Juvenile Dermatomyositis Research Articles

Exploring paediatric rheumatology care: a ten-year retrospective analysis of the patient population in Ghana

BackgroundRheumatic diseases can seriously impact children’s general health, development, and growth. However, due to a lack of resources, paediatric rheumatology is a largely underdeveloped speciality in many African nations. Children with rheumatic disorders face obstacles in accessing specialized medical care, including lack of specialists, care centres, medication access, and limited research and education to increase understanding of paediatric rheumatic disease among healthcare practitioners. This study described the disease characteristics, prevalence, and challenges faced by paediatric rheumatic disease patients receiving care at a teaching hospital in Accra, Ghana.MethodsA retrospective record-based study was conducted among all paediatric cases presenting to the rheumatology clinic of the Korle Bu Teaching Hospital (KBTH) from January 2011 to December 2021. Data collected include clinical features, laboratory findings at disease presentation, andtherapeutic regimens prescribed per standard guidelines and experiences.ResultsA total of 121 cases were identified as of 2021, indicating a point prevalence of 0.0011%. The majority (73%) were females with a mean age of 13.4 ± 3.2 years. The mean duration of symptoms in months experienced by patients before being successfully referred to a rheumatologist was 18 months. There were significant differences between referred and confirmed diagnoses, especially in cases involving mixed connective tissue diseases (MCTD), systemic lupus erythematosus (SLE), and juvenile dermatomyositis (JDM), suggesting that these conditions may be under-recognised. Arthralgia and arthritis were the most common presenting symptoms. More than three-quarters (86.8%) of the cases studied were treated with steroids (oral or intravenous). In cases requiring immunosuppressive therapy, methotrexate was the most commonly prescribed in 33.9% of instances. Mortality was recorded at 8.3%, with the majority involving SLE cases. Most (95.7%) of the primary caregivers expressed positive experiences regarding care received at the adult rheumatology clinic.ConclusionThere were significant delays in diagnosis and diagnostic accuracy for patients with paediatric rheumatic disease (PRD). This highlights the pressing need for strengthening paediatric rheumatology services in Africa, including increasing awareness about these conditions among the public and healthcare providers to improve early diagnosis and quality of life for children with these conditions.

Reduced expressions of apoptosis-related proteins TRAIL, Bcl-2, and TNFR1 in NK cells of juvenile-onset systemic lupus erythematosus patients: relations with disease activity, nephritis, and neuropsychiatric involvement.

Lupus pathogenesis is mainly ascribed to increased production and/or impaired clearance of dead cell debris. Although self-reactive T and B lymphocytes are critically linked to lupus development, neutrophils, monocytes, and natural killer (NK) cells have also been implicated. This study assessed apoptosis-related protein expressions in NK cells of patients with juvenile-onset systemic lupus erythematosus (jSLE) and relations to disease activity parameters, nephritis, and neuropsychiatric involvement. Thirty-six patients with jSLE, 13 juvenile dermatomyositis (JDM) inflammatory controls, and nine healthy controls had Fas, FasL, TRAIL, TNFR1, Bcl-2, Bax, Bim, and caspase-3 expressions in NK cells (CD3-CD16+CD56+) simultaneously determined by flow cytometry. Disease activity parameters included Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score, erythrocyte sedimentation rate, C-reactive protein level, anti-double strain DNA antibody level, complement fractions C3 and C4 levels. Patients with jSLE had a profile of significantly reduced expression of TRAIL, Bcl-2, and TNFR1 proteins in NK cells when compared to healthy controls. Similar profile was observed in patients with jSLE with active disease, positive anti-dsDNA, nephritis, and without neuropsychiatric involvement. Patients with jSLE with positive anti-dsDNA also had reduced expression of Bax in NK cells when compared healthy controls and to those with negative anti-dsDNA. Yet, patients with jSLE with negative anti-dsDNA had reduced mean fluorescence intensity (MFI) of Bim in NK cells compared to healthy controls. Patients with jSLE with nephritis also had reduced MFI of Fas in NK cells when compared to those without nephritis. In addition, in patients with jSLE, the proportion of FasL-expressing NK cells directly correlated with the SLEDAI-2K score (rs = 0.6, p = 0.002) and inversely correlated with the C3 levels (rs = -0.5, p = 0.007). Moreover, patients with jSLE had increased NK cell percentage and caspase-3 protein expression in NK cells when compared to JDM controls. This study extends to NK cells an altered profile of TRAIL, Bcl-2, TNFR1, Fas, FasL, Bax, Bim, and caspase-3 proteins in patients with jSLE, particularly in those with active disease, positive anti-dsDNA, nephritis, and without neuropsychiatric involvement. This change in apoptosis-related protein expressions may contribute to the defective functions of NK cells and, consequently, to lupus development. The full clarification of the role of NK cells in jSLE pathogenesis may pave the way for new therapies like those of NK cell-based.

