Immunopathological features of myopathy associated with small-to-medium-sized vessel vasculitis and differences from autoimmune myositis.

OBJECTIVES: Patients with systemic vasculitis may develop myalgia as an initial symptom. However, the immunopathology of vasculitic myopathy remains unclear. We investigated the immunopathological features of skeletal muscle in small-to-medium-sized vessel vasculitis. METHODS: We analysed muscle tissue biopsies from 15 patients with vasculitis, including antineutrophil cytoplasmic antibodyassociated vasculitis and polyarteritis nodosa, and 15 patients with autoimmune myositis (AIM), including polymyositis and immune-mediated necrotising myopathy, as comparison disease controls. Immunohistochemical staining for CD56/neural cell adhesion molecule (NCAM), major histocompatibility complex class I, C5b-9/membrane attack complex (MAC), and CD31 was performed. The vascularity score was defined as the total number of CD31-expressing blood vessels. The association between CD56/NCAM-expressing myofibers and clinical findings was evaluated in patients with vasculitis. RESULTS: Patients with vasculitis had a significantly lower frequency of CD56/NCAM-expressing myofibers than those with AIM and a positive correlation between the frequency of CD56/NCAM-expressing myofibers and serum aldolase levels. Patients with vasculitis had significantly fewer major histocompatibility complex class I-expressing myofibers and C5b-9/MAC deposits on the sarcolemma than those with AIM. C5b-9/MAC deposits in blood vessels were observed in >70% of patients with vasculitis. Patients with vasculitis had significantly higher vascularity scores in the endomysium than those with AIM. CONCLUSIONS: Patients with vasculitis demonstrated mild myofiber damage based on the lower involvement of CD56/NCAM-expressing myofibers compared to those with AIM. Complement component deposits on the vessel walls and hypervascularity in the endomysium areas may be immunopathological features of vasculitic myopathy.

Clinical characteristics of patients with myalgia as the initial manifestation of small and medium-sized vasculitis: a retrospective study.

Myalgia is a common symptom in small and medium-sized systemic vasculitis, sometimes occurring as the initial or only clinical manifestation of vasculitis. This study investigated the clinical features and diagnostic process in patients presenting with myalgia as the initial symptom of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) or polyarteritis nodosa (PAN). We included 93 patients diagnosed with AAV or PAN by retrospectively reviewing their clinical records at the initial diagnosis. Clinical findings and diagnostic methods were assessed in patients with myalgia. Of 93 patients, myalgia was observed in 21 (22.6%) patients, with diagnostic classifications of microscopic polyangiitis (MPA) in 12 (52.4%), granulomatosis with polyangiitis in 2 (9.5%), eosinophilic granulomatosis with polyangiitis in 2 (9.5%), and PAN in 5 (23.8%). Myalgia was present in the lower extremities of all patients; more than 80% of patients had pain in the calf muscle. In 10 patients with myalgia, including 7 with MPA and 3 with PAN, muscle biopsy was performed because myalgia was the main symptom and no other impaired organs were suitable for biopsy. Consequently, 8 patients had necrotizing vasculitis, leading to MPA or PAN diagnosis, although muscle pathology was not evaluated in patients without myalgia. Muscle magnetic resonance imaging was useful in determining the biopsy site. Myalgia, especially in the lower limbs, may be an initial clinical sign of vasculitis, particularly in MPA or PAN patients. Moreover, the histological evidence of muscular vasculitis can contribute to a definite diagnosis especially in patients presenting with myalgia as an early symptom of AAV or PAN.

Amelioration of intracellular Ca2+ regulation by exon-45 skipping in Duchenne muscular dystrophy-induced pluripotent stem cell-derived cardiomyocytes.

