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1.
Acta Neurol Scand ; 138(3): 219-226, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29736936

RESUMO

OBJECTIVES: Myasthenia gravis (MG) represents a spectrum of clinical subtypes with differences in disease mechanisms and treatment response. MG with muscle-specific tyrosine kinase (MuSK) antibodies accounts for 1%-10% of all MG patients. We conducted a meta-analysis to evaluate the association between HLA genes and MuSK-MG susceptibility. SUBJECTS AND METHODS: Studies were searched in Pubmed, EMBASE database and other sources between 2001 and 2018. Genotype, allele and haplotype frequencies of HLA loci in MuSK-MG patients and healthy controls were extracted from each included study. RESULTS: The meta-analysis showed that HLA DQB1*05, DRB1*14 and DRB1*16 were strongly associated with an increased risk of MuSK-MG (P < .0001), whereas HLA DQB*03 was less frequent in MuSK patients compared with healthy controls (P < .05). Haplotype analysis showed that these DQB1 and DRB1 alleles were closely linked, forming both risk (DQ5-DR14, DQ5-DR16, P < .0001) and protective (DQ3-DR4, DQ3-DR11, P < .05) haplotypes. CONCLUSION: The distinct genetic patterns of MuSK-MG indicate that variation in HLA class II genes plays an important role in the pathogenesis of MuSK-MG patients.


Assuntos
Predisposição Genética para Doença/genética , Antígenos de Histocompatibilidade Classe II/genética , Miastenia Gravis/genética , Receptores Proteína Tirosina Quinases/imunologia , Receptores Colinérgicos/imunologia , Alelos , Feminino , Frequência do Gene , Genótipo , Haplótipos , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Miastenia Gravis/imunologia
2.
Eur J Neurol ; 24(6): 844-850, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28470860

RESUMO

BACKGROUND AND PURPOSE: Myasthenia gravis (MG) is an autoimmune disease caused by antibody mediated impairment in the neuromuscular junction. Seronegative MG (SNMG) without antibodies against acetylcholine receptor (AChR) and muscle-specific kinase (MuSK) by routine assays accounts for about 20% of all MG patients. METHODS: Plasma from 81 Chinese MG patients previously found to be seronegative was tested by routine assays for AChR and MuSK antibodies. These samples were screened by (i) a novel, highly sensitive radioimmunoassay for AChR antibodies; (ii) cell-based assays for clustered AChR, MuSK and lipoprotein receptor-related protein 4 (LRP4) antibodies; (iii) a radioimmunoassay for titin antibodies. RESULTS: Antibodies to AChR, MuSK, LRP4 and titin were found in 25% (20/81), 4% (3/81), 7% (6/81) and 6% (5/78) of SNMG patients, respectively. In total, 37% of SNMG patients were found to be positive for at least one of the tested antibodies. AChR antibody positive patients had more severe disease (P = 0.008) and a trend towards fewer remissions/minimal manifestations than AChR antibody negative patients. The four patients with coexistence of antibodies had more severe disease, whilst the seronegative patients had milder MG (P = 0.015). CONCLUSIONS: Detection of multiple muscle antibodies by more sensitive assays provides additional information in diagnosing and subgrouping of MG and may guide MG treatment.


Assuntos
Autoanticorpos/sangue , Conectina/imunologia , Proteínas Relacionadas a Receptor de LDL/imunologia , Miastenia Gravis/imunologia , Receptores Proteína Tirosina Quinases/imunologia , Receptores Colinérgicos/imunologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/sangue , Radioimunoensaio , Adulto Jovem
3.
Acta Neurol Scand ; 128(2): 107-13, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23190324

RESUMO

OBJECTIVES: There are limited data on treatment effect in early and drug-naïve Parkinson's disease (PD) outside of clinical trials. We sought to review the treatment effects on motor symptoms in early, unselected PD patients. METHODS: We included 183 drug-naïve patients from a longitudinal cohort (The Norwegian ParkWest study). At the time of diagnosis, motor symptoms were assessed and rated. Treatment was unrestricted, aimed at treating each patient optimally. Patients were reassessed after 12 months, and then grouped according to treatment: No dopaminergic treatment (NDT), dopamine agonists (DA) or levodopa. All strategies could be combined with monoamine oxidase B inhibitors. RESULTS: In general, the chosen treatment was coherent with current practice. During follow-up, patients given NDT (n = 40) had unaltered clinical motor symptoms, as opposed to improvement in the DA- and levodopa-treated patients (n = 140). The overall improvement in these two groups was fairly similar, but axial symptoms did not improve in levodopa-treated patients as opposed to the younger DA-treated patients. CONCLUSIONS: Twelve months after the diagnosis, motor symptoms in approximately one-fifth of PD patients remained clinically stable. Tremor, bradykinesia and rigidity improved in the dopaminergic-treated patients. Axial symptoms were more treatment resistant, and the different symptomatic effects found between treatment strategies may be age related.


