The recurrent deep intronic pseudoexon-inducing variant COL6A1 c.930+189C>T results in a consistently severe phenotype of COL6-related dystrophy: Towards clinical trial readiness for splice-modulating therapy.

Collagen VI-related dystrophies (COL6-RDs) manifest with a spectrum of clinical phenotypes, ranging from Ullrich congenital muscular dystrophy (UCMD), presenting with prominent congenital symptoms and characterised by progressive muscle weakness, joint contractures and respiratory insufficiency, to Bethlem muscular dystrophy, with milder symptoms typically recognised later and at times resembling a limb girdle muscular dystrophy, and intermediate phenotypes falling between UCMD and Bethlem muscular dystrophy. Despite clinical and immunohistochemical features highly suggestive of COL6-RD, some patients had remained without an identified causative variant in COL6A1, COL6A2 or COL6A3. With combined muscle RNA-sequencing and whole-genome sequencing we uncovered a recurrent, de novo deep intronic variant in intron 11 of COL6A1 (c.930+189C>T) that leads to a dominantly acting in-frame pseudoexon insertion. We subsequently identified and have characterised an international cohort of forty-four patients with this COL6A1 intron 11 causative variant, one of the most common recurrent causative variants in the collagen VI genes. Patients manifest a consistently severe phenotype characterised by a paucity of early symptoms followed by an accelerated progression to a severe form of UCMD, except for one patient with somatic mosaicism for this COL6A1 intron 11 variant who manifests a milder phenotype consistent with Bethlem muscular dystrophy. Characterisation of this individual provides a robust validation for the development of our pseudoexon skipping therapy. We have previously shown that splice-modulating antisense oligomers applied in vitro effectively decreased the abundance of the mutant pseudoexon-containing COL6A1 transcripts to levels comparable to the in vivo scenario of the somatic mosaicism shown here, indicating that this therapeutic approach carries significant translational promise for ameliorating the severe form of UCMD caused by this common recurrent COL6A1 causative variant to a Bethlem muscular dystrophy phenotype.

Theabrownin from Fu Brick tea ameliorates high-fat induced insulin resistance, hepatic steatosis, and inflammation in mice by altering the composition and metabolites of gut microbiota.

Fu Brick tea belongs to fermented dark tea, which is one of the six categories of tea. Fu Brick tea has been reported to reduce adiposity and has beneficial effects in the treatment of hypercholesterolemia and cardiovascular disease. Theabrownin (TB) is one of the pigments with the most abundant content in Fu Brick tea. TB has also been reported to have lipid-lowering effects, but its mechanism remains unclear. We found that TB could effectively reduce the insulin resistance and fat deposition induced by a high fat diet (HFD), decrease inflammation in the liver, improve intestinal integrity, and reduce endotoxins in circulation. Further studies showed that TB increased the abundance of Verrucomicrobiota and reduced the abundance of Firmicutes and Desulfobacterota in the intestinal tract of obese mice. The alteration of gut microbiota is closely linked to the metabolic phenotype after TB treatment through correlation analysis. Moreover, TB changed the gut microbial metabolites including L-ornithine, α-ketoglutarate, and glutamine, which have also been found to be upregulated in the liver after TB intervention. In vitro, L-ornithine, α-ketoglutarate, or glutamine significantly reduced lipopolysaccharide (LPS)-induced inflammation in macrophages. Therefore, our results suggest that TB can reduce adiposity, systemic insulin resistance, and liver inflammation induced by a HFD through altering gut microbiota and improving the intestinal tight junction integrity. The metabolites of gut microbiota might also play a role in ameliorating the HFD-induced phenotype by TB.

Cardiac atrial pathology in Duchenne muscular dystrophy.

