Clinical analysis of 50 children with juvenile dermatomyositis

Advances in Juvenile Dermatomyositis: Pathophysiology, Diagnosis, Treatment and Interstitial Lung Diseases-A Narrative Review

Juvenile idiopathic inflammatory myopathy (JIIM) is a rare systemic autoimmune disease characterized by skeletal muscle weakness with or without a skin rash. Juvenile dermatomyositis (JDM) is the most common subtype of JIIM, accounting for 80% of JIIM. Recent studies identified several myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs). Each MSA or MAA is associated with distinct clinical features and outcomes, although there are several differences in the prevalence of MSA/MAA and autoantibody-phenotype relationships between age and ethnic groups. Histopathological studies have revealed critical roles of type I interferons and vasculopathy in the development of JDM. Serological classification mostly corresponds to clinicopathological classification. Novel therapeutic agents, such as biologics and Janus kinase inhibitors (JAKi), have been developed; however, to date, there is a lack of high-level evidence. As advances in treatment have reduced the mortality rate of JIIM, recent studies have focused on medium- and long-term outcomes. However, rapidly progressive interstitial lung disease (RP-ILD) remains a major cause of death in anti-melanoma differentiation gene 5 autoantibody-positive JDM. Early diagnosis and intervention using a multi-drug regimen is critical for the treatment of RP-ILD. Rituximab and JAKi may reduce mortality in patients with JDM-associated RP-ILD refractory to conventional therapy.

Biomarkers and their Clinical Applications in Pediatrics

Biomarker studies are becoming increasingly interesting for many fields of medicine. The use of biomarkers in medicine is involved in detecting diseases and supporting diagnosis and treatment decisions. New research and new discoveries on the molecular basis of the disease show that there may be a number of promising new biomarkers for use in daily clinical practice. Clinical trials in children lag behind adult research both in quality and quantity. The number of biomarkers validated to optimize pediatric patient management is limited. In the pathogenesis of many diseases, it should not be extrapolated to the pediatric clinical setting, taking into account that biomarkers that are effective in adults are clearly different in children and that ontogeny directly affects disease development and therapeutic response in children. The search for ideal biomarkers or markers that can make an early and definitive diagnosis in neonatal sepsis is still ongoing. The ideal biomarker for pediatric diseases should be costeffective, noninvasive, applicable to pediatric specific diseases, and its results should correspond to age-related physiological changes. Lactate, troponin and B-type natriuretic peptide are valuable biomarkers in the evaluation and management of critically ill children with cardiac disease. Tumor markers in children are biochemical substances used in the clinical treatment of pediatric tumors and to detect the presence of cancer (regression or progression). In this chapter, current and brief information about biomarkers and their clinical applications used in the diagnosis and monitoring of pediatric diseases is presented.;

Successful rituximab treatment for severe rapidly progressive interstitial lung disease with anti-MDA5 antibody-positive juvenile dermatomyositis: a case report and literature review

BACKGROUND

Rapidly progressive (RP) interstitial lung disease (ILD) is a life-threatening complication of juvenile dermatomyositis (JDM); however, it is generally refractory to treatment; to the best of our knowledge, no evidence-based treatment has been established for RP-ILD yet. We present the case of a 2-year-old girl with RP-ILD who showed resistance to treatment with methylprednisolone, cyclosporine A, cyclophosphamide, immunoglobulin, and plasma exchange (PE) and was finally treated with extracorporeal membrane oxygenation. We further present a literature review of 18 cases of JDM with RP-ILD.

CASE PRESENTATION

A 2-year-old girl presented with malar rash, mild muscle weakness, and weight loss for a few months before admission. She had a history of dry cough and dyspnea for a few days, followed by rapid respiratory failure. The patient was diagnosed with JDM with RP-ILD through physical examination (malar rashes and Gottron's sign) and based on the finding of myositis on femoral magnetic resonance imaging, elevated levels of serum muscle enzymes, positive anti-melanoma differentiation-association gene 5 (MDA5) antibody (> 7,500 index), elevated level of Krebs von den Lungen-6 glycoprotein (KL-6; 3,420 U/mL), and extensive ground-glass opacities with consolidation in the bilateral lungs on chest high-resolution computed tomography. She received combination therapy, including methylprednisolone pulse therapy, followed by oral prednisolone and intravenous cyclosporine A, cyclophosphamide, and immunoglobulin. On day 11 of hospitalization, she was placed on ventilation support and PE was initiated. However, her respiratory condition continued to deteriorate and veno-venous extracorporeal membrane oxygenation was started on day 24 of hospitalization. Rituximab was administered on day 28. After 2 weeks of rituximab therapy initiation, her respiratory condition showed gradual improvements. Eventually, on day 52 of hospitalization, the patient could be weaned off extracorporeal membrane oxygenation. Finally, she was discharged with minimal ventilation support and no neurological complications 11 months after admission.

