Design of the muscles in motion study: a randomized controlled trial to evaluate the efficacy and feasibility of an individually tailored home-based exercise training program for children and adolescents with juvenile dermatomyositis

BACKGROUND: Juvenile dermatomyositis (JDM) is a rare, often chronic, systemic autoimmune disease of childhood, characterized by inflammation of the microvasculature of the skeletal muscle and skin. Prominent clinical features include significant exercise intolerance, muscle weakness, and fatigue. Despite pharmacological improvements, these clinical features continue to affect patients with JDM, even when the disease is in remission. Exercise training is increasingly utilized as a non-pharmacological intervention in the clinical management of (adult) patients with chronic inflammatory conditions; however no randomized controlled trials (RCT) have been performed in JDM. In the current study, the efficacy and feasibility of an exercise training program in patients with JDM will be examined. METHODS/DESIGN: Subjects (n = 30) will include 8–18 year olds diagnosed with JDM. The intervention consists of an individually tailored 12-weeks home-based exercise training program in which interval training on a treadmill is alternated with strength training during each session. The program is based on previous literature and designed with a defined frequency, intensity, time, and type of exercise (FITT principles). Primary outcome measures include aerobic exercise capacity, isometric muscle strength, and perception of fatigue. The study methodology has been conceived according to the standards of the CONSORT guidelines. The current study will be a multi-center (4 Dutch University Medical Centers) RCT, with the control group also entering the training arm directly after completion of the initial protocol. Randomization is stratified according to age and gender. DISCUSSION: The current study will provide evidence on the efficacy and feasibility of an individually tailored 12-week home-based exercise training program in youth with JDM. TRIAL REGISTRATION: Medical Ethics Committee of the University Medical Center Utrecht, the Netherlands: 11–336; Netherlands Trial Register (NTR): NTR 3184

Periodic fever in MVK deficiency: a patient initially diagnosed with incomplete Kawasaki disease.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Mevalonate kinase deficiency (MKD) is a rare autosomal recessive disorder causing 1 of 2 phenotypes, hyperimmunoglobulin D syndrome and mevalonic aciduria, presenting with recurrent fever episodes, often starting in infancy, and sometimes evoked by stress or vaccinations. This autoinflammatory disease is caused by mutations encoding the mevalonate kinase (MVK) gene and is classified in the group of periodic fever syndromes. There is often a considerable delay in the diagnosis among pediatric patients with recurrent episodes of fever. We present a case of an 8-week-old girl with fever of unknown origin and a marked systemic inflammatory response. After excluding infections, a tentative diagnosis of incomplete Kawasaki syndrome was made, based on the finding of dilated coronary arteries on cardiac ultrasound and fever, and she was treated accordingly. However, the episodes of fever recurred, and alternative diagnoses were considered, which eventually led to the finding of increased excretion of mevalonic acid in urine. The diagnosis of MKD was confirmed by mutation analysis of the MVK gene. This case shows that the initial presentation of MKD can be indistinguishable from incomplete Kawasaki syndrome. When fever recurs in Kawasaki syndrome, other (auto-)inflammatory diseases must be ruled out to avoid inappropriate diagnostic procedures, ineffective interventions, and treatment delay

Systemic and Tissue Inflammation in Juvenile Dermatomyositis: From Pathogenesis to the Quest for Monitoring Tools

Juvenile Dermatomyositis (JDM) is a systemic immune-mediated disease of childhood, characterized by muscle weakness, and a typical skin rash. Other organ systems and tissues such as the lungs, heart, and intestines can be involved, but may be under-evaluated. The inflammatory process in JDM is characterized by an interferon signature and infiltration of immune cells such as T cells and plasmacytoid dendritic cells into the affected tissues. Vasculopathy due to loss and dysfunction of endothelial cells as a result of the inflammation is thought to underlie the symptoms in most organs and tissues. JDM is a heterogeneous disease, and several disease phenotypes, each with a varying combination of affected tissues and organs, are linked to the presence of myositis autoantibodies. These autoantibodies have therefore been extensively studied as biomarkers for the disease phenotype and its associated prognosis. Next to identifying the JDM phenotype, monitoring of disease activity and disease-inflicted damage not only in muscle and skin, but also in other organs and tissues, is an important part of clinical follow-up, as these are key determinants for the long-term outcomes of patients. Various monitoring tools are currently available, among which clinical assessment, histopathological investigation of muscle and skin biopsies, and laboratory testing of blood for specific biomarkers. These investigations also give novel insights into the underlying immunological processes that drive inflammation in JDM and suggest a strong link between the interferon signature and vasculopathy. New tools are being developed in the quest for minimally invasive, but sensitive and specific diagnostic methods that correlate well with clinical symptoms or reflect local, low-grade inflammation. In this review we will discuss the types of (extra)muscular tissue inflammation in JDM and their relation to vasculopathic changes, critically assess the available diagnostic methods including myositis autoantibodies and newly identified biomarkers, and reflect on the immunopathogenic implications of identified markers

