Juvenile dermatomyositis and other idiopathic inflammatory myopathies of childhood

Clinical and genetic analysis of macrophage activation syndrome complicating juvenile idiopathic inflammatory myopathies

BACKGROUND

Macrophage activation syndrome (MAS) is a serve complication of juvenile idiopathic inflammatory myopathies (JIIMs). This study delineates the clinical manifestations and genetic underpinnings of JIIM-MAS patients.

METHODS

We retrospectively analysed clinical and UNC13D gene from JIIM patients admitted to our centre between 2011 and 2021 to identify cases of MAS. Additionally, a literature review summarising reported cases of JIIMs and MAS was performed.

RESULTS

Of 773 JIIM patients, 10 (1.3%) were diagnosed with MAS. All patients presented with persistent fever and hyperferritinaemia. Seventy percent of patients met the HLH-2004 criteria, while 90% met the 2016 sJIA-MAS criteria. Most patients received combined treatment of corticosteroids and immunosuppressants. UNC13D gene analysis was performed in six patients. A homozygous pathogenic mutation (c.2588G>A) was detected in one patient with recurrent MAS, and twenty-eight single-nucleotide polymorphisms (SNPs) were detected. Eighty percent of patients exhibiting a consistent combination of ten SNPs compared to JIIM patients without MAS (35%).

CONCLUSION

MAS is an early and often overlooked complication of JIIMs. The 2016 sJIA-MAS criteria may facilitate early diagnosis. Combined corticosteroid and immunosuppressant therapy prove effective. An increased prevalence of UNC13D gene polymorphisms was observed in JIIM-MAS patients, highlighting the necessity for further investigations.

IMPACT

This study aimed to delineate the clinical manifestations and genetic underpinnings of macrophage activation syndrome (MAS) in ten patients with juvenile idiopathic inflammatory myopathies (JIIMs). MAS has been recognised as a complication of JIIMs. However, only a few case reports provide comprehensive descriptions of MAS in JIIM patients, and there are few reports related to UNC13D mutations in these patients. This article offers single-centre clinical insights to enhance the identification and management of MAS in JIIM patients, while also highlighting the potential association between MAS occurrence and UNC13D gene polymorphisms.

Inflammatory Causes of Dysphagia in Children

Gastroesophageal reflux (GER) and eosinophilic esophagitis (EoE) are the most common inflammatory causes of pediatric dysphagia, but several other less prevalent conditions should be considered. These conditions can affect one or several aspects of the swallowing process. In some inflammatory conditions dysphagia may be an early symptom. Esophagoscopy and instrumental swallow studies are often needed to determine the underlying diagnosis and best treatment plan. In some inflammatory conditions dysphagia can portend a worse outcome and need for more aggressive treatment of the underlying condition. Consultations with speech language pathology, gastroenterology, dietetics, allergy/immunology and/or rheumatology are often needed to optimize management.

Familial clustering of dysbiotic oral and fecal microbiomes in juvenile dermatomyositis

Juvenile dermatomyositis (JDM) is a rare immune-mediated disease of childhood with putative links to microbial exposures. In this multi-center, prospective, observational cohort study, we evaluated whether JDM is associated with discrete oral and gut microbiome signatures. We generated 16S rRNA sequencing data from fecal, saliva, supragingival, and subgingival plaque samples from JDM probands (n = 28). To control for genetic and environmental determinants of microbiome community structure, we also profiled microbiomes of unaffected family members (n = 27 siblings, n = 26 mothers, and n = 17 fathers). Sample type (oral-vs-fecal) and nuclear family unit were the predominant variables explaining variance in microbiome diversity, more so than having a diagnosis of JDM. The oral and gut microbiomes of JDM probands were more similar to their own unaffected siblings than they were to the microbiomes of other JDM probands. In a sibling-paired within-family analysis, several potentially immunomodulatory bacterial taxa were differentially abundant in the microbiomes of JDM probands compared to their unaffected siblings, including Faecalibacterium (gut) and Streptococcus (oral cavity). While microbiome features of JDM are often shared by unaffected family members, the loss or gain of specific fecal and oral bacteria may play a role in disease pathogenesis or be secondary to immune dysfunction in susceptible individuals.

Of oranges and lemons: you are what you eat

A young boy presented with increasing lower limb pain and swelling for a month. At the time of his hospitalisation, he was unable to walk. We report the patient's clinical journey with clinical commentary throughout, highlighting the importance that uncommon diseases may be diagnosed with a high index of suspicion and thorough history taking.

A rare case report of bilateral Purtscher-like retinopathy in juvenile dermatomyositis

Purpose

To report a rare case of bilateral Purtscher-like retinopathy (PLR) in a young adult diagnosed with dermatomyositis.

Method

A case report with multi-modal imaging.

Result

A 17-year-old male presented with subacute marked diminution of vision along with arthralgia, weakness of all four limbs and development of multiple rashes around body. Fundus examination revealed bilateral multiple Purtscher flecken, pseudo-cherry red spot, and intra-retinal haemorrhages with cotton wool spots. Systemic and laboratory examinations, magnetic resonance imaging (MRI) and biopsy of tissue confirmed the diagnosis of juvenile dermatomyositis with PLR.

Conclusion

Dermatomyositis, being a rare cause of PLR, should essentially be considered as one of the differentials as timely intervention can alter the course of disease and prove life-saving for the patient.

Artificial intelligence for nailfold capillaroscopy analyses - a proof of concept application in juvenile dermatomyositis

BACKGROUND

Biomarkers for idiopathic inflammatory myopathies are difficult to identify and may involve expensive laboratory tests. We assess the potential for artificial intelligence (AI) to differentiate children with juvenile dermatomyositis (JDM) from healthy controls using nailfold capillaroscopy (NFC) images. We also assessed the potential of NFC images to reflect the range of disease activity with JDM.

METHODS

A total of 1,120 NFC images from 111 children with active JDM, diagnosed between 1990 and 2020, and 321 NFC images from 31 healthy controls were retrieved from the CureJM JDM Registry. We built a lightweight and explainable deep neural network model called NFC-Net. Images were downscaled by interpolation techniques to reduce the computational cost.

RESULTS

NFC-Net achieved high performance in differentiating patients with JDM from controls, with an area under the ROC curve (AUROC) of 0.93 (0.84, 0.99) and accuracy of 0.91 (0.82, 0.92). With sensitivity (0.85) and specificity (0.90) resulted in model precision of 0.95. The AUROC and accuracy for predicting clinical disease activity from inactivity were 0.75 (0.61, 0.81) and 0.74 (0.65, 0.79).

CONCLUSION

The good performance of the NFC-Net demonstrates that NFC images are sufficient for detecting often unrecognized JDM disease activity, providing a reliable indicator of disease status.

IMPACT

Proposed NFC-Net can accurately predict children with JDM from healthy controls using nailfold capillaroscopy (NFC) images. Additionally, it predicts the scores to JDM disease activity versus no activity. Equipped with gradients, NFC-Net is explainable and gives visual information beside the reported accuracies. NFC-Net is computationally efficient since it is applied to substantially downscaled NFC images. Furthermore, the model can be wrapped within an edge-based device like a mobile application that is accessible to both clinicians and patients.

Defining criteria for disease activity states in juvenile dermatomyositis based on the Juvenile Dermatomyositis Activity Index

OBJECTIVES

To develop and validate the cut-offs in the Juvenile DermatoMyositis Activity Index (JDMAI) to distinguish the states of inactive disease (ID), low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA) in children with juvenile dermatomyositis (JDM).

METHODS

For cut-off definition, data from 139 patients included in a randomised clinical trial were used. Among the six versions of the JDMAI, JDMA1 (score range 0-40) and JDMAI2 (score range 0-39) were selected. Optimal cut-offs were determined against external criteria by calculating different percentiles of score distribution and through receiver operating characteristic curve analysis. External criteria included the modified Pediatric Rheumatology International Trials Organization (PRINTO) criteria for clinically ID in JDM (for ID) and PRINTO levels of improvement in the clinical trial (for LDA and HDA). MDA cut-offs were set at the score interval between LDA and HDA cut-offs. Cut-off validation was conducted by assessing construct and discriminative ability in two cohorts including a total of 488 JDM patients.

RESULTS

The calculated JDMAI1 cut-offs were ≤2.4 for ID, ≤6.6 for LDA, 6.7-11 for MDA and >11 for HDA. The calculated JDMAI2 cut-offs were ≤5.2 for ID, ≤8.5 for LDA, 8.6-11.3 for MDA and >11.3 for HDA. The cut-offs discriminated strongly among disease activity states defined subjectively by caring physicians and parents, parents' satisfaction or non-satisfaction with illness outcome, levels of pain, fatigue, physical functional impairment and physical well-being.