Longitudinal assessment of disease activity and muscle strength in juvenile dermatomyositis: a multicentre registry study.

To define disease activity measures, muscle strength and functional assessments in new-onset juvenile dermatomyositis (JDM) patients, at disease onset and follow up. A registry was set up in 18 hospitals, enrolling patients over 3-years (2015-2018). Clinical assessments were performed at baseline, and at 6, 12, 18 and 24 months after diagnosis. Disease Activity Score (DAS20), skin and musculoskeletal DAS sub-scales; Manual Muscle Test (MMT8); Childhood Myositis Assessment Scale (CMAS); Childhood Health Assessment Questionnaire disability index (CHAQ_DI 0-3) and 10 cm Visual Analog Scale (VAS) for overall wellbeing scores were compared by Poisson Model and Wald post-test for repeated measures. Ninety-six cases, being 61 (64%) females, median age 10 years had JDM diagnosis and 12 (13%) onset calcinosis. Mean ±SD scores at diagnosis and 6 months intervals for DAS20 (0-20) were 7.8±5, 6.3 ±4.8, 5±4, 4.9 ±5 and 0.5 ±2.3; with significant difference from baseline (p<0.01). Skin DAS subscales were 2.8±3.3, 1.8±2.9, 1,1±2.2, 0.6±1.8, 0.4±1.5. MMT (0-80) 62.6±20.4, 70.2±13.5, 73.3±11, 75.7±7.9 and 74.8±7.8, with significant difference from baseline up to 6 months (p=0.016); CMAS (0-53) 29.5±11.4, 33.1±8.3, 34.2±5.8, 34±6 and 33.3±5.4. CHAQ-DI (0-3) 1±0.9, 0.6±0.7, 0.8±0.8, 1±0.8 and 1±0.3; parents VAS 4.1±2.5, 2±2.1; 1.3±2.8, 4.1±3.1, 1.7±2.2. There was no significant difference for CMAS, CHAQ-DI and parents VAS from baseline up to 24-month assessment. DAS20 scores improved gradually during follow up, MMT8 improved significantly during the first 6 months and CMAS, CHAQ-DI and parents VAS scores had no significant improvement with persistent functional impairment over 2-years.

Inclusion Body Myositis in Children: Does it Exist?

Context: Sporadic inclusion body myositis (sIBM) is a rare type of juvenile idiopathic inflammatory myopathies (JIIMs). It mainly affects skeletal muscles but can also affect the skin and other organs in the body. Sporadic inclusion body myositis prevalence in children under 18 years old is very rare. Objectives: This review provides an overview of the evidence of sIBM in children, discusses the possible clinical and pathological features, and explores the proposed pathogenesis. Methods: A literature review of over 44 articles in PubMed and other medical libraries, such as Google Scholar and Web of Science, was carried out using terms such as JIIM, IBM, Inflammatory Myopathies in Children, and Inherited IBM. Two documented reports for sIBM were found, and the rest included the disease pathogenesis, prevalence of inherited IBM, and other myopathies in children. Results: This review discussed the prevalence and incidence of JIIM, in particular sIBM in children. While IBM is typically sporadic, there have been rare cases where it is familial and inherited. Genetic susceptibility factors are believed to play a role in sIBM. Most patients with sIBM are over 50 years old and experience significant weakness in the quadriceps; however, patients with inherited IBM (h-IBM) typically present earlier in adulthood with a distinct pattern of weakness. Sporadic inclusion body myositis can be misdiagnosed as other forms of myopathies, such as juvenile dermatomyositis (JDM) or limb-girdle muscular dystrophy (LGMD), during the early stages of the disease. The exact causes of sIBM are still unknown; however, environmental factors, genetic predispositions, and immune dysregulation might contribute to the pathogenesis of the disease. Conclusions: Sporadic inclusion body myositis is a rare form of JIIMs. Its early diagnosis in children can be challenging due to the presence of other coexisting diseases. Discussions have revolved around potential environmental factors, such as viral infections, specific myositis-specific antibodies (MSAs), such as anti-Ro52, and possibly certain human leukocyte antigen (HLA) haplotypes. Given the rarity of reported cases of sIBM in children, it is important to encourage further studies to better understand the underdiagnosed instances of this condition.

