Juvenile Dermatomyositis

Connective tissue disease-associated lung disease in children

Connective tissue diseases are a heterogeneous group of autoimmune diseases that can affect a variety of organ systems. Lung parenchymal involvement is an important contributor to morbidity and mortality in children with connective tissue disease. Connective tissue disease-associated lung disease in children often manifests as one of several radiologic-pathologic patterns of disease, with certain patterns having a propensity to occur in association with certain connective tissue diseases. In this article, key clinical, histopathologic, and computed tomography (CT) features of typical patterns of connective tissue disease-associated lung disease in children are reviewed, with an emphasis on radiologic-pathologic correlation, to improve recognition of these patterns of lung disease at CT and to empower the pediatric radiologist to more fully contribute to the care of pediatric patients with these conditions.

A Video-Based Augmented Reality System for Human-in-the-Loop Muscle Strength Assessment of Juvenile Dermatomyositis

As the most common idiopathic inflammatory myopathy in children, juvenile dermatomyositis (JDM) is characterized by skin rashes and muscle weakness. The childhood myositis assessment scale (CMAS) is commonly used to measure the degree of muscle involvement for diagnosis or rehabilitation monitoring. On the one hand, human diagnosis is not scalable and may be subject to personal bias. On the other hand, automatic action quality assessment (AQA) algorithms cannot guarantee 100% accuracy, making them not suitable for biomedical applications. As a solution, we propose a video-based augmented reality system for human-in-the-loop muscle strength assessment of children with JDM. We first propose an AQA algorithm for muscle strength assessment of JDM using contrastive regression trained by a JDM dataset. Our core insight is to visualize the AQA results as a virtual character facilitated by a 3D animation dataset, so that users can compare the real-world patient and the virtual character to understand and verify the AQA results. To allow effective comparisons, we propose a video-based augmented reality system. Given a feed, we adapt computer vision algorithms for scene understanding, evaluate the optimal way of augmenting the virtual character into the scene, and highlight important parts for effective human verification. The experimental results confirm the effectiveness of our AQA algorithm, and the results of the user study demonstrate that humans can more accurately and quickly assess the muscle strength of children using our system.

The clinical features of juvenile dermatomyositis: A single-centre inception cohort

INTRODUCTION

Juvenile Dermatomyositis (JDM), a severe and rare autoimmune disease, is the most common idiopathic inflammatory myopathy in children. We describe the clinical features of a large single-centre cohort.

METHODS

We studied an inception cohort (0-18 years old) referred for diagnosis to the JDM clinic at The Hospital for Sick Children (SickKids), between January 1989 and September 2017. Probable or definite diagnosis of JDM was done according to the 2017 ACR/EULAR Criteria. We excluded children who had treatment started at another hospital. The data were collected retrospectively from clinical charts and the SickKids JDM database.

RESULTS

172/230 (74.8%) patients were included. They were most often female (female:male = 1.8:1); the age at diagnosis was 8.5±4.3 years. There was a positive family history for autoimmune disease in 52%, mainly rheumatoid arthritis. No patient died. The most common signs at inception were muscle weakness (85.5%), nailfold capillary abnormalities (83.4%), Gottron papules (78.5%), heliotrope rash (66.3%), abnormal gait (55.8%), and malar/facial rash (54.7%). The prevalence of Gottron papules, heliotrope rash, facial/malar rash, nailfold capillary abnormalities, Raynaud phenomenon, dysphonia/dysphagia (a frequent cause of hospitalization), mouth ulcers, calcinosis, eye problems, joint involvement, acanthosis nigricans and lipodystrophy increased during follow-up. Muscle enzymes, namely CK, ALT, AST, were often normal or only slightly raised despite active muscle disease; conversely LD was often high. Anti-Nuclear Autoantibodies were positive in 49.7% of patients at diagnosis. The course of the disease was: 29.1% monocyclic, 5.3% polycyclic, 33.1% chronic. The course of 56 patients (32.5%) was not classifiable due to length of follow-up. Corticosteroids were used as treatment in almost all our patients and 30% required intravenous therapy due to the severity of the presentation; methotrexate was added in 64%, more often in recent years. Unresponsive patients were treated mostly with intravenous immunoglobulins (IVIG).

