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1.
Brain ; 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39197036

RESUMO

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting motor neurons, with a typical lifespan of 3-5 years. Altered metabolism is a key feature of ALS that strongly influences prognosis, with an increase in whole-body energy expenditure and changes in skeletal muscle metabolism, including greater reliance on fat oxidation. Dyslipidemia has been described in ALS as part of the metabolic dysregulation, but its role in the pathophysiology of the disease remains controversial. Among the lipids, cholesterol is of particular interest as a vital component of cell membranes, playing a key role in signal transduction and mitochondrial function in muscle. The aim of this study was to investigate whether motor dysfunction in ALS might be associated with dysregulation of muscle cholesterol metabolism. We determined cholesterol content and analyzed the expression of key determinants of the cholesterol metabolism pathway in muscle biopsies from thirteen ALS patients and ten asymptomatic ALS-mutation gene carriers compared to sixteen controls. Using human control primary myotubes, we further investigated the potential contribution of cholesterol dyshomeostasis to reliance on mitochondrial fatty acid. We found that cholesterol accumulates in the skeletal muscle of ALS patients and that cholesterol overload significantly correlates with disease severity evaluated by the Revised ALS Functional Rating Scale. These defects are associated with overexpression of the genes of the lysosomal cholesterol transporters Niemann-Pick type C1 (NPC1) and 2 (NPC2), which are required for cholesterol transfer from late endosomes/lysosomes to cellular membranes. Most notably, a significant increase in NPC2 mRNA levels could be detected in muscle samples from asymptomatic ALS-mutation carriers, long before disease onset. We found that filipin-stained unesterified cholesterol accumulated in the lysosomal compartment in ALS muscle samples, suggesting dysfunction of the NPC1/2 system. Accordingly, we report here that experimental NPC1 inhibition or lysosomal pH alteration in human primary myotubes was sufficient to induce the overexpression of NPC1 and NPC2 mRNA. Finally, acute NPC1 inhibition in human control myotubes induced a shift towards a preferential use of fatty acids, thus reproducing the metabolic defect characteristic of ALS muscle. We conclude that cholesterol homeostasis is dysregulated in ALS muscle from the presymptomatic stage. Targeting NPC1/2 dysfunction may be a new therapeutic strategy for ALS to restore muscle energy metabolism and slow motor symptom progression.

2.
Rheumatology (Oxford) ; 62(6): 2220-2229, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-36200845

RESUMO

OBJECTIVES: Idiopathic inflammatory myopathies are mainly defined by inflammatory infiltrates within the muscle (lymphocytes and macrophages). Eosinophil muscle infiltration has been described in idiopathic eosinophilic myositis (IEM) and rarely in EF. This study aimed to further delineate the nosological frame of idiopathic eosinophil muscle infiltration through the exhaustive analysis of IEM and EF patients. METHODS: This multicentre retrospective case series included IEM patients diagnosed between 2000 and 2022. IEM inclusion criteria were eosinophilic muscle infiltration with myositis pathological features, after the exclusion of differential diagnoses. An additional group of EF patients diagnosed between 2016 and 2022 was constituted. Inclusion criteria were an EF diagnosis and fascia thickening with inflammatory infiltrate. RESULTS: A total of 20 IEM cases and 10 EF cases were included. The median (interquartile range) age at diagnosis was 65 (49-70) years; there were 18 males. Data analysis delineated four subgroups: focal EM (FEM, n = 3), diffuse EM (DEM, n = 6), eosinophilic myofasciitis (EMF, n = 11) and EF (n = 10). FEM represented a limited and benign form of myositis. DEM cases presented objective muscle impairment with eosinophilic muscle infiltration. EMF patients presented subjective muscle impairment (myalgia, 55%), fasciitis (on histology and/or imaging), eosinophilic muscle infiltration and frequent hypereosinophilia (55%). EF patients presented myalgia (50%), muscle lesions on histology with fascia-restricted inflammatory infiltrates with (60%) or without (40%) eosinophils. CONCLUSIONS: The analysis of IEM and EF patient characteristics delineates four subgroups (FEM, DEM, EMF and EF) in terms of clinical, laboratory, imaging, pathological and outcome specificities, and proposes an adapted diagnostic and care management approach.


Assuntos
Eosinofilia , Fasciite , Miosite , Masculino , Humanos , Idoso , Mialgia/patologia , Estudos Retrospectivos , Miosite/diagnóstico , Miosite/patologia , Eosinofilia/diagnóstico , Eosinofilia/patologia , Fáscia , Músculos/patologia , Fasciite/diagnóstico
3.
Rheumatology (Oxford) ; 62(12): 3932-3939, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37010495

