National registry of patients with juvenile idiopathic inflammatory myopathies in Hungary—Clinical characteristics and disease course of 44 patients with juvenile dermatomyositis

Calcinosis in Juvenile Dermatomyositis-Epidemiology, Pathogenesis, Clinical Features, and Treatment: A Systematic Review

PURPOSE OF REVIEW

We performed a systematic review of the literature on the epidemiology, pathogenesis, clinical and laboratory characterization, and treatment of calcinosis in patients with juvenile dermatomyositis (JDM). A qualitative systematic review was conducted from January 1975 to April 2023 according to the PRISMA protocol using three electronic databases: PubMed, Web of Science, and Scopus. Studies were analyzed based on the following eligibility criteria: at least one combination of the terms described in the search strategy appeared in the title, written in English, Portuguese, or Spanish, and addressed the epidemiology, pathogenesis, diagnosis, and treatment of calcinosis in juvenile dermatomyositis. Systematic or scoping reviews, letters, clinical images, book chapters, abstracts, inflammatory myopathy in other connective tissue diseases, idiopathic inflammatory myopathies in adults, and purely qualitative studies were excluded.

RECENT FINDINGS

Seventy-five studies were included. According to the literature, calcinosis is common in women, around five years old, with three years of disease in association with osteoarticular, cutaneous, pulmonary manifestations, and fever. The pathogenesis is still unknown, but the participation of interleukin 1 and 6, tumor necrosis factor alpha, and innate immunity dysregulation seem to be involved. Common autoantibodies are anti-NXP-2, anti-MDA-5, and anti-Mi-2, and their treatment remains controversial. Prospective, randomized, controlled studies are needed to evaluate treatment protocols and map the natural history of this serious complication. Calcinosis seems to be more common in White female children with muscle weakness, fever, arthritis, severe pulmonary, and skin involvement with anti-NXP-2, anti-MDA-5, and anti-Mi-2 autoantibodies. The multitargets and aggressive treatment is recommended.

Assessment of Thigh MRI Radiomics and Clinical Characteristics for Assisting in Discrimination of Juvenile Dermatomyositis

Magnetic resonance imaging (MRI) is an important non-invasive examination in the early diagnosis of juvenile dermatomyositis (JDM). We aimed to evaluate the feasibility of radiomics to establish a quantitative analysis of MRI images. Radiomics and machine learning were used to retrospectively analyze MRI T2 fat suppression sequences and relevant clinical data. The model associated with radiomics features was established using a cohort of patients who underwent thigh MRI at the children's hospital from June 2014 to September 2021. In total, 75 patients with JDM and 75 control children were included in the training cohort (n = 102) and validation cohort (n = 48). The independent factors including lower muscle strength (OR, 0.75; 95% CI, 0.59-0.90), higher creatine kinase (CK) level (OR, 1.65; 95% CI, 1.20-2.38), and higher radiomics score (OR, 2.30; 95% CI, 1.63-3.62) were associated with a clinical diagnosis of JDM. The combined model achieved good discrimination performance compared the radiomics score model under linear discriminant analyses in the training cohort (AUC, 0.949; 95% CI, 0.912-0.986 vs. AUC, 0.912; 95% CI, 0.858-0.967; p = 0.02) and in the validation cohort (AUC, 0.945; 95% CI, 0.878-1 vs. AUC, 0.905; 95% CI, 0.812-0.998; p = 0.03). The combined model showed the diagnostic value was not weaker than the biopsy (AUC, 0.950; 95% CI, 0.919-0.981, n = 150 vs. AUC, 0.952; 95% CI, 0.889-1, n = 72; p = 0.95) and electromyogram (EMG) (AUC, 0.950; 95% CI, 0.919-0.981 vs. AUC, 0.900; 95% CI, 0.852-0.948; p = 0.10) among all the patients. The combination of radiomics features extracted from the MRI and non-invasive clinical characteristics obtained a pronounced discriminative performance to assist in discriminating JDM.