CONCLUSIONS

Both JDMAI1 and JDMAI2 cut-offs revealed good metrologic properties in validation analyses and are, therefore, suited for application in clinical practice and research.

Clinically amyopathic dermatomyositis associated with cutaneous ulcerations: a case-based review

Introduction and importance

Dermatomyositis (DM) is an autoimmune myopathy primarily affecting both muscles and skin. When muscle weakness is not clinically apparent, but characteristic skin lesions are present, the condition is referred to as clinically amyopathic dermatomyositis (CADM).

Case presentation

The authors present the case of a 52-year-old female with a typical DM rash, interstitial pneumonia, and multiple skin ulcers. The skin biopsy was consistent with DM, and there were no signs of muscle involvement. Myositis-related and myositis-specific autoantibodies were also negative. Significant improvement was not observed until the patient received successive monthly pulses of methylprednisolone and the introduction of methotrexate. This treatment regimen allowed for the complete tapering of prednisone and resulted in sustained disease control.

Clinical discussion

In addition to the case presentation, a narrative literature review was conducted using the MEDLINE database, and an evidence-based treatment flowchart is proposed. CADM is a subtype of DM, related to higher incidences of interstitial lung disease, skin vasculopathy and malignancy. When ulcers or interstitial pneumonia are present, treatment should be early and aggressive. Active screening for neoplasms is recommended, particularly within the first 5 years.

Conclusion

The authors presented a case of seronegative CADM featuring skin vasculopathy, successfully treated with consecutive methylprednisolone pulses. Our literature review emphasized the importance of focused CADM management trials, highlighting the need for further research.

[Advances in the diagnostics and treatment of juvenile dermatomyositis]

Juvenile dermatomyositis (JDM) is by far the most frequent inflammatory myopathy in childhood and adolescence. It is clinically characterized by inflammatory changes of the skin and muscles but as a multisystemic disease can also affect the skeletal system, the gastrointestinal tract, lungs and heart. Intrinsic (multigenetic risk) and extrinsic factors (triggers) are involved in the pathogenesis resulting in endothelial damage, involvement of fascies, activation of the interferon system and autoimmune reactions including formation of myositis-specific autoantibodies (MSA). In contrast to dermatomyositis in adults, in children and adolescents there are no associations with malignant diseases. The variable expression, the rarity of the disease and the risk of long-term damage and complications necessitate pediatric rheumatological experience in the diagnostics and treatment. Recently, new approaches in drug treatment have substantially improved the outcome and prognosis but a multidisciplinary treatment (including physicians, physiotherapists, psychologists, social workers) is mandatory, especially in the first phases of the disease. Particularly important is a professionally correct treatment of the functional sequelae, which are a particular focus of this article.

Clinical nomogram assisting in discrimination of juvenile dermatomyositis-associated interstitial lung disease

OBJECTIVE

To establish a prediction model using non-invasive clinical features for early discrimination of DM-ILD in clinical practice.

METHOD

Clinical data of pediatric patients with JDM were retrospectively analyzed using machine learning techniques. The early discrimination model for JDM-ILD was established within a patient cohort diagnosed with JDM at a children's hospital between June 2015 and October 2022.

RESULTS

A total of 93 children were included in the study, with the cohort divided into a discovery cohort (n = 58) and a validation cohort (n = 35). Univariate and multivariate analyses identified factors associated with JDM-ILD, including higher ESR (OR, 3.58; 95% CI 1.21-11.19, P = 0.023), higher IL-10 levels (OR, 1.19; 95% CI, 1.02-1.41, P = 0.038), positivity for MDA-5 antibodies (OR, 5.47; 95% CI, 1.11-33.43, P = 0.045). A nomogram was developed for risk prediction, demonstrating favorable discrimination in both the discovery cohort (AUC, 0.736; 95% CI, 0.582-0.868) and the validation cohort (AUC, 0.792; 95% CI, 0.585-0.930). Higher nomogram scores were significantly associated with an elevated risk of disease progression in both the discovery cohort (P = 0.045) and the validation cohort (P = 0.017).

CONCLUSION

The nomogram based on the ESIM predictive model provides valuable guidance for the clinical evaluation and long-term prognosis prediction of JDM-ILD.

Treat-to-Target in Pediatric Rheumatic Diseases

PURPOSE OF REVIEW

To summarize the current evidence on the adoption of the treat-to-target (T2T) strategy in pediatric rheumatic diseases (PRD).

RECENT FINDINGS

The recent advances in the management of PRD have markedly increased the ability to achieve disease remission. Complete disease quiescence is regarded as the ideal therapeutic goal because its attainment leads to lesser long-term damage and physical disability, and to optimization of quality of life. Studies in adult rheumatic diseases have shown that patient outcomes are improved if complete suppression of the inflammatory process is aimed for by frequent adjustments of therapy according to quantitative indices. This approach, which underlies the T2T concept, has been applied in strategic trials in rheumatoid arthritis (RA). Furthermore, recommendations for the T2T have been issued for RA and other adult rheumatic diseases. There is currently a growing interest for the introduction of T2T in PRD, and recommendations for treating juvenile idiopathic arthritis (JIA) to target were promulgated. A similar initiative has been undertaken for childhood-onset systemic lupus erythematosus. Preliminary therapeutic studies have explored the T2T design in JIA. The T2T strategy is a modern therapeutic approach that holds the promise of improving the outcomes in patients with PRD.

Anti-Inflammatory and Immunomodulatory Effect of High-Dose Immunoglobulins in Children: From Approved Indications to Off-Label Use

BACKGROUND

The large-scale utilization of immunoglobulins in patients with inborn errors of immunity (IEIs) since 1952 prompted the discovery of their key role at high doses as immunomodulatory and anti-inflammatory therapy, in the treatment of IEI-related immune dysregulation disorders, according to labelled and off-label indications. Recent years have been dominated by a progressive imbalance between the gradual but constant increase in the use of immunoglobulins and their availability, exacerbated by the SARS-CoV-2 pandemic.

OBJECTIVES

To provide pragmatic indications for a need-based application of high-dose immunoglobulins in the pediatric context.

SOURCES

A literature search was performed using PubMed, from inception until 1st August 2023, including the following keywords: anti-inflammatory; children; high dose gammaglobulin; high dose immunoglobulin; immune dysregulation; immunomodulation; immunomodulatory; inflammation; intravenous gammaglobulin; intravenous immunoglobulin; off-label; pediatric; subcutaneous gammaglobulin; subcutaneous immunoglobulin. All article types were considered.

IMPLICATIONS

In the light of the current imbalance between gammaglobulins' demand and availability, this review advocates the urgency of a more conscious utilization of this medical product, giving indications about benefits, risks, cost-effectiveness, and administration routes of high-dose immunoglobulins in children with hematologic, neurologic, and inflammatory immune dysregulation disorders, prompting further research towards a responsible employment of gammaglobulins and improving the therapeutical decisional process.

Lung involvement in juvenile idiopathic inflammatory myopathy: A systematic review

OBJECTIVE

Juvenile idiopathic inflammatory myopathies (JIIM) are a group of connective tissue disorders characterized by muscle inflammation and variable systemic involvement, including interstitial lung disease (ILD). Available data on JIIM-associated ILD are very limited. We performed a systematic review of the available clinical, laboratory, and radiological features of JIIM-associated ILD.

METHODS

A systematic literature review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

A total of 90 patients were identified, of whom 77.8% had JDM, 10% amyopathic JDM, 7.8% anti-synthetase syndrome, 3.3% overlap syndrome, and 1.1% juvenile polymyositis. Anti-melanoma differentiation-associated gene 5 (MDA-5/CADM-140) was the most frequently reported myositis-specific antibody (32.2%). At diagnosis of ILD, 55.5% of patients had respiratory symptoms. Ground glass opacity was the most reported radiological feature (52.9%). Thirty-three % of patients developed rapidly progressive (RP) lung disease; 26.7% were admitted to the intensive care unit (ICU); 28.9% died; all deaths were due to ILD, with a median interval of 2 months (IQR 1.5-4.7) between the onset of respiratory symptoms and death. Patients admitted to the ICU and who died of ILD were more likely to be male, to have a rapidly progressive pattern, progression of radiological features, and a higher level of KL-6.

CONCLUSIONS

MDA-5/CADM-14 is associated with RP-ILD. ILD is a rare but severe manifestation among the spectrum of systemic involvement associated with JIIM, with a high rate of ICU admission and mortality. Early recognition and aggressive treatment are needed to prevent a severe outcome.

Role of mitochondria in the myopathy of juvenile dermatomyositis and implications for skeletal muscle calcinosis

OBJECTIVES

To elucidate mechanisms contributing to skeletal muscle calcinosis in patients with juvenile dermatomyositis.