Increased percentage of HLA-DR T cells in untreated juvenile dermatomyositis

This study investigates HLA-DR expression on activated T cells and serum neopterin levels in Juvenile Dermatomyositis (JDM) children pre- and post-treatment. Sixty-nine JDM children (less than 18 years) were included. Elevated HLA-DR+ T cells (>7 %) were observed in 19 % of untreated cases. Post-treatment, mean HLA-DR+ T cells decreased from 5.1 to 2.9 (P < 0.001), and serum neopterin levels declined from 19.3 to 9.1 nmol/L (P < 0.0001). A positive correlation between serum neopterin and HLA-DR T cell percentage was observed (r = 0.39, P = 0.01). Intravenous steroid treatment exhibited a 47.4 % improvement in HLA-DR+ T cells and a 50.5 % reduction in serum neopterin levels, in contrast to 14.8 % and 34.1 % in the oral steroid group. In conclusion, treatment, particularly with IV steroids, significantly improved HLA-DR+ T cells percentage and neopterin levels. A correlation between HLA-DR+ T cells percentage and serum neopterin was noted in untreated JDM patients.

Interferon type I signature associated with skin disease in juvenile dermatomyositis.

Interferon type I (IFN-I) signaling system hyperactivation plays an important role in the pathogenesis of juvenile dermatomyositis (JDM). To analyze IFN-I score with disease activity in patients with JDM. Clinical manifestations laboratory data, and treatment options were analyzed in 15 children with JDM. Disease activity was assessed by CMAS (childhood myositis assessment tool) and CAT (cutaneous assessment tool) scores. IFN I-score was assessed by RT-PCR quantitation of 5 IFN I-regulated transcripts (IFI44L, IFI44, IFIT3, LY6E, MXA1). All patients had skin and muscle involvement, some had a fever (n = 8), swallowing disorders (n = 4), arthritis (n = 5), calcinosis (n = 3), lipodystrophy (n = 2), and interstitial lung disease (n = 5). Twelve patients had elevated IFN I-score and it was correlated with skin disease activity. Ten patients had clinically active disease and the level of IFN I-score and its components were higher than in patients with inactive disease (8.8 vs. 4.2, p = 0.011). IFN I-score was evaluated in nine patients during follow-up. The simultaneous reduction of IFN I-score and its components, CMAS and CAT scores was observed. Skin involvement in refractory JDM is a challenging problem requiring the use of additional medications. Serum IFN I-score might be suggested as the promising biomarker of skin disease activity in JDM patients. Further investigations on patients with JDM and recurrent disease activity are needed, especially concerning biomarkers that determine the response to JAK inhibitors and treatment options for patients who don't respond to them.

Genetic changes from type I interferons and JAK inhibitors: clues to drivers of juvenile dermatomyositis.