INTRODUCTION/AIMS: Duchenne muscular dystrophy (DMD) is characterized by fibrofatty replacement of muscle. This has been documented in the ventricular myocardium of DMD patients, but there is limited description of atrial involvement. The purpose of this study is to examine the arrhythmia and ectopy burden in patients with DMD and non-DMD dilated cardiomyopathy (DCM) and to characterize the cardiac histopathologic changes in DMD patients across the disease spectrum. METHODS: This was a retrospective analysis of age-matched patients with DMD and non-DMD DCM who received a Holter monitor and cardiac imaging within 100 days of each other between 2010 and 2020. Twenty-four-hour Holter monitors were classified based on the most recent left ventricular ejection fraction at the time of monitoring. Cardiac histopathologic specimens from whole-heart examinations at the time of autopsy from three DMD patients and one DCM patient were reviewed. RESULTS: A total of 367 patients with 1299 Holter monitor recordings were included over the study period, with 94% representing DMD patients and 6% non-DMD DCM. Patients with DMD had more atrial ectopy across the cardiac function spectrum (p < 0.05). There was no difference in ventricular ectopy. Four DMD patients developed symptomatic atrial arrhythmias. Autopsy specimens from DMD patients demonstrated fibrofatty infiltration of both atrial and ventricular myocardium. DISCUSSION: The atrial myocardium in patients with DMD is unique. Autopsy specimens reveal fibofatty replacement of the atrial myocardium, which may be a nidus for both ectopy and arrhythmias in DMD patients.

Appendicular lean mass index changes in patients with Duchenne muscular dystrophy and Becker muscular dystrophy.

INTRODUCTION: Mutations in the 79 exons of the dystrophin gene result in muscle wasting and weakness of varying clinical severity, ranging from severe/typical Duchenne muscular dystrophy (DMD) to intermediate DMD and mild Becker muscular dystrophy (BMD), depending on the frameshift of the mutation. We previously reported that males with DMD have progressively declining appendicular lean mass (ALM) and ALM index (ALMI) with age and worsening functional motor ability compared with healthy controls. These indices have not been studied in patients with intermediate DMD and BMD phenotypes and across DMD genotypes. In this study, we compared age-related trajectories of ALM and ALMI of patients who had (1) BMD without functional mobility deficits with patients who had DMD at different stages of disease and healthy controls; (2) a DMD intermediate phenotype with patients who had a typical DMD phenotype; and (3) DMD categorized by genotype. METHODS: We conducted a retrospective review of ALM and ALMI data from 499 patients (ages 5-23 years) with DMD (466 typical and 33 intermediate) and 46 patients (ages 5-21 years) with BMD (without functional mobility deficits and functional mobility score of 1). Patients were grouped according to age reflecting disease stage (ages 5 to <7, 7 to <10, 10 to <14, and 14 to <20 years) and genotype (mutations in exons 1-30, 31-44, 45-62, and 63-79). RESULTS: ALM and ALMI trajectories of patients with BMD paralleled those of healthy controls until adolescence, in contrast to patients with DMD. ALMI Z-scores of patients with BMD remained within ±2 SD without decline while those of patients with DMD fell below -2 SD around age 12 years. Patients with BMD had increasing ALM and ALMI with age, with peak accrual between ages 10 to <14 years. ALMI declined after age 14 years for those with intermediate DMD compared with 10 years for patients with typical DMD. Patients with mutations in exons 63-79 had a greater decline in ALMI as compared with those with other genotypes after age 10 years. CONCLUSIONS: Age-related changes in ALMI in patients with BMD and intermediate DMD differ from those with typical DMD, reflecting their clinical phenotypes. ALM and ALMI should be further studied in patients with BMD and DMD subtypes for their potential value as surrogate markers to characterize the severity of BMD and DMD and inform clinical care decisions and clinical trial designs.

An evaluation of clinical presentation and genetic testing approaches for patients with neuromuscular disorders.