Assuntos
Antiparkinsonianos/uso terapêutico , Doença de Parkinson/terapia , Atividades Cotidianas , Idoso , Estudos de Coortes , Dopaminérgicos/uso terapêutico , Feminino , Humanos , Levodopa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Noruega , Doença de Parkinson/epidemiologia , Doença de Parkinson/psicologia , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
4.
Acta Neurol Scand ; 127(4): 290-4, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22998158

RESUMO

OBJECTIVES: Autonomic symptoms are present in early stages of Parkinson's disease (PD), but evidence on how they are influenced by dopaminergic treatment remains unclear. The aim of this study was to investigate the impact of dopaminergic treatment on autonomic symptoms in early PD in a population-based cohort. METHODS: A total of 171 drug-naive patients with PD were investigated at diagnosis and 12 months later. Orthostatic blood pressure was measured, and autonomic symptoms were assessed by a preliminary version of the Movement Disorders Society-sponsored new version of the Unified Parkinson's Disease Rating Scale (range 0-4). RESULTS: In the 82% using dopaminergic treatment after 1 year, constipation and orthostatic blood pressure drop increased. There was a tendency towards increased orthostatic dizziness and urinary dysfunction. Dysphagia scores were reduced, and this was associated with higher levodopa-equivalent daily dose. CONCLUSIONS: Dopaminergic treatment during the first year after initiation seems to have only a minor impact on autonomic symptoms in early PD. It may increase constipation and orthostatic dizziness, while dysphagia can improve. Autonomic symptoms remained mild after 1 year of dopaminergic treatment.


Assuntos
Antiparkinsonianos/uso terapêutico , Doenças do Sistema Nervoso Autônomo/tratamento farmacológico , Doenças do Sistema Nervoso Autônomo/etiologia , Dopaminérgicos/uso terapêutico , Doença de Parkinson/complicações , Doença de Parkinson/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Resultado do Tratamento
5.
Mov Disord ; 25(12): 1847-52, 2010 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-20669310

RESUMO

Both environmental and genetic factors contribute to the development of Parkinson's disease (PD). We have examined environmental risk factors in a Norwegian population of incident PD patients and controls, the Norwegian ParkWest study. All five neurological wards in the study area of Western Norway participated in the study. A 4-step diagnostic procedure was used to establish a representative cohort of patients with incident PD at a high level of diagnostic accuracy. 212 incident PD patients and 175 age- and gender-matched controls were included. PD patients and controls were asked for information on occupation, education, exposure to pesticides, tobacco, alcohol, and caffeine. Agricultural work was associated with a higher risk of PD (OR 1.75 (1.03-3.0) P = 0.009). There were no differences as to other occupations. Smoking (OR 0.63 (0.42-0.95) P = 0.016) and alcohol use (OR 0.55 P = 0.008) were associated with a lower risk for PD. Interestingly, this inverse association was only seen in postural instability gait difficulties (PIGD) PD (P = 0.046 for smoking, P = 0.07 for alcohol consumption), and not in tremor dominant (TD) PD which was similar to controls. Consumption of coffee was lower in PD patients (3.3 ± 1.8 cups per day vs. 3.8 ± 2.0 in controls P = 0.02). In the regression model including intake of alcohol, coffee, and smoke, only coffee (P = 0.007) and alcohol intake (P = 0.021) remained significant whereas smoking was no longer significant. Thus, it seems as though only coffee intake reduces the risk of PD in general while associations to alcohol and smoking differ between PIGD and TD-PD patients.


Assuntos
Marcha , Doença de Parkinson/etiologia , Equilíbrio Postural , Consumo de Bebidas Alcoólicas/efeitos adversos , Café/efeitos adversos , Comportamento de Ingestão de Líquido , Humanos , Doença de Parkinson/fisiopatologia , Análise de Regressão , Fatores de Risco , Índice de Gravidade de Doença , Fumar/efeitos adversos , Estatísticas não Paramétricas
6.
Eur J Neurol ; 17(7): 893-902, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20402760