RESUMO

OBJECTIVE: Among specific autoantibodies in DM, the anti-small ubiquitin-like modifier activating enzyme (SAE) antibody is rare. We aim to describe the clinical characteristics, cancer prevalence, and muscle pathology of anti-SAE-positive DM. METHODS: Patients with a diagnosis of DM and sera positive for the anti-SAE antibody were recruited from 19 centres in this retrospective observational study. The available muscular biopsies were reviewed. We conducted a comparison with anti-SAE-negative DM and a review of the literature. RESULTS: Of the patients in the study (n = 49), 84% were women. Skin involvement was typical in 96% of patients, with 10% having calcinosis, 18% ulceration and 12% necrosis; 35% presented with a widespread skin rash. Muscular disease affected 84% of patients, with mild weakness [Medical Research Council (MRC) scale 4 (3, 5)], although 39% of patients had dysphagia. Muscular biopsies showed typical DM lesions. Interstitial lung disease was found in 21% of patients, mainly with organizing pneumonia pattern, and 26% of patients showed dyspnoea. Cancer-associated myositis was diagnosed in 16% of patients and was responsible for the majority of deaths, its prevalence being five times that of the general population. IVIG therapy was administered to 51% of the patients during the course of the disease. Comparison with anti-SAE-negative DM (n = 85) showed less and milder muscle weakness (P = 0.02 and P = 0.006, respectively), lower creatinine kinase levels (P < 0.0001) and less dyspnoea (P = 0.003). CONCLUSION: Anti-SAE positive DM is a rare subgroup associated with typical skin features but a potentially diffuse rash, a mild myopathy. Interstitial lung disease defines an organizing pneumonia pattern. Cancer associated DM prevalence is five times that of the general population. TRIAL REGISTRATION: ClinicalTrials.gov, http://clinicaltrials.gov, NCT04637672.


Assuntos
Dermatomiosite , Exantema , Doenças Pulmonares Intersticiais , Miosite , Neoplasias , Humanos , Feminino , Masculino , Autoanticorpos , Dermatomiosite/complicações , Miosite/diagnóstico , Exantema/epidemiologia , Neoplasias/epidemiologia , Neoplasias/complicações , Enzimas Ativadoras de Ubiquitina , Doenças Pulmonares Intersticiais/epidemiologia , Doenças Pulmonares Intersticiais/complicações , Dispneia , Estudos Observacionais como Assunto
4.
Eur J Neurol ; 30(3): 745-748, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36403110

RESUMO

BACKGROUND AND PURPOSE: Amyloid myopathy is a rare and severe manifestation of systemic light chain (AL) amyloidosis. Early diagnosis and staging are mandatory for optimal therapy, given the rapid progression of muscle weakness. Despite the efficacy of bortezomib-based treatment regimens, there is a lack of therapeutic alternatives in non-responsive patients. METHOD: The case report of a patient with systemic AL amyloidosis myopathy treated with daratumumab is presented. RESULTS: A 70-year-old man displayed severe proximal muscle weakness which had developed over a 10-month period. Blood tests revealed an immunoglobulin A lambda monoclonal gammopathy, whilst muscle biopsy showed amyloid deposits within the arteriolar walls, confirming the diagnosis of amyloid myopathy associated with AL amyloidosis. Initial treatment with a bortezomib-based regimen showed no clinical or hematological improvement. After switching to daratumumab monotherapy, our patient achieved a favorable evolution with respect to functional muscle scoring and a complete hematological response. CONCLUSION: To our knowledge, this is the first case report of an amyloid myopathy showing a remarkable clinical improvement in response to daratumumab monotherapy. It thereby highlights the potential of daratumumab as a monotherapeutical approach to the treatment of amyloid myopathy complicating AL amyloidosis.


Assuntos
Amiloidose , Amiloidose de Cadeia Leve de Imunoglobulina , Doenças Musculares , Masculino , Humanos , Idoso , Amiloidose de Cadeia Leve de Imunoglobulina/complicações , Amiloidose de Cadeia Leve de Imunoglobulina/tratamento farmacológico , Amiloidose de Cadeia Leve de Imunoglobulina/diagnóstico , Bortezomib/uso terapêutico , Amiloidose/complicações , Amiloidose/tratamento farmacológico , Amiloidose/diagnóstico , Doenças Musculares/complicações , Doenças Musculares/tratamento farmacológico , Doenças Musculares/diagnóstico , Debilidade Muscular
5.
Rheumatology (Oxford) ; 61(11): 4514-4520, 2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-35199139

RESUMO

OBJECTIVES: To assess the efficacy and tolerance of the conventional first-line treatment by MTX and CS in patients with JDM regardless of severity. METHODS: We conducted a monocentric retrospective study of patients with newly diagnosed JDM treated with MTX and CS from 2012 to 2020. The proportion of clinically inactive disease (CID) within 6 months of MTX initiation was evaluated using both Paediatric Rheumatology International Trials Organisation (PRINTO) criteria (evaluating muscle inactive disease) and DAS (evaluating skin inactive disease). We compared responders and non-responders using univariate analyses. RESULTS: Forty-five patients with JDM, out of which 30 (67%) severe JDM, were included. After 6 months of treatment with MTX and CS, complete CID, muscle CID and skin CID were achieved in 14/45 (31%), 19/45 (42%) and 15/45 (33%) patients, respectively. The absence of myositis-specific (MSA) or myositis-associated autoantibodies (MAA) at diagnosis was associated with a better overall, cutaneous and muscular therapeutic response, compared with antibody-positive forms (P < 0.01). Requirement for ICU (P = 0.029) and cutaneous ulcerations (P = 0.018) were associated with a less favourable muscle response. MTX was stopped due to intolerance in six patients (13%) before month 6. CONCLUSIONS: Conventional first-line treatment with MTX was not efficient in a large subset of JDM patients, especially in patients with MSA-positive forms, and in patients with severe JDM. Larger, multicentre cohorts are required to confirm these data and to identify new predictive biomarkers of MTX response, in order to treat patients with JDM as early as possible with appropriate targeted drugs.