Inherited neuromuscular disorders (NMDs) are a large group of genetic conditions characterized by impaired peripheral nerve, motor neuron, neuromuscular junction, or skeletal muscle function. These conditions are also known to have clinical and genetic heterogeneity and variable ages of onset. Clinical evaluation for NMDs has increasingly incorporated molecular genetics. However, genetic testing is complicated by the variety of testing options and the ambiguity of NMD phenotypes. Examining test selection and yield may elucidate testing recommendations and improve the diagnostic journey for these patients. This retrospective chart review evaluated the clinical presentations, genetic testing approaches, and diagnostic outcomes of 155 patients with suspected NMDs at Cincinnati Children's Hospital Medical Center. A total of 262 individual tests were ordered, averaging 1.7 tests per patient. The clinic utilized 26 separate genetic tests, with test yields ranging from 0% to 66%. Overall, 21% of patients received a genetic diagnosis. Of all the clinical findings evaluated, elevated CPK levels with or without muscle weakness were the most informative symptoms correlated with a diagnostic result. This study highlights several genetic testing considerations for NMDs, including the variability of diagnostic outcomes. This knowledge is relevant to clinicians and patients, especially during the pretest counseling and consenting process.

Pamrevlumab, a Fully Human Monoclonal Antibody Targeting Connective Tissue Growth Factor, for Non-Ambulatory Patients with Duchenne Muscular Dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a neuromuscular disease stemming from dystrophin gene mutations. Lack of dystrophin leads to progressive muscle damage and replacement of muscle with fibrotic and adipose tissue. Pamrevlumab (FG-3019), a fully human monoclonal antibody that binds to connective tissue growth factor (CTGF), is in Phase III development for treatment of DMD and other diseases. METHODS: MISSION (Study 079; NCT02606136) was an open-label, Phase II, single-arm trial of pamrevlumab in 21 non-ambulatory patients with DMD (aged≥12 years, receiving corticosteroids) who received 35-mg/kg intravenous infusions every 2 weeks for 2 years. The primary endpoint was change from baseline in percent predicted forced vital capacity (ppFVC). Secondary endpoints included other pulmonary function tests, upper limb function and strength assessments, and changes in upper arm fat and fibrosis scores on magnetic resonance imaging. RESULTS: Fifteen patients completed the trial. Annual change from baseline (SE) in ppFVC was -4.2 (0.7) (95% CI -5.5, -2.8). Rate of decline in ppFVC in pamrevlumab-treated patients was slower than observed in historical published trials of non-ambulatory patients. MISSION participants experienced slower-than-anticipated muscle function declines compared with natural history and historical published trials of non-ambulatory patients with DMD. Pamrevlumab was well-tolerated. Treatment-emergent adverse events were mild to moderate, and none led to study discontinuation. CONCLUSIONS: nti-CTGF therapy with pamrevlumab represents a potential treatment for DMD. The lack of internal control group limits the results.

DMD Genotypes and Motor Function in Duchenne Muscular Dystrophy: A Multi-institution Meta-analysis With Implications for Clinical Trials.

BACKGROUND AND OBJECTIVES: Clinical trials of genotype-targeted treatments in Duchenne muscular dystrophy (DMD) traditionally compare treated patients with untreated patients with the same DMD genotype class. This avoids confounding of drug efficacy by genotype effects but also shrinks the pool of eligible controls, increasing challenges for trial enrollment in this already rare disease. To evaluate the suitability of genotypically unmatched controls in DMD, we quantified effects of genotype class on 1-year changes in motor function endpoints used in clinical trials. METHODS: More than 1,600 patient-years of follow-up (>700 patients) were studied from 6 real-world/natural history data sources (UZ Leuven, PRO-DMD-01 shared by CureDuchenne, iMDEX, North Star UK, Cincinnati Children's Hospital Medical Center, and the DMD Italian Group), with genotypes classified as amenable to skipping exons 44, 45, 51, or 53, or other skippable, nonsense, and other mutations. Associations between genotype class and 1-year changes in North Star Ambulatory Assessment total score (ΔNSAA) and in 10-m walk/run velocity (Δ10MWR) were studied in each data source with and without adjustment for baseline prognostic factors. RESULTS: The studied genotype classes accounted for approximately 2% of variation in ΔNSAA outcomes after 12 months, whereas other prognostic factors explained >30% of variation in large data sources. Based on a meta-analysis across all data sources, pooled effect estimates for the studied skip-amenable mutation classes were all small in magnitude (<2 units in ΔNSAA total score in 1-year follow up), smaller than clinically important differences in NSAA, and were precisely estimated with standard errors <1 unit after adjusting for nongenotypic prognostic factors. DISCUSSION: These findings suggest the viability of trial designs incorporating genotypically mixed or unmatched controls for up to 12 months in duration for motor function outcomes, which would ease recruitment challenges and reduce numbers of patients assigned to placebos. Such trial designs, including multigenotype platform trials and hybrid designs, should ensure baseline balance between treatment and control groups for the most important prognostic factors, while accounting for small remaining genotype effects quantified in this study.