Clinical Characteristics of Juvenile Idiopathic Inflammatory Myopathy and Comparison With Adult Patients: Analysis From a Multicentric Cohort in Spain

METHODS

This study reviewed the medical records of patients from the REMICAM cohort, a multicentric longitudinal study carried out in patients with IIM, followed up between 1980 and 2014 in 12 hospitals in Madrid, Spain. Patients with definite or probable JPM, JDM, adult DM, and adult PM according to the modified Bohan and Peter criteria were selected. We compared the characteristics between JDM and JPM, and between JIIM and adult IIM.

RESULTS

Eighty-six juvenile patients (75 JDMs and 11 JPMs) and 283 adult patients (133 DMs and 150 PMs) were included. Compared with patients with JDM, patients with JPM were older at diagnosis, had more fever and arthritis, and were less frequently treated with disease-modifying antirheumatic drugs (these differences were not statistically significant). Compared with patients with adult DM, those with JDM presented more frequently with calcinosis (33.8% vs 6.9%, p < 0.0001) and had less severe infections (4.3% vs 23.4%, p < 0.0001), malignancies (1.3% vs 25.6%, p < 0.0001), and mortality (3.5% vs 33%, p < 0.0001). Patients with JDM were treated less frequently with azathioprine (10.8% vs 44.7%, p < 0.0001).

CONCLUSIONS

Our findings confirm that JIIMs are a heterogeneous group of diseases with relevant differences compared with adult IIMs.

Transbronchial Lung Cryobiopsy in children

BACKGROUND

Transbronchial Lung Cryobiopsy (TBLC) is a novel technique, available globally only in a limited number of centers. Since the data on the role of TBLCs amongst pediatric patients is limited, the aim was to evaluate its efficacy in diagnosing lung diseases amongst children.

METHODS

The records of 28 pediatric patients were retrospectively reviewed from October 2016 till September 2018. The participants' demographic information, procedural indications, sample adequacy, diagnostic utility, and the complications associated with this type of bronchoscopy apparatus were further assessed.

RESULTS

Twenty-eight pediatric patients aged 22 months to 17 years underwent TBLC. From the 73 obtained biopsies, 97% had an adequate sampling size. The diagnostic yield of this method was 92.8%. The most common complication was mild bleeding. Transient hypoxemia and bronchospasm were observed in eleven and eight patients, respectively. Furthermore, most of them (78.6%) had uneventful post-procedure and recovery.

CONCLUSIONS

TBLC was a relatively safe and effective method with high accuracy and fewer complications in diagnosing and monitoring lung diseases in the selected children. However, more extensive multicentre trials are warranted to corroborate the potential benefits of this novel technique.

Novel associations between cytokines and pulmonary involvement in juvenile dermatomyositis - a cross-sectional study of long-term disease

OBJECTIVES

To examine associations between cytokines and pulmonary involvement in patients with medium- to long-term JDM.

METHODS

In a cross-sectional study, 58 patients examined median (range) 16.8 (6.6-27.0) years after symptom onset were stratified in inactive (JDM-inactive) and active (JDM-active) disease (updated PRINTO criteria); 56 age/sex matched controls were included. Twenty-nine cytokines (in serum) were analysed (Luminex technology/ELISA). Pulmonary function test included forced vital capacity, total lung capacity (TLC) and diffusing capacity for carbon monoxide reported as % of predicted and low forced vital capacity/TLC/diffusing capacity for carbon monoxide. In patients, the presence of clinical pulmonary damage was assessed and high resolution computed tomography scans were scored for interstitial lung disease, chest wall calcinosis and airways disease.

RESULTS

Median age of patients was 21 (7-55) years, 59% were female and 36% inactive. In JDM-active and all patients, higher MCP-1, IP-10 and eotaxin correlated with high-resolution computed tomography findings (rs 0.34-0.61; P < 0.05). MCP-1 and eotaxin correlated with pulmonary damage in JDM-active and all patients (rs 0.41-0.49; P < 0.01). Higher TGF-β1 and PDGF (growth factors) were associated with lower lung volumes (forced vital capacity/TLC measures) in all patients; PDGF in JDM-active and TGF-β1 in JDM-inactive patients. IP-10 correlated with TLC% in JDM-active patients. No associations between cytokines and pulmonary function test were found in controls.

