Cancer can occur in patients with inflammatory myopathies. This association is mainly observed in dermatomyositis, and myositis-specific antibodies have allowed us to delineate patients at an ...increased risk. Malignancy is also reported in patients with necrotizing autoimmune myopathies, but the risk remains elusive. Anti-signal recognition particle or anti-HMGCR antibodies have been specifically associated with necrotizing autoimmune myopathies. We aimed at screening the incidence of cancer in necrotizing autoimmune myopathies. A group of patients (n = 115) with necrotizing autoimmune myopathies with or without myositis-specific antibodies was analysed. Malignancy occurred more frequently in seronegative necrotizing autoimmune myopathies patients and in HMGCR-positive patients compared to anti-signal recognition particle positive patients. Synchronous malignancy was diagnosed in 21.4% and 11.5% of cases, respectively, and incidence of cancer was higher compared to the general population in both groups. No specific type of cancer was predominant. Patients suffering from a synchronous cancer had a decreased median survival time. Cancer screening is necessary in seronegative necrotizing autoimmune myopathies and in HMGCR-positive patients but not in anti-signal recognition particle-positive patients.
Highlights • In case of immunosuppressant-resistant myasthenia gravis, rituximab appears to be efficient in 50%. • The treatment with rituximab may be considered as an early 3rd line therapy in the ...management of severe myasthenia gravis. • Rituximab increases the risk of progressive multifocal leukoencephalopathy in patients with myasthenia gravis under chronic immunosuppressant therapy. • Rituximab seems to reduce the use of prednisone in case of resistant myasthenia gravis.
To determine the effects of 10 years of enzyme replacement therapy (ERT) in adult patients with Pompe disease, focusing on individual variability in treatment response.
In this prospective, ...multicenter cohort study, we studied 30 patients from the Netherlands and France who had started ERT during the only randomized placebo-controlled clinical trial with ERT in late-onset Pompe disease (NCT00158600) or its extension (NCT00455195) in 2005 to 2008. Main outcomes were walking ability (6-minute walk test 6MWT), muscle strength (manual muscle testing using Medical Research Council MRC grading), and pulmonary function (forced vital capacity FVC in the upright and supine positions), assessed at 3- to 6-month intervals before and after the start of ERT. Data were analyzed with linear mixed-effects models for repeated measurements.
Median follow-up duration on ERT was 9.8 years (interquartile range IQR 8.3-10.2 years). At the group level, baseline 6MWT was 49% of predicted (IQR 41%-60%) and had deteriorated by 22.2 percentage points (pp) at the 10-year treatment point (
< 0.001). Baseline FVC upright was 54% of predicted (IQR 47%-68%) and decreased by 11 pp over 10 years (
< 0.001). Effects of ERT on MRC sum score and FVC supine were similar. At the individual level, 93% of patients had initial benefit of ERT. Depending on the outcome measured, 35% to 63% of patients had a secondary decline after ≈3 to 5 years. Still, at 10 years of ERT, 52% had equal or better 6MWT and/or FVC upright compared to baseline.
The majority of patients with Pompe disease benefit from long-term ERT, but many patients experience some secondary decline after ≈3 to 5 years. Individual variation, however, is considerable.
This study provides Class IV evidence that for the majority of adults with Pompe disease, long-term ERT positively affects, or slows deterioration in, muscle strength, walking ability, and/or pulmonary function.
Oculopharyngeal muscular dystrophy (OPMD) is a late-onset autosomal dominant genetic disease mainly characterized by ptosis and dysphagia. We conducted a phase I/IIa clinical study ...(ClinicalTrials.gov NCT00773227) using autologous myoblast transplantation following myotomy in adult OPMD patients. This study included 12 patients with clinical diagnosis of OPMD, indication for cricopharyngeal myotomy, and confirmed genetic diagnosis. The feasibility and safety end points of both autologous myoblast transplantation and the surgical procedure were assessed by videoendoscopy in addition to physical examinations. Potential therapeutic benefit was also assessed through videoendoscopy and videofluoroscopy of swallowing, quality of life score, dysphagia grade, and a drink test. Patients were injected with a median of 178 million myoblasts following myotomy. Short and long-term (2 years) safety and tolerability were observed in all the patients, with no adverse effects. There was an improvement in the quality of life score for all 12 patients, and no functional degradation in swallowing was observed for 10 patients. A cell dose-dependant improvement in swallowing was even observed in this study. This trial supports the hypothesis that a local injection of autologous myoblasts in the pharyngeal muscles is a safe and efficient procedure for OPMD patients.