Use of supported standing in males with Duchenne muscular dystrophy: Individual and family perspectives.

PURPOSE: This study aimed to explore stander use in individuals with Duchenne Muscular Dystrophy (DMD). METHODS: This mixed method research study employed a survey with categorical and open-ended questions related to stander use. Categorical responses were analyzed quantitatively. Qualitative analysis of open-ended responses was linked to the International Classification of Function. Qualitative and quantitative results were merged to derive meta-inferences. RESULTS: Of 147 respondents, 28.6% (n = 42) reported stander use. Equipment used included sit-to-stand stander (n = 27), power standing feature in a wheelchair (n = 13), and unspecified equipment (n = 2). Economic services were the most common barrier to stander obtainment. Age of loss of ambulation (LOA) and age of start of stander use were positively correlated (r = 0.61, p < 0.0001, n = 36), with 59.5% initiating stander use after LOA. Twenty-nine respondents reported standing less than the recommended dose of 60-90 minutes at least five days a week, with frequency directionally less than five days per week (p = 0.06) and time significantly less than 60-90 minutes (p = 0.002). Respondents' total dose was significantly lower than the recommended 300 minutes (p = 0.02). Lack of time and presence of contractures contributed to decreased duration of use. CONCLUSION: This study provides a greater understanding of stander use among individuals with DMD and can assist with decision making about stander use prior to complications of disease progression to promote optimal health despite reported barriers.

A longitudinal study of creatine kinase and creatinine levels in Duchenne muscular dystrophy.

INTRODUCTION/AIMS: Management of Duchenne muscular dystrophy (DMD) has entered an era featuring novel treatments. Trackable noninvasive biomarkers could improve disease progression monitoring and drug effect detection. Our aim in this study was to measure changes in selected noninvasive biomarkers and assess their relationship to age and motor function. METHODS: We retrospectively studied 555 patients with DMD who had at least 12 months of treatment of glucocorticoids and were not enrolled in trials of potential disease-modifying therapies. We extracted biomarker data of serum creatine kinase (CK), serum creatinine (Cr), urine Cr, and urine Cr/urine osmolality (osm), as well as functional data for age at loss of ambulation and Functional Motor Scale (FMS) values from patients' clinical records. Data were analyzed using linear mixed-model analyses. RESULTS: CK, serum Cr, urine Cr, and urine Cr/urine osm all decreased with declining motor function. CK consistently decreased and FMS score consistently worsened with age without clear inflection points. There was an increased odds ratio for LOA with lower values of CK, serum Cr, urine Cr, and urine Cr/urine osm, most notably for urine Cr. DISCUSSION: Although individual biomarker values are challenging to directly apply clinically, our study has demonstrated that trends over time may complement functional measures in the assessment of individuals with DMD. Future studies could elucidate predictive utility of these biomarkers in assessing motor function changes in DMD.

Identification of Biallelic dystrophin gene variants during maternal carrier testing for Becker muscular dystrophy and review of the DMD exon 49-51 deletion phenotype.