CONCLUSIONS

In JDM, we found a novel association (not previously described in myositis) between eotaxin and pulmonary involvement; we have previously shown an association between eotaxin and cardiac dysfunction. The associations between IP-10/growth factors/MCP-1 and pulmonary involvement are novel in JDM and were mostly seen in JDM-active patients.

Anti-Ro52 autoantibodies are associated with interstitial lung disease and more severe disease in patients with juvenile myositis

OBJECTIVES

Anti-Ro52 autoantibodies are associated with more severe interstitial lung disease (ILD) in adult myositis patients with antiaminoacyl transfer (t)RNA synthetase autoantibodies. However, few studies have examined anti-Ro52 autoantibodies in juvenile myositis. The purpose of this study was to define the prevalence and clinical features associated with anti-Ro52 autoantibodies in a large cohort of patients with juvenile myositis.

METHODS

We screened sera from 302 patients with juvenile dermatomyositis (JDM), 25 patients with juvenile polymyositis (JPM) and 44 patients with juvenile connective tissue disease-myositis overlap (JCTM) for anti-Ro52 autoantibodies by ELISA. Clinical characteristics were compared between myositis patients with and without anti-Ro52 autoantibodies.

RESULTS

Anti-Ro52 autoantibodies were found in 14% patients with JDM, 12% with JPM and 18% with JCTM. Anti-Ro52 autoantibodies were more frequent in patients with antiaminoacyl tRNA synthetase (64%, p<0.001) and anti-MDA5 (31%, p<0.05) autoantibodies. After controlling for the presence of myositis-specific autoantibodies, anti-Ro52 autoantibodies were associated with the presence of ILD (36% vs 4%, p<0.001). Disease course was more frequently chronic, remission was less common, and an increased number of medications was received in anti-Ro52 positive patients.

CONCLUSIONS

Anti-Ro52 autoantibodies are present in 14% of patients with juvenile myositis and are strongly associated with anti-MDA5 and antiaminoacyl tRNA synthetase autoantibodies. In all patients with juvenile myositis, those with anti-Ro52 autoantibodies were more likely to have ILD. Furthermore, patients with anti-Ro52 autoantibodies have more severe disease and a poorer prognosis.

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.

Expression of the OAS Gene Family Is Highly Modulated in Subjects Affected by Juvenile Dermatomyositis, Resembling an Immune Response to a dsRNA Virus Infection

Background: Juvenile dermatomyositis (JDM) is a systemic, autoimmune, interferon (IFN)-mediated inflammatory muscle disorder that affects children younger than 18 years of age. JDM primarily affects the skin and the skeletal muscles. Interestingly, the role of viral infections has been hypothesized. Mammalian 2′-5′-oligoadenylate synthetase (OAS) genes have been thoroughly characterized as components of the IFN-induced antiviral system, and they are connected to several innate immune-activated diseases. The main purpose of the paper is to define the potential interrelationship between the OAS gene family network and the molecular events that characterize JDM along with double-stranded RNA (dsRNA) molecular pathways. Methods: We analyzed three microarray datasets obtained from the NCBI in order to verify the expression levels of the OAS gene family network in muscle biopsies (MBx) of JDM patients compared to healthy controls. Furthermore, From GSE51392, we decided to select significant gene expression profiles of primary nasal and bronchial epithelial cells isolated from healthy subjects and treated with polyinosinic-polycytidylic acid (poly(I:C)), a synthetic analog of double-stranded RNA (dsRNA), a molecular pattern associated with viral infection. Results: The analysis showed that all OAS genes were modulated in JDM muscle biopsies. Furthermore, 99% of OASs gene family networks were significantly upregulated. Of importance, 39.9% of modulated genes in JDM overlapped with those of primary epithelial cells treated with poly(I:C). Moreover, the microarray analysis showed that the double-stranded dsRNA virus gene network was highly expressed. In addition, we showed that the innate/adaptive immunity markers were significantly expressed in JDM muscles biopsies. and that their levels were positively correlated to OAS gene family expression. Conclusion: OAS gene expression is extremely modulated in JDM as well as in the dsRNA viral gene network. These data lead us to speculate on the potential involvement of a viral infection as a trigger moment for this systemic autoimmune disease. Further in vitro and translational studies are needed to verify this hypothesis in order to strategically plan treatment interventions.