Duchenne muscular dystrophy (DMD) is a devastating muscle disorder caused by frameshift mutations in the DMD gene. DMD involves cardiac muscle, and the presence of ventricular arrhythmias or congestive failure is critical for prognosis. Several novel therapeutic approaches are being evaluated in ongoing clinical trials. Among them, exon-skipping therapy to correct frameshift mutations with antisense oligonucleotides is promising; however, their therapeutic efficacies on cardiac muscle in vivo remain unknown. In this study, we established induced-pluripotent stem cells (iPSCs) from T cells from a DMD patient carrying a DMD-exon 46-55 deletion, differentiated the iPSCs into cardiomyocytes, and treated them with phosphorodiamidate morpholino oligomers. The efficiency of exon-45 skipping increased in a dose-dependent manner and enabled restoration of the DMD gene product, dystrophin. Further, Ca2+-imaging analysis showed a decreased number of arrhythmic cells and improved transient Ca2+ signaling after exon skipping. Thus, exon-45 skipping may be effective for cardiac involvement in DMD patients harboring the DMD-exon 46-55 deletion.

Comparison of the phenotypes of patients harboring in-frame deletions starting at exon 45 in the Duchenne muscular dystrophy gene indicates potential for the development of exon skipping therapy.

Exon skipping therapy has recently received attention for its ability to convert the phenotype of lethal Duchenne muscular dystrophy (DMD) to a more benign form, Becker muscular dystrophy (BMD), by correcting the open reading frame. This therapy has mainly focused on a hot-spot (exons 45-55) mutation in the DMD gene. Exon skipping of an entire stretch of exons 45-55 is an approach applicable to 46.9% of DMD patients. However, the resulting phenotype is not yet fully understood. Here we examined the clinical profiles of 24 patients with BMD resulting from deletions starting at exon 45. The Δ45-55 group ranged in age from 2 to 87 years; no mortality was observed, and one patient was ambulatory at 79 years of age. The age at which patients became wheelchair-bound in the Δ45-48 group (18-88 years old) was approximately 50 years. Cardiomyopathy was well controlled by pharmaceuticals in both deletion groups. In contrast, the Δ45-47 and Δ45-49 groups exhibited more severe phenotypes than those with other mutations: the age at which patients in the Δ45-49 group became wheelchair-bound was around 30-40 years. Our study shows that clinical severity differs between each hot-spot deletion.

Differential roles of MMP-9 in early and late stages of dystrophic muscles in a mouse model of Duchenne muscular dystrophy.

Matrix metalloprotease (MMP)-9 is an endopeptidase associated with the pathogenesis of Duchenne muscular dystrophy (DMD). The precise function of MMP-9 in DMD has not been elucidated to date. We investigated the effect of genetic ablation of MMP-9 in the mdx mouse model (mdx/Mmp9(-/-)). At the early disease stage, the muscles of mdx/Mmp9(-/-) mice showed reduced necrosis and neutrophil invasion, accompanied by down-regulation of chemokine MIP-2. In addition, muscle regeneration was enhanced, which coincided with increased macrophage infiltration and upregulation of MCP-1, and resulted in increased muscle strength. The mdx/Mmp9(-/-) mice also displayed accelerated upregulation of osteopontin expression in skeletal muscle at the acute onset phase of dystrophy. However, at a later disease stage, the mice exhibited muscle growth impairment through altered expression of myogenic factors, and increased fibroadipose tissue. These results showed that MMP-9 might have multiple functions during disease progression. Therapy targeting MMP-9 may improve muscle pathology and function at the early disease stage, but continuous inhibition of this protein may result in the accumulation of fibroadipose tissues and reduced muscle strength at the late disease stage.

Deletion of exons 3-9 encompassing a mutational hot spot in the DMD gene presents an asymptomatic phenotype, indicating a target region for multiexon skipping therapy.