RESUMO

BACKGROUND: Important progress has been made in our understanding of the autoimmune neuromuscular transmission (NMT) disorders; myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS) and neuromyotonia (Isaacs' syndrome). METHODS: To prepare consensus guidelines for the treatment of the autoimmune NMT disorders, references retrieved from MEDLINE, EMBASE and the Cochrane Library were considered and statements prepared and agreed on by disease experts. CONCLUSIONS: Anticholinesterase drugs should be given first in the management of MG, but with some caution in patients with MuSK antibodies (good practice point). Plasma exchange is recommended in severe cases to induce remission and in preparation for surgery (recommendation level B). IvIg and plasma exchange are effective for the treatment of MG exacerbations (recommendation level A). For patients with non-thymomatous MG, thymectomy is recommended as an option to increase the probability of remission or improvement (recommendation level B). Once thymoma is diagnosed, thymectomy is indicated irrespective of MG severity (recommendation level A). Oral corticosteroids are first choice drugs when immunosuppressive drugs are necessary (good practice point). When long-term immunosuppression is necessary, azathioprine is recommended to allow tapering the steroids to the lowest possible dose whilst maintaining azathioprine (recommendation level A). 3,4-Diaminopyridine is recommended as symptomatic treatment and IvIG has a positive short-term effect in LEMS (good practice point). Neuromyotonia patients should be treated with an antiepileptic drug that reduces peripheral nerve hyperexcitability (good practice point). For paraneoplastic LEMS and neuromyotonia optimal treatment of the underlying tumour is essential (good practice point). Immunosuppressive treatment of LEMS and neuromyotonia should be similar to MG (good practice point).


Assuntos
Doenças Autoimunes/terapia , Protocolos Clínicos/normas , Doenças da Junção Neuromuscular/terapia , Doenças Autoimunes/tratamento farmacológico , Doenças Autoimunes/imunologia , Medicina Baseada em Evidências/métodos , Medicina Baseada em Evidências/tendências , Humanos , Síndrome de Isaacs/tratamento farmacológico , Síndrome de Isaacs/imunologia , Síndrome de Isaacs/terapia , Síndrome Miastênica de Lambert-Eaton/tratamento farmacológico , Síndrome Miastênica de Lambert-Eaton/imunologia , Síndrome Miastênica de Lambert-Eaton/terapia , MEDLINE , Metanálise como Assunto , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/imunologia , Miastenia Gravis/terapia , Doenças da Junção Neuromuscular/tratamento farmacológico , Doenças da Junção Neuromuscular/imunologia , Literatura de Revisão como Assunto
7.
Eur J Neurol ; 15(10): 1029-33, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18717725

RESUMO

Paraneoplastic myasthenia gravis (MG) is accompanied by a neoplasm, usually thymoma. In patients with thymoma and a specific genetic make-up, the paraneoplastic immune response develops further in thymic remnant or peripheral lymphatic tissue. Paraneoplastic MG and late-onset MG (age >or= 50 years) share a similar immunological profile with high titin and ryanodine receptor (RyR) antibody prevalence. This profile is the most important predictor of clinical outcome in paraneoplastic MG. The presence of a thymoma per se does not cause more severe MG. MG severity is linked to the patient's immunological profile. Paraneoplastic MG causes a distinctive non-limb symptom profile at MG onset, characterized by bulbar, ocular, neck, and respiratory symptoms. When the diagnosis of paraneoplastic MG is established, the neoplasm should be removed surgically. Pre-thymectomy plasmapheresis or iv-IgG should be considered in these patients to minimize post-thymectomy MG exacerbation risk. Paraneoplastic MG usually continues after thymectomy. The pharmacological treatment of paraneoplastic MG does not differ from non-paraneoplastic MG, except for tacrolimus that should be considered in difficult cases. Tacrolimus is an immunosuppressant acting specifically in RyR antibody positive patients through enhancing RyR-related sarcoplasmic calcium release that in theory might be blocked by RyR antibodies, causing symptomatic relief in paraneoplastic MG.


Assuntos
Miastenia Gravis/etiologia , Polineuropatia Paraneoplásica/etiologia , Timoma/complicações , Neoplasias do Timo/complicações , Idade de Início , Atrofia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Terapia Combinada , Conectina , Humanos , Hiperplasia , Imunossupressores/uso terapêutico , Pessoa de Meia-Idade , Proteínas Musculares/imunologia , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/epidemiologia , Miastenia Gravis/imunologia , Proteínas do Tecido Nervoso/imunologia , Polineuropatia Paraneoplásica/tratamento farmacológico , Polineuropatia Paraneoplásica/imunologia , Plasmaferese , Prognóstico , Proteínas Quinases/imunologia , Receptores Colinérgicos/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Timectomia , Timoma/imunologia , Timoma/cirurgia , Timo/patologia , Neoplasias do Timo/imunologia , Neoplasias do Timo/cirurgia
8.
Acta Neurol Scand Suppl ; 183: 19-23, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16637922