BACKGROUND: Dystrophinopathies are X-linked recessive conditions caused by pathogenic variants in the dystrophin (DMD) gene. In a family that included two boys with Becker muscular dystrophy (BMD) due to a DMD deletion of exons 45-47, maternal carrier testing unexpectedly identified biallelic DMD deletions of exons 45-47 and 49-51. METHODS: The patient's mild phenotype in the setting of biallelic DMD variants prompted further investigation of the exon 49-51 deletion in particular, via literature review and retrospective chart review of patients who have been evaluated in our institution's comprehensive neuromuscular center and/or diagnosed in our clinical genetic testing laboratory. RESULTS: To our knowledge, this is only the fifth case of confirmed biallelic DMD variants in a female. In males, the DMD exon 49-51 deletion appears to result in a mild BMD phenotype with low or normal creatine kinase levels. This deletion comprised 19% (4/21) of dystrophinopathies diagnosed by chromosomal microarray (CMA) in males during the past ten years in our clinical laboratory. Most individuals identified by chart review were diagnosed through CMA, despite the fact that microarray was genome-wide and not DMD-specific. This case raised important genetic counseling issues. CONCLUSION: The DMD exon 49-51 deletion appears to cause a variable but generally mild BMD phenotype. Its relatively frequent detection by CMA suggests it may be underdiagnosed.

Obesity and loss of ambulation are associated with lower extremity oedema in Duchenne muscular dystrophy.

Patients with Duchenne muscular dystrophy have multiple risk factors for lower extremity oedema. This study sought to define the frequency and predictors of oedema. Patients aged 15 years and older were screened by patient questionnaire, and the presence of oedema was confirmed by subsequent physical exam. Twenty-four of 52 patients (46%) had oedema, 12 of whom had swelling extending above the foot and two with sores/skin breakdown. There was no significant difference in age, frequency, or duration of glucocorticoid use, non-invasive respiratory support use, forced vital capacity, cardiac medication use, or ejection fraction between patients with and without oedema (all p > 0.2). Those with oedema had a greater time since the loss of ambulation (8.4 years versus 3.5 years; p = 0.004), higher body mass index (28.3 versus 24.8; p = 0.014), and lower frequency of deflazacort use (67% versus 89%; p = 0.008). Multivariate analysis revealed a longer duration of loss of ambulation (p = 0.02) and higher body mass index (p = 0.009) as predictors of oedema. Lower extremity oedema is common in Duchenne muscular dystrophy but independent of cardiac function. Interventions focused on minimising body mass index increases over time may be a therapeutic target.

Dual-energy X-ray absorptiometry measures of lean body mass as a biomarker for progression in boys with Duchenne muscular dystrophy.

We evaluated whether whole-body dual-energy X-ray absorptiometry (DXA) measures of lean body mass can be used as biomarkers for disease progression and treatment effects in patients with Duchenne muscular dystrophy. This post hoc analysis utilized data from a randomized, 2-period study of domagrozumab versus placebo in 120 ambulatory boys with DMD. DXA measures of lean body mass were obtained from the whole body (excluding head), arms, legs and appendicular skeleton at baseline and every 16 weeks. Treatment effects on DXA measures for domagrozumab versus placebo were assessed at Week 49. At Week 49, domagrozumab statistically significantly increased lean body mass versus placebo in the appendicular skeleton (p = 0.050) and arms (p < 0.001). The relationship between lean body mass at Week 49 and functional endpoints at Week 97 was evaluated. Changes in lean body mass at Week 49 in all regions except arms were significantly correlated with percent change from baseline in 4-stair climb (4SC) at Week 97. DXA-derived percent lean mass at Week 49 also correlated with 4SC and North Star Ambulatory Assessment at Week 97. These data indicate that whole-body DXA measures can be used as biomarkers for treatment effects and disease progression in patients with DMD, and warrant further investigation.Trial registration: ClinicalTrials.gov, NCT02310763; registered 8 December 2014.