To better understand the pathogenesis of juvenile dermatomyositis (JDM), we examined the effect of the cytokines type I interferons (IFN I) and JAK inhibitor drugs (JAKi) on gene expression in bioengineered pediatric skeletal muscle. Myoblasts from three healthy pediatric donors were used to create three-dimensional skeletal muscle units termed myobundles. Myobundles were treated with IFN I, either IFNα or IFNβ. A subset of IFNβ-exposed myobundles was treated with JAKi tofacitinib or baricitinib. RNA sequencing analysis was performed on all myobundles. Seventy-six myobundles were analysed. Principal component analysis showed donor-specific clusters of gene expression across IFNα and IFNβ-exposed myobundles in a dose-dependent manner. Both cytokines upregulated interferon response and proinflammatory genes; however, IFNβ led to more significant upregulation. Key downregulated pathways involved oxidative phosphorylation, fatty acid metabolism and myogenesis genes. Addition of tofacitinib or baricitinib moderated the gene expression induced by IFNβ, with partial reversal of upregulated inflammatory and downregulated myogenesis pathways. Baricitinib altered genetic profiles more than tofacitinib. IFNβ leads to more pro-inflammatory gene upregulation than IFNα, correlating to greater decrease in contractile protein gene expression and reduced contractile force. JAK inhibitors, baricitinib more so than tofacitinib, partially reverse IFN I-induced genetic changes. Increased IFN I exposure in healthy bioengineered skeletal muscle leads to IFN-inducible gene expression, inflammatory pathway enrichment, and myogenesis gene downregulation, consistent with what is observed in JDM.

Exploring cardiovascular implications of juvenile dermatomyositis: Insights from aortic stiffness analysis and 3D echocardiography.

Our goal was to use three dimensional (3D) strain analysis to evaluate myocardial function and ascending aorta elasticity changes in juvenile dermatomyositis (JDM). Between 2019 and 2021, 23 JDM patients and 20 healthy volunteers participated. Both groups underwent 2D and 3D strain analysis, assessing aortic stiffness using aortic distensibility, stiffness index, strain, and elastic modulus. JDM patients had a median age of 13.3±5.2 years, while controls had a median age of 13.8±4.76 years. 3D strain analysis revealed significantly lower global longitudinal (GLS) and circumferential strain (GCS) in JDM patients compared to controls. Specifically, 3D GLS was notably reduced in patients (-28.1% vs. -31%, p=.047) compared to controls, and 3D GCS was also lower in patients (-27.5% vs. -30.5%, p=.019) compared to controls. Aortic strain and elastic modulus were significantly lower in JDM patients, while aortic stiffness index and distensibility showed no significant differences. Correlation analyses within the JDM group revealed a negative correlation between 3D GLS and age at diagnosis (r=-.561, p=.04), as well as a positive correlation between 3D GLS and both aortic strain (r=.514, p=.0001) and elastic modulus (r=.320, p=.03) in JDM patients. Our study demonstrated a trend towards lower ejection fraction and strain in patients with JDM, along with increased aortic stiffness using 3D echocardiography. These findings suggest potential cardiovascular involvement in juvenile dermatomyositis, emphasizing the importance of comprehensive cardiac assessments in these patients.

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

ObjectivesTo 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...

Disease activity trajectories in juvenile dermatomyositis from childhood to adulthood.

To assess whether there are identifiable subgroups of disease activity trajectory in a population of JDM patients-followed throughout childhood and into adulthood-and determine factors that predict those trajectory groupings. This is a retrospective, longitudinal inception cohort of patients with idiopathic inflammatory myopathies, largely JDM. We sought to identify baseline factors that predict membership into different groups (latent classes) of disease activity trajectory. A total of 172 patients (64% females), with median age at diagnosis of 7.7 years, were analysed. We studied 4725 visits (1471 patient-years). We identified three latent classes of longitudinal disease activity, as measured by the modified DAS (DASm), with distinct class trajectories predicted by DASm at baseline, and by the changes of DASm from either baseline to 3 months or baseline to 6 months (early response to therapy). In the analysis in which DASm at baseline and the changes of DASm from baseline to 6 months are included as predictors, Class 1 (10%) has persistently high disease activity, Class 2 (34%) is characterized by moderate disease activity and Class 3 (56%) is characterized by individuals with a high early disease activity but an apparently good response to treatment and long-term low disease activity. High early disease activity, and treatment resistance in the first few months, predict a more chronic longitudinal course of JDM.