Assuntos
Dermatomiosite , Doenças Musculares , Miosite , Criança , Humanos , Dermatomiosite/complicações , Metotrexato/uso terapêutico , Estudos Retrospectivos , Miosite/complicações , Corticosteroides/uso terapêutico , Doenças Musculares/tratamento farmacológico
6.
Rheumatology (Oxford) ; 60(12): 5801-5808, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33576769

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of Janus kinase inhibitors (JAKis) in JDM. METHODS: We conducted a single-centre retrospective study of patients with JDM treated by JAKi with a follow-up of at least 6 months. Proportion of clinically inactive disease (CID) within 6 months of JAKi initiation was evaluated using PRINTO criteria and skin Disease Activity Score. Serum IFN-α concentration was measured by Simoa assay. RESULTS: Nine refractory and one new-onset patients with JDM treated with ruxolitinib (n = 7) or baricitinib (n = 3) were included. The main indications for treatment were refractory muscle involvement (n = 8) and ulcerative skin disease (n = 2). CID was achieved in 5/10 patients (two/two anti-MDA5, three/four anti-NXP2, zero/three anti-TIF1γ-positive patients) within 6 months of JAKi introduction. All responders could withdraw plasmatic exchange, immunoadsorption and other immunosuppressive drugs. The mean daily steroid dose decreased from 1.1 mg/kg (range 0.35-2 mg/kg/d) to 0.1 (range, 0-0.3, P = 0.008) in patients achieving CID, and was stopped in two. Serum IFN-α concentrations were elevated in all patients at the time of treatment initiation and normalized in both responder and non-responder. A muscle biopsy repeated in one patient 26 months after the initiation of JAKi, showed a complete restoration of muscle endomysial microvascular bed. Herpes zoster and skin abscesses developed in three and two patients, respectively. CONCLUSION: JAKis resulted in a CID in a subset of new-onset or refractory patients with JDM and may dramatically reverse severe muscle vasculopathy. Overall tolerance was good except for a high rate of herpes zoster infection.


Assuntos
Azetidinas/uso terapêutico , Dermatomiosite/tratamento farmacológico , Inibidores de Janus Quinases/uso terapêutico , Nitrilas/uso terapêutico , Purinas/uso terapêutico , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Sulfonamidas/uso terapêutico , Adolescente , Autoanticorpos/sangue , Autoanticorpos/imunologia , Biomarcadores/sangue , Criança , Pré-Escolar , Dermatomiosite/sangue , Dermatomiosite/imunologia , Feminino , Humanos , Interferon-alfa/sangue , Janus Quinases , Masculino , Estudos Retrospectivos , Resultado do Tratamento
7.
Medicina (Kaunas) ; 57(5)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069603

RESUMO

Designed by a group of ME/CFS researchers and health professionals, the European Network on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (EUROMENE) has received funding from the European Cooperation in Science and Technology (COST)-COST action 15111-from 2016 to 2020. The main goal of the Cost Action was to assess the existing knowledge and experience on health care delivery for people with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) in European countries, and to enhance coordinated research and health care provision in this field. We report our findings and make recommendations for clinical diagnosis, health services and care for people with ME/CFS in Europe, as prepared by the group of clinicians and researchers from 22 countries and 55 European health professionals and researchers, who have been informed by people with ME/CFS.


Assuntos
Síndrome de Fadiga Crônica , Consenso , Atenção à Saúde , Europa (Continente) , Síndrome de Fadiga Crônica/diagnóstico , Síndrome de Fadiga Crônica/epidemiologia , Síndrome de Fadiga Crônica/terapia , Humanos
8.
Rheumatology (Oxford) ; 59(8): 1927-1937, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31755959

RESUMO

OBJECTIVES: JDM and juvenile overlap myositis represent heterogeneous subtypes of juvenile idiopathic inflammatory myopathy (JIIM). Chronic evolution can occur in up to 60% of cases, and morbidity/mortality is substantial. We aimed to describe the clinical, biological, histological and type I IFN status in JIIM associated with anti-melanoma differentiation-associated protein 5 (anti-MDA5) autoantibodies at presentation (group 1) in comparison with other JIIM (group 2). METHODS: This was a retrospective and prospective study of patients with JIIM ascertained from three French paediatric rheumatology reference centres between 2013 and 2019. Muscle biopsies were reviewed. Type I interferon pathway activity was assessed by dosage of IFNα serum protein and the expression of IFN-stimulated genes. RESULTS: Sixty-four patients were included, 13 in group 1 (54% JDM and 46% juvenile overlap myositis) and 51 in group 2 (76% JDM and 24% juvenile overlap myositis). Group 1 patients demonstrated more arthritis, skin ulcerations, lupus features and interstitial lung disease, and a milder muscular involvement. Serum IFNα levels were higher in group 1 than 2, and decreased after treatment or improvement in both groups. Outcome was similar in both groups. Unconventional treatment (more than two lines) was required in order to achieve remission, especially when skin ulceration was reported. CONCLUSION: This study indicates a higher frequency of arthritis, skin ulcerations and interstitial lung disease, but milder muscular involvement, in JIIM with positive anti-MDA5 autoantibodies compared with other JIIM. Our data support an important role of systemic IFNα in disease pathology, particularly in the anti-MDA5 auto-antibody-positive subgroup. In severe and refractory forms of JIIM, IFNα may represent a therapeutic target.