Cutaneous dermatomyositis disease course followed over time using the Cutaneous Dermatomyositis Disease Area and Severity Index

BACKGROUND

Limited studies describe the longitudinal course of cutaneous dermatomyositis (DM).

OBJECTIVE

To characterize disease course in treated cutaneous DM by using the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI), a validated outcome instrument.

METHODS

A retrospective cohort included patients with DM who had their CDASI activity subscore recorded for at least 2 years. Disease progression was classified as improved, worsened, or stable, and disease course was classified as monophasic, polyphasic, or chronic. Subjects were divided into groups with disease of mild (n = 16) and moderate-to-severe (n = 24) baseline severity.

RESULTS

A total of 40 patients with DM met inclusion criteria. The majority demonstrated improvement in disease activity (n = 21 [52.5%]) rather than worsening (n = 7 [17.5%]) and stable (n = 12 [30.0%]) disease. Most patients with mild disease remained stable (n = 10 [62.5%]), whereas most with moderate-to-severe disease improved (n = 19 [79.2%]). A polyphasic course (n = 33 [82.5%]) predominated over monophasic (n = 5 [12.5%]) and chronic (n = 2 [5%]) courses. The average number of flares per year per number of years of follow-up was independent of baseline disease activity.

LIMITATIONS

The retrospective design, potential referral bias, and cutoff values in classification criteria are limitations.

CONCLUSION

Baseline CDASI activity score is associated with particular patterns of disease course and progression in cutaneous DM.

Juvenile dermatomyositis forty years on: Case report

We present a case report of a 42 year old female, diagnosed at the age of 3 with Juvenile Dermatomyositis. The clinical course was severe and refractory to immunosuppressive therapy. Currently, she is mostly affected by severe muscle atrophy, large joint contractures, calcinosis, and a lipodystrophy associated metabolic syndrome with hypertriglyceridemia, insulin resistance, high total testosterone and hepatic steatosis. She developed Hodgkin´s lymphoma in the course of her disease. Personalized therapeutic choices are discussed as regards juvenile dermatomyositis complications.

Muscle MRI at the time of questionable disease flares in Juvenile Dermatomyositis (JDM)

BACKGROUND

The course of JDM has improved substantially over the last 70 years with early and aggressive treatments. Yet it remains difficult to detect disease flares as symptoms may be mild; signs of rash and muscle weakness vary widely and are often equivocal; laboratory tests of muscle enzyme levels are often normal; electromyography and muscle biopsy are invasive. Alternative tools are needed to help decide if more aggressive treatment is needed. Our objective is to determine the effectiveness of muscle Magnetic Resonance Imaging (MRI) in detecting JDM flares, and how an MRI affects physician's decision-making regarding treatment.

METHODS

This study was approved by the Institutional Review Board of Nationwide Children's Hospital. JDM patients were consulted between 1/2005 and 6/2015. MRIs were performed on both lower extremities without contrast sequentially: axial T1, axial T2 fat saturation, axial and coronal inversion recovery, and axial diffusion weighted. The physician decision that a JDM patient was in a flare was considered the gold standard. MRI results were compared with physician's decisions on whether a relapse had occurred, and if there was a concordance between the assessment methods.

RESULTS

Forty-five JDM patients were studied. Eighty percent had weakness at diagnosis, 100% typical rash, and 73% typical nail-fold capillary changes. At diagnosis, muscle enzymes were compatible with JDM generally (CK 52%, LDH 62%, aldolase 72%, AST 54% abnormal). EMG was abnormal in 3/8, muscle biopsy typical of JDM in 10/11, and MRI abnormal demonstrating myositis in 31/40. Thirteen patients had a repeat MRI for possible flares with differing indications. Three repeat MRI's were abnormal, demonstrating myositis. There was moderate agreement about flares between MRI findings and physician's treatment decisions (kappa = 0.59). In each abnormal MRI case the physician decided to increase treatment (100% probability for flares). MRI was negative for myositis in 10 patients, by which 7/10 the physicians chose to continue or to taper the medications (70% probability for non-flares).