METHODS

A well-characterized cohorts of JDM (n = 68), disease controls (polymyositis, n = 7; juvenile SLE, n = 10, and RNP + overlap syndrome, n = 12), and age-matched health controls (n = 17) were analyzed for circulating levels of mitochondrial (mt) markers including mtDNA, mt-nd6, and anti-mitochondrial antibodies (AMAs) using standard qPCR, ELISA, and novel-in-house assays, respectively. Mitochondrial calcification of affected tissue biopsies was confirmed using electron microscopy and energy dispersive X-ray analysis. A human skeletal muscle cell line, RH30, was used to generate an in vitro calcification model. Intracellular calcification is measured by flow cytometry and microscopy. Mitochondria were assessed for mtROS production and membrane potential by flow cytometry and real-time oxygen consumption rate by Seahorse bioanalyzer. Inflammation (interferon-stimulated genes) was measured by qPCR.

RESULTS

In the current study, patients with JDM exhibited elevated levels of mitochondrial markers associated with muscle damage and calcinosis. Of particular interest are AMAs predictive of calcinosis. Human skeletal muscle cells undergo time- and dose-dependent accumulation of calcium phosphate salts with preferential localization to mitochondria. Calcification renders skeletal muscle cells mitochondria stressed, dysfunctional, destabilized, and interferogenic. Further, we report that inflammation induced by interferon-alpha amplifies mitochondrial calcification of human skeletal muscle cells via the generation of mitochondrial reactive oxygen species (mtROS).

CONCLUSIONS

Overall, our study demonstrates the mitochondrial involvement in the skeletal muscle pathology and calcinosis of JDM and mtROS as a central player in the calcification of human skeletal muscle cells. Therapeutic targeting of mtROS and/or upstream inducers, such as inflammation, may alleviate mitochondrial dysfunction, leading to calcinosis. AMAs can potentially identify patients with JDM at risk for developing calcinosis.

Currently recommended skin scores correlate highly in the assessment of patients with Juvenile Dermatomyositis (JDM)

BACKGROUND

Juvenile Dermatomyositis (JDM) is a rare, chronic, and life-threatening childhood autoimmune disease. Currently, there are recommended, reliable and validated measurement tools for assessment of skin disease activity in JDM including the Disease Activity Score (skinDAS), Cutaneous Assessment Tool (CAT), and the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). The Physician's global assessment skin visual analog scale (Skin VAS) is also widely used for skin activity in JDM. For the purpose of comparative international studies, we wanted to compare these tools to the Physician's skin VAS (as a standard) to identify which performs better.

OBJECTIVES

We sought to compare the correlations of these scoring tools, and separately assess the responsiveness each tool demonstrates following patient treatment, in order to see if one tool may be preferred. This was determined by assessing how well these tools correlate with each other, and the Physician's skin VAS over time, as well as the responsiveness of each tool after patient treatment.

METHODS

Skin scores were recorded at a baseline (first visit after June 1^st, 2018) and all follow-up office visits at the Juvenile Dermatomyositis Clinic. Following baseline visits, patients were followed up as clinically indicated. A subset of newly diagnosed patients (inception cohort) was identified. Correlations were assessed at the baseline visit and over time for the whole cohort. The correlations over time were derived using Generalized Estimating Equations (GEEs). Standardized response means with 95% confidence intervals were calculated to test score responsiveness for the nested inception cohort.

RESULTS

The skinDAS, CAT and CDASI all correlated highly with each other and with the Physician's skin VAS. The three scoring tools accurately reflected Physician's skin VAS scores over time. In addition, all tools showed moderate to high responsiveness following treatment.

CONCLUSION

All studied skin score tools performed well in our study and appear to be useful. Since no tool far outperforms the others, arbitrary consensus will be needed to select a single standard measurement tool for the purposes of efficiency and global comparability.

Characterization of the biomarkers related to the clinical course and outcomes of juvenile dermatomyositis

OBJECTIVE

This study aimed to evaluate the clinical characteristics of children diagnosed with juvenile dermatomyositis (JDM) in a tertiary medical centre in Taiwan and to identify important biomarkers for predicting the disease course and outcomes of JDM.

METHODS

We retrospectively reviewed patients with JDM diagnosed at the National Taiwan University Hospital between 1 January 2001 and 31 December 2021. The endpoints for disease assessment included complete clinical response or remission. The JDM courses were divided into monocyclic, polycyclic, and chronic continuous statuses. The significant relationship between the predictors and outcomes was further analysed.

RESULTS

A total of 47 patients were included in this study. The mean age at disease onset was 7.5 years. The female-to-male ratio was 1.35. The most common initial presentations were Gottron's sign (74%), followed by muscle weakness (66%) and facial rash (66%). Among all included patients, 35 (74.5%) patients achieved complete clinical remission, 15 (31.9%) had a monocyclic course, six (12.7%) had a polycyclic course, and 24 (51.1%) had a chronic continuous course. Negative facial rash and arthralgia were favourable factors for achieving complete clinical remission. Muscle weakness, higher lactate dehydrogenase (LDH), and higher erythrocyte sedimentation rate (ESR) at disease onset were related to the chronic continuous course. The most common long-term complication was calcinosis (29.8%).

CONCLUSION

Juvenile dermatomyositis is a rare disease, and only a few studies have been conducted in Asia. Our results identified the important predictors of the disease course and outcomes. The chronic continuous course requires more attention and aggressive treatment.

Adipokine profile in long-term juvenile dermatomyositis, and associations with adipose tissue distribution and cardiac function: a cross-sectional study

OBJECTIVES

In long-term juvenile dermatomyositis (JDM), altered adipose tissue distribution and subclinical cardiac dysfunction have been described. Our aims were to compare adipokine levels in patients with JDM after long-term disease with controls, and explore associations between adipokines and (1) adipose tissue distribution and (2) cardiac function.

METHODS

The study cohort included 59 patients with JDM (60% female, mean age 25.2 years, mean disease duration 16.9 years), and 59 age/sex-matched controls. Updated Pediatric Rheumatology International Trials Organization criteria for clinically inactive JDM were used to stratify patients into active (JDM-active) or inactive (JDM-inactive) disease groups. Lipodystrophy was clinically assessed in all patients. In all study participants, we measured adipose tissue distribution by dual-energy X-ray absorptiometry and cardiac function by echocardiography. Serum adipokines (adiponectin, apelin-12, lipocalin-2, leptin, visfatin and resistin) were analysed using ELISA.

RESULTS

Patients with JDM had higher leptin levels compared with controls (p≤0.01). In JDM-active, apelin-12 and visfatin were higher compared with JDM-inactive (p≤0.05). In JDM-total and JDM-active, lower adiponectin correlated with lipodystrophy and total fat mass. Also, systolic dysfunction correlated with: lower adiponectin in JDM-total, JDM-inactive and JDM-active, and with lower apelin-12 in JDM-total and JDM-active and resistin in JDM-active (all p≤0.05). Lower adiponectin correlated with diastolic dysfunction in JDM-total and JDM-active.

CONCLUSION

After long-term disease, leptin levels were unfavourably regulated in patients with JDM compared with controls, and apelin-12 and visfatin in JDM-active versus JDM-inactive. We found associations between adipokines and both adipose tissue distribution and cardiac systolic function in all patients with JDM, which was most prominent in patients with active disease.

Experience with the use of mycophenolate mofetil in juvenile idiopathic inflammatory myopathies

OBJECTIVE

The objective of this study was to evaluate the efficacy and safety of MMF in juvenile idiopathic inflammatory myopathies (JIIMs).

METHODS

Patients diagnosed with JIIM and treated with MMF enrolled in the Juvenile Dermatomyositis Research Group (JDRG) in the UK or followed at the Giannina Gaslini Institute in Genoa, Italy, were included. The following information was collected retrospectively at MMF initiation, at 3, 6 and 12 months after treatment start, and at last follow-up visit: clinical manifestations, laboratory data, physicians' subjective assessment of disease activity, standardized outcome measures of muscle strength/endurance, cutaneous disease activity, physical function, global disease activity, cumulative damage, and ongoing treatment.

RESULTS

Of the 29 patients included, 23 had juvenile DM and 6 had overlap myositis. During administration of MMF, improvement in measures of muscle strength, skin disease activity, and overall disease activity was seen, with an increase in the frequency of normal scores for Manual Muscle Test-8 from 50.0% to 83.3%, Childhood Myositis Activity Score from 53.5% to 88.9%, muscle component of DAS from 55.2% to 84.2%, skin component of DAS from 31.0% to 42.1%, visual analogue scale for skin disease activity from 25.0% to 47.4%, and visual analogue scale for overall disease activity from 7.1% to 42.1%. The number of patients with inactive disease increased from 10.3% at baseline to 68.5% at last follow-up. CS dose was significantly reduced, from 0.3 to 0.1 mg/kg/day. No relevant side effects were reported.