Assuntos
Autoanticorpos/imunologia , Helicase IFIH1 Induzida por Interferon/imunologia , Interferon-alfa/metabolismo , Músculo Esquelético/metabolismo , Miosite/metabolismo , Transdução de Sinais/fisiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Músculo Esquelético/imunologia , Músculo Esquelético/patologia , Miosite/imunologia , Miosite/patologia , Estudos Prospectivos , Estudos Retrospectivos
9.
Mol Biol Rep ; 47(8): 5755-5761, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32666437

RESUMO

Dysferlinopathies belong to the heterogeneous group of autosomal recessive muscular disorders, caused by mutations in the dysferlin gene and characterized by a high degree of clinical variability even though within the same family. This study aims to describe three cases, belonging to a consanguineous Tunisian family, sharing a new splicing mutation in the dysferlin gene and presenting intra-familial variability of dysferlinopathies: Proximal-distal weakness and distal myopathy with anterior tibial onset. We performed the next generation sequencing for mutation screening and reverse transcriptase-PCR for gene expression analysis. Routine muscle histology was used for muscle biopsy processing. The clinical presentation demonstrated heterogeneous phenotypes between the three cases: Two presented intermediate phenotypes of dysferlinopathy with proximal-distal weakness and the third had a distal myopathy with anterior tibial onset. Genetic analysis yielded a homozygous splicing mutation (c.4597-2A>G) in the dysferlin gene, giving rise to the suppression of 28 bp of the exon 43. The splicing mutation found in our family (c.4597-2A>G) is responsible for the suppression of 28 bp of the exon 43 and a wide clinical intra-familial variability.


Assuntos
Disferlina/genética , Doenças Musculares/genética , Distrofia Muscular do Cíngulo dos Membros/genética , Feminino , Predisposição Genética para Doença , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Musculares/patologia , Distrofia Muscular do Cíngulo dos Membros/patologia , Mutação , Fenótipo , Splicing de RNA
10.
Rheumatology (Oxford) ; 57(5): 873-879, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29474663

RESUMO

Objectives: Myositis-specific autoantibodies (MSAs) are increasingly used to delineate distinct subgroups of JDM. The aim of our study was to explore without a priori hypotheses whether MSAs are associated with distinct clinical-pathological changes and severity in a monocentric JDM cohort. Methods: Clinical, biological and histological findings from 23 JDM patients were assessed. Twenty-six histopathological parameters were subjected to multivariate analysis. Results: Autoantibodies included anti-NXP2 (9/23), anti-TIF1γ (4/23), anti-MDA5 (2/23), no MSAs (8/23). Multivariate analysis yielded two histopathological clusters. Cluster 1 (n = 11) showed a more severe and ischaemic pattern than cluster 2 (n = 12) assessed by: total score severity ⩾ 20 (100.0% vs 25.0%); visual analogic score ⩾6 (100.0% vs 25.0%); the vascular domain score >1 (100.0% vs 41.7%); microinfarcts (100% vs 58.3%); ischaemic myofibrillary loss (focal punched-out vacuoles) (90.9 vs 25%); and obvious capillary loss (81.8% vs 16.7). Compared with cluster 2, patients in cluster 1 had strikingly more often anti-NXP2 antibodies (7/11 vs 2/12), more pronounced muscle weakness, more gastrointestinal involvement and required more aggressive treatment. Furthermore, patients with anti-NXP2 antibodies, mostly assigned in the first cluster, also displayed more severe muscular disease, requiring more aggressive treatment and having a lower remission rate during the follow-up period. Conclusion: Marked muscle ischaemic involvement and the presence of anti-NXP2 autoantibodies are associated with more severe forms of JDM.


Assuntos
Adenosina Trifosfatases/imunologia , Autoanticorpos/imunologia , Proteínas de Ligação a DNA/imunologia , Dermatomiosite/complicações , Isquemia/etiologia , Músculo Esquelético/irrigação sanguínea , Adenosina Trifosfatases/metabolismo , Biomarcadores/metabolismo , Biópsia , Proteínas de Ligação a DNA/metabolismo , Dermatomiosite/imunologia , Dermatomiosite/metabolismo , Progressão da Doença , Feminino , Seguimentos , Humanos , Isquemia/diagnóstico , Isquemia/imunologia , Masculino , Músculo Esquelético/diagnóstico por imagem , Índice de Gravidade de Doença
11.
Neuropathol Appl Neurobiol ; 41(7): 952-63, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25711697