RESUMO

Some myasthenia gravis (MG) patients have antibodies against skeletal muscle antigens in addition to the acetylcholine receptor (AChR). Two major antigens for non-AchR antibodies in MG are the Ca(2+) release channel of the sarcoplasmic reticulum, the ryanodine receptor (RyR) and titin, a gigantic filamentous muscle protein essential for muscle structure, function and development. RyR and titin antibodies are found mainly in thymoma MG patients and in a few late-onset MG patients and correlate with a severe MG disease. The presence of titin antibodies, which bind to key regions near the A/I junction and in the central I-band, correlates with myopathy. The immunosuppressant (FK506), which enhances Ca(2+) release from the RyR, seems to have a symptomatic effect on MG patients with RyR antibodies. The RyR antibodies recognize a region near the N-terminus important for channel regulation and inhibit Ca(2+) release in vitro. However, evidence that antibodies against the intracellular antigens RyR and titin are pathogenic in vivo is still missing.


Assuntos
Anticorpos/fisiologia , Proteínas Musculares/imunologia , Miastenia Gravis/imunologia , Proteínas Quinases/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Conectina , Humanos , Miastenia Gravis/diagnóstico , Miastenia Gravis/terapia , Índice de Gravidade de Doença
9.
Acta Neurol Scand Suppl ; 183: 28-32, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16637925

RESUMO

OBJECTIVES: To investigate the role of acetylcholine receptor (AChR) and other anti-muscle autoantibodies in myasthenia gravis (MG). Since many of these autoantibodies target proteins with structural or signalling functions, we examined the effect of MG sera on muscle cell morphology. MATERIALS AND METHODS: Primary human myoblast cultures were exposed to MG sera and morphological changes observed by light and fluorescence microscopy. RESULTS: MG patient sera caused changes in cell shape (cell retraction) and led to the formation of inclusion bodies and intracellular vesicles. A disordered arrangement of actin microfilaments was also observed. The effects were not complement-mediated, were both dose- and time-dependent, and appeared to correlate with disease severity of the MG donor. CONCLUSION: The factors responsible for these effects in vitro may also play a role in the pathogenesis of MG in vivo. Further study of these factors may improve our understanding of MG pathogenesis.


Assuntos
Autoanticorpos/fisiologia , Proteínas Musculares/imunologia , Miastenia Gravis/patologia , Mioblastos/patologia , Receptores Colinérgicos/imunologia , Soro/fisiologia , Apoptose/fisiologia , Técnicas de Cultura de Células , Núcleo Celular/patologia , Citoesqueleto/patologia , Humanos , Miastenia Gravis/imunologia
10.
Eur J Neurol ; 13(7): 691-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16834699

RESUMO

Important progress has been made in our understanding of the cellular and molecular processes underlying the autoimmune neuromuscular transmission (NMT) disorders; myasthenia gravis (MG), Lambert-Eaton myasthenic syndrome (LEMS) and neuromyotonia (peripheral nerve hyperexcitability; Isaacs syndrome). To prepare consensus guidelines for the treatment of the autoimmune NMT disorders. References retrieved from MEDLINE, EMBASE and the Cochrane Library were considered and statements prepared and agreed on by disease experts and a patient representative. The proposed practical treatment guidelines are agreed upon by the Task Force: (i) Anticholinesterase drugs should be the first drug to be given in the management of MG (good practice point). (ii) Plasma exchange is recommended as a short-term treatment in MG, especially in severe cases to induce remission and in preparation for surgery (level B recommendation). (iii) Intravenous immunoglobulin (IvIg) and plasma exchange are equally effective for the treatment of MG exacerbations (level A Recommendation). (iv) For patients with non-thymomatous autoimmune MG, thymectomy (TE) is recommended as an option to increase the probability of remission or improvement (level B recommendation). (v) Once thymoma is diagnosed TE is indicated irrespective of the severity of MG (level A recommendation). (vi) Oral corticosteroids is a first choice drug when immunosuppressive drugs are necessary in MG (good practice point). (vii) In patients where long-term immunosuppression is necessary, azathioprine is recommended together with steroids to allow tapering the steroids to the lowest possible dose whilst maintaining azathioprine (level A recommendation). (viii) 3,4-diaminopyridine is recommended as symptomatic treatment and IvIg has a positive short-term effect in LEMS (good practice point). (ix) All neuromyotonia patients should be treated symptomatically with an anti-epileptic drug that reduces peripheral nerve hyperexcitability (good practice point). (x) Definitive management of paraneoplastic neuromyotonia and LEMS is treatment of the underlying tumour (good practice point). (xi) For immunosuppressive treatment of LEMS and NMT it is reasonable to adopt treatment procedures by analogy with MG (good practice point).