Glycogen storage diseases are important causes of myopathy and cardiomyopathy. We describe 10 patients from 8 families with childhood or juvenile onset of myopathy, 8 of whom also had rapidly ...progressive cardiomyopathy, requiring heart transplant in 4. The patients were homozygous or compound heterozygous for missense or truncating mutations in RBCK1, which encodes for a ubiquitin ligase, and had extensive polyglucosan accumulation in skeletal muscle and in the heart in cases of cardiomyopathy. We conclude that RBCK1 deficiency is a frequent cause of polyglucosan storage myopathy associated with progressive muscle weakness and cardiomyopathy. Ann Neurol 2013;74:914–919
Tubular aggregates are regular arrays of membrane tubules accumulating in muscle with age. They are found as secondary features in several muscle disorders, including alcohol- and drug-induced ...myopathies, exercise-induced cramps, and inherited myasthenia, but also exist as a pure genetic form characterized by slowly progressive muscle weakness. We identified dominant STIM1 mutations as a genetic cause of tubular-aggregate myopathy (TAM). Stromal interaction molecule 1 (STIM1) is the main Ca2+ sensor in the endoplasmic reticulum, and all mutations were found in the highly conserved intraluminal Ca2+-binding EF hands. Ca2+ stores are refilled through a process called store-operated Ca2+ entry (SOCE). Upon Ca2+-store depletion, wild-type STIM1 oligomerizes and thereby triggers extracellular Ca2+ entry. In contrast, the missense mutations found in our four TAM-affected families induced constitutive STIM1 clustering, indicating that Ca2+ sensing was impaired. By monitoring the calcium response of TAM myoblasts to SOCE, we found a significantly higher basal Ca2+ level in TAM cells and a dysregulation of intracellular Ca2+ homeostasis. Because recessive STIM1 loss-of-function mutations were associated with immunodeficiency, we conclude that the tissue-specific impact of STIM1 loss or constitutive activation is different and that a tight regulation of STIM1-dependent SOCE is fundamental for normal skeletal-muscle structure and function.
Glycogen storage disease type III (GSDIII) is a rare disorder of glycogenolysis due to
AGL
gene mutations, causing glycogen debranching enzyme deficiency and storage of limited dextrin. Patients with ...GSDIIIa show involvement of liver and cardiac/skeletal muscle, whereas GSDIIIb patients display only liver symptoms and signs. The International Study on Glycogen Storage Disease (ISGSDIII) is a descriptive retrospective, international, multi-centre cohort study of diagnosis, genotype, management, clinical course and outcome of 175 patients from 147 families (86 % GSDIIIa; 14 % GSDIIIb), with follow-up into adulthood in 91 patients. In total 58
AGL
mutations (non-missense mutations were overrepresented and 21 novel mutations were observed) were identified in 76 families. GSDIII patients first presented before the age of 1.5 years, hepatomegaly was the most common presenting clinical sign. Dietary management was very diverse and included frequent meals, uncooked cornstarch and continuous gastric drip feeding. Chronic complications involved the liver (hepatic cirrhosis, adenoma(s), and/or hepatocellular carcinoma in 11 %), heart (cardiac involvement and cardiomyopathy, in 58 % and 15 %, respectively, generally presenting in early childhood), and muscle (pain in 34 %). Type 2 diabetes mellitus was diagnosed in eight out of 91 adult patients (9 %). In adult patients no significant correlation was detected between (non-) missense
AGL
genotypes and hepatic, cardiac or muscular complications. This study demonstrates heterogeneity in a large cohort of ageing GSDIII patients. An international GSD patient registry is warranted to prospectively define the clinical course, heterogeneity and the effect of different dietary interventions in patients with GSDIII.
Up to one-third of patients with myotonic dystrophy type 1 die suddenly. Thus far, no intervention has effectively prevented sudden death.
To determine whether an invasive strategy based on ...systematic electrophysiological studies and prophylactic permanent pacing is associated with longer survival in patients presenting with myotonic dystrophy type 1 and major infranodal conduction delays than a noninvasive strategy.
A retrospective study, the DM1 Heart Registry included 914 consecutive patients older than 18 years with genetically confirmed myotonic dystrophy type 1 who were admitted to the Neurological Unit of the Myology Institute of Pitié-Salpêtrière Hospital, a teaching medical center in Paris, France, between January 2000 and December 2009.