CONCLUSIONS

The information obtained from this relatively large number of patients adds to the growing knowledge base of this rare disease.

TRIAL REGISTRATION

SickKids Research Ethics Board approved the study.

Feasibility of the wingate anaerobic exercise test as a clinical measure in patients with juvenile dermatomyositis

BACKGROUND

Core sets, while widely adopted for clinical assessment in juvenile dermatomyositis (JDM), have some drawbacks - they are time consuming, were developed primarily for research, and require an experienced multidisciplinary team. We propose the Wingate Anaerobic Test, a 30-s all out test performed on a cycle ergometer, as a potential alternative; it is valid and reliable in this patient population. We aimed to determine the feasibility of performing the Wingate test as part of a typical clinic visit, and to determine if it is correlated to current measures of disease activity.

METHODS

Patients 5-18 years of age, with JDM, were recruited from the JDM clinic at a large Canadian academic children's hospital. Participants underwent a standard clinic assessment, then completed a Wingate test at the end of the visit.

RESULTS

Twenty-six patients participated in the study, representing a recruitment rate of 81%; of those, 88% were able to complete the Wingate test. Patients liked the Wingate test and felt it should be included as a regular clinic test. Absolute peak power (watts) on the Wingate test was strongly correlated to the manual muscle test (MMT-8) and the timed squat test. Relative peak power (watts/kg) on the Wingate test was strongly correlated to the timed squat test and the Childhood Myositis Assessment Scale (CMAS). Exploratory principal components analysis revealed that Wingate relative average power explained almost 2/3 of the variance of the CMAS, MMT and timed squats combined.

CONCLUSION

The Wingate test is a feasible test for children with JDM and correlates well with standard clinical assessments. Given its brevity, it has the potential to replace more standard measures of physical function currently used in clinical assessments for children with JDM. Future work should focus on how best to operationalize Wingate testing in clinic without the use of dedicated personnel.

Genetic Analysis for Type 1 Diabetes Genes in Juvenile Dermatomyositis Unveils Genetic Disease Overlap

OBJECTIVES

Juvenile dermatomyositis (JDM) is a serious autoimmune and complex genetic disease. Another autoimmune genetic disease, type 1 diabetes (T1D), has been observed for significantly increased prevalence in families with JDM, while increased JDM risk has also been observed in T1D cases. This study aimed to study whether these two autoimmune diseases, JDM and T1D, share common genetic susceptibility.

METHODS

From 169 JDM families, 121 unrelated cases with European ancestry (EA) were identified by genome-wide genotyping, principal component analysis (PCA), and identical-by-descent (IBD) analysis. T1D genetic risk score (GRS) were calculated in these cases, and were compared with 361 EA T1D cases and 1943 non-diabetes EA controls. 113 cases of the 121 unrelated European cases were sequenced by whole exome sequencing (WES).

RESULTS

We observed increased T1D GRS in JDM cases (P=9.42E-05). Using whole exome sequencing (WES), we uncovered the T1D genes, phospholipase B1 (PLB1), cystic fibrosis transmembrane conductance regulator (CFTR), tyrosine hydroxylase (TH), CD6 molecule (CD6), perforin 1 (PRF1), and dynein axonemal heavy chain 2 (DNAH2), potentially associated with JDM by the burden test of rare functional coding variants.

CONCLUSION

Novel mechanisms of JDM related to these T1D genes are suggested by this study, which may imply novel therapeutic targets for JDM and warrant further study.

Juvenile dermatomyositis in Thai children: Retrospective review of 30 cases from a tertiary care center

BACKGROUND

Juvenile dermatomyositis is a rare condition, but it is the most common idiopathic inflammatory myopathy in pediatric patients.

AIM

To study the clinical manifestations, investigations, treatment, clinical course, and outcomes of juvenile dermatomyositis in Thai children.

METHOD

This retrospective study included juvenile dermatomyositis patients treated at Siriraj Hospital, a 2,300-bed national tertiary referral center in Bangkok, Thailand, from 1994 to 2019.