CONCLUSIONS

Our literature review suggest that JDM with RP-ILD has a high mortality rate. In JDM, rituximab may be a promising treatment option for RP-ILD. In the future, the efficacy of rituximab in the early phases of ILD should be investigated.

Updates on Juvenile Dermatomyositis from the Last Decade: Classification to Outcomes

Juvenile dermatomyositis (JDM) is a heterogeneous disease with new classification criteria and updates in myositis-specific autoantibody and myositis-associated antibody groups. There are many validated assessment tools for assessing disease activity in JDM. Future studies will optimize these tools and improve feasibility in clinical and research contexts. Genetic and environmental risk factors, mechanisms of muscle pathology, role of interferon, vascular markers, and changes in immune cells provide insights to JDM pathogenesis. Outcomes have improved, but chronic disease, damage, and mortality highlight the need for better outcome predictors and treatments. Increased collaboration of stakeholders may help overcome research barriers and improve JDM treatment.

Use of Rescue Therapy with IVIG or Cyclophosphamide in Juvenile Myositis

PURPOSE OF REVIEW

This review aims to present the literature available to date on the use of intravenous immunoglobulin and cyclophosphamide for juvenile patients with inflammatory myopathies, to evaluate the strength of the evidence so far for both these medications, and to reach conclusions about their efficacy.

RECENT FINDINGS

Juvenile idiopathic inflammatory myopathies, mainly represented by juvenile dermatomyositis (JDM), are rare diseases but quite debilitating for the patients. JDM is an autoimmune condition with predominantly muscle and skin involvement but also systemic features affecting the cardiovascular, respiratory, and gastrointestinal systems. The mainstay therapy is based on corticosteroids and methotrexate, but often other therapeutic alternatives are sought for patients with severe or refractory disease. The rarity of these conditions makes research for new medications even more challenging. Innovative trial designs or statistical methods can be used to emulate a randomized study and investigate drug effectiveness. Despite the lack of Level I evidence on the use and efficacy of intravenous immunoglobulin and cyclophosphamide, their use is advocated by a substantial number of case reports and case series as well as analyses using marginal structural models.

Treatment of Calcinosis in Juvenile Dermatomyositis

PURPOSE OF REVIEW

Juvenile dermatomyositis (JDM) is a rare autoimmune disease characterised by muscle and skin involvement. Calcinosis is a debilitating complication of JDM which is difficult to treat and may cause long-term morbidity. The purpose of this review is to provide an update for the treatment of JDM-associated calcinosis based on previously published studies.

RECENT FINDINGS

Evidence-based studies are lacking for the management of calcinosis, and current treatment modalities have been largely based on case reports, case series, cohort studies, limited controlled studies and anecdotal clinical experience. The use of early aggressive therapy for resistant cases is strongly suggested to halt persistent disease activity which may help in reducing steroid use and their associated complications. Recent insights into disease pathogenesis, myositis-specific antibodies and genetic associations have led to identification of novel therapeutic targets such as Janus kinase (JAK) 1/2. Different treatment regimens with variable outcomes are in use for the treatment of refractory calcinosis; nevertheless, the level of evidence is not sufficient to propose specific guidelines. Recently, JAK 1/2 inhibitors have shown to be effective as an emerging therapeutic option highlighting that translational and clinical research is crucial to develop targeted treatment for JDM-associated calcinosis.

Clinical practice guidance for juvenile dermatomyositis (JDM) 2018-Update

Juvenile dermatomyositis is the most common type of juvenile idiopathic inflammatory myopathy mainly affecting the skin and proximal muscles. We have published the Japanese version of 'Clinical practice guidance for juvenile dermatomyositis (JDM) 2018 'consisting of a review of articles in the field and evidence-informed consensus-based experts' opinion on the treatment strategy in collaboration with The Pediatric Rheumatology Association of Japan and The Japan College of Rheumatology under the financial support by 'Research on rare and intractable diseases, Health and Labor Sciences Research Grants'. This article is a digest version of the Japanese guidance.