Assuntos
Doenças Autoimunes do Sistema Nervoso/terapia , Doenças da Junção Neuromuscular/terapia , Corticosteroides/uso terapêutico , Azatioprina/uso terapêutico , Humanos , Imunossupressores/uso terapêutico , Síndrome Miastênica de Lambert-Eaton/terapia , MEDLINE/estatística & dados numéricos , Miastenia Gravis/terapia , Ácido Micofenólico/análogos & derivados , Ácido Micofenólico/uso terapêutico , Troca Plasmática/métodos , Timectomia/métodos
11.
Arch Neurol ; 57(11): 1596-600, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11074791

RESUMO

BACKGROUND: Myasthenia gravis (MG) is caused by autoantibodies to the acetylcholine receptor (AChR). Non-AChR muscle autoantibodies are present in many MG serum samples, mainly from patients with thymoma or late-onset MG. The exact relationship between MG severity and several non-AChR muscle antibodies is unknown. OBJECTIVE: To study the correlation between the severity of MG and the concentration of antibodies against striated muscle tissue sections, titin, citric acid antigen, ryanodine receptor, and AChR. SETTING: The severity of MG was graded in 146 consecutive patients with MG, and their serum samples were tested for the presence of autoantibodies. Ten patients who were titin antibody positive were observed in longitudinal follow-up. RESULTS: No significant difference was found in MG severity between late-onset and thymoma MG. Titin, citric acid antigen, and ryanodine receptor antibodies occurred significantly more often among patients with severe MG than among patients with less severe disease. Changes in MG severity correlated with changes in titin antibody titer in the individual patient. Titin antibodies showed a better longitudinal correlation with disease severity than the AChR antibodies. CONCLUSIONS: Non-AChR muscle autoantibodies occurred more frequently in severe MG regardless of MG subgroup. Thymoma per se does not generate a more severe MG. It may well be the presence of a humoral immune response to non-AChR muscle antigens such as titin, citric acid antigen, and ryanodine receptor that leads to a severe disease, not the presence of thymoma or a late age of onset. These antibodies can serve as important prognostic markers in MG regardless of the presence of thymoma.


Assuntos
Autoanticorpos/sangue , Ácido Cítrico/imunologia , Proteínas Musculares/imunologia , Músculo Esquelético/imunologia , Miastenia Gravis/imunologia , Proteínas Quinases/imunologia , Receptores Colinérgicos/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Adulto , Idade de Início , Conectina , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Timoma/complicações , Neoplasias do Timo/complicações
12.
Arch Neurol ; 56(4): 457-61, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10199335

RESUMO

BACKGROUND: Tumor necrosis factor (TNF) alpha and TNF-beta are proinflammatory cytokines thought to be involved in the pathogenesis of myasthenia gravis (MG). OBJECTIVE: To examine whether TNF polymorphisms are associated with MG, MG subgroups, and the presence of titin and ryanodine-receptor antibodies. PATIENTS AND METHODS: We did genotyping on 30 patients with MG and 92 healthy blood donors for 2 biallelic TNFA polymorphisms (G to A at positions -238 and -308) and 1 TNFB polymorphism (NcoI digestive site) using methods based on the polymerase chain reaction. RESULTS: Patients with thymoma were typically homozygous for both the TNFA*T1 and the TNFB*2 alleles, but patients having an early onset of MG without thymoma were carriers of the TNFA*T2 and TNFB*1 alleles. Patients without thymoma who had the titin antibody had the same high frequency of TNFA*T1 and TNFB*2 as patients with thymoma, whereas patients without the titin antibody carried the same allele, TNFA*T2 and TNFB*1, regardless of age and thymic disease. No association was found with acetylcholine-receptor levels or disease severity for any of the TNFA or TNFB polymorphisms. CONCLUSION: Patients having MG, including those with thymoma, who have the titin antibody are most often homozygous for the TNFA*T1 and TNFB*2 alleles, whereas the presence of the TNFA*T2 and TNFB*1 alleles correlates with early-onset MG and the absence of titin antibodies.


Assuntos
Linfotoxina-alfa/genética , Miastenia Gravis/genética , Polimorfismo Genético , Timoma/genética , Neoplasias do Timo/genética , Fator de Necrose Tumoral alfa/genética , Adulto , Idade de Início , Alelos , Sequência de Aminoácidos , Conectina , Feminino , Humanos , Linfotoxina-alfa/imunologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteínas Musculares/imunologia , Miastenia Gravis/imunologia , Miastenia Gravis/fisiopatologia , Reação em Cadeia da Polimerase , Proteínas Quinases/imunologia , Timoma/imunologia , Timoma/fisiopatologia , Neoplasias do Timo/imunologia , Neoplasias do Timo/fisiopatologia , Fator de Necrose Tumoral alfa/imunologia
13.
J Neuroimmunol ; 111(1-2): 169-76, 2000 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11063835