RESULTS

Thirty patients (22 females and 8 males) were included with a female to male ratio of 2.7:1. Median age at diagnosis was 5.1 years (range, 2.6-14.8 years). Median duration of illness before diagnosis was 6.5 months (range, 0.3-84.0 months). Acute and subacute onset occurred in the majority of patients. Presenting symptoms included muscle weakness in 27/30 (90%), skin rash in 26/30 (86.7%), muscle pain in 17/26 (65.4%), and arthralgia in 4/18 (22.2%) of patients. Dermatologic examination revealed Gottron's rash, heliotrope rash, and periungual telangiectasia in 25/30 (83.3%), 21/30 (70.0%), and 15/24 (62.5%) of patients, respectively. Interestingly, scalp dermatitis was found in 8/21 (38.1%) of patients. The most commonly used treatment regimen in this series was a combination of prednisolone and methotrexate. During the median follow-up of 3.1 years (range, 0.0-18.5 years), only one-third of patients were seen to have monocyclic disease. Extraskeletal osteosarcoma at a previous lesion of calcinosis cutis was observed in one patient at 12 years after juvenile dermatomyositis onset.

LIMITATIONS

This was a retrospective single-center study, and our results may not be generalizable to other healthcare settings. Prospective multicenter studies are needed to confirm the findings of this study.

CONCLUSION

juvenile dermatomyositis usually poses a diagnostic and therapeutic challenge, which can be compounded by the ethnic variations in the clinical presentation, as observed in this study. Asian patients tend to present with acute or subacute onset of disease, and arthralgia and/or arthritis are less common than in Caucasian patients. Scalp dermatitis is not uncommon in pediatric juvenile dermatomyositis patients. An association between juvenile dermatomyositis and malignancy, though rare, can occur.

Pulmonary Manifestations of Rheumatic Diseases in Children

Children with rheumatic disease have rare pulmonary manifestations that may cause significant morbidity and mortality. These children are often clinically asymptomatic until disease has significantly progressed, so they should be screened for pulmonary involvement. There has been recent recognition of a high mortality-related lung disease in systemic-onset juvenile idiopathic arthritis; risk factors include onset of juvenile idiopathic arthritis less than 2 years of age, history of macrophage activation syndrome, presence of trisomy 21, and history of anaphylactic reaction to biologic therapy. Early recognition and treatment of lung disease in children with rheumatic diseases may improve outcomes.

Juvenile Dermatomyositis: Advances in Pathogenesis, Assessment, and Management

BACKGROUND

Juvenile dermatomyositis is the most common inflammatory myopathy in the pediatric age group and a major cause of mortality and morbidity in individuals with childhood rheumatic diseases. Mounting evidence suggests that early diagnosis and timely aggressive treatment are associated with better outcomes.

OBJECTIVE

The purpose of this article is to provide readers with an update on the evaluation, diagnosis, and the treatment of juvenile dermatomyositis.

METHODS

A PubMed search was performed in Clinical Queries using the key term "juvenile dermatomyositis" in the search engine. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Juvenile dermatomyositis is a chronic autoimmune inflammatory condition characterized by systemic capillary vasculopathy that primarily affects the skin and muscles with possible involvement of other organs. In 2017, the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) developed diagnostic criteria for juvenile idiopathic inflammatory myopathies and juvenile dermatomyositis. In the absence of muscle biopsies which are infrequently performed in children, scores (in brackets) are assigned to four variables related to muscle weakness, three variables related to skin manifestations, one variable related to other clinical manifestations, and two variables related to laboratory measurements to discriminate idiopathic inflammatory myopathies from non-idiopathic inflammatory myopathies as follows: objective symmetric weakness, usually progressive, of the proximal upper extremities (0.7); objective symmetric weakness, usually progressive, of the proximal lower extremities (0.8); neck flexors relatively weaker than neck extensors (1.9); leg proximal muscles relatively weaker than distal muscles (0.9); heliotrope rash (3.1); Gottron papules (2.1); Gottron sign (3.3); dysphagia or esophageal dysmotility (0.7); the presence of anti-Jo-1 autoantibody (3.9); and elevated serum levels of muscle enzymes (1.3). In the absence of muscle biopsy, a definite diagnosis of idiopathic inflammatory myopathy can be made if the total score is ≥7.5. Patients whose age at onset of symptoms is less than 18 years and who meet the above criteria for idiopathic inflammatory myopathy and have a heliotrope rash, Gottron papules or Gottron sign are deemed to have juvenile dermatomyositis. The mainstay of therapy at the time of diagnosis is a high-dose corticosteroid (oral or intravenous) in combination with methotrexate.