Among 486 patients whose electrocardiogram showed a PR interval greater than 200 milliseconds, a QRS duration greater than 100 milliseconds, or both, the outcome of 341 (70.2%) who underwent an invasive strategy was compared with 145 (29.8%) who underwent a noninvasive strategy. A propensity score risk adjustment and propensity-based matching analysis was used to account for selection biases.
Rates of overall survival (main outcome measure) and sudden death, respiratory death, and other deaths (secondary outcome measures).
Over a median follow-up of 7.4 years (range, 0-9.9 years), 50 patients died in the invasive strategy group and 30 died in the noninvasive strategy group (hazard ratio HR, 0.74 95 CI, 0.47-1.16; P = .19), corresponding to an overall 9-year survival of 74.4% (95% CI, 69.2%-79.9%). Regardless of the technique used to adjust for between-group differences in baseline characteristics, the invasive strategy was associated with a longer survival, with adjusted HRs ranging from 0.47 (95% CI, 0.26-0.84; P = .01) for a covariate-adjusted analysis of propensity-matched data to 0.61 (95% CI, 0.38-0.99; P = .047) for an analysis adjusted for propensity score quintiles. The survival difference was largely attributable to a lower incidence of sudden death, which occurred in 10 patients in the invasive strategy group and in 16 patients in the noninvasive strategy group, with HRs ranging from 0.24 (95% CI, 0.10-0.56; P = .001) for an analysis adjusted for propensity score quintiles and covariates to 0.28 (95% CI, 0.13-0.61; P = .001) for an unadjusted analysis of propensity-matched data.
Among patients with myotonic dystrophy type 1, an invasive strategy was associated with a higher rate of 9-year survival than a noninvasive strategy.
clinicaltrials.gov Identifier: NCT01136330.
Phosphoglycerate kinase (PGK) deficiency is a rare X‐linked metabolic disorder caused by mutations in the PGK1 gene. Patients usually develop various combinations of nonspherocytic hemolytic anemia ...(NSHA), myopathy, and central nervous system disorders. In this national multicenter observational retrospective study, we recorded all known French patients with PGK deficiency, and 3 unrelated patients were identified. Case 1 was a 32‐year‐old patient with severe chronic axonal sensorimotor polyneuropathy resembling Charcot–Marie–Tooth (CMT) disease, mental retardation, microcephaly, ophthalmoplegia, pes cavus, and the new c.323G > A PGK1 hemizygous mutation. Case 2 was a 71‐year‐old patient with recurrent exertional rhabdomyolysis, and a c.943G > A PGK1 hemizygous mutation. Case 3 was a 48‐year‐old patient with NSHA, retinitis pigmentosa, mental retardation, seizures, stroke, parkinsonism, and a c.491A > T PGK1 hemizygous mutation. This study confirms that PGK deficiency is an extremely rare disorder with a wide phenotypic spectrum, and demonstrates for the first time that PGK deficiency may affect the peripheral nervous system and present as a CMT‐like disorder.
Pompe's disease is a metabolic myopathy caused by a deficiency of acid alpha glucosidase (GAA), an enzyme that degrades lysosomal glycogen. Late-onset Pompe's disease is characterized by progressive ...muscle weakness and loss of respiratory function, leading to early death. We conducted a randomized, placebo-controlled trial of alglucosidase alfa, a recombinant human GAA, for the treatment of late-onset Pompe's disease.
Ninety patients who were 8 years of age or older, ambulatory, and free of invasive ventilation were randomly assigned to receive biweekly intravenous alglucosidase alfa (20 mg per kilogram of body weight) or placebo for 78 weeks at eight centers in the United States and Europe. The two primary end points were distance walked during a 6-minute walk test and percentage of predicted forced vital capacity (FVC).
At 78 weeks, the estimated mean changes from baseline in the primary end points favored alglucosidase alfa (an increase of 28.1+/-13.1 m on the 6-minute walk test and an absolute increase of 3.4+/-1.2 percentage points in FVC; P=0.03 and P=0.006, respectively). Similar proportions of patients in the two groups had adverse events, serious adverse events, and infusion-associated reactions; events that occurred only in patients who received the active study drug included anaphylactic reactions and infusion-associated reactions of urticaria, flushing, hyperhidrosis, chest discomfort, vomiting, and increased blood pressure (each of which occurred in 5 to 8% of the patients).
In this study population, treatment with alglucosidase alfa was associated with improved walking distance and stabilization of pulmonary function over an 18-month period. (ClinicalTrials.gov number, NCT00158600.)
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