Juvenile Dermatomyositis: Key Roles of Muscle Magnetic Resonance Imaging and Early Aggressive Treatment

Juvenile dermatomyositis is a rare systemic connective tissue disease with onset during childhood. It presents clinically with proximal muscle weakness and characteristic skin involvement. Diagnosis is based on the Bohan and Peter criteria, though many authors are now substituting biopsy with muscle magnetic resonance imaging (MRI) for both diagnosis and follow-up. Without intensive early treatment, complications such as calcinosis cutis and lipodystrophy can develop in the chronic phases of the disease. Early recognition is therefore key to management. We present a series of 5 patients who were diagnosed with Juvenile dermatomyositis on muscle MRI without undergoing muscle biopsy and who received early treatment. We draw attention to the usefulness of muscle MRI for the diagnosis of muscle involvement and to the importance of early initiation of intensive treatment to prevent complications.

How Often are Pediatric Patients with Clinically Amyopathic Dermatomyositis Truly Amyopathic?

BACKGROUND

Pediatric patients can present with skin manifestations of dermatomyositis without overt weakness (clinically amyopathic juvenile dermatomyositis [JDM]), but it is unclear how often this happens and how often they have subclinical muscle inflammation.

OBJECTIVE

Our goal was to determine the frequency of clinically amyopathic JDM and the frequency with which a thorough evaluation uncovers subclinical myositis at a single institution.

METHODS

A retrospective review was performed of 46 patients diagnosed with JDM at Children's Hospital of Wisconsin.

RESULTS

Of 46 patients presenting with skin findings consistent with dermatomyositis, 10 patients (21.7%) did not have evidence of muscle involvement on history or exam, and these tended to be the younger patients. Of these 10, only 2 (4% of all the JDM patients) were truly amyopathic upon further evaluation (all five muscle enzymes [aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase and aldolase], magnetic resonance imaging [MRI], muscle biopsy). In our series, muscle biopsy was not helpful in identifying subclinical myositis. In contrast, MRI did uncover subclinical muscle disease.

CONCLUSION

These data suggest that truly amyopathic JDM is rare and that a thorough workup that includes all five muscle enzymes and MRI may uncover occult myositis.

Clinical analysis and outcome of interstitial lung disease complicated with juvenile dermatomyositis and juvenile polymyositis

OBJECTIVES

The aim of this study was to determine the clinical phenotype and outcome of interstitial lung disease (ILD) complicated with juvenile dermatomyositis (JDM) or juvenile polymyositis (JPM).

METHODS

This was a single-center retrospective study. From 1984 to 2015, we retrospectively reviewed 29 patients who were diagnosed with JDM/JPM, among whom eight cases were ILD and 21 were non-ILD. The clinical features and laboratory findings included chest computed tomography (CT) images that were compared between the patients with ILD and non-ILD.

RESULTS

Eight cases (27.6%) were complicated with ILD. The mean age was 6.3 years, and 75% of the patients were women. We found that high fever, arthralgia, muscle weakness, and high serum Krebs von den Lungen-6 (KL-6) level were significantly associated with the presence of ILD (p < 0.05). Two patients were positive for the anti-Jo-1 antibody, and two other patients were positive for the anti-MDA5 antibody. Three cases were identified as rapidly progressive (RP)-ILD. The chest CT images of the ILD patients appeared to show ground glass opacity (GGO) with a lower lobe predominance, reticulation, and traction bronchiectasis consolidation. Three patients with RP-ILD showed random subpleural GGO with/without consolidation patterns. Further, three patients with RP-ILD died of respiratory failure (p < 0.01).

CONCLUSION

ILD is one of the most serious complications of JDM/JPM. In the early phase of ILD, high levels of serum KL-6 can be detected, regardless of the respiratory symptoms. Additionally, RP-ILD can be predicted based on the presence of anti-MDA5 antibodies and the chest CT findings, including random subpleural GGO with/without consolidation patterns.

Myositis registries and biorepositories: powerful tools to advance clinical, epidemiologic and pathogenic research

PURPOSE OF REVIEW

Clinical registries and biorepositories have proven extremely useful in many studies of diseases, especially rare diseases. Given their rarity and diversity, the idiopathic inflammatory myopathies, or myositis syndromes, have benefited from individual researchers' collections of cohorts of patients. Major efforts are being made to establish large registries and biorepositories that will allow many additional studies to be performed that were not possible before. Here, we describe the registries developed by investigators and patient support groups that are currently available for collaborative research purposes.

