SMDT1 variants impair EMRE-mediated mitochondrial calcium uptake in patients with muscle involvement.

Ionic calcium (Ca) is a key messenger in signal transduction and its mitochondrial uptake plays an important role in cell physiology. This uptake is mediated by the mitochondrial Ca uniporter (MCU), which is regulated by EMRE (essential MCU regulator) encoded by the SMDT1 (single-pass membrane protein with aspartate rich tail 1) gene. This work presents the genetic, clinical and cellular characterization of two patients harbouring SMDT1 variants and presenting with muscle problems.

Rhabdomyolysis after COVID-19 Comirnaty Vaccination: A Case Report.

Rhabdomyolysis is an acute disruption in skeletal muscle integrity, leading to the rapid release of 4 muscle contents into the bloodstream, such as creatine kinase (CK). It can have various causes, including infections. Throughout the pandemic, multiple cases of rhabdomyolysis following COVID-19 infections have been reported.

Pathogenic variants in three families with distal muscle involvement.

Three families suspected of distal hereditary motor neuropathy underwent genetic screening with the aim to identify the molecular defect underlying the disease. The description of the identification reflects the shift in molecular diagnostics that was made during the last decades. Our candidate gene approach yielded a known pathogenic variant in BSCL2 (p.

Distal spinal muscular atrophy featured by predominant calf muscle involvement in VRK1 associated disease - Case series and review.

We describe the shared clinical, biochemical, radiological and myopathological characteristics of four patients with distal spinal muscular atrophy (dSMA) caused by vaccinia-related kinase 1 (VRK1) variants and provide a review of the literature on phenotype-genotype correlations in VRK1-related disease. The clinical phenotype was characterized by adult-onset dSMA with predominant calf muscle involvement and mildly elevated serum creatinine kinase (CK) levels. Muscle imaging showed predominant atrophy and fatty replacement of calf muscles.

Intravenous immunoglobulins as first-line treatment in idiopathic inflammatory myopathies: a pilot study.

Objectives: We explored efficacy and safety of IVIg as first-line treatment in patients with an idiopathic inflammatory myopathy.

Methods: In this investigator-initiated phase 2 open-label study, we included 20 adults with a newly diagnosed, biopsy-proven idiopathic inflammatory myopathy, and a disease duration of less than 9 months. Patients with IBM and prior use of immunosuppressants were excluded.

Biomarker profiles of endothelial activation and dysfunction in rare systemic autoimmune diseases: implications for cardiovascular risk.

Objectives: Vasculopathy is an important hallmark of systemic chronic inflammatory connective tissue diseases (CICTD) and is associated with increased cardiovascular risk. We investigated disease-specific biomarker profiles associated with endothelial dysfunction, angiogenic homeostasis and (tissue) inflammation, and their relation to disease activity in rare CICTD.

Methods: A total of 38 serum proteins associated with endothelial (dys)function and inflammation were measured by multiplex-immunoassay in treatment-naive patients with localized scleroderma (LoS, 30), eosinophilic fasciitis (EF, 8) or (juvenile) dermatomyositis (34), 119 (follow-up) samples during treatment, and 65 controls.

Autosomal recessive limb-girdle and Miyoshi muscular dystrophies in the Netherlands: The clinical and molecular spectrum of 244 patients.

In this retrospective study, we conducted a clinico-genetic analysis of patients with autosomal recessive limb-girdle muscular dystrophy (LGMD) and Miyoshi muscular dystrophy (MMD). Patients were identified at the tertiary referral centre for DNA diagnosis in the Netherlands and included if they carried two mutations in CAPN3, DYSF, SGCG, SGCA, SGCB, SGCD, TRIM32, FKRP or ANO5 gene. DNA was screened by direct sequencing and multiplex ligand-dependent probe amplification (MLPA) analysis.

Galectin-9 and CXCL10 as Biomarkers for Disease Activity in Juvenile Dermatomyositis: A Longitudinal Cohort Study and Multicohort Validation.

Objective: Objective evaluation of disease activity is challenging in patients with juvenile dermatomyositis (DM) due to a lack of reliable biomarkers, but it is crucial to avoid both under- and overtreatment of patients. Recently, we identified 2 proteins, galectin-9 and CXCL10, whose levels are highly correlated with the extent of juvenile DM disease activity. This study was undertaken to validate galectin-9 and CXCL10 as biomarkers for disease activity in juvenile DM, and to assess their disease specificity and potency in predicting the occurrence of flares.