CONCLUSION

For mild to moderate active muscle disease, early aggressive treatment with high-dose oral prednisone alone or in combination with methotrexate is the cornerstone of management. Pulse intravenous methylprednisolone is often preferred to oral prednisone in more severely affected patients, patients who respond poorly to oral prednisone, and those with gastrointestinal vasculopathy. Other steroid-sparing immunosuppressive agents such as cyclosporine and cyclophosphamide are reserved for patients with contraindications or intolerance to methotrexate and for refractory cases, as the use of these agents is associated with more adverse events. Various biological agents have been used in the treatment of juvenile dermatomyositis. Data on their efficacy are limited, and their use in the treatment of juvenile dermatomyositis is considered investigational.

Pilot Study of the Juvenile Dermatomyositis Consensus Treatment Plans: A CARRA Registry Study

OBJECTIVES

To determine the feasibility of comparing the Childhood Arthritis and Rheumatology ResearchAlliance (CARRA) consensus treatment plans (CTP) in treating moderate new-onset juvenile dermatomyositis (JDM) using the CARRA registry, and to establish appropriate analytic methods to control for confounding by indication and missing data.

METHODS

A pilot cohort of 39 patients with JDM from the CARRA registry was studied. Patients were assigned by the treating physician, considering patient/family preferences, to 1 of 3 CTP: methotrexate (MTX) and prednisone (MP); intravenous (IV) methylprednisolone, MTX, and prednisone (MMP); or IV methylprednisolone, MTX, prednisone, and IV immunoglobulin (MMPI). The primary outcome was the proportion of patients achieving moderate improvement at 6 months under each CTP. Statistical methods including multiple imputation and inverse probability of treatment weighting were used to handle missing data and confounding by indication.

RESULTS

Patients received MP (n = 13), MMP (n = 18) and MMPI (n = 8). Patients in all CTP had significant improvement in disease activity. Of the 36 patients who remained in our pilot study at 6 months, 16 (44%) of them successfully achieved moderate improvement at 6 months (6/13, 46% for MP; 7/15, 47% for MMP; 3/8, 38% for MMPI). After correcting for confounding, there were no statistically significant pairwise differences between the CTP (P = 0.328-0.88).

CONCLUSION

We gained valuable experience and insight from our pilot study that can be used to guide the design and analysis of comparative effectiveness studies using the CARRA registry CTP approach. Our analytical methods can be adopted for future comparative effectiveness studies and applied to other rare disease observational studies.

Being on the juvenile dermatomyositis rollercoaster: a qualitative study

BACKGROUND

Juvenile Dermatomyositis is a rare, potentially life-threatening condition with no known cure. There is no published literature capturing how children and young people feel about their condition, from their perspective. This study was therefore unique in that it asked children and young people what is it like to live with Juvenile Dermatomyositis.

METHODS

Data were obtained from fifteen young people with Juvenile Dermatomyositis, between eight and nineteen years of age from one Paediatric Rheumatology department using audio-recorded interpretive phenomenology interviews. Data were analyzed phenomenologically, using a process that derives narratives from transcripts resulting in a collective composite of participants shared experiences, called a 'phenomenon'.

RESULTS

The overarching metaphor of a rollercoaster captures the phenomenon of living with Juvenile Dermatomyositis as a young person, with the ups and downs at different time points clearly described by those interviewed. The five themes plotted on the rollercoaster, began with confusion; followed by feeling different, being sick, steroidal and scared from the medications; uncertainty; and then ended with acceptance of the disease over time.

CONCLUSION

Young people were able to talk about their experiences about having Juvenile Dermatomyositis. Our findings will aid clinicians in their practice by gaining a deeper understanding of what daily life is like and highlighting ways to enhance psychosocial functioning. Hopefully, this study and any further resulting studies, will raise understanding of Juvenile Dermatomyositis worldwide and will encourage health care professionals to better assess psychosocial needs in the future.