Real-world and natural history data for drug evaluation in Duchenne muscular dystrophy: suitability of the North Star Ambulatory Assessment for comparisons with external controls.

Using external controls based on real-world or natural history data (RWD/NHD) for drug evaluations in Duchenne muscular dystrophy (DMD) is appealing given the challenges of enrolling placebo-controlled trials, especially for multi-year trials. Comparisons to external controls, however, face risks of bias due to differences in outcomes between trial and RWD/NHD settings. To assess this bias empirically, we conducted a multi-institution study comparing mean 48-week changes in North Star Ambulatory Assessment (NSAA) total score between trial placebo arms and RWD/NHD sources, with and without adjustment for baseline prognostic factors. Analyses used data from three placebo arms (235 48-week intervals, N = 235 patients) and three RWD/NHD sources (348 intervals, N = 202 patients). Differences in mean ΔNSAA between placebo arms and RWD/NHD sources were small before adjustment (-1.2 units, 95% CI: [-2.0 -0.5]) and were attenuated and no longer statistically significant after adjustment (0.1 units (95% CI: [-0.6, 0.8]). Results were similar whether adjusting using multivariable regression or propensity score matching. This consistency in ΔNSAA between trial placebo arms and RWD/NHD sources accords with prior findings for the six-minute walk distance, provides a well-validated framework for baseline adjustment of prognostic factors, and supports the suitability of RWD/NHD external controls for drug evaluations in ambulatory DMD.

Quantitative magnetic resonance imaging measures as biomarkers of disease progression in boys with Duchenne muscular dystrophy: a phase 2 trial of domagrozumab.

Duchenne muscular dystrophy (DMD) is a progressive, neuromuscular disorder caused by mutations in the DMD gene that results in a lack of functional dystrophin protein. Herein, we report the use of quantitative magnetic resonance imaging (MRI) measures as biomarkers in the context of a multicenter phase 2, randomized, placebo-controlled clinical trial evaluating the myostatin inhibitor domagrozumab in ambulatory boys with DMD (n = 120 aged 6 to < 16 years). MRI scans of the thigh to measure muscle volume, muscle volume index (MVI), fat fraction, and T2 relaxation time were obtained at baseline and at weeks 17, 33, 49, and 97 as per protocol. These quantitative MRI measurements appeared to be sensitive and objective biomarkers for evaluating disease progression, with significant changes observed in muscle volume, MVI, and T2 mapping measures over time. To further explore the utility of quantitative MRI measures as biomarkers to inform longer term functional changes in this cohort, a regression analysis was performed and demonstrated that muscle volume, MVI, T2 mapping measures, and fat fraction assessment were significantly correlated with longer term changes in four-stair climb times and North Star Ambulatory Assessment functional scores. Finally, less favorable baseline measures of MVI, fat fraction of the muscle bundle, and fat fraction of lean muscle were significant risk factors for loss of ambulation over a 2-year monitoring period. These analyses suggest that MRI can be a valuable tool for use in clinical trials and may help inform future functional changes in DMD.Trial registration: ClinicalTrials.gov identifier, NCT02310763; registered December 2014.