Few cases of dystrophinopathy show an asymptomatic phenotype with mutations in the 5' (exons 3-7) hot spot in the Duchenne muscular dystrophy (DMD) gene. Our patient showed increased serum creatine kinase levels at 12 years of age. A muscle biopsy at 15 years of age led to a diagnosis of Becker muscular dystrophy. The patient showed a slight decrease in cardiac function at the age of 21 years and was administered a ß-blocker, but there was no muscle involvement even at the age of 27 years. A deletion of exons 3-9 encompassing a mutational hot spot in the DMD gene was detected, and dystrophin protein expression was ∼15% that of control level. We propose that in-frame deletion of exons 3-9 may produce a functional protein, and that multiexon skipping therapy targeting these exons may be feasible for severe dystrophic patients with a mutation in the 5' hot spot of the DMD gene.

Elevation of serum heat-shock protein levels in amyotrophic lateral sclerosis.

Heat-shock proteins (HSPs) have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). In this study, we aimed to examine whether the serum levels of HSPs (HSP27, HSP70, and HSP90) are altered in patients with ALS. We included 58 patients diagnosed with ALS and 85 control individuals. Serum HSP levels of patients and controls were determined using enzyme-linked immunosorbent assay. The serum levels of HSP70 and HSP90 were significantly higher in patients than in controls. In contrast, serum levels of HSP27 did not differ significantly between the patient and control groups. Moreover, serum levels of HSP70 and HSP90 in patients remained high throughout the duration of the disease. Taken together, our findings suggest that HSPs might have a role in ALS progression throughout the course of the disease. Further studies are needed to clarify the role of HSPs in the pathogenesis of ALS.

Matrix metalloproteinase-2 ablation in dystrophin-deficient mdx muscles reduces angiogenesis resulting in impaired growth of regenerated muscle fibers.

Matrix metalloproteases (MMPs) are a family of endopeptidases classified into subgroups based on substrate preference in normal physiological processes such as embryonic development and tissue remodeling, as well as in various disease processes via degradation of extracellular matrix components. Among the MMPs, MMP-9 and MMP-2 have been reported to be up-regulated in skeletal muscles in the lethal X-linked muscle disorder Duchenne muscular dystrophy (DMD), which is caused by loss of dystrophin. A recent study showed that deletion of the MMP9 gene in mdx, a mouse model for DMD, improved skeletal muscle pathology and function; however, the role of MMP-2 in the dystrophin-deficient muscle is not well known. In this study, we aimed at verifying the role of MMP-2 in the dystrophin-deficient muscle by using mdx mice with genetic ablation of MMP-2 (mdx/MMP-2(-/-)). We found impairment of regenerated muscle fiber growth with reduction of angiogenesis in mdx/MMP-2(-/-) mice at 3 months of age. Expression of vascular endothelial growth factor-A (VEGF-A), an important angiogenesis-related factor, decreased in mdx/MMP-2(-/-) mice at 3 months of age. MMP-2 had not a critical role in the degradation of dystrophin-glycoprotein complex (DGC) components such as ß-dystroglycan and ß-sarcoglycan in the regeneration process of the dystrophic muscle. Accordingly, MMP-2 may be essential for growth of regenerated muscle fibers through VEGF-associated angiogenesis in the dystrophin-deficient skeletal muscle.

Restoring Dystrophin Expression with Duchenne Muscular Dystrophy Exon 45 Skipping in Induced Pluripotent Stem Cell-Derived Cardiomyocytes.

Induced pluripotent stem cell (iPSC)-based disease model is a useful tool that can represent the pathophysiology of patient organs that are inaccessible due to invasiveness. Here, we present a method to induce differentiation of Duchenne muscular dystrophy (DMD) patient-derived iPSCs into cardiomyocytes and restore dystrophin expression by exon skipping using antisense nucleic acids. This involves a 20-day multi-step culture process for differentiation to cardiomyocytes, followed by exon-skipping experiments. Additionally, RT-PCR, western blotting, and immunocytochemistry are used to confirm the restoration of dystrophin expression.

Efficacy of exon-skipping therapy for DMD cardiomyopathy with mutations in actin binding domain 1.