RESUMO

OBJECTIVE: To analyse the paradox of a lack of giant cell formation and fibrosis in chronic lesions of macrophagic myofasciitis (MMF) in comparison with muscular sarcoidosis (MuS). METHODS: Inflammatory lesions and contiguous muscle regions from biopsy samples of 10 patients with MuS and 10 patients with MMF were cut out by laser microdissection. Mediators of the T helper cell (Th)1 inducing classical macrophage activation (e.g. STAT1, IFNγ and CXCR3), and Th2 inducing alternative activation of macrophages (e.g. CD206/MRC1, STAT6, SOCS1), molecules involved in development of fibrosis (e.g. TGFß) and giant cells (e.g. TYROBP), were assessed by immunohistochemistry and real-time polymerase chain reaction (PCR). RESULTS: STAT6-induced Th2 immunity was associated with up-regulated gene expression of MRC1, SOCS1 and TGFB in inflammatory foci, in comparison with adjacent tissue. TYROBP and TREM2, genes regulating giant cell formation, were more strongly expressed in lesions of MuS patients than in those of MMF. TGFß co-localized with CD206(+) macrophages in MuS but not in MMF. Conversely, Th1 immunity was illustrated by STAT1 staining both in macrophages and myofibres in MuS, but not in MMF. Also, STAT1-induced IFNG and CXCR3 expression in lesions and the surrounding tissue was elevated compared with normal controls, but without statistically significant differences. CONCLUSION: Giant cell and typical granuloma formations, including fibrogenesis, is dependent on two main mechanisms, both involving specific macrophage activation: a strong Th2-M2 polarization and a significant expression of TYROBP and TGFß in macrophages. The low-grade alternative activation of macrophages in MMF lesions and poor TYROBP and TGFßco-expression are obviously insufficient to produce giant cells.


Assuntos
Fasciite/imunologia , Macrófagos/imunologia , Músculo Esquelético/imunologia , Miosite/imunologia , Sarcoidose/imunologia , Células Th2/imunologia , Adulto , Idoso , Fasciite/patologia , Feminino , Humanos , Ativação de Macrófagos , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Miosite/patologia , Sarcoidose/patologia , Células Th2/patologia , Adulto Jovem
12.
Am J Pathol ; 182(6): 2298-309, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23624156

RESUMO

Dysferlinopathy refers to a group of autosomal recessive muscular dystrophies due to mutations in the dysferlin gene causing deficiency of a membrane-bound protein crucially involved in plasma membrane repair. The condition is characterized by marked clinical heterogeneity, the different phenotypes/modes of presentation being unrelated to the genotype. For unknown reasons, patients are often remarkably active before the onset of symptoms. Dysferlin deficiency-related persistence of mechanically induced sarcolemma disruptions causes myofiber damage and necrosis. We postulate that limited myodamage may initially remain hidden with well-preserved resistance to physical strains. By subjecting dysferlin-deficient B6.A/J-Dysf(prmd) mice to long-term swimming exercise, we observed that concentric/isometric strain improved muscle strength and alleviated muscular dystrophy by limiting the accumulation of membrane lesions. By contrast, eccentric strain induced by long-term running in a wheel worsened the dystrophic process. Myofiber damage induced by eccentric strain increased with age, reflecting the accumulation of non-necrotic membrane lesions up to a critical threshold. This phenomenon was modulated by daily spontaneous activity. Transposed to humans, our results may suggest that the past activity profile shapes the clinical phenotype of the myopathy and that patients with dysferlinopathy should likely benefit from concentric exercise-based physiotherapy.


Assuntos
Distrofia Muscular do Cíngulo dos Membros/reabilitação , Condicionamento Físico Animal/fisiologia , Envelhecimento/patologia , Envelhecimento/fisiologia , Animais , Membrana Celular/ultraestrutura , Disferlina , Locomoção/fisiologia , Proteínas de Membrana/deficiência , Camundongos , Camundongos Mutantes , Microscopia Eletrônica , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/patologia , Força Muscular/fisiologia , Músculo Esquelético/fisiopatologia , Distrofia Muscular do Cíngulo dos Membros/etiologia , Distrofia Muscular do Cíngulo dos Membros/patologia , Distrofia Muscular do Cíngulo dos Membros/fisiopatologia , Necrose , Músculo Quadríceps/ultraestrutura , Corrida/fisiologia , Natação/fisiologia
13.
Am J Pathol ; 183(3): 893-904, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23850081

RESUMO

Muscle fibers do not normally express major histocompatibility complex class I (MHC-I) molecules, and their reexpression is a hallmark of inflammatory myopathies. It has been shown in mice that overexpression of MHC-I induces a poorly inflammatory myositis accompanied by the unfolded protein response (UPR), but it is unclear whether it is attributable to T-cell-mediated MHC-I-dependent immune responses or to MHC-I forced expression per se. Indeed, besides presenting antigenic peptides to CD8(+) T cells, MHC-I may also possibly exert nonimmunologic, yet poorly understood pathogenic effects. Thus, we investigated the pathogenicity of MHC-I expression in muscle independently of its immune functions. HT transgenic mice that conditionally overexpress H-2K(b) in muscle were bred to an immunodeficient Rag2(-/-) background. The muscle proteome was analyzed by label-free high-resolution protein quantitation and Western blot. Despite the absence of adaptive immunity, HT Rag2(-/-) mice developed a very severe myopathy associated with the cytoplasmic accumulation of H-2K(b) molecules. The UPR was manifest by up-regulation of characteristic proteins. In humans, we found that HLA class I molecules not only were expressed at the sarcolemma but also could accumulate intracellularly in some patients with inclusion body myositis. Accordingly, the UPR was triggered as a function of the degree of HLA accumulation in myofibers. Hence, reexpression of MHC-I in normally negative myofibers exerts pathogenic effects independently of its immune function.