Effective cauda equina decompression in two siblings with Charcot-Marie-Tooth disease type 1B.

Two siblings with Charcot-Marie-Tooth (CMT) 1B due to a c.517G>C (p.Gly173Arg) mutation in the MPZ gene both developed an acute cauda syndrome with unbearable back pain radiating to both legs, progressive muscle weakness of the legs, and saddle hypesthesia with fecal and urinary incontinence.

Combining MRI and muscle biopsy improves diagnostic accuracy in subacute-onset idiopathic inflammatory myopathy.

Introduction: In 10-20% of patients with subacute-onset idiopathic inflammatory myopathy (IIM), muscle biopsy is normal or shows nonspecific findings. MRI can be used as a triage test before muscle biopsy and as an add-on test if the biopsy is nondiagnostic.

Methods: MRI scans of skeletal muscles and muscle biopsies were evaluated prospectively in 48 patients suspected to have IIM.

Long-term follow-up of 62 patients with myositis.

The aim of this work is to evaluate disease-related mortality and the course of the disease including functional outcome and quality of life. We did a follow-up study on a large prospective cohort of 62 patients with subacute-onset idiopathic inflammatory myopathy (IIM) (dermatomyositis (n = 24), nonspecific myositis (n = 34), necrotizing autoimmune myopathy (n = 4)) after treatment with corticosteroids only (randomized controlled trial comparing daily high-dosage prednisone with pulse therapy of dexamethasone). Development of connective tissue disease (CTD) or malignancy, disease course and mortality, functional outcome and quality of life were evaluated.

Immunosuppressant and immunomodulatory treatment for dermatomyositis and polymyositis.

Background: Idiopathic inflammatory myopathies are chronic diseases with significant mortality and morbidity. Whilst immunosuppressive and immunomodulatory therapies are frequently used, the optimal therapeutic regimen remains unclear. This is an update of a review first published in 2005.

WITHDRAWN: Immunosuppressant and immunomodulatory treatment for dermatomyositis and polymyositis.

Background: Idiopathic inflammatory myopathies are chronic skeletal diseases with significant mortality and morbidity despite treatment by corticosteroids. Immunosuppressive agents and immunomodulatory therapy are used to improve disease control and reduce the long-term side effects of corticosteroids. While these treatments are used commonly in routine clinical practice, the optimal therapeutic regimen remains unclear.

Tubuloreticular structures in different types of myositis: implications for pathogenesis.

In dermatomyositis (DM) there is strong histopathological evidence of a microvascular pathogenesis, including endothelial microtubular inclusions. In nonspecific myositis, perimysial and perivascular infiltrates in the muscle biopsy similar to DM are found. Microtubular inclusions in endothelial cells were systematically searched for and found in 4 of the 20 muscle biopsies of nonspecific myositis patients (20%).

Inclusion body myositis. Clinical features and clinical course of the disease in 64 patients.

The clinical features of inclusion body myositis (IBM) were of minor importance in the design of consensus diagnostic criteria, mainly because of controversial views on the specificity of signs and symptoms, although some authors reported "typical" signs. To re-assess the clinical spectrum of IBM, a single investigator using a standard protocol studied a cohort of 64 patients cross-sectionally. Symptom onset was before the age of 50 years in 20% of cases.

Polymyositis: an ongoing discussion about a disease entity.

Since its first description more than a century ago, there has been much debate about the diagnostic entity polymyositis. Because initial observations were of individuals with dermatomyositis, it appeared that polymyositis was not possible without skin lesions. Distinctive clinical and histologic features of polymyositis were not established until the late 20th century.

Comparison of weakness progression in inclusion body myositis during treatment with methotrexate or placebo.

We investigated whether 5 to 20mg per week oral methotrexate could slow down disease progression in 44 patients with inclusion body myositis in a randomized double-blind placebo-controlled study over 48 weeks. Mean change of quantitative muscle strength testing sum scores was the primary study outcome measure. Quantitative muscle strength testing sum scores declined in both treatment groups, -0.