Exon-skipping therapy is a promising treatment strategy for Duchenne muscular dystrophy (DMD), which is caused by loss-of-function mutations in the DMD gene encoding dystrophin, leading to progressive cardiomyopathy. In-frame deletion of exons 3-9 (Δ3-9), manifesting a very mild clinical phenotype, is a potential targeted reading frame for exon-skipping by targeting actin-binding domain 1 (ABD1); however, the efficacy of this approach for DMD cardiomyopathy remains uncertain. In this study, we compared three isogenic human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) expressing Δ3-9, frameshifting Δ3-7, or intact DMD. RNA sequencing revealed a resemblance in the expression patterns of mechano-transduction-related genes between Δ3-9 and wild-type samples. Furthermore, we observed similar electrophysiological properties between Δ3-9 and wild-type hiPSC-CMs; Δ3-7 hiPSC-CMs showed electrophysiological alterations with accelerated CaMKII activation. Consistently, Δ3-9 hiPSC-CMs expressed substantial internally truncated dystrophin protein, resulting in maintaining F-actin binding and desmin retention. Antisense oligonucleotides targeting exon 8 efficiently induced skipping exons 8-9 to restore functional dystrophin and electrophysiological parameters in Δ3-7 hiPSC-CMs, bringing the cell characteristics closer to those of Δ3-9 hiPSC-CMs. Collectively, exon-skipping targeting ABD1 to convert the reading frame to Δ3-9 may become a promising therapy for DMD cardiomyopathy.

Natural history of Becker muscular dystrophy: a multicenter study of 225 patients.

OBJECTIVE: Becker muscular dystrophy (BMD) is a milder variant of Duchenne muscular dystrophy (DMD), a lethal X-linked muscular disorder. Here, we aim to investigat the clinical involvement of skeletal, respiratory, cardiac, and central nervous systems in patients with BMD, as well as genotype-phenotype relationships. METHODS: This nationwide cohort study investigated the clinical manifestations and genotype-phenotype relationships in 225 patients with BMD having in-frame deletion from 22 medical centers. The primary outcome was to elucidate the association of genotype with skeletal muscle, respiratory, cardiac, and central nervous system disorders. Descriptive statistics were used to analyze the data. RESULTS: The average age of the subjects was 31.5 (range, 1-81) years. Initial symptoms of BMD were muscular (60%), followed by asymptomatic hypercreatine kinasemia (32.4%) and central nervous system disorders (5.3%). Gait disturbance was observed in 53.8% of patients and the average age at wheelchair introduction was 36.5 years. The ventilator introduction rate was 6.7% at an average age of 36.6 years. More than 30% of patients had an abnormal electrocardiogram and approximately 15% had heart failure symptoms. Cardiac function on echocardiography varied significantly among the patients. The frequencies of seizures and intellectual/developmental disability were 8.0% and 16.9%, respectively. Exon 45-47deletion (del) was the most common (22.6%), followed by exon 45-48del (13.1%). Patients with exon 45-49del patients demonstrated severe skeletal muscle damage. Patients with exon 45-47del and exon 45-55del patients did not require ventilator use. INTERPRETATION: The study provides important prognostic information for patients and clinicians to establish therapy plans and to implement preventative medicine.

[Dropped head sign and tongue atrophy in systemic sclerosis-associated myopathy: a case report].

We report a 70-year-old man with a 5-year history of Raynaud's phenomenon and slow progression of weight loss, easy fatigability, muscle weakness, skin sclerosis, and dropped head sign. The patient was assumed to have motor neuron disease by his attending physician, and was referred to our hospital. Physical examination showed skin sclerosis on the fingers, hands, forearms, face, and neck. Neurological examination showed advanced systemic muscle atrophy and weakness, especially in the neck, tongue, and proximal limb muscles. Fasciculations were not observed in these involved muscles. Deep tendon reflexes were hypoactive and pathological reflexes were negative. Sensory disturbance was absent. Laboratory tests showed moderately elevated serum creatine kinase level, and increased serum antinuclear antibody titer (1:5120 with a nucleolar pattern). Needle electromyography showed a typical myogenic pattern in proximal muscles. The patient was diagnosed as having systemic sclerosis (SSc) with SSc-associated myopathy. Severe systemic muscle involvements, including dropped head sign and tongue atrophy, are rare manifestations in patients with SSc-associated myopathy. Our observations suggest that it is essential to pay attention to the dermatological findings of SSc in differential diagnosis of patients with muscular atrophy.