Assuntos
Antígenos de Histocompatibilidade Classe I/metabolismo , Músculos/imunologia , Músculos/patologia , Doenças Musculares/imunologia , Doenças Musculares/patologia , Linfócitos T/patologia , Resposta a Proteínas não Dobradas , Animais , Estresse do Retículo Endoplasmático , Humanos , Imuno-Histoquímica , Espaço Intracelular/metabolismo , Camundongos , Camundongos SCID , Camundongos Transgênicos , Fibras Musculares Esqueléticas/patologia , Proteínas Musculares/metabolismo , Músculos/ultraestrutura , Miosite de Corpos de Inclusão/imunologia , Miosite de Corpos de Inclusão/patologia , Regulação para Cima
14.
Bull Acad Natl Med ; 198(1): 37-48; discussion 49-53, 2014 Jan.
Artigo em Francês | MEDLINE | ID: mdl-26259285

RESUMO

Aluminium oxyhydroxide (alum), a nanocrystalline compound that forms agglomerates, has been widely used as a vaccine adjuvant since 1927, but the mechanisms by which it stimulates immune responses remain poorly understood. Although generally well tolerated, alum may occasionally cause chronic health problems in presumably susceptible individuals. Some individuals may rarely develop delayed-onset diffuse myalgia, chronic exhaustion and cognitive dysfunction, associated with long-term persistence (up to 12 years) of alum-loaded macrophages at site of i.m. immunization, defining so-called macrophagic myofasciitis (MMF). Symptoms are consistent with the chronic fatigue/myalgic encephalomyelitis (CFS/ME) syndrome, and have been used as a paradigm of the "autoimmune/inflammatory syndrome induced by adjuvants" (ASIA). Cognitive dysfunction is reminiscent of that described in workers exposed to inhaled Al particles. Individual susceptibility may influence both alum biopersistence and difusion away from injection sites. Biopersistent particles such as fluorescent alum-coated nanohybrids, when injected into mouse muscle, are captured by monocyte-lineage cells and then carried to distant organs, draining lymph nodes and blood, probably via the thoracic duct, with delayed and accumulative translocation to the brain (microglial cells). Brain penetration occurs at extremely low levels in normal conditions, possibly explaining the good tolerance of alum despite its high neurotoxic potential. However, systemic diffusion is considerably enhanced by the potentiating effect of MCP-1, the main monocyte chemoattractant factor, the production of which is subject to marked variations linked to age and to genetic and environmental factors. Selective MCP-1 elevation is the only known circulating biomarker of MMF.


Assuntos
Adjuvantes Imunológicos/farmacocinética , Compostos de Alúmen/farmacocinética , Adjuvantes Imunológicos/efeitos adversos , Compostos de Alúmen/efeitos adversos , Quimiocina CCL2/análise , Fasciite/induzido quimicamente , Humanos , Injeções Intramusculares , Macrófagos/química , Miosite/induzido quimicamente , Vacinas/química
15.
Toxics ; 12(7)2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-39058143

RESUMO

(1) Background: Macrophagic myofasciitis (MMF) is an inflammatory histopathological lesion demonstrating long-term biopersistence of vaccine-derived aluminum adjuvants within muscular phagocytic cells. Affected patients suffer from widespread myalgia and severe fatigue consistent with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a poorly understood disorder suspected to result from chronic immune stimulation by infectious and inorganic particles. (2) Methods: In this study we determined the immuno-metabolic properties of MMF phagocytic cells compared to controls, at rest and upon exposure to aluminum oxyhydroxide adjuvant, with or without adsorbed antigens, using protein quantification and an oxygen consumption assay. (3) Results: MMF and control cells similarly internalized the adjuvant and vaccine but MMF cells specifically expressed Rubicon and Nox2, two molecules unique to the LC3-associated phagocytosis (LAP) machinery, a non-canonical autophagic pathway able to downregulate canonical autophagy. MMF cells exhibited an altered inflammatory secretome, producing more pain-inducing CXC chemokines and less TNF-α than controls, consistent with chronic myalgia and exhaustion of the immune system previously documented in ME/CFS. MMF cells exhibited mitochondrial metabolism dysfunction, with exacerbated reaction to adjuvanted vaccine, contrasting with limited spare respiratory capacity and marked proton leak weakening energy production. (4) Conclusions: MMF phagocytes seemingly use LAP to handle aluminum oxyhydroxide vaccine particles, secrete pain-inducing molecules, and exhibit exacerbated metabolic reaction to the vaccine with limited capacity to respond to ongoing energetic requests.