CONCLUSION

Our experience suggests that MMF is a valuable therapeutic option for the management of JIIM.

Early-onset juvenile dermatomyositis: A tertiary referral center experience and review of the literature

BACKGROUND/OBJECTIVES

The aim of our study is twofold: To evaluate the presentation, diagnosis, clinical course, and management of juvenile dermatomyositis (JDM) in children under three years of age, and to compare with older-onset patients.

METHODS

Nine patients with early-onset, and 63 patients with older-onset JDM followed between December 2010 and April 2022 are included. We also reviewed the literature on early-onset JDM from the inceptions of the PubMed/MEDLINE and Scopus databases up to April 1st, 2022.

RESULTS

Early-onset JDM patients were characterized by longer median diagnostic delay (p = 0.005), calcinosis (p = 0.006), anti-NXP2 antibody (p = 0.049). Diagnostic pathway included muscle biopsy (77.7% versus 50.8%). Muscle biopsy findings were more severe in the early-onset group (p<0.001). Although there was no difference in the partial and complete remission rates, the relapse rate was significantly higher in the early-onset group (p = 0.001), reflected to requirement of intravenous immunoglobulin (p = 0.001), cyclophosphamide (p = 0.011), and biological agents (p = 0.016). Literature search revealed 32 articles reporting 75 patients. The median diagnostic delay was 5 (1-30) months. Calcinosis was present in 29.5%. Twenty-three of the 44 patients (52.3%) had a muscle biopsy. Forty-one patients (64.1%) received second and third-line treatments. Complete remission was achieved in almost half of these patients (48.9%), but relapse was observed in 75%. The mortality rate was 10.2%.

CONCLUSION

Diagnosis can be challenging and delayed in early-onset JDM patients. Compared to older-onset JDM patients, this group had higher relapse rate, more severe muscle biopsy findings, and received intensive immunosuppressive treatment.

Low copy numbers of complement C4 and C4A deficiency are risk factors for myositis, its subgroups and autoantibodies

BACKGROUND

Idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases characterised by myositis-related autoantibodies plus infiltration of leucocytes into muscles and/or the skin, leading to the destruction of blood vessels and muscle fibres, chronic weakness and fatigue. While complement-mediated destruction of capillary endothelia is implicated in paediatric and adult dermatomyositis, the complex diversity of complement C4 in IIM pathology was unknown.

METHODS

We elucidated the gene copy number (GCN) variations of total C4, C4A and C4B, long and short genes in 1644 Caucasian patients with IIM, plus 3526 matched healthy controls using real-time PCR or Southern blot analyses. Plasma complement levels were determined by single radial immunodiffusion.

RESULTS

The large study populations helped establish the distribution patterns of various C4 GCN groups. Low GCNs of C4T (C4T=2+3) and C4A deficiency (C4A=0+1) were strongly correlated with increased risk of IIM with OR equalled to 2.58 (2.28-2.91), p=5.0×10^-53 for C4T, and 2.82 (2.48-3.21), p=7.0×10^-57 for C4A deficiency. Contingency and regression analyses showed that among patients with C4A deficiency, the presence of HLA-DR3 became insignificant as a risk factor in IIM except for inclusion body myositis (IBM), by which 98.2% had HLA-DR3 with an OR of 11.02 (1.44-84.4). Intragroup analyses of patients with IIM for C4 protein levels and IIM-related autoantibodies showed that those with anti-Jo-1 or with anti-PM/Scl had significantly lower C4 plasma concentrations than those without these autoantibodies.

CONCLUSIONS

C4A deficiency is relevant in dermatomyositis, HLA-DRB1*03 is important in IBM and both C4A deficiency and HLA-DRB1*03 contribute interactively to risk of polymyositis.

An Unusual Presentation of Juvenile Polymyositis in an Adolescent Girl

Juvenile idiopathic inflammatory myopathies (JIIMs) are a group of diverse, systemic autoimmune diseases that manifest in childhood and are characterized by weakness and chronic inflammation of skeletal muscles. One of the relatively rare variants of JIIMs is juvenile polymyositis (JPM). JPM patients present with proximal and distal muscle weakness, gait instability with falls, muscle pain and tenderness, and high levels of creatine kinase (CK) during adolescence. There are currently few people being diagnosed with JPM, which raises the question of whether or not it is a distinct disease. We discuss the case of a 13-year-old girl who presented to the hospital with generalized body swelling and difficulty swallowing solid food. She also had drooling of saliva during the presentation and a history of difficulty climbing up and down the stairs for three months. Her extensive laboratory workup showed a positive antinuclear antibody (ANA) test and increased muscle enzyme. A muscle biopsy was ordered, and she was diagnosed with JPM. Such a unique presentation has rarely been reported in the pediatric literature. This case report outlines an unusual JPM presentation that could help clinicians identify the condition and start treatment as soon as possible to minimize complications.

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.

An Unusual Cause of Necrotising Fasciitis in a Young Male with Juvenile Dermatomyositis

Juvenile dermatomyositis (JDM) is a rare condition worldwide, affecting children younger than 16 years. It is characterized by weakness in the proximal skeletal muscles and a pathognomonic skin rash. Patients with JDM develop complications that are usually a consequence of vasculopathy affecting multiple organ systems. Occult gastrointestinal (GI) perforation is an uncommon complication and is associated with an increased risk of mortality due to a delay in diagnosis. We report on a 14-year-old male with JDM with an aggressive course over two years and severe clinical manifestations. The patient developed necrotizing fasciitis, an unusual rapidly progressing lethal infection of the fascia resulting from bowel contents seeping from multiple intestinal perforations. This case, less commonly seen in males, highlights the occurrence of multiple phenomena—JDM complicated by skin and gastrointestinal vasculopathy with resultant development of multiple GI perforations and consequently life-threatening necrotizing fasciitis of the leg. Physicians need a high index of suspecting GI perforation in JDM patients as the delayed recognition of this complication can result in significant morbidity and/or mortality since the typical symptoms of perforation may be absent.

Cardiovascular Abnormalities in Juvenile Dermatomyositis: A Scoping Review for the Clinical Rheumatologists

Juvenile dermatomyositis (JDM) is a common form of inflammatory myositis in children. Vasculopathy and endothelial dysfunction play significant roles in the pathogenesis of JDM. Cardiac involvement in JDM is often underestimated, and it may be a potential indicator of poor prognosis. Cardiac dysfunction in JDM can occur both in the acute and chronic stages of the disease. Amongst the acute complications, acute congestive heart failure (CHF), myocarditis, arrhythmia, and complete heart block are common. However, these remain unrecognized due to a lack of overt clinical manifestations. Increased rates of cardiovascular abnormalities have been noted with anti-SRP and anti-Jo 1 auto-antibody positivity. Long-term follow-up studies in JDM have shown an increased prevalence of hypertension, atherosclerosis, coronary artery disease, and metabolic syndrome in adolescence and adulthood. Monitoring of body-mass index, blood pressure, and laboratory evaluation of fasting glucose and lipid profile may help in identifying metabolic syndrome in children with JDM. Steroid-sparing agents, daily exercise, and a healthy diet may reduce such long-term cardiac morbidities. Current use of multimodality imaging such as stress-echocardiography, contrast-enhanced echocardiography, cardiac magnetic resonance imaging, and positron emission tomography has increased the diagnostic yield of subclinical heart disease during acute and chronic stages of JDM. This review elaborates on different aspects of cardiac dysfunction in JDM. It also emphasizes the importance of cardiac screening in long-term follow-up of children with JDM.

Anti-nuclear matrix protein 2+ juvenile dermatomyositis with severe skin ulcer and infection: A case report and literature review

BACKGROUND

Juvenile dermatomyositis (JDM) is an idiopathic inflammatory myopathy that occurs in childhood. It is characterized by muscle weakness and a characteristic rash. Previous literature reports have rarely described JDM with severe skin ulcers and infections.

CASE SUMMARY

Herein, we describe a case of a 2-year-old female patient who suffered from JDM, whose myositis-specific autoantibodies were positive for anti-nuclear matrix protein 2 antibody, with progressively worsening skin ulcers and severe infections. The patient was treated with glucocorticoids and various immunosuppressants. Nevertheless, further progression of the disease and the combination of primary disease and severe infection in the later period were fatal.

CONCLUSION

In children, anti-nuclear matrix protein 2+ JDM combined with skin ulcers often indicates severe disease. In such cases, personalized treatment for the primary disease and infection prevention and control are essential.