A Bayesian semiparametric Markov regression model for juvenile dermatomyositis

Juvenile dermatomyositis (JDM) is a rare autoimmune disease that may lead to serious complications, even to death. We develop a 2-state Markov regression model in a Bayesian framework to characterise disease progression in JDM over time and gain a better understanding of the factors influencing disease risk. The transition probabilities between disease and remission state (and vice versa) are a function of time-homogeneous and time-varying covariates. These latter types of covariates are introduced in the model through a latent health state function, which describes patient-specific health over time and accounts for variability among patients. We assume a nonparametric prior based on the Dirichlet process to model the health state function and the baseline transition intensities between disease and remission state and vice versa. The Dirichlet process induces a clustering of the patients in homogeneous risk groups. To highlight clinical variables that most affect the transition probabilities, we perform variable selection using spike and slab prior distributions. Posterior inference is performed through Markov chain Monte Carlo methods. Data were made available from the UK JDM Cohort and Biomarker Study and Repository, hosted at the UCL Institute of Child Health.

Familiäres Auftreten der Dermatomyositis bei Working Kelpies

Acht eng verwandte Mitglieder einer Linie von Working Kelpies zeigten Symptome einer Dermatomyositis in Form von Alopezie, Krusten, Ulzerationen der Haut, Depigmentation von Nasenspiegel und Lefzen, Onychodystrophie und Muskelatrophie, vor allem der Kaumuskeln. Die Symptome waren bei den betroffenen Tieren unterschiedlich stark oder nur teilweise ausgeprägt. Die klinische Diagnose wurde bei drei Hunden durch histologische Untersuchung von Hautbioptaten, nicht jedoch Muskelbioptaten bestätigt. Therapeutisch kamen verschiedene immunmodulatorische Medikamente (Steroide, Ciclosporin, Mycophenolat-Mofetil, Pentoxifyllin, Doxycylin/Niacinamid, Omega-3-Fettsäuren, Vitamin E) mit unterschiedlichem Erfolg zum Einsatz. Bei der Dermatomyositis handelt es sich um eine immunvermittelte Erkrankung mit genetischem Hintergrund bei Mensch und Hund. Die verantwortlichen Gene sind weitgehend unbekannt. Für die Hunderassen Collie und Shetland Sheepdog besteht eine Prädisposition. Zudem wird eine familiäre Häufung beim Beauceron beschrieben. Da die Rasse Working Kelpie im 19. Jahrhundert aus schottischen Hunden des Collie-Typs entstanden ist, wäre eine genetische Prädisposition für die Dermatomyositis erklärbar.

The family impact of caring for a child with juvenile dermatomyositis

Background Juvenile dermatomyositis (JDM), a rare autoimmune disease, accounts for more than 80% of idiopathic inflammatory myopathy childhood cases, making it the most common idiopathic inflammatory myopathy among children. The average age of onset is approximately 7 years and commonly leads a chronic course. Symptoms of JDM include cutaneous features (Gottron's rash, heliotrope rash, or nail fold capillary changes), musculoskeletal features, calcinosis and lipodystrophy (a symmetrical deficit of subcutaneous fatty tissue), and acanthosis (thickening of the skin). Despite improvement in treatment regimens and the lowering of mortality rates, some children still lose their lives to JDM. This study assessed the effects of caring for a child diagnosed with JDM on the family system. Methods Participants included 36 mothers and 3 fathers of a child diagnosed with JDM. Parents were administered self-report measures, which assessed the overall family functioning (PedsQL-Family Impact Module), and the parents' mood and level of distress (profile of mood states). Additionally, parents were administered a semi-structured interview that included background information, psychosocial information, and sources of support. Results and conclusion Families of children with JDM reported difficulties in family functioning, communication problems, and an increased number of conflicts. Parents appeared to be experiencing higher than average levels of worry, worse physical functioning, and family relationships when compared to normative populations. Parents would benefit from psychosocial support due to the many challenges associated with caring for a child with JDM.