16.
Neurol Neuroimmunol Neuroinflamm ; 11(2): e200195, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38170952

RESUMO

BACKGROUND AND OBJECTIVES: Immune-mediated small fiber neuropathy (SFN) is increasingly recognized. Acute-onset SFN (AOSFN) remains poorly described. Herein, we report a series of AOSFN cases in which immune origins are debatable. METHODS: We included consecutive patients with probable or definite AOSFN. Diagnosis of SFN was based on the NEURODIAB criteria. Acute onset was considered when the maximum intensity and extension of both symptoms and signs were reached within 28 days. We performed the following investigations: clinical examination, neurophysiologic assessment encompassing a nerve conduction study to rule out large fiber neuropathy, laser-evoked potentials (LEPs), warm detection thresholds (WDTs), electrochemical skin conductance (ESC), epidermal nerve fiber density (ENF), and patient serum reactivity against mouse sciatic nerve teased fibers, mouse dorsal root ganglion (DRG) sections, and cultured DRG. The serum reactivity of healthy subjects (n = 10) and diseased controls (n = 12) was also analyzed. Data on baseline characteristics, biological investigations, and disease course were collected. RESULTS: Twenty patients presenting AOSFN were identified (60% women; median age: 44.2 years [interquartile range: 35.7-56.2]). SFN was definite in 18 patients (90%) and probable in 2 patients. A precipitating event was present in 16 patients (80%). The median duration of the progression phase was 14 days [5-28]. Pain was present in 17 patients (85%). Twelve patients (60%) reported autonomic involvement. The clinical pattern was predominantly non-length-dependent (85%). Diagnosis was confirmed by abnormal LEPs (60%), ENF (55%), WDT (39%), or ESC (31%). CSF analysis was normal in 5 of 5 patients. Antifibroblast growth factor 3 antibodies were positive in 4 of 18 patients (22%) and anticontactin-associated protein-2 antibodies in one patient. In vitro studies showed IgG immunoreactivity against nerve tissue in 14 patients (70%), but not in healthy subjects or diseased controls. Patient serum antibodies bound to unmyelinated fibers, Schwann cells, juxtaparanodes, paranodes, or DRG. Patients' condition improved after a short course of oral corticosteroids (3/3). Thirteen patients (65%) showed partial or complete recovery. Others displayed relapses or a chronic course. DISCUSSION: AOSFN primarily presents as an acute, non-length-dependent, symmetric painful neuropathy with a variable disease course. An immune-mediated origin has been suggested based on in vitro immunohistochemical studies.


Assuntos
Doenças do Sistema Nervoso Periférico , Neuropatia de Pequenas Fibras , Adulto , Animais , Feminino , Humanos , Masculino , Camundongos , Anticorpos , Axônios , Fibras Nervosas , Dor , Neuropatia de Pequenas Fibras/diagnóstico , Pessoa de Meia-Idade
17.
Neuromuscul Disord ; 36: 6-15, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38306719

RESUMO

The aim of this study was to identify key routinely used myopathologic biomarkers of FSHD1. Needle muscle biopsies were taken in 34 affected muscles (m. quadriceps femoris (QF), n = 20, m. tibialis anterior (TA), n = 13, m. biceps brachii, n = 1) from 22 patients (age, 53.5 (10) years; M = 12, F = 10). Eleven patients had more than one biopsy (2xQF, n = 1; QF+TA, n = 9; 2xQF+TA, n = 1). Histochemistry, immunoperoxidase, and immunofluorescence stainings were performed and compared to age and muscle type matched muscle specimens of 11 healthy controls. Myopathologic features observed in our FSHD1 cohort were internalized nuclei, type 1 fibre hypertrophy and NADH central clearances/cores. We observed a prominent inflammatory response with MAC deposits, MHC I expression, and muscle regeneration that correlated with the inflammatory score. Our up-to-date characterization of FSHD1 points towards MHC I, MAC, and embryonic Myosin Heavy Chain/muscle regeneration as useful myopathologic readouts of FSHD1.


Assuntos
Distrofia Muscular Facioescapuloumeral , Humanos , Pessoa de Meia-Idade , Complexo de Ataque à Membrana do Sistema Complemento , Biópsia , Músculo Esquelético , Regeneração
18.
BMC Med ; 11: 99, 2013 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-23557144

RESUMO

BACKGROUND: Long-term biodistribution of nanomaterials used in medicine is largely unknown. This is the case for alum, the most widely used vaccine adjuvant, which is a nanocrystalline compound spontaneously forming micron/submicron-sized agglomerates. Although generally well tolerated, alum is occasionally detected within monocyte-lineage cells long after immunization in presumably susceptible individuals with systemic/neurologic manifestations or autoimmune (inflammatory) syndrome induced by adjuvants (ASIA). METHODS: On the grounds of preliminary investigations in 252 patients with alum-associated ASIA showing both a selective increase of circulating CCL2, the major monocyte chemoattractant, and a variation in the CCL2 gene, we designed mouse experiments to assess biodistribution of vaccine-derived aluminum and of alum-particle fluorescent surrogates injected in muscle. Aluminum was detected in tissues by Morin stain and particle induced X-ray emission) (PIXE) Both 500 nm fluorescent latex beads and vaccine alum agglomerates-sized nanohybrids (Al-Rho) were used. RESULTS: Intramuscular injection of alum-containing vaccine was associated with the appearance of aluminum deposits in distant organs, such as spleen and brain where they were still detected one year after injection. Both fluorescent materials injected into muscle translocated to draining lymph nodes (DLNs) and thereafter were detected associated with phagocytes in blood and spleen. Particles linearly accumulated in the brain up to the six-month endpoint; they were first found in perivascular CD11b+ cells and then in microglia and other neural cells. DLN ablation dramatically reduced the biodistribution. Cerebral translocation was not observed after direct intravenous injection, but significantly increased in mice with chronically altered blood-brain-barrier. Loss/gain-of-function experiments consistently implicated CCL2 in systemic diffusion of Al-Rho particles captured by monocyte-lineage cells and in their subsequent neurodelivery. Stereotactic particle injection pointed out brain retention as a factor of progressive particle accumulation. CONCLUSION: Nanomaterials can be transported by monocyte-lineage cells to DLNs, blood and spleen, and, similarly to HIV, may use CCL2-dependent mechanisms to penetrate the brain. This occurs at a very low rate in normal conditions explaining good overall tolerance of alum despite its strong neurotoxic potential. However, continuously escalating doses of this poorly biodegradable adjuvant in the population may become insidiously unsafe, especially in the case of overimmunization or immature/altered blood brain barrier or high constitutive CCL-2 production.