Characterization of deletion breakpoints in patients with dystrophinopathy carrying a deletion of exons 45-55 of the Duchenne muscular dystrophy (DMD) gene.

Deletion of exons 45-55 (del45-55) in the Duchenne muscular dystrophy gene (DMD) has gained particular interest in the field of molecular therapy, because it causes a milder phenotype than DMD, and therefore, may represent a good candidate for the goal of a multiple exon-skipping strategy. We have precisely characterized deletion breakpoints in three patients with del45-55 in DMD. Two of them were young adult males of the X-linked dilated cardiomyopathy phenotype, and the third patient revealed the mild Becker muscular dystrophy phenotype of late onset. The deletion breakpoints differed among patients. The deletion started at nt 226 604, 231 518, 117 284 in intron 44, and ended at nt 64 994, 59 314, 71 806 in intron 55, respectively. Deletion junctions showed no significant homology between the sequences adjacent to the distal and proximal end joints in these patients. Deletion breakpoints were not primarily associated with any particular sequence element, or with a matrix attachment region. However, there were several palindromic sequences and short tandem repeats at or near the breakpoints. These sequences, with a marked propensity to form secondary DNA structure intermediates, may predispose local DNA to breakage and intragenic recombination in these patients.

Spinocerebellar ataxia type 6 (SCA6): clinical pilot trial with gabapentin.

The clinical effect of the GABAergic drug gabapentin was evaluated in 11 patients with spinocerebellar ataxia type 6 (SCA6). The total period of gabapentin treatment was 4 weeks, and outcome measures were determined with the International Cooperative Ataxia Rating Scales (ICARS) and postural sway studies. At week 4, 5 patients showed a decrease of the ICARS values by more than 10% compared with the pre-treatment baseline. Eight patients showed a more than 10% decrease of the sway area (SA) and/or sway path length (SPL) values in postural sway studies. The ICARS values and SA/SPL values were not necessarily consistent in each patient, but 3 patients showed a more than 10% decrease in the ICRAS, SA, and SPL values at week 4 when compared to the pre-treatment baseline. As a whole, the efficacy of gabapentin was not statistically confirmed in the 4-week trial because of the variation in efficacy in each patient, but the data are indicative that some SCA6 patients could benefit from gabapentin treatment.

A Patient with Limbic Encephalitis Associated with Anti-leucine-rich Glioma-inactivated 1 (LGI1) Antibody Presenting with Slowly Progressive Cognitive Impairment and Fluctuating Striatal Lesions.

We herein report the case of a 59-year-old man with anti-leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis who presented with slowly progressive cognitive impairment mimicking dementia for over 3 years and then developed seizures. Unique brain magnetic resonance imaging (MRI) findings of fluctuating striatal lesions were observed during the disease course. He was treated with intravenous methylprednisolone pulse therapy followed by oral prednisolone, which dramatically improved his neurological function. Taken together, these findings indicate that anti-LGI1 encephalitis may present as slowly progressive cognitive impairment mimicking dementia and that fluctuating MRI striatal lesions may be a characteristic radiological finding of this disorder.

GCH1 mutations in dopa-responsive dystonia and Parkinson's disease.