Survey of parent and carer experiences and expectations of paediatric rheumatology care in New South Wales

Objective The aim of the present survey of parent and carers was to document the level of care and services currently provided to children diagnosed with rheumatic diseases (RD) in New South Wales (NSW), Australia. Methods The survey included parents and carers of children presenting to paediatric rheumatology (PR) services in NSW. Subjects attending PR clinics in both public and private settings were invited to participate in an online or paper survey. Results Overall, 148 surveys were completed. The process of obtaining the diagnosis of RD was described as being ‘difficult’ or ‘very difficult’ by 56.1% (n = 83) of the surveyed cohort, and 41.2% (n = 61) saw four or more different clinicians before diagnosis. Between symptom onset and final diagnosis, 42.6% (n = 63) of participants reported a delay of 5 months or more, and 16.9% (n = 25) waited longer than 12 months. Eventually, 91% (n = 134) were referred to a paediatric rheumatologist and 63.5% (n = 94) were seen within 4 weeks from initial referral. More than half the respondents felt that general practitioners (GPs) and general paediatricians were not aware of RD. Overall, respondents felt that improved knowledge of PR diseases among GPs, improved access to PR clinics, improved educational materials for patients and families, access to speciality rheumatology nurses and coordinated rheumatology teams would have significantly improved the experience of their child’s disease. Conclusions Children with RD in NSW still experience significant delays from symptom onset to final diagnosis through consultations with multiple healthcare professionals. Multidisciplinary team care was not the norm for this patient group, despite established national and international management standards. What is known about the topic? Early diagnosis and management by a multidisciplinary team is the gold standard in PR management. Delays in diagnosis may significantly impair the outcomes of children diagnosed with RD, with reduced quality of life, increased pain level and worse long-term prognosis. What does this paper add? Children diagnosed with RD in NSW endure significant delays from symptom onset until a final diagnosis is made, with multiple consultations with different healthcare professionals. When the referral to PR services in NSW is made, RD children are mostly seen within 4 weeks, faster than other international standards. GPs and paediatric rheumatologists in NSW helped improve the children’s and their family’s experience of the diagnosis and treatment of a rheumatic condition and better informed them using appropriate educational materials. What are the implications for practitioners? This paper provides new evidence to practitioners to increase their knowledge of the current experiences and expectation of the paediatric rheumatology care in NSW.

A hyper-ferritinemia syndrome evolving in recurrent macrophage activation syndrome, as an onset of amyopathic juvenile dermatomyositis: a challenging clinical case in light of the current diagnostic criteria

Juvenile dermatomyositis is an immune-mediated inflammatory multi-system disease involving mainly striated muscles and skin. Typical dermatological features are fundamental to establish the diagnosis, especially whenever the myopathy is very mild or absent, as it occurs in the form called as amyopathic juvenile dermatomyositis. Sometimes, systemic rheumatic diseases can develop a hyperferritinemia syndrome characterized by hemophagocytosis, namely macrophage activation syndrome, which represents a severe and life-threatening complication. Here, we describe a complex clinical history characterized by a hyper-ferritinemia syndrome after infectious mononucleosis, leading to recurrent episodes of macrophage activation syndrome. Finally, the late onset of several skin changes brought to a diagnosis of amyopathic juvenile dermatomyositis.

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.

Pulmonary complications of childhood rheumatic disease

The array of paediatric pulmonary complications of the various rheumatologic disorders illustrates both the complexities and challenges of the underlying disorders and the continuing lack of detailed knowledge of the pathophysiology and optimal treatment paradigms in children. While the vertical transfer of information has made much progress from adult studies, such as with the diagnosis and management of pulmonary arterial hypertension, in many instances underlying disorders may differ between children and adults in important and fundamental respects. Recognition of pulmonary complications of rheumatic disorders in children is often more difficult and requires anticipation and a high index of suspicion. Further progress in understanding and treating the various paediatric disorders is hampered by the lack of paediatric-specific information. Crucial to further progress are the expansion of orphan childhood disease databases and research networks. In this way a comprehensive approach to determining basic natural history, risks and outcomes, and defining the next generation of therapies in a disease-specific and age-specific manner can be achieved.