Abstract
We asked whether myopathology features of immune or inflammatory myopathies (IIM), without reference to clinical or laboratory attributes, correlate with serum autoantibodies. Retrospective ...study included 148 muscle biopsies with: B-cell inflammatory foci (BIM), myovasculopathy, perimysial pathology (IMPP), myofiber necrosis without perimysial or vessel damage or inflammation (MNec), inflammation and myofiber vacuoles or mitochondrial pathology (IM-VAMP), granulomas, chronic graft-versus-host disease, or none of these criteria. 18 IIM-related serum autoantibodies were tested. Strong associations between myopathology and autoantibodies included: BIM with PM/Scl-100 (63%; odds ratio OR = 72); myovasculopathies with TIF1-γ or NXP2 (70%; OR = 72); IMPP with Jo-1 (33%; OR = 28); MNec with SRP54 (23%; OR = 37); IM-VAMP with NT5C1a (95%; OR = 83). Hydroxymethylglutaryl-CoA reductase (HMGCR) antibodies related to presence of myofiber necrosis across all groups (82%; OR = 9), but not to one IIM pathology group. Our results validate characterizations of IIM by myopathology features, showing strong associations with some serum autoantibodies, another objective IIM-related marker. BIM with PM/Scl-100 antibodies can be described pathologically as polymyositis. Tif1-γ and NXP2 antibodies are both common in myovasculopathies. HMGCR antibodies associate with myofiber necrosis, but not one IIM pathology subtype. Relative association strengths of IIM-related autoantibodies to IIM myopathology features versus clinical characteristics require further study.
We compared features of nerve enlargement in inherited and acquired demyelinating neuropathies using ultrasound. We measured median and ulnar nerve cross-sectional areas in proximal and distal ...regions in 128 children and adults with inherited Charcot–Marie–Tooth-1 (CMT-1) (
n
= 35) and acquired chronic inflammatory demyelinating polyneuropathy (CIDP) (
n
= 55), Guillaine–Barre syndrome (GBS) (
n
= 21) and multifocal motor neuropathy (MMN) (
n
= 17) demyelinating neuropathies. We classified nerve enlargement by degree and number of regions affected. We defined patterns of nerve enlargement as: none, no enlargement; mild, nerves enlarged but never more than twice normal; regional, nerves normal in at least one region and enlarged more than twice normal in at least one region; diffuse, nerves enlarged at all four regions with at least one region more than twice normal size. Nerve enlargement was commonly diffuse (89 %) and generally more than twice normal size in CMT-1, but not (
p
< 0.001) in acquired disorders which mostly had either no, mild or regional nerve enlargement CIDP (64 %), GBS (95 %), and MMN (100 %). In CIDP, subjects treated within 3 months of disease onset had less nerve enlargement than those treated later. Ultrasound identified patterns of diffuse nerve enlargement can be used to screen patients suspected of having CMT-1. Normal, mildly, or regionally enlarged nerves in demyelinating polyneuropathy suggests an acquired etiology. Early treatment in CIDP may impede nerve enlargement.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Summary Background Mutations in SOD1 cause 13% of familial amyotrophic lateral sclerosis. In the SOD1 Gly93Ala rat model of amyotrophic lateral sclerosis, the antisense oligonucleotide ISIS 333611 ...delivered to CSF decreased SOD1 mRNA and protein concentrations in spinal cord tissue and prolonged survival. We aimed to assess the safety, tolerability, and pharmacokinetics of ISIS 333611 after intrathecal administration in patients with SOD1 -related familial amyotrophic lateral sclerosis. Methods In this randomised, placebo-controlled, phase 1 trial, we delivered ISIS 333611 by intrathecal infusion using an external pump over 11·5 h at increasing doses (0·15 mg, 0·50 mg, 1·50 mg, 3·00 mg) to four cohorts of eight patients with SOD1 -positive amyotrophic lateral sclerosis (six patients assigned to ISIS 333611, two to placebo in each cohort). We did the randomisation with a web-based system, assigning patients in blocks of four. Patients and investigators were masked to treatment assignment. Participants were allowed to re-enrol in subsequent cohorts. Our primary objective was to assess the safety and tolerability of ISIS 333611. Assessments were done during infusion and over 28 days after infusion. This study was registered with Clinicaltrials.gov , number NCT01041222. Findings Seven of eight (88%) patients in the placebo group versus 20 of 24 (83%) in the ISIS 333611 group had adverse events. The most common events were post-lumbar puncture syndrome (3/8 38% vs 8/24 33%), back pain (4/8 50% vs 4/24 17%), and nausea (0/8 0% vs 3/24 13%). We recorded no dose-limiting toxic effects or any safety or tolerability concerns related to ISIS 333611. No serious adverse events occurred in patients given ISIS 333611. Re-enrolment and re-treatment were also well tolerated. Interpretation This trial is the first clinical study of intrathecal delivery of an antisense oligonucleotide. ISIS 333611 was well tolerated when administered as an intrathecal infusion. Antisense oligonucleotides delivered to the CNS might be a feasible treatment for neurological disorders. Funding The ALS Association, Muscular Dystrophy Association, Isis Pharmaceuticals.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Objective
To define the genetic landscape of amyotrophic lateral sclerosis (ALS) and assess the contribution of possible oligogenic inheritance, we aimed to comprehensively sequence 17 known ALS ...genes in 391 ALS patients from the United States.