Repeated intravenous cardiosphere-derived cell therapy in late-stage Duchenne muscular dystrophy (HOPE-2): a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Cardiosphere-derived cells (CDCs) ameliorate skeletal and cardiac muscle deterioration in experimental models of Duchenne muscular dystrophy. The HOPE-2 trial examined the safety and efficacy of sequential intravenous infusions of human allogeneic CDCs in late-stage Duchenne muscular dystrophy. METHODS: In this multicentre, randomised, double-blind, placebo-controlled, phase 2 trial, patients with Duchenne muscular dystrophy, aged 10 years or older with moderate upper limb impairment, were enrolled at seven centres in the USA. Patients were randomly assigned (1:1) using stratified permuted blocks to receive CAP-1002 (1·5 × 108 CDCs) or placebo intravenously every 3 months for a total of four infusions. Clinicians, caregivers, patients, and clinical operations personnel were fully masked to treatment groups. The primary outcome was the change in mid-level elbow Performance of Upper Limb version 1.2 (PUL 1.2) score at 12 months, assessed in the intention-to-treat population. Safety was assessed in all individuals who received an investigational product. This trial is registered with ClinicalTrials.gov, NCT03406780. FINDINGS: Between March 1, 2018, and March 31, 2020, 26 male patients with Duchenne muscular dystrophy were enrolled, of whom eight were randomly assigned to the CAP-1002 group and 12 to the placebo group (six were not randomised due to screening failure). In patients who had a post-treatment PUL 1.2 assessment (eight in the CAP-1002 group and 11 in the placebo group), the mean 12-month change from baseline in mid-level elbow PUL1.2 favoured CAP-1002 over placebo (percentile difference 36·2, 95% CI 12·7-59·7; difference of 2·6 points; p=0·014). Infusion-related hypersensitivity reactions without long-term sequelae were observed in three patients, with one patient discontinuing therapy due to a severe allergic reaction. No other major adverse reactions were noted, and no deaths occurred. INTERPRETATION: CAP-1002 cell therapy appears to be safe and effective in reducing deterioration of upper limb function in patients with late-stage Duchenne muscular dystrophy. Various measures of cardiac function and structure were also improved in the CAP-1002 group compared with the placebo group. Longer-term extension studies are needed to confirm the therapeutic durability and safety of CAP-1002 beyond 12 months for the treatment of skeletal myopathy and cardiomyopathy in Duchenne muscular dystrophy. FUNDING: Capricor Therapeutics.

Desmin Modulates Muscle Cell Adhesion and Migration.

Cellular adhesion and migration are key functions that are disrupted in numerous diseases. We report that desmin, a type-III muscle-specific intermediate filament, is a novel cell adhesion regulator. Expression of p.R406W mutant desmin, identified in patients with desmin-related myopathy, modified focal adhesion area and expression of adhesion-signaling genes in myogenic C2C12 cells. Satellite cells extracted from desmin-knock-out (DesKO) and desmin-knock-in-p.R405W (DesKI-R405W) mice were less adhesive and migrated faster than those from wild-type mice. Moreover, we observed mislocalized and aggregated vinculin, a key component of cell adhesion, in DesKO and DesKI-R405W muscles. Vinculin expression was also increased in desmin-related myopathy patient muscles. Together, our results establish a novel role for desmin in cell-matrix adhesion, an essential process for strength transmission, satellite cell migration and muscle regeneration. Our study links the patho-physiological mechanisms of desminopathies to adhesion/migration defects, and may lead to new cellular targets for novel therapeutic approaches.

The Effect of Adiposity on Cardiovascular Function and Myocardial Fibrosis in Patients With Duchenne Muscular Dystrophy.

Background Patients with Duchenne muscular dystrophy (DMD) develop cardiomyopathy because of a dystrophin deficiency causing fibrofatty replacement of the myocardium. Corticosteroid use and mobility limitations place these patients at risk for increased adiposity. We sought to determine the association of adiposity with cardiovascular dysfunction in patients with DMD. Methods and Results This was a retrospective review of patients with DMD who underwent both cardiac magnetic resonance imaging and dual-energy x-ray absorptiometry within 1 year. The cardiac magnetic resonance imaging parameters included left ventricular ejection fraction and the presence of late gadolinium enhancement (LGE positive [LGE+]). The adiposity indices, measured by dual-energy x-ray absorptiometry, included percentage of body fat, whole body fat mass indexed to height, and body mass index. A total of 324 patients were identified. Fifty-two percent had LGE+, and 36% had cardiac dysfunction (left ventricular ejection fraction <55%). Patients with cardiac dysfunction had higher whole body fat mass indexed to height and body mass index on univariate analysis (mean difference between patients with and without cardiac dysfunction: +2.9 kg/m, P=0.001; and +1.5 kg/m2, P=0.03, respectively). whole body fat mass indexed to height remained independently associated with cardiac dysfunction on multivariable analysis after adjusting for age, LGE+, and corticosteroid duration. High whole body fat mass indexed to height and percentage of body fat were associated with LGE+ on univariate analysis (mean difference between patients with and without LGE+: +2.0 kg/m, P=0.02; and +2.4%, P=0.02, respectively). Using multivariable analysis, including age and cardiac dysfunction, high percentage of body fat remained independently associated with LGE+. Conclusions This study demonstrates an independent association of adiposity with cardiac dysfunction and LGE+ in patients with DMD. Preventing adiposity may mitigate the later development of ventricular dysfunction in DMD.