Guanosine triphosphate cyclohydrolase I (GCH1) mutations are associated with increased risk for dopa-responsive dystonia (DRD) and Parkinson's disease (PD). Herein, we investigated the frequency of GCH1 mutations and clinical symptoms in patients with clinically diagnosed PD and DRD. We used the Sanger method to screen entire exons in 268 patients with PD and 26 patients with DRD, with the examinations of brain magnetic resonance imaging scans, striatal dopamine transporter scans, and [123I] metaiodobenzylguanidine (MIBG) myocardiac scintigraphy scans. We identified 15 patients with heterozygous GCH1 mutations from seven probands and five sporadic cases. The prevalence of GCH1 mutations in probands was different between PD [1.9% (5/268)] and DRD [26.9% (7/26)] (p value < 0.0001). The onset age tends to be different between PD and DRD patients: 35.4 ± 25.3 and 16.5 ± 13.6, respectively (average ± SD; p = 0.08). Most of the patients were women (14/15). Dystonia was common symptom, and dysautonomia and cognitive decline were uncommon in our PD and DRD. All patients presented mild parkinsonism or dystonia with excellent response to levodopa. Seven of seven DRD and three of five PD presented normal heart-to-mediastinum ratio on MIBG myocardial scintigraphy. Five of six DRD and three of four PD demonstrated normal densities of dopamine transporter. Our findings elucidated the clinical characteristics of PD and DRD patients due to GCH1 mutations. PD patients with GCH1 mutations also had different symptoms from those seen in typical PD. The patients with GCH1 mutations had heterogeneous clinical symptoms.

Protein-losing Gastroenteropathy Related to Mixed Connective Tissue Disease: A Case Report of a Successful Outcome and Literature Review.

We herein report the case of a 44-year-old woman who developed protein-losing gastroenteropathy (PLGE) with hypoalbuminemia as the first manifestation of mixed connective tissue disease (MCTD). Albumin leakage from the stomach and intestinal tract was demonstrated by 99mTc-labeled human serum albumin scintigraphy. The patient's response to prednisolone therapy was insufficient; therefore, additional cyclosporin A (CsA) treatment was administered, and clinical remission was achieved. We concluded that although PLGE is a rare complication of MCTD, it may manifest as an initial clinical episode of MCTD. Furthermore, CsA can be a useful treatment option for refractory PLGE related to MCTD.

Hypertrophic Pachymeningitis as an Early Manifestation of Relapsing Polychondritis: Case Report and Review of the Literature.

Neurological involvement in relapsing polychondritis (RP) is relatively rare. We describe the case of an 80-year-old man who presented with hypertrophic pachymeningitis (HP) together with arthritis as the first manifestation of RP. Auricular chondritis, which subsequently determined the diagnosis of RP, occurred a few weeks after the detection of HP. The neurological symptoms, as well as arthritis, were promptly improved by treatment with corticosteroids. It is generally difficult to diagnose RP in the absence of typical cartilaginous involvement; however, the present case suggests that HP may occur as an early clinical manifestation of RP.

Crossed Cerebellar Diaschisis in Status Epilepticus.

Crossed cerebellar diaschisis (CCD) is an interesting phenomenon which classically refers to the depressed blood flow and metabolism affecting one cerebellar hemisphere after a contralateral hemispheric infarction. However, CCD can also be caused by a prolonged seizure. We herein report a case of CCD due to status epilepticus in a patient who showed unique magnetic resonance imaging findings.

Multifocal Fibrosclerosis with Hypertrophic Pachymeningitis and a Soft Tissue Mass around the Thoracic Vertebral Bodies: A Case Report with Review of the Literature.

Multifocal fibrosclerosis is the term used to represent a combination of similar fibrous lesions occurring at different anatomical sites. We herein report a hypertrophic pachymeningitis patient with a soft tissue mass around the thoracic vertebral bodies. A histopathological analysis of the biopsied tissues from both lesions showed dense fibrosis and a marked infiltration of lymphocytes and plasma cells, which lead to the diagnosis of multifocal fibrosclerosis. This pathological condition closely resembles that of IgG4-related disease and is a very rare combination of manifestations. Our case suggests that hypertrophic pachymeningitis patients need to also undergo a whole body examination.