Environmental factors associated with juvenile idiopathic inflammatory myopathy clinical and serologic phenotypes

BACKGROUND

Environmental exposures have been associated with the juvenile idiopathic inflammatory myopathies (JIIM). We undertook a questionnaire-based study to evaluate patient-reported exposures as possible risk factors for JIIM.

FINDINGS

One-hundred-seven patients with JIIM were enrolled in a myositis natural history protocol and completed environmental questionnaires. Frequencies of exposures in clinical and myositis-specific autoantibody (MSA) groups were examined. Patients with juvenile dermatomyositis (JDM) and juvenile connective tissue myositis (JCTM) more frequently received an immunization within 1 year of diagnosis compared to juvenile polymyositis (57.5 and 71.4% vs 0.0%, p ≤ 0.017). JCTM patients were more often underweight at diagnosis relative to JDM patients (42.9% vs 7.0%, p = 0.002). MSA-negative patients more frequently had gastroenteritis within a year of diagnosis compared to patients with anti-MDA5 autoantibodies (28.6% vs 0.0%, p = 0.032). Heavy exercise was more frequent in MSA-negative and anti-MDA5 groups compared to the anti-TIF-1 autoantibody group (42.9 and 35.3% vs. 9.0%, p ≤ 0.047). Medications received within 1 year of diagnosis were more frequent in MSA-negative patients relative to those with anti-MDA5 autoantibodies (92.9% vs. 52.8% p = 0.045). Being breastfed > 6 months was more frequent in MSA-negative patients (88.9%) compared to anti-TIF-1 and anti-MDA5 autoantibody groups (41.2 and 28.6%, p ≤ 0.036).

CONCLUSIONS

Certain environmental exposures prior to diagnosis differed among clinical and serologic subgroups of JIIM, suggesting additional exposures to be explored as possible risk factors for JIIM phenotypes.

Standardised interpretation of capillaroscopy in autoimmune idiopathic inflammatory myopathies: A structured review on behalf of the EULAR study group on microcirculation in Rheumatic Diseases

OBJECTIVE

We conducted a systematic review, on behalf of the EULAR Study Group on Microcirculation in Rheumatic Diseases (EULAR SG MC/RD), to investigate the value of nailfold videocapillaroscopy (NVC) in idiopathic inflammatory myopathies (IIM).

METHODS

Three electronic databases were systematically searched to find all relevant manuscripts reporting NVC outcomes in IIM patients. Articles were assessed based on study design, population, NVC methodology and description of NVC results. To allow comparison between the articles, all NVC results were interpreted according to standardised capillaroscopic terminology, as previously consented by the EULAR SG MC/RD and the Scleroderma Clinical Trials Consortium (SCTC) Group on Capillaroscopy.

RESULTS

Of the 653 identified records; five were retained after critical appraisal on title, abstract and manuscript level. A marked difference in NVC was observed between (juvenile) dermatomyositis [(j)DM] versus polymyositis, healthy controls and systemic sclerosis patients. In addition, reduced capillary density and scleroderma pattern seem to be associated with active disease in (j)DM, while immunosuppressive treatment appears to reduce NVC abnormalities.

CONCLUSION

This is the first systematic review investigating NVC in IIM, interpreting the results according to an international consented standardised manner, as proposed by the EULAR SG MC/RD and SCTC Group on Capillaroscopy. We can conclude that NVC presents a promising asset in the diagnosis of (j)DM. Moreover, NVC could be a biomarker for organ involvement and follow-up. Large multicentre prospective standardised studies are further needed to definitely describe associations with clinical and laboratory parameters in the different IIM subtypes.

Juvenile Dermatomyositis

Die juvenile Dermatomyositis (JDM) ist die häufigste chronische entzündliche Myopathie des Kindesalters. In dieser Übersicht soll der aktuelle Kenntnisstand hinsichtlich der Diagnostik, Behandlung und Überwachung der JDM dargestellt werden. So liegen häufig myositis-spezifische Antikörper vor, die mit klinischen Phänotypen und dem Verlauf der Erkrankung korrelieren. Typ I Interferone spielen eine wichtige Rolle in der Pathogenese der Erkrankung. Möglicherweise kann diese Beobachtung in der Zukunft zu gezielten Therapien führen. Da langfristig schwerwiegende Komplikationen, wie z. B. Kalzinosen oder Lipodystrophie, drohen, besonders bei auf Dauer unzureichend kontrollierter Erkrankung, ist eine möglichst rasche und effektive Behandlung anzustreben. Zu diesem Zweck sollte eine intensive Remissionsinduktionstherapie, gefolgt von einer zielgerichteten Therapie angestrebt werden. Verschiedene validierte Messinstrumente stehen zur Verfügung, um den Verlauf der Erkrankung zu beurteilen. Die Pro-KIND-Initiative der Gesellschaft für Kinder- und Jugendrheumatologie hat Praxis- und Konsens-basiert in Deutschland sowohl eine diagnostische als auch eine Treat-to-Target-Behandlungsstrategie entwickelt. Im Rahmen nationaler und internationaler Kollaborationen soll sich die Behandlung der JDM in der Zukunft weiter verbessern.

Physiotherapie und Sport bei Kinderrheuma – Shake your bones

Im Rahmen kindlicher rheumatischer Erkrankungen haben die zumeist schmerzhaften Entzündungsvorgänge am muskulo-skelettalen System (z. B.: Gelenke, Muskeln, Sehnen, Gefäße) Auswirkungen auf die tägliche Mobilität der Betroffenen. Immobilität, körperliche und sportliche Inaktivität sind oft die Folge. Die geltenden Richtlinien der Nationalen Empfehlungen für Bewegung und Bewegungsförderung werden daher oftmals nicht erreicht. Bewegungsreduzierte oder -inaktive Patienten können jedoch durch verschiedene Maßnahmen in ihrem Bewegungsverhalten gefördert werden. Die Physiotherapie bietet eine erste Möglichkeit in geschütztem Rahmen und unter fachlicher Aufsicht körperlich und sportlich aktiv zu sein. Neben der Wiederherstellung und Verbesserung des physiologischen Bewegungsausmaßes liegen die Erhaltung der Selbstständigkeit und Lebensqualität im Vordergrund der physiotherapeutischen Behandlung. Dazu zählen Aktivierung, Anbahnung von physiologischen Bewegungsabläufen, Korrektur von Gelenkachsen und das Vermitteln von Körperwahrnehmung bei körperlicher Aktivität. Medizinisches Fachwissen und Verständnis sowie Wissen über die Anforderungen verschiedener Sportartenprofile ermöglicht gezielte Hilfestellungen. Durch kontinuierliche, engmaschige Begleitung und langsame Steigerung von Intensität und Umfang in der Physiotherapie können Ängste und Bedenken bezüglich dem Wiedereinstieg bzw. Einstieg in sportliche Betätigung abgebaut werden. Der jeweilige Gesundheitszustand und die Situation der Entzündungsaktivität sind maßgebend für die Therapieinterventionen. Sport gilt heute in der Physiotherapie als Therapieelement und hilft Beschwerden zu lindern, verbessert körperliche Defizite und vermittelt dabei Freude an der Bewegung. Für Alltagsaktivitäten und den Freizeitsport kann eine individuelle Sportberatung basierend auf dem bestehenden Erkrankungsstatus, dem funktionellen und sportmotorischen Leistungsniveau sowie den eigenen Interessen wirkungsvoll zu einem aktiven Lebensstil beitragen. Eine weitere Möglichkeit der angeleiteten Bewegungsförderung stellt der Schulsport dar. Individuelle, differenzierte Schulsportteilnahmebescheinigungen verbessern die Inklusion. Ein auf den Erkrankungsstatus angepasstes und vorgegebenes Trainingsprogramm kann mithilfe konkreter Vorgaben bei der Umsetzung der sportlichen Ziele unterstützen. In Zukunft soll ein digital gestütztes professionelles Monitoring die Bewegungsempfehlungen für zuhause noch weiter verbessern und helfen den Mangel an flächendeckenden Beratungsstellen für Erkrankte mit kindlichem Rheuma zu verringern.

A rare case of suspected lupus erythematous panniculitis as the presenting skin feature of juvenile dermatomyositis: A case report

Juvenile dermatomyositis is a rare autoimmune myopathy of childhood, associated with systemic vasculopathy, primarily affecting the capillaries. Panniculitis is seen histologically in about 10% of patients with dermatomyositis; however, its clinical presentation is rare, with only 30 cases presented in the literature to date. The histopathology overlaps with other inflammatory disease states, and is almost identical to the panniculitis seen in lupus erythematous panniculitis. In the cases with both panniculitis and dermatomyositis, skin and muscle inflammation is usually the first clinical manifestation. We present a case of a 16-year-old female with panniculitis as the initial presenting feature of juvenile dermatomyositis in the context of a prior diagnosis of indeterminate colitis.