The effect of oral bisphosphonate therapy on vertebral morphometry and fractures in patients with Duchenne muscular dystrophy and glucocorticoid-induced osteoporosis.

INTRODUCTION/AIMS: Glucocorticoid-induced osteoporosis with vertebral fractures is frequent in patients with Duchenne muscular dystrophy (DMD). In this study, we evaluated the effects of oral bisphosphonate (BP) therapy on the prevalence and severity of vertebral fractures by vertebral morphometry assessment. METHODS: We reviewed the records and radiographs of patients with DMD who had been treated with oral BP (weekly alendronate) and had undergone routine spine radiographic monitoring for glucocorticoid-induced osteoporosis at Cincinnati Children's Hospital Medical Center between 2010 and 2017. Study outcomes were thoracic and lumbar vertebral fracture prevalence and severity, assessed by Genant semiquantitative grading of vertebral morphometry, for up to 5 years of treatment. RESULTS: Fifty-two patients (median age, 11.8 years; 88% prepubertal; 31% nonambulatory) had been treated with long-term glucocorticoids (median duration, 4.7 years at BP start). Most patients (75%) had mild vertebral height loss or fractures (Genant grade = 0 or 1) at baseline. The prevalence of vertebral fractures at each year of treatment was not statistically different from that at baseline (P = .08-1.00). Serial radiographs showed no longitudinal change in severity by Genant grade in most vertebrae (64%-80%). Improvement in vertebral fracture grade was observed in some patients. DISCUSSION: We observed stable prevalence of vertebral fractures and no change in severity by Genant grade in most vertebrae for up to 5 years of treatment. Oral BP may mitigate development or progression of vertebral fractures and be beneficial for secondary prevention of glucocorticoid-induced osteoporosis in this population.

Emergency Planning as Part of Healthcare Transition Preparation for Patients with Duchenne Muscular Dystrophy.

BACKGROUND: Emergency care planning is an important component of healthcare transition, particularly for patients with medical complexity. Duchenne muscular dystrophy (DMD) is a complex, progressive pediatric-onset disease affecting multiple organ systems including impairment of cardiac and pulmonary function, high risk for fractures, fat embolism, adrenal crisis and malignant hyperthermia. Appropriate interdisciplinary emergency management is critical for survival for these patients. The purpose of this quality improvement project was to develop a process to reliably share an individualized emergency care plan (ECP) with patients and their families as part of a larger plan to develop an integrated transition program. METHODS: An interdisciplinary team of nurses and clinicians used the principles of quality improvement to develop a reliable process to assure patients with DMD received an individualized, multidisciplinary ECP at routine interdisciplinary clinic visits. Additionally, the project used surveys to assess patient and family satisfaction with the letter and whether it improved their knowledge of emergency care. RESULTS: Sixty-two patients were seen during the study timeframe. All received an ECP. Sixty-two surveys were sent and twenty-three surveys were returned. Of those that responded, the majority stated the ECP increased their knowledge of emergency care. CONCLUSION: ECPs can be developed and disseminated to patients with DMD and their caregivers. This tool can potentially promote timely and appropriate emergency care for these patients with unique and complex medical needs.