CONCLUSION

A muscle MRI would facilitate objective assessments of JDM flares. When an MRI shows myositis, physicians tend to treat 100% of the time. When an MRI shows no myositis, physicians continued the same medications or tapered medications 70% of the time. Further studies would help confirm the utility and cost-effectiveness of MRI to determine JDM flares.

Comparative Long-Term Evaluation of Patients With Juvenile Inflammatory Myopathies

OBJECTIVES

We conducted a retrospective study analyzing the clinical features, laboratory findings, demographics, and long-term prognoses of patients with juvenile inflammatory myopathies to determine possible predictors indicating the use of aggressive immunotherapy and the response to and complications of treatment.

METHODS

The medical records of 41 patients with juvenile inflammatory myopathies seen at University of Tennessee-affiliated hospitals in Memphis from 1969 to 2008 were evaluated. Patients' clinical characteristics, laboratory studies, muscle biopsies, and electromyography were reviewed. All patients were treated with prednisone initially; additionally, 14 patients received varying combinations of other immunosuppressant therapies.

RESULTS

Seventy-three percent of the patients experienced remission. Patients in the group that did not go into remission had specific characteristics at onset: they were comparatively older and had more severe rashes, contractures, arthritis, and systemic involvement. Also, patients with positive autoantibodies (antinuclear antibody, rheumatoid arthritis factor) had better outcomes.

CONCLUSIONS

Juvenile inflammatory myopathies have relatively good prognoses. Initial presentation at advanced age or with severe rash, systemic vasculopathies, anemia, or arthritis portends refractory disease; in these patients, second- and third-line therapies improve outcome.

Whole-body MRI: non-oncological applications in paediatrics

Whole-body magnetic resonance imaging (WBMRI) is a fast and accurate method for detecting and monitoring of diseases throughout the entire body without exposure to ionizing radiation. Among emerging non-oncological potential applications of WBMRI, rheumatological diseases play an important role. Rheumatological WBMRI applications include the evaluation of chronic multifocal recurrent osteomyelitis, dermatomyositis, fever of unknown origin, arthritis, and connective tissue diseases. Aim of this review is to give an overview of the use of WBMRI in rheumatological field.

Dermatomyositis: factors predicting relapse

BACKGROUND

The course of dermatomyositis (DM) can be chronic with relapses, which are associated with major morbidity.

OBJECTIVE

The aim of this study was to identify presentation features that predict DM relapses.

METHODS

We retrospectively reviewed data of patients with DM recorded from 1990 to 2011, including muscle biopsy results. Characteristics of patients with and without relapses were compared. Hazard ratios (HRs) were estimated using a Cox model.

RESULTS

We identified 34 patients, with a mean age of 46 ± 17 years (range, 18-77) and 24 (71%) women. The muscle and skin abnormalities relapsed in 21 (61%) patients. By univariate analysis, two presentation features were significantly associated with a subsequently relapsing course, namely, dysphonia [HR = 3.2 (1.2-8.5)] and greater skin lesion severity defined as a Cutaneous Disease Area Severity Index [CDASI] > 20 [HR = 3.5 (1.2-7.9)].

CONCLUSION

Dysphonia and skin lesion severity at disease onset must be recorded, as they significantly predict a relapsing disease course.

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.

The heart and pediatric rheumatology

Recent advances in Kawasaki disease have included attempts to define genes involved in its pathogenesis. There have been recent advances in the studies of rheumatic carditis, leading to a better understanding of the mechanism of the disease. Histologic evaluation of patients with neonatal lupus erythematosus has revealed fibrosis with collagen deposition and calcification of the atrioventricular node. Therapy for cardiac involvement in systemic juvenile idiopathic arthritis should involve treatment of the underlying disease and systemic inflammatory state, and typically includes nonsteroidal antiinflammatory drugs, corticosteroids, disease-modifying drugs, and biologic therapies targeting tumor necrosis factor-alpha, interleukin-1, and interleukin-6.