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.

Angioedema-like presentation as the presenting finding of juvenile myositis and juvenile dermatomyositis in 2 patients

BACKGROUND

Juvenile dermatomyositis (JDM) is the most common subtype of idiopathic inflammatory myopathies in childhood. Gottron's papules, shawl sign, periorbital heliotrope rash, and periungual telengiectasis are characteristic skin findings of the disease. Besides characteristic skin involvement, some other skin findings, such as angioedema, may be seen prior or in the course of the disease. The presence of angioedema in JDM is emphasized in this report.

CASE PRESENTATIONS

We present 2 unrelated girls, aged 2 (case 1) and 12 years (case 2), who had developed symmetrical weakness in the proximal muscles, muscle pain, elevated muscle enzymes and angioedema. Both cases had abnormal muscle magnetic resonance imaging findings, suggestive of inflammatory myositis. Muscle biopsy was performed only in case 1, and major histocompatibility complex-1 expression on myofibers was shown consistent with JDM. Cases were diagnosed as probable and definite JDM, respectively. Angioedema was prominent, particularly in the lips and extremities of both cases, without laboratory evidence of C1 inhibitor deficiency or capillary leak syndrome, and absence of family history. Mast cell-mediated, acquired angioedema was the most likely diagnosis. In both cases, skin and muscle findings improved significantly with steroid treatment.

CONCLUSION

We suggest that angioedema may be among the characteristic skin findings in JDM, and may be included in subsequent definitions.

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.

Comparison of treatments and outcomes of children with juvenile dermatomyositis followed at two European tertiary care referral centers

OBJECTIVES

To compare the treatment approaches and disease outcomes of children with JDM followed in two European tertiary care peadiatric rheumatology centres.

METHODS

The medical notes of patients with JDM seen at Istituto Giannina Gaslini (IGG) of Genoa, Italy or Great Ormond Street Hospital (GOSH) of London, UK between January 2000 and December 2015 within 6 months after disease onset and followed for at least 6 months were reviewed. Demographic, clinical and therapeutic data were collected. At each visit, the caring physician was asked to rate the disease state subjectively.

RESULTS

A total of 127 patients were included, 88 at GOSH and 39 at IGG. At 24 months, the median values of muscle strength and disease activity were at the normal end of the scale and around three quarters of patients were said to have inactive disease. Also, at 2 years, 38.6% and 36% of British and Italian patients, respectively, had damage. Cyclophosphamide, azathioprine, infliximab, rituximab and mycophenolate mofetil were used more frequently by UK physicians, whereas ciclosporin, intravenous immunoglobulin and hydroxychloroquine were prescribed by Italian physicians.

CONCLUSION

This study shows a significant difference in the choice of medications between pediatric rheumatologists practising in the two centres. Despite this, a high proportion of patients had inactive disease at 2 years and there was a low frequency of damage: modern treatments have improved outcomes.

Body composition in longstanding juvenile dermatomyositis; Associations with disease activity, muscle strength and cardiometabolic measures

OBJECTIVE

To (i) compare body composition parameters in patients with longstanding juvenile dermatomyositis (JDM) and controls and (ii) explore associations between body composition and disease activity/inflammation, muscle strength, health-related quality of life (HRQL) and cardiometabolic measures.

METHODS

In a cross-sectional study, we included 59 patients (median disease duration 16.7 y; median age 21.5 y) and 59 age- and sex-matched controls. Active/inactive disease were defined by the PRINTO criteria. Body composition was assessed by total body dual-energy absorptiometry (DXA), inflammation by hs-CRP and cytokines, muscle strength by manual muscle test (MMT-8), HRQL by 36-item short form survey physical component score (SF-36 PCS) and cardiometabolic function by echocardiography (systolic and diastolic function) and serum-lipids.

RESULTS

DXA analyses revealed lower appendicular lean mass index (ALMI) (reflecting limb skeletal muscle mass), higher body fat percentage (BF%) and higher android: gynoid fat ratio (A: G ratio) (reflecting central fat distribution) in patients than controls, despite similar BMI. Patients with active disease had lower ALMI and higher BF% than those with inactive disease; lower ALMI and higher BF% were associated with inflammation (elevated monocyte attractant protein-1 (MCP-1) and hs-CRP). Lower ALMI was associated with reduced muscle strength; higher BF% was associated with impaired HRQL. Central fat distribution (higher A: G ratio) was associated with impaired cardiac function and unfavorable serum-lipids.

CONCLUSION

: Despite normal BMI, patients with JDM, especially those with active disease, had unfavorable body composition, which was associated with impaired HRQL/muscle strength and cardiometabolic function. The association between central fat distribution and cardiometabolic alterations is a novel finding in JDM.

Mapping the current psychology provision for children and young people with juvenile dermatomyositis

Objectives

Juvenile Dermatomyositis (JDM) is a rare, chronic autoimmune condition of childhood, with known psychosocial implications. In this study, we sought to establish current psychological support for children and young people across the UK with rheumatic conditions, with a specific focus on those with JDM.

Methods

Electronic surveys were distributed to the 15 centres that belong to the JDM Research Group in the UK, collecting responses from health-care professionals in the fields of medicine, nursing and psychology.

Results

One hundred per cent of professionals from medicine and nursing replied from all 15 centres. Of these, 7 (47%) did not have a named psychologist as part of their rheumatology team, despite the majority [13 (87%)] having >200 paediatric rheumatology patients. Of the remaining centres, hospital psychology provision varied considerably. When rating their service, only 3 (8%) of 40 professionals scored their service as five (where one is poor and five is excellent); there were wide discrepancies in these scores. Many challenges were discussed, including limited psychology provision, lack of time and difficulties in offering support across large geographical areas.

Conclusion

Many of the challenges discussed are applicable to other centres worldwide. Suggestions have been proposed that might help to improve the situation for children and young people with rheumatic conditions, including JDM. Based on these findings, we suggest that rheumatology teams maximize use of these data to advocate and work toward more comprehensive psychology provision and support in their individual centres.

The First Reported Case of Juvenile Dermatomyositis in an Adolescent with Down Syndrome and the Clinical Considerations for Therapy

Background:

Down Syndrome (DS) is one of the most common birth conditions in the United States of America, with approximately 5300 births annually, resulting in an estimated birth prevalence of 12.6 per 10,000 live births and a population prevalence in the USA since 2010 of 6.7 per 10,000 inhabitants. Children with DS have complex medical challenges that present due to changes in their immune system that results in increased rates of infection, malignancy, and autoimmune disease. Juvenile Dermatomyositis (JDM) is a rare, autoimmune disease, and the most common inflammatory myopathy of childhood. Reports suggest an increased incidence of arthritis in children with DS, but there have been no reports of JDM in children with DS. Additionally, those with DS pose unique challenges with an increase in adverse effects and ineffectiveness of immunosuppressive therapy.

Case :

We describe the first case of an adolescent female with DS who developed JDM with a positive anti-p155/140 antibody and characteristic clinical phenotype. We discuss increased awareness of autoimmune disease in adolescents with DS and clinical considerations for therapy with immunosuppression.

Conclusion:

Adolescents with DS are at increased risk for autoimmune disease, including JDM. Awareness, early recognition of the signs and symptoms of autoimmune disease in those with DS is important, so appropriate therapy can be implemented.

The Vasculopathy of Juvenile Dermatomyositis: Endothelial Injury, Hypercoagulability, and Increased Arterial Stiffness

OBJECTIVE

Vasculopathy is considered central to the pathogenesis of juvenile dermatomyositis (DM) and is associated with severe extramuscular manifestations. We undertook this study to investigate the hypothesis that the vasculopathy of juvenile DM can be noninvasively tracked by examining biomarkers of endothelial injury, subclinical inflammation, hypercoagulability, and vascular arterial stiffness.

METHODS

The study population was a UK cohort of children with juvenile DM. Circulating endothelial cells (CECs) and microparticles (MPs) were identified using immunomagnetic bead extraction and flow cytometry, respectively. Plasma thrombin generation was determined using a fluorogenic assay. Cytokine and chemokine levels were measured by electrochemiluminescence. Arterial stiffness was assessed using pulse wave velocity (PWV). Results were expressed as the median and interquartile range (IQR), and statistical significance was assessed using nonparametric analyses.