RESUMO

To elucidate the mechanism of immune damage caused by titin and ryanodine receptor (RyR) autoantibodies in myasthenia gravis (MG), we studied the complement-activating capacity and the IgG subclass distribution of these autoantibodies in sera from 49 MG patients. Complement activation occurred in 38 out of 49 titin antibody positive sera, and in 14 out of 21 RyR antibody positive sera. The titin antibodies occurred only in the IgG 1 and IgG 4 subclasses, whereas the RyR antibodies occurred in all four IgG subclasses but with IgG 1 predominance. Complement-activating RyR antibodies occurred with higher frequency in sera of thymoma MG than of late-onset MG. RyR IgG 1 antibodies occurred more often in severe MG than in mild and moderate disease groups. Mean total IgG and IgG 1 titin and RyR antibody titers fell during long-time patient observation together with an improvement of the MG symptoms.


Assuntos
Autoanticorpos/imunologia , Ativação do Complemento/imunologia , Imunoglobulina G/imunologia , Proteínas Musculares/imunologia , Miastenia Gravis/imunologia , Proteínas Quinases/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Adulto , Idade de Início , Idoso , Autoanticorpos/sangue , Conectina , Feminino , Humanos , Imunoglobulina G/sangue , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Receptores Colinérgicos/imunologia , Timoma/imunologia
14.
J Neuroimmunol ; 81(1-2): 173-6, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9521619

RESUMO

The Fcgamma receptors, FcgammaRIIA and FcgammaRIIIB contain polymorphisms with different capacity for IgG binding and phagocytosis. Thirty myasthenia gravis (MG) patients and 49 healthy controls were genotyped for the FcgammaRIIA and FcgammaRIIIB polymorphisms using polymerase chain reaction. The frequency of the FcgammaRIIA-H/H genotype was increased in thymoma MG patients compared to other MG patients (P = 0.05) and controls (P = 0.02). The distribution of FcgammaRIIIB alleles in MG patients did not differ from the controls, but MG patients with the NA1/NA1 genotype had the most severe MG (P = 0.01). Levels of AChR-antibodies and frequency of titin or ryanodine receptor antibodies were not associated with the FcgammaRIIA or FcgammaRIIIB genotypes. The results suggest different pathogenetic mechanisms in paraneoplastic and non-paraneoplastic autoimmune MG.


Assuntos
Doenças Autoimunes/genética , Miastenia Gravis/genética , Polimorfismo Genético , Receptores de IgG/genética , Idade de Início , Alelos , Doenças Autoimunes/epidemiologia , Doenças Autoimunes/etiologia , Doenças Autoimunes/imunologia , Suscetibilidade a Doenças , Frequência do Gene , Genótipo , Humanos , Miastenia Gravis/epidemiologia , Miastenia Gravis/etiologia , Miastenia Gravis/imunologia , Receptores de IgG/classificação , Timoma/complicações , Neoplasias do Timo/complicações
15.
J Neuroimmunol ; 81(1-2): 98-108, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9521611

RESUMO

Myasthenia gravis (MG) patients develop autoantibodies primarily against the acetylcholine receptor in the motor endplate, but also against intracellular striated muscle proteins, notably titin, the giant elastic protein of the myofibrillar cytoskeleton. Titin antibodies have previously been shown to be directed against a single epitope on the molecule, located at the A-band/I-band junction and referred to as the main immunogenic region (MIR) of titin. By using immunofluorescence microscopy on stretched single myofibrils, we now report that approximately 40% of the sera from 18 MG/thymoma patients and 8 late-onset MG patients with thymus atrophy contain antibodies that bind to a more central I-band titin region. This region consists of homologous immunoglobulin domains and is known to be differentially spliced dependent on muscle type. All patients with I-band titin antibodies also had antibodies against the MIR. Although a statistically significant correlation between the occurrence of I-band titin antibodies and MG severity was not apparent, the results could hint at an initial immunoreactivity to titin's MIR, followed by reactivity along the titin molecule in the course of the disease.


