared with twelve normal subjects. This result implies that anti-sulfatide antibodies are disease-related. A total of sixteen human B lymphocyte clones producing anti-sulfatide autoantibodies were isolated from MS patients, GBS patients and a human fetus. Seven of the clones were from three MS patients, four of the clones were from three GBS patients and five were from the spleen of a twenty-week human fetus. Sequences have been obtained for the heavy and light chain variable regions (VDJ and VJ regions) of all of the anti-sulfatide immunoglobulins. Seven of the sixteen antibodies used VH3 for the variable region gene of the heavy chain consistent with the rate of VH3 usage in randomly selected B cells. Somatic mutations were significantly more frequent in the patient antibodies than in the fetus and somatic mutations in CDR's (Complementarity Determining Region) were significantly more frequent than in framework regions. No significant difference was found between patients and fetus in length of VH CDRIII. However, it is reported that antibodies from randomly selected normal adult B cells have longer CDRIII lengths than those of the fetus (Sanz I, 1991 Journal of Immunology Sep 1;147(5):1720-9). Our results are consistent with derivation of the precursors of B cells producing these autoantibodies from B cells related to those of the fetal repertoire. These findings are consistent with a model in which quiescent B cells from clones produced early in development undergo proliferation in dysregulated disease states, accumulating somatic mutations and increasing in reactivity toward self-antigens. ^ Epitope mapping and molecular modeling were done to elucidate the relationships between antibody structure and binding characteristics. The autoantibodies were tested for binding activity to three different antigens: sulfatide, galactoceramide and ceramide. Molecular modeling suggests that antibodies with positive charge surrounded by or adjacent to hydrophobic groups in the binding pocket bind to the head of sulfatide via the sulfate group through electrostatic interactions. However, the antibodies with hydrophobic groups separated from positive charges appear to bind to the hydrophobic tail of sulfatide. This observation was supported by a study of the effect of NaCl concentration on antigen binding. The result suggested that electrostatic interactions played a major role in sulfate group binding and that hydrophobic interactions were of greater importance for binding to the ceramide group. Our three-dimensional structure data indicated that epitope specificity of these antibodies is more predictable at the level of tertiary than primary structure and suggested positive selection based on structure occurred in the. formation of those autoantibodies. ^

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The adult skeletal muscle Na+ channel mu1 possesses a highly conserved segment between subunit domains III and IV containing a consensus protein kinase C (PKC) phosphorylation site that, in the neuronal isoform, acts as a master control for "convergent" regulation by PKC and cAMP-dependent protein kinase. It lacks an approximately 200-aa segment between domains I and II though to modulate channel gating. We here demonstrate that mu1 is regulated by PKC (but not cAMP-dependent protein kinase) in a manner distinct from that observed for the neuronal isoforms, suggesting that under the same conditions muscle excitation could be uncoupled from motor neuron input. Maximal phosphorylation by PKC, in the presence of phosphatase inhibitors, reduced peak Na+ currents by approximately 90% by decreasing the maximal conductance, caused a -15 mV shift in the midpoint of steady-state inactivation, and caused a slight speeding of inactivation. Surprisingly, these effects were not affected by mutation of the conserved serine (serine-1321) in the interdomain III-IV loop. the pattern of current suppression and gating modification by PKC resembles the response of muscle Na+ channels to inhibitory factors present in the serum and cerebrospinal fluid of patients with Guillain-Barré syndrome, multiple sclerosis, and idiopathic demyelinating polyradiculoneuritis.

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We conducted a systematic literature review on psychological and behavioral comorbidities in patients with inflammatory neuropathies. In Guillain-Barré syndrome (GBS), psychotic symptoms are reported during early stages in 30% of patients. Typical associations include mechanical ventilation, autonomic dysfunction, inability to communicate, and severe weakness. Anxiety and depression are frequent comorbidities. Anxiety may increase post-hospital admissions and be a predictor of mechanical ventilation. Post-traumatic stress disorder may affect up to 20% of ventilated patients. Sleep disturbances are common in early-stage GBS, affecting up to 50% of patients. In chronic inflammatory demyelinating polyradiculoneuropathy, memory and quality of sleep may be impaired. An independent link between depression and pre-treatment upper limb disability and ascites was reported in POEMS (Polyneuropathy, Organomegaly, Endocrinopathy, M-protein, Skin) syndrome, with an association with early death. Hematological treatment of POEMS appears effective on depression. Published literature on psychological/behavioral manifestations in inflammatory neuropathies remains scarce, and further research is needed. This article is protected by copyright. All rights reserved.

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Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

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Post-transplantation lymphoproliferative disorders (PTLD) arise in the immunosuppressed and are frequently Epstein-Barr virus (EBV) associated. The most common PTLD histological sub-type is diffuse large B-cell lymphoma (EBV+DLBCL-PTLD). Restoration of EBV-specific T-cell immunity can induce EBV+DLBCL-PTLD regression. The most frequent B-cell lymphoma in the immunocompetent is also DLBCL. ‘EBV-positive DLBCL of the elderly’ (EBV+DLBCL) is a rare but well-recognized DLBCL entity that occurs in the overtly immunocompetent, that has an adverse outcome relative to EBV-negative DLBCL. Unlike PTLD (which is classified as viral latency III), literature suggests EBV+DLBCL is typically latency II, i.e. expression is limited to the immuno-subdominant EBNA1, LMP1 and LMP2 EBV-proteins. If correct, this would be a major impediment for T-cell immunotherapeutic strategies. Unexpectedly we observed EBV+DLBCL-PTLD and EBV+DLBCL both shared features consistent with type III EBV-latency, including expression of the immuno-dominant EBNA3A protein. Extensive analysis showed frequent polymorphisms in EBNA1 and LMP1 functionally defined CD8+ T-cell epitope encoding regions, whereas EBNA3A polymorphisms were very rare making this an attractive immunotherapy target. As with EBV+DLBCL-PTLD, the antigen presenting machinery within lymphomatous nodes was intact. EBV+DLBCL express EBNA3A suggesting it is amenable to immunotherapeutic strategies.