Clinical features and disease course of patients with juvenile dermatomyositis

OBJECTIVE

To describe the clinical features and course of a cohort of patients with juvenile dermatomyositis (JDM) at a tertiary referral pediatric centre in Australia and examine changes in diagnostic and therapeutic approach over time.

METHODS

Retrospective review of patients diagnosed with JDM at the Royal Children's Hospital, Melbourne, between 1989 and 2010.

RESULTS

Fifty-seven patients were identified. The female : male ratio was 2 : 1 and median age at diagnosis was 7.1 years (2.2-15.3). At diagnosis, 95% had weakness, all had typical rash and 68% had nailfold capillary changes. Calcinosis was not present in any patients at diagnosis and occurred in 18% over time. Creatine kinase, lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase and aldolase levels were abnormal in 65%, 92%, 88%, 58% and 100%, respectively. Magnetic resonance imaging (MRI) was abnormal in 97% of patients, electomyograph (EMG) in 83% and muscle biopsy in all four patients in whom it was performed. MRI was used in 86% (24/28) of patients diagnosed after 2000. Muscle biopsy was used in four and EMG in no patients over the same period. Treatment used throughout the disease course included oral steroids (93%), high-dose pulse intravenous steroids (82%), methotrexate (63%), intravenous immunoglobulin (32%) and cyclosporin (18%). The disease was monophasic in 46.7% (21/45), polyphasic in 17.7% (8/45) and chronic in 35.5% (16/45).

CONCLUSIONS

Australian patients with JDM have similar characteristics to previously described cohorts. In practice, MRI has replaced the invasive diagnostic tests included in the Bohan and Peter criteria for the diagnosis of JDM. The early use of disease-modifying anti-rheumatic drugs has become the most common treatment approach.

Idiopathic inflammatory myopathies: current trends in pathogenesis, clinical features, and up-to-date treatment recommendations

Recently, there have been important advances in the understanding of the pathophysiologic features, assessment, and management of patients with a newly diagnosed idiopathic inflammatory myopathy (IIM). Myositis-specific autoantibodies have been identified to define patient subgroups and offer prognostic implications. Similarly, proinflammatory cytokines, such as interleukin 6 and type 1 interferon-dependent genes, may serve as potential biomarkers of disease activity in adult and juvenile patients with dermatomyositis (DM). Moreover, magnetic resonance imaging has become an important modality for the assessment of muscle inflammation in adult IIM and juvenile DM. Immune-mediated necrotizing myopathies also are being recognized as a subset of IIM triggered by medications such as statins. However, confusion exists regarding effective management strategies for patients with IIM because of the lack of large-scale, randomized, controlled studies. This review focuses primarily on our current management and treatment algorithms for IIM including the care of pediatric patients with juvenile DM. For this review, we conducted a search of PubMed and MEDLINE for articles published from January 1, 1970, to December 1, 2011, using the following search terms: idiopathic inflammatory myopathies, dermatomyositis, polymyositis, juvenile dermatomyositis, sporadic inclusion body myositis, inclusion body myositis, inflammatory myositis, myositis, myopathies, pathogenesis, therapy, and treatment. Studies published in English were selected for inclusion in our review as well as additional articles identified from bibliographies.

Long-term muscular outcome and predisposing and prognostic factors in juvenile dermatomyositis: A case-control study

OBJECTIVE

To compare muscle strength, physical health, and HLA-DRB1 allele carriage frequencies in patients with longstanding juvenile dermatomyositis (DM) with that of controls, and to determine the presence of and risk factors for muscle weakness and magnetic resonance imaging (MRI)-detected muscle damage in juvenile DM patients.