Assuntos
Adjuvantes Imunológicos/farmacocinética , Compostos de Alúmen/farmacocinética , Encéfalo/imunologia , Quimiocina CCL2/metabolismo , Músculos/imunologia , Nanopartículas , Vírion/patogenicidade , Animais , Ásia , Barreira Hematoencefálica/imunologia , Encéfalo/metabolismo , Movimento Celular , Quimiocina CCL2/sangue , Humanos , Imunização/efeitos adversos , Injeções Intramusculares/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/imunologia , Músculos/metabolismo , Distribuição Tecidual , Vacinas/administração & dosagem , Vacinas/efeitos adversos
19.
Ann Rheum Dis ; 72(3): 445-52, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22962315

RESUMO

OBJECTIVES: The pathophysiology of dermatomyositis (DM) remains unclear, combining immunopathological mechanisms with ischaemic changes regarded as a consequence of membranolytic attack complex (MAC)-induced capillary destruction. The study is a reappraisal of the microvascular involvement in light of the microvascular organisation in normal human muscle. METHODS: Muscle microvasculature organisation was analysed using 3D reconstructions of serial sections immunostained for CD31, and histoenzymatic detection of endogenous alkaline phosphatase activity of microvessels. An unbiased point pattern analysis-based method was used to evaluate focal capillary loss. Double immunostainings identified cell types showing MAC deposits. RESULTS: The normal arterial tree includes perimysial arcade arteries, transverse arteries penetrating perpendicularly into the endomysium and terminal arterioles feeding a microvascular unit (MVU) of six to eight capillaries contacting an average of five myofibres. Amyopathic DM cases (n=3) and non-necrotic fascicles of early DM cases (n=27), showed patchy capillary loss in the form of 6-by-6 capillary drop-out, corresponding to depletion of one or multiple MVUs. MAC deposits were also clustered (5-8 immunostained structures, including endothelial cells, but also pericytes, mesenchymal cells and myosatellite cells). CONCLUSIONS: Capillary loss may not be the primary cause of muscle ischaemia in DM. The primary event rather stands upstream, probably at the level of perimysial arcade arteries around which inflammatory infiltrates predominate and which lumen may show narrowing in chronic DM. Ischaemia-reperfusion injury, which is favoured by autoimmune backgrounds in experimental models and which activates the complement cascade in capillaries, could represent an hitherto unsuspected (and potentially preventable) mechanism of muscle damage in DM.


Assuntos
Dermatomiosite/patologia , Microvasos/patologia , Músculo Esquelético/irrigação sanguínea , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imageamento Tridimensional , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Adulto Jovem
20.
BJU Int ; 111(7): 1105-16, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23470219

RESUMO

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Cell therapy using muscle precursor cell (MPC) injections has shown promise for urinary incontinence due to intrinsic sphincter deficiency (ISD), but the cell-preparation process is complex and costly. Implantation of freshly isolated myofibres carrying MPCs, mainly satellite cells, was very efficient in repairing muscle damage in recent animal experiments. In a phase I clinical trial, we investigated whether periurethral myofibre implantation generated local myogenesis and improved continence in 10 patients (five men and five women) with ISD. We found that myofibre implantation increased intraurethral pressure and periurethral electromyographic activity in patients with ISD. There were no serious side-effects. OBJECTIVES: To assess the safety of periurethral myofibre implantation in patients with urinary incontinence due to intrinsic sphincter deficiency (ISD) To assess the resulting myogenic process and effects on urinary continence. PATIENTS AND METHODS: An open-label non-randomised phase I clinical trial was conducted in five men and five women with ISD (mean age, 62.5 years). A free muscle strip from the patient's gracilis muscle was implanted around the urethra as a means to deliver locally myofibres and muscle precursor cells (MPCs). Patients were assessed for collection formation and incomplete bladder emptying. The maximum urethral closure pressure (MUCP) and concomitant periurethral electromyographic (EMG) activity were recorded before surgery and 1 and 3 months after surgery. Continence was assessed using the 24-h pad test and self-completed questionnaires, for 12 months. RESULTS: There were no serious side-effects. Continence improved significantly during the 12-month follow-up in four of the five women, including two who recovered normal continence. In the women, MUCP increased two-fold and de novo EMG periurethral activity was recorded. In the men, MUCP and EMG recordings showed similar improvements but the effect on continence was moderate. The few patients enrolled could affect these results. CONCLUSIONS: This is the first report of a one-step procedure for transferring autologous MPCs via myofibre implantation in patients with ISD. EMG and urodynamic assessments showed improvement of periurethral muscle activity. Further work is needed to confirm and improve the therapeutic efficiency of this procedure.


Assuntos
Células Musculares/transplante , Músculo Liso/transplante , Uretra/fisiopatologia , Incontinência Urinária/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Animais , Feminino , Humanos , Injeções , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Recuperação de Função Fisiológica , Inquéritos e Questionários , Resultado do Tratamento , Incontinência Urinária/fisiopatologia , Urodinâmica
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