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Infection by Epstein-Barr virus (EBV) occurs in approximately 95% of the world s population. EBV was the first human virus implicated in oncogenesis. Characteristic for EBV primary infection are detectable IgM and IgG antibodies against viral capsid antigen (VCA). During convalescence the VCA IgM disappears while the VCA IgG persists for life. Reactivations of EBV occur both among immunocompromised and immunocompetent individuals. In serological diagnosis, measurement of avidity of VCA IgG separates primary from secondary infections. However, in serodiagnosis of mononucleosis it is quite common to encounter, paradoxically, VCA IgM together with high-avidity VCA IgG, indicating past immunity. We determined the etiology of this phenomenon and found that, among patients with cytomegalovirus (CMV) primary infection a large proportion (23%) showed antibody profiles of EBV reactivation. In contrast, EBV primary infection did not appear to induce immunoreactivation of CMV. EBV-associated post-transplant lymphoproliferative disease (PTLD) is a life threatening complication of allogeneic stem cell or solid organ transplantation. PTLD may present with a diverse spectrum of clinical symptoms and signs. Due to rapidity of PTLD progression especially after stem cell transplantation, the diagnosis must be obtained quickly. Pending timely detection, the evolution of the fatal disease may be halted by reduction of immunosuppression. A promising new PTLD treatment (also in Finland) is based on anti-CD-20 monoclonal antibodies. Diagnosis of PTLD has been demanding because of immunosuppression, blood transfusions and the latent nature of the virus. We set up in 1999 to our knowledge first in Finland for any microbial pathogen a real-time quantitative PCR (qPCR) for detection of EBV DNA in blood serum/plasma. In addition, we set up an in situ hybridisation assay for EBV RNA in tissue sections. In collaboration with a group of haematologists at Helsinki University Central Hospital we retrospectively determined the incidence of PTLD among 257 allogenic stem cell transplantations (SCT) performed during 1994-1999. Post-mortem analysis revealed 18 cases of PTLD. From a subset of PTLD cases (12/18) and a series of corresponding controls (36), consecutive samples of serum were studied by the new EBV-qPCR. All the PTLD patients were positive for EBV-DNA with progressively rising copy numbers. In most PTLD patients EBV DNA became detectable within 70 days of SCT. Of note, the appearance of EBV DNA preceded the PTLD symptoms (fever, lymphadenopathy, atypical lymphocytes). Among the SCT controls, EBV DNA occurred only sporadically, and the EBV-DNA levels remained relatively low. We concluded that EBV qPCR is a highly sensitive (100%) and specific (96%) new diagnostic approach. We also looked for and found risk factors for the development of PTLD. Together with a liver transplantation group at the Transplantation and Liver Surgery Clinic we wanted to clarify how often and how severely do EBV infections occur after liver transplantation. We studied by the EBV qPCR 1284 plasma samples obtained from 105 adult liver transplant recipients. EBV DNA was detected in 14 patients (13%) during the first 12 months. The peak viral loads of 13 asymptomatic patients were relatively low (<6600/ml), and EBV DNA subsided quickly from circulation. Fatal PTLD was diagnosed in one patient. Finally, we wanted to determine the number and clinical significance of EBV infections of various types occurring among a large, retrospective, nonselected cohort of allogenic SCT recipients. We analysed by EBV qPCR 5479 serum samples of 406 SCT recipients obtained during 1988-1999. EBV DNA was seen in 57 (14%) patients, of whom 22 (5%) showed progressively rising and ultimately high levels of EBV DNA (median 54 million /ml). Among the SCT survivors, EBV DNA was transiently detectable in 19 (5%) asymptomatic patients. Thereby, low-level EBV-DNA positivity in serum occurs relatively often after SCT and may subside without specific treatment. However, high molecular copy numbers (>50 000) are diagnostic for life-threatening EBV infection. We furthermore developed a mathematical algorithm for the prediction of development of life-threatening EBV infection.

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El presente trabajo fue realizado en la granja avícola "La Trinidad", propiedad de la Empresa perteneciente a la TIP - TOP Industrial S.A. ubicado en el Km. 26 Carretera a Masaya, entrada principal a Nindirí 5 Km al Norte de la comunidad San Francisco, el experimento se realizó entre el 28 de Febrero y 10 de Abril de 1996, se utilizaro n 85.680 pollos de engorde (machos y hembras), de un día de nacido incluyéndose para dichos experimentos cuatro tratamientos con dos repeticiones cada uno, T1 en el cual se aplicó un programa de 23 hrs/luz durante el intervalo de edad de los 12 a los 42 días, T2 a partir de los 15 días a 42 días con un suministro de 23 H/Luz; T3 a partir de 18dlas a 42 días con 23 h/Luz (Tratamiento testigo), T4 entre los 21 días a los 42 días con 23 h/Luz. Las variables estudiadas para el experimento fueron las siguientes: Consumo de Alimento, Peso Vivo, Conversión de Alimento, Ganancia Media Diaria y Mortalidad.