RECENT FINDINGS

We have identified 46 myositis research registries, including many with biorepositories, which have been developed for a wide variety of purposes and have resulted in great advances in understanding the range of phenotypes, clinical presentations, risk factors, pathogenic mechanisms, outcome assessment, therapeutic responses, and prognoses. These are now available for collaborative use to undertake additional studies. Two myositis patient registries have been developed for research, and myositis patient support groups maintain demographic registries with large numbers of patients available to be contacted for potential research participation.

SUMMARY

Investigator-initiated myositis research registries and biorepositories have proven extremely useful in understanding many aspects of these rare and diverse autoimmune diseases. These registries and biorepositories, in addition to those developed by myositis patient support groups, deserve continued support to maintain the momentum in this field as they offer major opportunities to improve understanding of the pathogenesis and treatment of these diseases in cost-effective ways.

Clinical course and outcomes of Iranian children with juvenile dermatomyositis and polymyositis

This study evaluated the clinical features, course, and outcomes of Iranian children with juvenile dermatomyositis (JDM), juvenile polymyositis (JPM), and other uncommon connective tissue disorders. A chart review of 85 Iranian children with JDM and JPM was performed during a 10-year period from 2003 to 2013. The patients' clinical signs and symptoms, laboratory data, and other factors affecting clinical outcomes were recorded using questionnaires. Statistical analysis was performed using SPSS software version 20. In all, 40 boys and 45 girls were included in the study (F/M, 1.1:1). Disease frequency was significantly higher in boys aged <5 years (F/M, 0.4:1) and girls aged >5 years (F/M, 1.6:1). The combined mean age at diagnosis was 7.5 years. Muscle weakness, particularly in the proximal muscles of lower extremities (96 %); fatigue (83 %); and heliotrope rash (71 %) were the most frequently recorded symptoms. Elevated lactate dehydrogenase level was the most common enzyme disturbance (98 %). Monocyclic course was seen in 60 % of patients. The mean treatment duration was 3 years. The incidence rate of complications such as calcinosis, lipodystrophy, and growth disturbances was 20, 9, and 30 %, respectively. The occurrence of these complications in patients with monocyclic disease was significantly lower. Vital organ involvement led to the death of four patients. The incidence of calcinosis was significantly lower in patients having a shorter interval between disease onset and treatment. Two important complications, failure to thrive and lipodystrophy, were significantly higher in patients having antinuclear antibodies. The incidence of the above three complications was higher in patients with polycyclic or continuous chronic disease. Respiratory failure was the most common cause of patient mortality.

Clinical characteristics of children with juvenile dermatomyositis: the Childhood Arthritis and Rheumatology Research Alliance Registry

OBJECTIVE

To investigate aspects of juvenile dermatomyositis (DM), including disease characteristics and treatment, through a national multicenter registry.

METHODS

Subjects meeting the modified Bohan and Peter criteria for definite juvenile DM were analyzed from the cross-sectional Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry between 2010 and 2012 from 55 US pediatric rheumatology centers. Demographics, disease characteristics, diagnostic assessments, and medication exposure data were collected at enrollment.

RESULTS

A total of 384 subjects met the criteria for analysis. At enrollment, the median Childhood Myositis Assessment Scale score was 51 (interquartile range [IQR] 46-52), the median Childhood Health Assessment Questionnaire score was 0 (IQR 0-0.5), and the median physician and subject global assessment scores were 1 (IQR 0-2) and 1 (IQR 0-3), respectively, out of a maximum of 10. Of the diagnostic assessments, magnetic resonance imaging was more likely than electromyography or muscle biopsy to show abnormalities. A total of 329 subjects had ≥2 diagnostic studies performed, and >34% of these subjects reported ≥1 negative study. Ninety-five percent had been treated with corticosteroids and 92% with methotrexate, suggesting that these medications were almost universally prescribed for juvenile DM in the US.

CONCLUSION

In 2 years, the ongoing CARRA Registry has collected clinical data on 384 children with juvenile DM and has the potential to become one of the largest juvenile DM cohorts in the world. More research is needed about prognostic factors in juvenile DM, and differences in therapy based on manifestations of disease need to be explored by practitioners. This registry provides the infrastructure needed to advance clinical and translational research and represents a major step toward improving outcomes of children with juvenile DM.