METHODS

Fifty-nine patients with juvenile DM examined a median of 16.8 years (range 2.0-38.1 years) after disease onset were compared with 59 age- and sex-matched controls. Muscle strength/endurance was measured by manual muscle testing (MMT) and the Childhood Myositis Assessment Scale (CMAS); health status was measured by the Short Form 36. HLA-DRB1 alleles were determined by sequencing in patients and 898 healthy controls. In patients, disease activity/damage was measured by the Disease Activity Score (DAS), Myositis Damage Index (MDI), Health Assessment Questionnaire/Childhood Health Assessment Questionnaire, and MRI scans of the thigh muscles. Early disease characteristics were obtained by chart review.

RESULTS

Patients had lower muscle strength/endurance (P < 0.001 for both) and physical health (P = 0.014) and increased HLA-DRB1*0301 (P = 0.01) and DRB1*1401 (P = 0.003) compared with controls. In patients, persistent muscle weakness was found in 42% with MMT (score <78) and in 31% with the CMAS (score <48), whereas MRI-detected muscle damage was found in 52%. Muscle weakness and MRI-detected muscle damage were predicted by MDI muscle damage and a high DAS 1 year postdiagnosis.

CONCLUSION

A median of 16.8 years after disease onset, juvenile DM patients were weaker than the controls; muscle weakness/reduced endurance was found in 31-42% of patients and MRI-detected muscular damage was found in 52% of patients. The outcomes were predicted by high disease activity and muscle damage present 1 year postdiagnosis.

A national registry for juvenile dermatomyositis and other paediatric idiopathic inflammatory myopathies: 10 years' experience; the Juvenile Dermatomyositis National (UK and Ireland) Cohort Biomarker Study and Repository for Idiopathic Inflammatory Myopathies

OBJECTIVES

The paediatric idiopathic inflammatory myopathies (IIMs) are a group of rare chronic inflammatory disorders of childhood, affecting muscle, skin and other organs. There is a severe lack of evidence base for current treatment protocols in juvenile myositis. The rarity of these conditions means that multicentre collaboration is vital to facilitate studies of pathogenesis, treatment and disease outcomes. We have established a national registry and repository for childhood IIM, which aims to improve knowledge, facilitate research and clinical trials, and ultimately to improve outcomes for these patients.

METHODS

A UK-wide network of centres and research group was established to contribute to the study. Standardized patient assessment, data collection forms and sample protocols were agreed. The Biobank includes collection of peripheral blood mononuclear cells, serum, genomic DNA and biopsy material. An independent steering committee was established to oversee the use of data/samples. Centre training was provided for patient assessment, data collection and entry.

RESULTS

Ten years after inception, the study has recruited 285 children, of which 258 have JDM or juvenile PM; 86% of the cases have contributed the biological samples. Serial sampling linked directly to the clinical database makes this a highly valuable resource. The study has been a platform for 20 sub-studies and attracted considerable funding support. Assessment of children with myositis in contributing centres has changed through participation in this study.

CONCLUSIONS

This establishment of a multicentre registry and Biobank has facilitated research and contributed to progress in the management of a complex group of rare muscloskeletal conditions.

Interstitial Lung Disease in Children Older Than 2 Years

The spectrum of childhood interstitial lung diseases (chILD) encompasses a group of heterogeneous, rare disorders in children characterized by diffuse pulmonary infiltrates and disordered gas exchange. Whereas the disorders that present in early life are unique to children, those that present in older children are also seen in adults. This review will concentrate on chILD presenting in children older than 2 years of age with a focus on the idiopathic interstitial pneumonias, connective tissue diseases, alveolar hemorrhage, and hypersensitivity pneumonitis. A systematic approach to diagnosis that includes a careful history and physical, computed tomography of the chest, bronchoalveolar lavage, and lung biopsy can be very helpful in establishing the correct diagnosis. Treatment approaches are described, including general supportive measures, indications for a trial of systemic corticosteroids, or other immunomodulating therapies, and when lung transplantation reserved for those with end-stage lung disease should be considered.