Methods
Targeted pooled‐sample sequencing was used to identify variants in 17 ALS genes. Fragment size analysis was used to define ATXN2 and C9ORF72 expansion sizes. Genotype–phenotype correlations were made with individual variants and total burden of variants. Rare variant associations for risk of ALS were investigated at both the single variant and gene level.
Results
A total of 64.3% of familial and 27.8% of sporadic subjects carried potentially pathogenic novel or rare coding variants identified by sequencing or an expanded repeat in C9ORF72 or ATXN2; 3.8% of subjects had variants in >1 ALS gene, and these individuals had disease onset 10 years earlier (p = 0.0046) than subjects with variants in a single gene. The number of potentially pathogenic coding variants did not influence disease duration or site of onset.
Interpretation
Rare and potentially pathogenic variants in known ALS genes are present in >25% of apparently sporadic and 64% of familial patients, significantly higher than previous reports using less comprehensive sequencing approaches. A significant number of subjects carried variants in >1 gene, which influenced the age of symptom onset and supports oligogenic inheritance as relevant to disease pathogenesis. ANN NEUROL 2015;77:100–113
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
OBJECTIVE:To assess safety and efficacy of deflazacort (DFZ) and prednisone (PRED) vs placebo in Duchenne muscular dystrophy (DMD).
METHODS:This phase III, double-blind, randomized, ...placebo-controlled, multicenter study evaluated muscle strength among 196 boys aged 5–15 years with DMD during a 52-week period. In phase 1, participants were randomly assigned to receive treatment with DFZ 0.9 mg/kg/d, DFZ 1.2 mg/kg/d, PRED 0.75 mg/kg/d, or placebo for 12 weeks. In phase 2, placebo participants were randomly assigned to 1 of the 3 active treatment groups. Participants originally assigned to an active treatment continued that treatment for an additional 40 weeks. The primary efficacy endpoint was average change in muscle strength from baseline to week 12 compared with placebo. The study was completed in 1995.
RESULTS:All treatment groups (DFZ 0.9 mg/kg/d, DFZ 1.2 mg/kg/d, and PRED 0.75 mg/kg/d) demonstrated significant improvement in muscle strength compared with placebo at 12 weeks. Participants taking PRED had significantly more weight gain than placebo or both doses of DFZ at 12 weeks; at 52 weeks, participants taking PRED had significantly more weight gain than both DFZ doses. The most frequent adverse events in all 3 active treatment arms were Cushingoid appearance, erythema, hirsutism, increased weight, headache, and nasopharyngitis.
CONCLUSIONS:After 12 weeks of treatment, PRED and both doses of DFZ improved muscle strength compared with placebo. Deflazacort was associated with less weight gain than PRED.
CLASSIFICATION OF EVIDENCE:This study provides Class I evidence that for boys with DMD, daily use of either DFZ and PRED is effective in preserving muscle strength over a 12-week period.
Mutations in the mitochondrial fusion protein mitofusin 2 (MFN2) are the most commonly identified cause of Charcot-Marie-Tooth type 2 (CMT2), a dominantly inherited disease characterized by ...degeneration of peripheral sensory and motor axons. However, the mechanism by which mutations in this ubiquitously expressed mitochondrial fusion protein lead to neuropathy has not yet been elucidated. To explore how MFN2 mutations lead to degeneration of peripheral axons, we expressed neuropathy-associated forms of MFN2 in cultured dorsal root ganglion neurons, cells preferentially affected in CMT2. Disease-associated MFN2 mutant proteins induced abnormal clustering of small fragmented mitochondria in both neuronal cell bodies and proximal axons. Interestingly, transport of mitochondria in axons was significantly impaired in neurons expressing disease-mutated forms of MFN2. The diminished axonal mitochondrial transport was not attributable to diminished ATP levels in the neurons, and oxidative respiration was normal in mutant MFN2-expressing cells. Additionally, mitochondrial oxidative enzyme activity was normal in muscle mitochondria from a CMT2 patient with an MFN2 mutation, further supporting that abnormal mitochondrial transport in neurons is independent from an energy production defect. This abnormal mitochondrial trafficking provides a likely explanation for the selective susceptibility of the longest peripheral axons to MFN2 mutations, in which proper localization of mitochondria is critical for axonal and synaptic function.