Elicitation of expert prior opinion:application to the MYPAN trial in childhood polyarteritis nodosa

Objectives Definitive sample sizes for clinical trials in rare diseases are usually infeasible. Bayesian methodology can be used to maximise what is learnt from clinical trials in these circumstances. We elicited expert prior opinion for a future Bayesian randomised controlled trial for a rare inflammatory paediatric disease, polyarteritis nodosa (MYPAN, Mycophenolate mofetil for polyarteritis nodosa). Methods A Bayesian prior elicitation meeting was convened. Opinion was sought on the probability that a patient in the MYPAN trial treated with cyclophosphamide would achieve disease remission within 6-months, and on the relative efficacies of mycophenolate mofetil and cyclophosphamide. Expert opinion was combined with previously unseen data from a recently completed randomised controlled trial in ANCA associated vasculitis. Results A pan-European group of fifteen experts participated in the elicitation meeting. Consensus expert prior opinion was that the most likely rates of disease remission within 6 months on cyclophosphamide or mycophenolate mofetil were 74% and 71%, respectively. This prior opinion will now be taken forward and will be modified to formulate a Bayesian posterior opinion once the MYPAN trial data from 40 patients randomised 1:1 to either CYC or MMF become available. Conclusions We suggest that the methodological template we propose could be applied to trial design for other rare diseases

Endothelial and Inflammation Biomarker Profiles at Diagnosis Reflecting Clinical Heterogeneity and Serving as a Prognostic Tool For Treatment Response in Two Independent Cohorts of Patients With Juvenile Dermatomyositis

Objective: Juvenile dermatomyositis (DM) is a heterogeneous systemic immune-mediated vasculopathy. This study was undertaken to 1) identify inflammation/endothelial dysfunction–related biomarker profiles reflecting disease severity at diagnosis, and 2) establish whether such biomarker profiles could be used for predicting the response to treatment in patients with juvenile DM. Methods: In total, 39 biomarkers related to activation of endothelial

Consensus-based recommendations for the management of juvenile localised scleroderma

In 2012, a European initiative called Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) was launched to optimise and disseminate diagnostic and management regimens in Europe for children and young adults with rheumatic diseases. Juvenile localised scleroderma (JLS) is a rare disease within the group of paediatric rheumatic diseases (PRD) and can lead to significant morbidity. Evidence-based guidelines are sparse and management is mostly based on physicians' experience. This study aims to provide recommendations for assessment and treatment of JLS. Recommendations were developed by an evidence-informed consensus process using the European League Against Rheumatism standard operating procedures. A committee was formed, mainly from Europe, and consisted of 15 experienced paediatric rheumatologists and two young fellows. Recommendations derived from a validated systematic literature review were evaluated by an online survey and subsequently discussed at two consensus meetings using a nominal group technique. Recommendations were accepted if ≥80% agreement was reached. In total, 1 overarching principle, 10 recommendations on assessment and 6 recommendations on therapy were accepted with ≥80% agreement among experts. Topics covered include assessment of skin and extracutaneous involvement and suggested treatment pathways. The SHARE initiative aims to identify best practices for treatment of patients suffering from PRDs. Within this remit, recommendations for the assessment and treatment of JLS have been formulated by an evidence-informed consensus process to produce a standard of care for patients with JLS throughout Europe

Elicitation of expert prior opinion: application to the MYPAN trial in childhood polyarteritis nodosa.

OBJECTIVES: Definitive sample sizes for clinical trials in rare diseases are usually infeasible. Bayesian methodology can be used to maximise what is learnt from clinical trials in these circumstances. We elicited expert prior opinion for a future Bayesian randomised controlled trial for a rare inflammatory paediatric disease, polyarteritis nodosa (MYPAN, Mycophenolate mofetil for polyarteritis nodosa). METHODS: A Bayesian prior elicitation meeting was convened. Opinion was sought on the probability that a patient in the MYPAN trial treated with cyclophosphamide would achieve disease remission within 6-months, and on the relative efficacies of mycophenolate mofetil and cyclophosphamide. Expert opinion was combined with previously unseen data from a recently completed randomised controlled trial in ANCA associated vasculitis. RESULTS: A pan-European group of fifteen experts participated in the elicitation meeting. Consensus expert prior opinion was that the most likely rates of disease remission within 6 months on cyclophosphamide or mycophenolate mofetil were 74% and 71%, respectively. This prior opinion will now be taken forward and will be modified to formulate a Bayesian posterior opinion once the MYPAN trial data from 40 patients randomised 1:1 to either CYC or MMF become available. CONCLUSIONS: We suggest that the methodological template we propose could be applied to trial design for other rare diseases