Assuntos
Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Proteínas do Citoesqueleto/imunologia , Epitopos/imunologia , Proteínas Musculares/imunologia , Miastenia Gravis/imunologia , Proteínas Quinases/imunologia , Adulto , Idoso , Doenças Autoimunes/etiologia , Conectina , Feminino , Humanos , Masculino , Microscopia de Fluorescência , Microscopia Imunoeletrônica , Pessoa de Meia-Idade , Miastenia Gravis/etiologia , Reação em Cadeia da Polimerase , Receptores Colinérgicos/imunologia , Índice de Gravidade de Doença , Timoma/complicações , Timoma/imunologia , Timo/patologia , Neoplasias do Timo/complicações , Neoplasias do Timo/imunologia
16.
Autoimmunity ; 20(2): 99-104, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7578874

RESUMO

We have tested sera from 21 thymectomized patients with onset of MG after 40 years of age and without thymoma for antibodies against titin, using ELISA with the titin peptide MGT-30. Titin is a myofibrillar protein unique to striated muscle and important for the elastic recoil of muscle cells. Titin antibodies were detected in 9 of the 21 sera. MG symptoms as assessed by a 6 point disability score (0-5) were significantly more severe in the titin antibody positive patients both at peak of illness; 3.7 vs. 3.1 (p < 0.02) and at latest follow up; 2.1 vs. 0.8 (p < 0.01). All titin antibody positive patients were on immunosuppressive drug treatment at least follow-up, whereas only 3 of 12 patients without titin antibodies used immunosuppressive drugs. The presence of circulating titin antibodies in late-onset non-thymoma MG patients indicates a more severe disease.


Assuntos
Autoanticorpos/sangue , Proteínas Musculares/imunologia , Miastenia Gravis/imunologia , Proteínas Quinases/imunologia , Fatores Etários , Idoso , Biomarcadores/análise , Conectina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/classificação , Miastenia Gravis/patologia , Timo/patologia
17.
Autoimmunity ; 26(2): 111-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9546812

RESUMO

Myasthenia gravis (MG) is mediated by autoantibodies against the acetylcholine receptor at the muscle endplate. Some MG patients have in addition antibodies (Ab) to the skeletal muscle proteins ryanodine receptor (RyR) and titin. We have examined GM and KM allotypes, RyR and titin Ab in 44 MG patients (37 thymoma patients and 7 non-thymoma, late-onset patients) and 292 non-MG controls to see if GM/KM allotypes associate with differences in autoantibody production. All patients had titin Ab, and 15 thymoma patients had also RyR Ab. The phenotype GM 1, 2, 3 23 5, 21 was significantly increased in the patients with titin Ab compared with the non-MG controls (chi2 = 4.93, p < 0.05). Thymoma patients with RyR Ab had a higher frequency of the GM 3 23 5 phenotype compared with RyR Ab negative patients and controls (chi2 = 7.1, p < 0.05). KM allotypes did not differ between RyR Ab positive or titin Ab positive patients and controls. GM phenotypes may thus be associated with an autoimmune response against the muscle proteins titin and RyR in MG patients.


Assuntos
Autoanticorpos/sangue , Alótipos Gm de Imunoglobulina/classificação , Proteínas Musculares/imunologia , Miastenia Gravis/imunologia , Proteínas Quinases/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Adulto , Idoso , Western Blotting , Proteínas de Ligação a Calmodulina/análise , Proteínas de Ligação a Calmodulina/imunologia , Proteínas de Transporte/análise , Proteínas de Transporte/imunologia , Conectina , Ensaio de Imunoadsorção Enzimática , Feminino , Alemanha , Haplótipos , Testes de Hemaglutinação , Humanos , Alótipos Gm de Imunoglobulina/sangue , Masculino , Proteínas de Membrana/análise , Proteínas de Membrana/imunologia , Pessoa de Meia-Idade , Proteínas Musculares/análise , Noruega , Fenótipo , Proteínas Quinases/análise , Canal de Liberação de Cálcio do Receptor de Rianodina/análise , Timoma/imunologia , Neoplasias do Timo/imunologia
18.
J Neurol ; 247(5): 369-75, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10896269

RESUMO

Myasthenia gravis (MG) is caused by autoantibodies to the acetylcholine receptor (AChR), but several other muscle autoantibodies have also been identified in patient sera. We studied muscle autoantibodies against AChR, striated muscle tissue sections (SH), titin, citric acid antigen (CA), and ryanodine receptor (RyR) in sera from 146 consecutive MG patients to evaluate whether a single test or several tests together can predict a thymoma. The MG patients were divided into five subgroups; ocular MG, early-onset MG (< 50 years), late-onset MG (> 50 years), MG with thymoma, and AChR antibody negative MG. AChR, SH, titin, CA, and RyR antibodies were detected in 85%, 34%, 34%, 25%, and 14% of the MG patients, respectively. For thymoma MG, AChR, SH, titin, CA, and RyR antibodies were detected in 100%, 75%, 95%, 70%, and 70% respectively. SH, titin, CA, RyR antibodies, and computed tomography of the anterior mediastinum have similar sensitivity for thymoma MG. The specificity of RyR, titin, CA, and SH antibodies for thymoma was 70%, 39%, 38%, and 31%, respectively, which is significantly higher for RyR antibodies than for the others. No single muscle antibody assay can predict a thymoma, and a combination of several antibody assays is preferred, although RyR antibody testing alone showed 70% sensitivity and specificity for thymoma MG. SH and CA antibodies provided only little additional information.