ACOX1 (acyl-CoA oxidase 1) encodes the first and rate-limiting enzyme of the very-long-chain fatty acid (VLCFA) β-oxidation pathway in peroxisomes and leads to H2O2 production. Unexpectedly, ...Drosophila (d) ACOX1 is mostly expressed and required in glia, and loss of ACOX1 leads to developmental delay, pupal death, reduced lifespan, impaired synaptic transmission, and glial and axonal loss. Patients who carry a previously unidentified, de novo, dominant variant in ACOX1 (p.N237S) also exhibit glial loss. However, this mutation causes increased levels of ACOX1 protein and function resulting in elevated levels of reactive oxygen species in glia in flies and murine Schwann cells. ACOX1 (p.N237S) patients exhibit a severe loss of Schwann cells and neurons. However, treatment of flies and primary Schwann cells with an antioxidant suppressed the p.N237S-induced neurodegeneration. In summary, both loss and gain of ACOX1 lead to glial and neuronal loss, but different mechanisms are at play and require different treatments.
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•Loss of dACOX1 leads to glial degeneration via accumulation of VLCFA•A de novo ACOX1N237S gain-of-function mutation also leads to glial loss•Glial loss in ACOX1N237S is associated with elevated ROS, not an increase in VLCFA•N-acetyl cysteine amide, an antioxidant, suppresses glial defects in ACOX1N237S flies
Chung et al. show that ACOX1, a peroxisomal protein required for degrading VLCFA, is mostly expressed in glial cells. Its loss causes an accumulation of VLCFA and glial loss. An ACOX1 gain-of-function mutation identified in three individuals leads to elevated ROS and glial loss and is potently suppressed by antioxidants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Introduction
Causes of small‐fiber peripheral neuropathies (SFN) are often undefined. In this study we investigated associations of serum autoantibodies, immunoglobulin G (IgG) vs fibroblast growth ...factor receptor‐3 (FGFR‐3), and immunoglobulin M (IgM) vs trisulfated heparan disaccharide (TS‐HDS) in cryptogenic SFN.
Methods
One hundred fifty‐five patients with biopsy‐proven SFN and no identified cause for their neuropathy were blindly tested for serum IgM vs TS‐HDS and IgG vs FGFR‐3.
Results
Forty‐eight percent of SFN patients had serum antibodies, 37% with IgM vs TS‐HDS and 15% with IgG vs FGFR‐3. TS‐HDS antibodies were more frequent in SFN patients than in controls (P = .0012). Both antibodies were more common in females, and with non–length‐dependent nerve pathology. Nintey‐two percent of patients with acute‐onset SFN had serum IgM vs TS‐HDS.
Discussion
Autoantibodies directed against TS‐HDS and FGFR‐3 suggest an immune disorder in otherwise idiopathic SFN. Serum IgM vs TS‐HDS may be a marker for SFN with an acute onset.
See editorial on pages 433–435 in this issue.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
Myopathies during chronic graft-versus-host disease (cGvHD) are syndromes for which tissue targets and mechanisms of muscle damage remain incompletely defined. This study reviewed, and ...pathologically analyzed, 14 cGvHD myopathies, comparing myopathology to other immune myopathies. Clinical features in cGvHD myopathy included symmetric, proximal weakness, associated skin, gastrointestinal and lung disorders, a high serum aldolase (77%), and a 38% 2-year survival. Muscle showed noninflammatory pathology involving all 3 tissue components. Perimysial connective tissue had damaged structure and histiocytic cells. Vessel pathology included capillary loss, and reduced α-l-fucosyl and chondroitin sulfate moieties on endothelial cells. Muscle fibers often had surface pathology. Posttranslational glycosylation moieties on α-dystroglycan had reduced staining and abnormal distribution in 86%. Chondroitin-SO4 was reduced in 50%, a subgroup with 3-fold longer times from transplant to myopathy, and more distal weakness. cGvHD myopathies have noninflammatory pathology involving all 3 tissue components in muscle, connective tissue, small vessels, and myofibers. Abnormal cell surface glycosylation moieties are common in cGvHD myopathies, distinguishing them from other immune myopathies. This is the first report of molecular classes that may be immune targets in cGvHD. Disordered cell surface glycosylation moieties could produce disease-related tissue and cell damage, and be biomarkers for cGvHD features and activity.
Pompe's disease is caused by a deficiency of acid alpha glucosidase, which degrades lysosomal glycogen. Late-onset Pompe's disease is characterized by progressive muscle weakness and loss of ...respiratory function, leading to early death. In this randomized, placebo-controlled trial of a recombinant human acid alpha glucosidase, walking distance improved and pulmonary function stabilized over an 18-month period in patients treated with the active drug.
Late-onset Pompe's disease is characterized by progressive muscle weakness and loss of respiratory function, leading to early death. In this trial of a recombinant human acid alpha glucosidase, walking distance improved and pulmonary function stabilized over an 18-month period in patients treated with the active drug.
Pompe's disease is a rare, autosomal recessive, progressive neuromuscular disease caused by a deficiency of acid α-glucosidase (GAA), which degrades lysosomal glycogen. In patients with the classic infantile form, the deposition of glycogen in the heart, skeletal, and respiratory muscles causes severe cardiomyopathy, hypotonia, and respiratory failure, typically leading to death within the first year of life.
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Children and adults, in contrast, have variable rates of disease progression. Glycogen deposition is confined mainly to skeletal and respiratory muscles, causing progressive limb-girdle myopathy and respiratory insufficiency.
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Respiratory failure is a major cause of death.
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No disease-specific . . .
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