RESULTS

Ninety patients with juvenile DM and 79 healthy control subjects were included. The median age of the patients was 10.21 years (IQR 6.68-13.40), and the median disease duration was 1.63 years (IQR 0.28-4.66). CEC counts were higher in all patients with juvenile DM compared to controls (median 96 cells/ml [IQR (40-192] and 12 cells/ml [IQR 8-24], respectively; P < 0.0001). Circulating MP numbers were also significantly higher in patients with active juvenile DM compared to controls (median 204.7 × 103 /ml [IQR 87.9-412.6] and 44.3 × 103 /ml [IQR 15.0-249.1], respectively; P < 0.0001). MPs were predominantly of platelet and endothelial origin. Enhanced plasma thrombin generation was demonstrated in patients with active juvenile DM compared to those with inactive disease (P = 0.0003) and controls (P < 0.0001). Carotid-radial PWV adjusted for age was increased in patients with juvenile DM compared to controls (P = 0.003).

CONCLUSION

We observed increased endothelial injury and increased levels of proinflammatory cytokines in patients with active juvenile DM. MP profiles reflected distinct disease activity status in juvenile DM and are markers of vascular pathology, platelet activation, and thrombotic propensity. Ongoing long-term vascular injury may result in increased arterial stiffness in patients with juvenile DM.

Metabolomics Analysis Identifies a Lipidomic Profile in Treatment Naïve Juvenile Dermatomyositis Patients versus Healthy Control Subjects

Objectives

To perform an exploratory study to identify a JDM serum metabolic profile that differs from healthy controls (HCs) and responds to immunosuppressive treatment.

Methods

Blood was collected from 9 HCs and 10 patients diagnosed with probable (n = 4) or definite (n = 6) JDM based on the criteria of Bohan and Peter for myositis, with 7 of the 10 providing longitudinal samples following initiation of treatment; these patients comprised the treatment-naïve cohort. Sera underwent mass spectroscopy–based measurements of targeted metabolic intermediates, including 15 amino acids, 45 acylcarnitines (ACs), 15 ceramides and 29 sphingomyelins. Principal components analysis reduced metabolites into smaller sets of factors each comprised of correlated metabolic intermediates. Factor scores and metabolite concentrations were compared with HCs using two-sample t-tests while treatment effects were evaluated using paired t-tests.

Results

Of eight principal components analysis–derived metabolite factors (one AC, two amino acids, three sphingosine and two ceramide), two were significantly associated with JDM: one AC factor containing mostly long-chain ACs (P = 0.049) and one ceramide factor (P < 0.01). For 12 individual ACs, mostly long chain, and three ceramides, concentrations were significantly greater for JDM than HCs. Factors based on these individual metabolites showed decreasing scores with treatment (P = 0.03 and P < 0.01, respectively).

Conclusion

While additional validation is needed, these lipids have potential as JDM serum diagnostic and/or treatment biomarkers. Additionally, the significant association of long-chain ACs and ceramides with JDM offers insights regarding pathogenesis, implicating dysregulation of mitochondrial fatty acid β-oxidation.

Myositis autoantibodies in a racially diverse population of children with idiopathic inflammatory myopathies

BACKGROUND

Juvenile idiopathic inflammatory myopathies (JIIMs) is a group of autoimmune disorders, including juvenile dermatomyositis (JDM), juvenile polymyositis (JPM) and overlap myositis, that are characterized by proximal muscle weakness, elevated levels of serum muscle enzymes, and pathognomonic skin findings. While the exact etiology of JIIMs is unclear, the presence of myositis specific autoantibodies (MSAs) have been associated with certain clinical phenotypes, organ involvement and disease prognosis. To date, there have been few studies of the associations between MSA presence and patient ethnicity. It is important to understand the extent to which ethnicity impacts disease manifestations, organ involvement and clinical outcomes. The goal of our study is to determine MSA and myositis associated autoantibody (MAA) presence, clinical phenotype, and disease course in a racially diverse population of pediatric patients with JIIMs.

METHODS

Patients age 2-21 years with a prior diagnosis of JDM, JPM or overlap myositis, who had been tested for MSA/MAA, were eligible for study inclusion. Clinical and laboratory data were collected retrospectively via manual chart review in this single-center study. Descriptive statistics were performed to summarize each variable. Given the small sample size, non-parametric testing was performed using Fischer's exact test, Wilcoxon rank sum test and Kruskal-Wallis test.

RESULTS

Thirty one patients were included in the analysis. Race and ethnicity were self-reported as Hispanic (48.4%), white (25.8%), and Black (25.8%). The most prevalent MSAs were anti-MDA5 (25.8%), anti-p155/140 (22.6%) and anti-MJ (19.4%). Presence of autoantibodies (p = 0.04) and pulmonary disease (p = 0.03) were significantly higher in patients of Black or Hispanic descent compared with white descent. Anti-MDA5 antibodies, cutaneous ulceration, cardiopulmonary involvement, hospitalizations and one death were only reported in patients with Black or Hispanic descent. Patients with anti-MDA5 antibodies were more likely to be male (p = 0.04) and to have cutaneous ulceration (p = 0.02).

CONCLUSIONS

This study describes the prevalence of MSA/MAA in a racially diverse group of patients with JIIM and further delineates clinical phenotype and disease complications in these groups. We found a relatively high proportion of children with anti-MDA5 antibodies and described potentially worse clinical courses in children of Black or Hispanic descent. Further investigation is warranted to examine these findings.

Type I Interferons in the Pathogenesis and Treatment of Autoimmune Diseases

Type I interferons (IFN-Is) are a very important group of cytokines that are produced by innate immune cells but also act on adaptive immune cells. IFN-Is possess antiviral, antitumor, and anti-proliferative effects, as well are associated with the initiation and maintenance of autoimmune disorders. Studies have shown that aberrantly expressed IFN-Is and/or type I IFN-inducible gene signatures in the serum or tissues of patients with autoimmune disorders are linked to their pathogenesis, clinical manifestations, and disease activity. Type I interferonopathies with mutations in genes impacting the type I IFN signaling pathway have shown symptoms and characteristics similar to those of systemic lupus erythematosus (SLE). Furthermore, both interventions in animal models and clinical trials of therapies targeting the type I IFN signaling pathway have shown efficacy in the treatment of autoimmune diseases. Our review aims to summarize the functions and targeted therapies (as well as clinical trials) of IFN-Is in both adult and pediatric autoimmune diseases, such as SLE, pediatric SLE (pSLE), rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM), Sjögren syndrome (SjS), and systemic sclerosis (SSc), discussing the potential abnormal regulation of transcription factors and epigenetic modifications and providing a potential mechanism for pathogenesis and therapeutic strategies for future clinical use.

Disease characteristics and clinical outcomes of adults and children with anti-MDA-5 antibody-associated myositis: a prospective observational bicentric study

To study the demographic, clinical and serologic characteristics of anti-MDA5-positive DM from two geographically and ethnically disparate inception cohorts in India. To identify the clinical and serological parameters at inception that could predict mortality among these individuals. Individuals with anti-MDA5 antibody-positive DM diagnosed between 2017 and 2020 from two centres in India were prospectively followed up. The clinical and serological characteristics at baseline and the treatment outcome at follow-up were assessed for this study. Anti-MDA5 antibody was positive in 25 (7.5%) out of the 330 individuals with myositis. These 25 (21 adults, 4 juvenile) patients were followed up for a median duration of 14 months. Among adults, a majority had cutaneous manifestations 21 (84%) followed by, arthritis 17 (80%), and interstitial lung disease 12 (ILD, 57.1%). Four (19%) had rapidly progressive ILD (RP-ILD). Eight (38%) presented as clinically amyopathic DM. Among cutaneous manifestations, majority (62%) had classic features (gottron's papules/sign, heliotrope rash) while 8 (38%) had cutaneous ulceration and 2 each had periorbital edema and tendon rupture. Eight (38%) were positive for anti-Ro-52 antibody. Out of 21 adults, 8 (38%) succumbed to the diseases. RP-ILD (n = 4; 19%), ulcerative gottron's (n = 5) and anti-Ro-52 (n = 8) were significantly associated with mortality (p < 0.05). Upon binary logistic regression, positive anti-Ro-52 antibody predicted mortality [HR 17.3 (95%CI 1.4-210, p = 0.025)]. All juvenile anti-MDA5-positive DMs had classic cutaneous features with 2 of them having ulcerative gottron's. None of the juvenile patients had ILD and everyone survived till the last follow-up. Indian adults with anti-MDA5 DM have high mortality. Rarer atypical features like tendon rupture or periorbital edema could assist in diagnosis. Ulcerative gottron's, positive anti-Ro 52 antibodies, and RP-ILD are valuable clinical-serological markers that portend poor prognosis.

Long-term outcome in patients with juvenile dermatomyositis: A case series

BACKGROUND

Follow-up of juvenile dermatomyositis (JDM) patients has demonstrated the impact of the disease on several organs in the long term.

OBJECTIVE

As there is little information on the long-term outcome of JDM, we aimed to assess long-term outcomes in a series of JDM patients.