Juvenile dermatomyositis: new developments in pathogenesis, assessment and treatment

Juvenile dermatomyositis (JDM) is a rare, potentially life-threatening systemic autoimmune disease primarily affecting muscle and skin. Recent advances in the recognition, standardised assessment and treatment of JDM have been greatly facilitated by large collaborative research networks. Through these networks, a number of immunogenetic risk factors have now been defined, as well as a number of potential pathways identified in the aetio-pathogenesis of JDM. Myositis-associated and myositis-specific autoantibodies are helping to sub-phenotype JDM, defined by clinical features, outcomes and immunogenetic risk factors. Partially validated tools to assess disease activity and damage have assisted in standardising outcomes. Aggressive treatment approaches, including multiple initial therapies, as well as new drugs and biological therapies for refractory disease, offer promise of improved outcomes and less corticosteroid-related toxicity.

Distribution and severity of weakness among patients with polymyositis, dermatomyositis and juvenile dermatomyositis

OBJECTIVE

To describe the distribution and severity of muscle weakness using manual muscle testing (MMT) in 172 patients with PM, DM and juvenile DM (JDM). The secondary objectives included characterizing individual muscle group weakness and determining associations of weakness with functional status and myositis characteristics in this large cohort of patients with myositis.

METHODS

Strength was assessed for 13 muscle groups using the 10-point MMT and expressed as a total score, subscores based on functional and anatomical regions, and grades for individual muscle groups. Patient characteristics and secondary outcomes, such as clinical course, muscle enzymes, corticosteroid dosage and functional status were evaluated for association with strength using univariate and multivariate analyses.

RESULTS

A gradient of proximal weakness was seen, with PM weakest, DM intermediate and JDM strongest among the three myositis clinical groups (P < or = 0.05). Hip flexors, hip extensors, hip abductors, neck flexors and shoulder abductors were the muscle groups with the greatest weakness among all three clinical groups. Muscle groups were affected symmetrically.

CONCLUSIONS

Axial and proximal muscle impairment was reflected in the five weakest muscles shared by our cohort of myositis patients. However, differences in the pattern of weakness were observed among all three clinical groups. Our findings suggest a greater severity of proximal weakness in PM in comparison with DM.

Juvenile dermatomyositis and other idiopathic inflammatory myopathies of childhood

Juvenile dermatomyositis, the most common inflammatory myopathy of childhood, is a rare systemic autoimmune vasculopathy that is characterised by weakness in proximal muscles and pathognomonic skin rashes. The length of time before the initiation of treatment affects presenting symptoms, laboratory measures, and pathophysiology. It also affects disease outcomes, including the development of pathological calcifications, which are associated with increased morbidity. Both genetic and environmental risk factors seem to have a role in the cause of juvenile dermatomyositis; HLA B8-DRB1*0301 ancestral haplotype is a strong immunogenetic risk factor, and antecedent infections and birth seasonality suggest that environmental stimuli might increase risk. Activation of dendritic cells with upregulation of genes induced by type-1 interferon (alpha) in muscle and peripheral blood seems to be central to disease pathogenesis. Treatment often includes combinations of corticosteroids, methotrexate, and other immunosuppressive agents. Disease outcome, if treatment is initiated early, is generally good. Randomised controlled trials are needed to define the most effective treatments.

The treatment and prognosis of dermatomyositis: an updated review

Dermatomyositis (DM) is an idiopathic inflammatory myopathy. The mainstay of treatment for DM is oral corticosteroids. However, the dose and length of treatment is debated. Adding to the confusion, there have been no randomized controlled studies comparing the use of various corticosteroid doses and taper rates, and no controlled long-term studies assessing the hypothesis that, unlike systemic lupus erythematous, patients with DM can often achieve long-term remission off therapy. This literature review supports an approach that prednisone should be started at about 1 mg/kg/d, which is then tapered slowly based on the response. As patients respond differently to prednisone, additional therapies may be necessary. When to initiate these therapies requires clinical judgment. In addition, as we learn more about the pathophysiology of DM, newer medications that target specific mechanisms in the immune response may help us better treat the disease. Evidence-based data with long-term follow-up will allow for selection of the best treatment to maximize long-term remission, not simply short-term lowering of the systemic corticosteroid dose.