Assuntos
Autoanticorpos/análise , Músculo Esquelético/imunologia , Miastenia Gravis/imunologia , Adulto , Idoso , Ácido Cítrico/imunologia , Conectina , Feminino , Previsões , Humanos , Masculino , Neoplasias do Mediastino/diagnóstico por imagem , Neoplasias do Mediastino/etiologia , Neoplasias do Mediastino/cirurgia , Pessoa de Meia-Idade , Proteínas Musculares/imunologia , Miastenia Gravis/complicações , Proteínas Quinases/imunologia , Receptores Colinérgicos/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Timectomia , Timoma/diagnóstico por imagem , Timoma/etiologia , Timoma/cirurgia , Tomografia Computadorizada por Raios X
19.
Vet Immunol Immunopathol ; 78(1): 97-105, 2001 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-11182151

RESUMO

Similar to human autoimmune myasthenia gravis (MG), canine MG occurs spontaneously and is associated with autoantibodies against the nicotinic acetylcholine receptor (AChR). In addition to AChR, human MG patients with thymoma or late-onset MG have antibodies against titin and ryanodine receptor (RyR). The objective of this study was to establish if dogs with confirmed MG (AChR antibody titer >0.6 nmol/l) also developed titin and RyR antibodies and identify possible associations with thymoma, late age of onset, or severity of clinical signs. Sera from dogs (n=430) with previously diagnosed autoimmune MG (N=415), other immune-mediated neuromuscular disorders including polymyositis (PM) and masticatory muscle myositis (N=5), and control dogs (N=10) were evaluated for the presence of titin antibodies in ELISA using MGT-30 as antigen, a peptide representing the main immunogenic region (MIR) for human titin antibodies. Titin antibody positive sera were further examined for RyR antibodies in Western blots using a RyR fusion protein (pc2-RyR) as antigen, which covers the MIR for human MG sera. Titin antibodies were found in sera of 80/430 dogs. Thymoma was present in 11/80 and age of onset was after 4 years in 66/80 titin positive dogs. Two of the titin positive dogs had PM. RyR antibodies were found in 13/80 sera (8/13 thymoma, 12/13 age of onset after 4 years, and 1/13 PM). Neither titin nor RyR antibodies were found in sera of healthy control dogs. Acute fulminating MG was described in five dogs with both titin and RyR antibodies. From these studies we conclude that titin and RyR antibodies in canine and human MG have a similar association with thymoma, late-onset MG, and possibly with more severe forms of MG.


Assuntos
Autoanticorpos/sangue , Doenças do Cão/imunologia , Proteínas Musculares/imunologia , Miastenia Gravis/veterinária , Proteínas Quinases/imunologia , Canal de Liberação de Cálcio do Receptor de Rianodina/imunologia , Timoma/imunologia , Timoma/veterinária , Neoplasias do Timo/veterinária , Idade de Início , Animais , Autoanticorpos/imunologia , Western Blotting/veterinária , Conectina , Cães , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Miastenia Gravis/imunologia , Radioimunoensaio/veterinária , Neoplasias do Timo/imunologia
20.
Parkinsonism Relat Disord ; 19(1): 53-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22841686

RESUMO

Parkinson's disease (PD) may be associated with a number of different diseases due to common risk factors or overlapping symptomatology. We have asked for possible associated disorders in a Norwegian population of incident PD patients and controls, the Norwegian ParkWest study. The patients were diagnosed according to the Gelb criteria. 212 incident PD patients and 175 age and gender matched controls were included. PD patients and controls were asked for information on earlier medical history and family history. PD patients had a higher frequency of self-reported symptoms of depression (p = 0.003) and anxiety disorders (p = 0.004) before baseline. They tended to have a higher frequency of diabetes (p = 0.09) and had a higher frequency of prior stroke or TIA (p = 0.004).


Assuntos
Transtornos de Ansiedade/complicações , Depressão/complicações , Complicações do Diabetes/epidemiologia , Doença de Parkinson/complicações , Acidente Vascular Cerebral/complicações , Idoso , Transtornos de Ansiedade/diagnóstico , Estudos de Coortes , Depressão/diagnóstico , Complicações do Diabetes/diagnóstico , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Noruega , Doença de Parkinson/diagnóstico , Estudos Prospectivos , Fatores de Risco , Índice de Gravidade de Doença , Acidente Vascular Cerebral/diagnóstico
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