METHODS

After selection of JDM patients, a consultation with a dermatologist and a rheumatologist was held for each patient. Cutaneous, muscle, and disease damage was assessed using different validated scores including the abbreviated Cutaneous Assessment Tool (aCAT), 8-muscle Manual Muscle Testing (MMT8), Childhood Myositis Assessment Scale (CMAS), Myositis Damage Index (MDI), Childhood Health Assessment Questionnaire (CHAQ), and Health Assessment Questionnaire (HAQ). Long-term disease outcomes were recorded including growth and pubertal development, educational and vocational achievement, and development of comorbidities.

RESULTS

Seven patients were included in the study. After a mean follow-up of 14.9±8.8 years, the mean aCAT score was 0.57±1.4 and only one patient had a positive aCAT activity score. The mean aCAT damage score was 1.4±1.3 and five (71%) patients had a score of ≥1. Five (71.4%) patients had normal muscle strength with an MMT8 score of >72, and none had severe muscle weakness (MMT8 ≤32, and CMAS<35). The mean total extent of damage according to the MDI was ≥1 in five (71%) patients and mainly involved the skin. Two (29%) patients had mild disability according to the CHAQ/HAQ disability index. In terms of quality of life, no patient had a score of<40 (1 SD below the mean for healthy controls).

CONCLUSIONS

Based on validated cutaneous and musculoskeletal scores, our study demonstrated the good functional outcomes of JDM at long-term follow-up.

The risk of ischemic stroke in patients with idiopathic inflammatory myopathies: a systematic review and meta-analysis

OBJECTIVE

Idiopathic inflammatory myopathies (IIM) are a group of chronic rheumatic diseases that can affect multiple systems; the risk of ischemic stroke in patients with IIM remains controversial. We aimed to systematically evaluate the risk of ischemic stroke in IIMs.

METHODS

The PubMed, Embase, and Cochrane library were searched for relevant studies. Pooled relative risk (RR) with a 95% confidence interval (CI) was calculated as effect size to evaluate the risk of ischemic stroke in patients with IIM. Random effects model was chosen when I² > 50%. We pooled all studies in a first total analysis to assess the risk of ischemic stroke in IIM. Subgroup analyses were conducted based on the subtypes of IIM (dermatomyositis) and country. Sensitivity analysis was performed to identify the heterogeneity sources.

RESULTS

A total of 6 studies with 5,114 IIM cases and 14,516,099 controls were included, and the results demonstrated that IIMs were associated with an increased risk of ischemic stroke (RR = 2.41, 95% CI: 1.31, 4.45). Subgroup analysis indicated that patients with dermatomyositis (DM) had a 49% excess risk of ischemic stroke than controls; Asian patients with IIM had an increased risk of ischemic stroke, although not for American patients.

CONCLUSION

IIMs, especially patients with DM, are associated with an increased risk of ischemic stroke. Appropriate intervention may be taken into account for patients with IIM, especially when accompanied by other traditional risk factors of ischemic stroke. Key Points • This study evaluated the risk of ischemic stroke in patients with IIMs. • Generally, IIMs are associated with an increased risk of ischemic stroke. • Patients with DM had a 49% excess risk of ischemic stroke than controls. • Subgroup analysis showed that Asian patients with IIMs were at increased risk of ischemic stroke, but not Americans.

Investigating genetic drivers of juvenile dermatomyositis pathogenesis using bioinformatics methods

Juvenile dermatomyositis (JDM) is a chronic autoimmune disease. The pathogenic mechanisms remain ill-defined. The purpose of this study was to identify key genes related to JDM. Microarray datasets were downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEG) were identified. Then, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, and protein-protein interaction (PPI) network were carried out. In addition, the hub genes were selected by cytoHubba. The expression profile and diagnostic capacity (receiver-operator curve [ROC]) of interested hub genes were verified. Gene set enrichment analysis (GSEA) was also carried out. Moreover, the signature of hub genes was then used as a search query to explore the Connectivity Map (CMAP). A total of 128 DEG were identified. The enriched functions and pathways of the DEG include response to virus, negative regulation of cell migration, cadmium ion transmembrane transport, defense response to Gram-negative bacterium, positive regulation of megakaryocyte differentiation, and negative regulation of angiogenesis. Twenty-one hub genes were identified. The expression levels of the interested genes were also confirmed. ROC analysis confirmed that the expression of these genes can distinguish JDM from controls. GSEA showed that these genes are mainly related to "inflammatory response", "complement", "interferon-α response", "IL6/JAK/STAT3 signaling", "TGF-β signaling", "IL2/STAT5 signaling" and "TNF-α signaling via NF-κB". The CMAP research found some compounds with the potential to counteract the effects of the dysregulated molecular signature in JDM. In this study, bioinformatics methods were used to identify DEG, which helps us understand the molecular mechanisms of JDM and provide candidate targets for diagnosis and treatment of JDM.

Risk factors associated with Pneumocystis jirovecii pneumonia in juvenile myositis in North America

OBJECTIVES

Pneumocystis jirovecii pneumonia (PJP) is associated with significant morbidity and mortality in adult myositis patients; however, there are few studies examining PJP in juvenile myositis [juvenile idiopathic inflammatory myopathy (JIIM)]. The purpose of this study was to determine the risk factors and clinical phenotypes associated with PJP in JIIM.

METHODS

An research electronic data capture (REDCap) questionnaire regarding myositis features, disease course, medications and PJP infection characteristics was completed by treating physicians for 13 JIIM patients who developed PJP (PJP+) from the USA and Canada. Myositis features and medications were compared with 147 JIIM patients without PJP (PJP-) from similar geographic regions who enrolled in National Institutes of Health natural history studies.

RESULTS

PJP+ patients were more often of Asian ancestry than PJP- patients [odds ratio (OR) 8.7; 95% CI 1.3, 57.9]. Anti- melanoma differentiation associated protein 5 (MDA5) autoantibodies (OR 12.5; 95% CI 3.0, 52.4), digital infarcts (OR 43.8; 95% CI 4.2, 460.2), skin ulcerations (OR 12.0; 95% CI 3.5, 41.2) and interstitial lung disease (OR 10.6; 95% CI 2.1, 53.9) were more frequent in PJP+ patients. Before PJP diagnosis, patients more frequently received pulse steroids, rituximab and more immunosuppressive therapy compared with PJP- patients. Seven PJP+ patients were admitted to the intensive care unit and four patients died due to PJP or its complications.

CONCLUSIONS

PJP is a severe infection in JIIM that can be associated with mortality. Having PJP was associated with more immunosuppressive therapy, anti-MDA5 autoantibodies, Asian race and certain clinical features, including digital infarcts, cutaneous ulcerations and interstitial lung disease. Prophylaxis for PJP should be considered in juvenile myositis patients with these features.

Anti-mitochondrial autoantibodies are associated with cardiomyopathy, dysphagia, and features of more severe disease in adult-onset myositis

We analyzed the prevalence of anti-mitochondrial autoantibodies (AMA) in adult- and juvenile-onset myositis longitudinal cohorts and investigated phenotypic differences in myositis patients with AMA. We screened sera from myositis patients including 619 adult- and 371 juvenile-onset dermatomyositis (DM, JDM), polymyositis (PM, JPM), inclusion body myositis (IBM), or amyopathic DM patients and from healthy controls, including 164 adults and 92 children, for AMA by ELISA. Clinical characteristics were compared between myositis patients with and without AMA. AMA were present in 5% of adult myositis patients (16 of 216 DM, 10 of 222 PM, 4 of 140 IBM, 1 of 19 amyopathic DM), 1% of juvenile myositis patients (3 of 302 JDM, 1 of 25 JPM), and 1% of both adult and juvenile healthy controls. In patients with adult-onset myositis, AMA were associated with persistent muscle weakness, Raynaud’s phenomenon, dysphagia, and cardiomyopathy. Adult myositis patients with AMA may have more severe or treatment refractory disease, as they more frequently received glucocorticoids and intravenous immunoglobulin. In juvenile myositis, children with AMA often had falling episodes and dysphagia, but no other clinical features or medications were significantly associated with AMA. AMA are present in 5% of adult myositis patients and associated with cardiomyopathy, dysphagia, and other signs of severe disease. The prevalence of AMA is not increased in patients with juvenile myositis compared to age-matched healthy controls. Our data suggest that the presence of AMA in adult myositis patients should prompt screening for cardiac and swallowing involvement.

Key Points • Approximately 5% of a large North American cohort of adult myositis patients have anti-mitochondrial autoantibodies. • Adults with anti-mitochondrial autoantibodies often have chronic weakness, Raynaud’s, dysphagia, cardiomyopathy, and more severe disease. • Anti-mitochondrial autoantibodies are rare in juvenile myositis and not associated with a specific clinical phenotype.