P15 A Case of Juvenile Dermatomyositis in a 15-year old African-descent Girl

Abstract A 15-year-old female with skin of colour (SOC), was diagnosed with Juvenile dermatomyositis (JDM) following a presentation with muscle weakness, swallowing difficulties and rash. Investigations showed CK&amp;gt;1300, positive Mi-2 alpha, beta antibodies and bilateral myositis on MRI pelvis. Her skin features commenced 2 months prior to her rheumatological presentation. They included erythematous pruritic patches on the limbs, generalised hyperpigmentation of the face and trunk, hyperpigmentation of palmar creases and nail folds, flagellate hyperpigmentation of the hands &amp; arms, and hypopigmented macules with follicular sparing across the face. She also presented skin thickening over the interphalangeal joints and nail fold capillary dilatation and infarctions. Skin biopsy showed interface dermatitis, in keeping with dermatomyositis. She was managed with weaning prednisolone, methotrexate, topical tacrolimus and sunscreen. JDM is a small-vessel autoimmune vasculopathy leading to muscle inflammation and skin changes. Unlike adult-onset disease, JDM is not associated with malignancy. The typically described violaceous skin features of JDM including photosensitive rash periorbitally, and over the knees and knuckles (Gottron’s sign) may be hyperpigmented rather than erythematous in skin of colour. Additional skin features described in SOC are generalised hyperpigmentation and pigmentation in skin creases. A flagellate dermatitis is uncommon, but recognised in association with Mi-2 antibodies in JDM. TIF1 antibodies have been reported in association with hypopigmented patches which may mimic vitiligo postulated possibly secondary to interface inflammation perhaps leading to dyspigmnentation. Notably our patient was negative for TIF1. This presentation highlights some of the less commonly described skin features of dyspigmentation in JDM in SOC.

O08 Severely pruritic juvenile dermatomyositis

Abstract A 7-year-old female with type IV skin and autism spectrum disorder presented with a 4 month history of progressive proximal myopathy, weight loss and 20 month history of a worsening, intensely pruritic rash. Cutaneous examination showed a widespread eczematous eruption, post-inflammatory hypopigmentation, heliotrope rash and firm subcutaneous changes, in addition to palmar-plantar papules, pustules and burrows. Extra-cutaneous findings included multiple fixed flexion deformities and muscle wasting. Investigations revealed a normocytic anaemia, elevated muscle enzymes, strongly positive anti-nuclear antibodies and negative myositis-specific antibodies. Whole body MRI reported proximal muscle oedema. Skin biopsy demonstrated lichenoid and perifollicular inflammation, dermal mucin and subcutaneous calcification. Clinical findings were consistent with a diagnosis of juvenile dermatomyositis (JDM), complicated by concurrent scabies. Prednisolone in combination with methotrexate was commenced as first-line therapy in line with current consensus JDM treatment plans, in addition to topical steroids and sun protection. Muscle power started to improve after 5 months but ongoing cutaneous inflammation prompted second-line therapy with IV immunoglobulin. Oral ivermectin was required for the management of scabies due to topical permethrin failure. JDM is a rare autoimmune small-vessel vasculopathy with significant morbidity and limited evidence-based guidelines. Unlike adult-onset disease there is no racial predilection or association with malignancy. Calcinosis is more common in children but early treatment reduces disease complications. JDM has a variable disease course with a median time to remission of 4.67 years. Residual skin changes are increasingly recognised to be an early predictor of prolonged recovery time and these patients may benefit from biologic agents.

Contribution of Complement, Microangiopathy and Inflammation in Idiopathic Inflammatory Myopathies.

Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group characterized by muscle weakness and skin symptoms and are categorized into six subtypes: dermatomyositis (DM), polymyositis (PM), anti-synthetase syndrome (ASS), immune-mediated myopathy (IMNM), inclusion body myopathy (IBM), and overlap myositis. Myositis-specific autoantibodies were detected for the diagnosis and classification of IIM. This review highlights the pathogenic contributions of the complement system, microangiopathy, and inflammation in IIM. Deposition of complement around capillaries and/or the sarcolemma was observed in muscle biopsy specimens from patients with DM, ASS, and IMNM, suggesting the pathomechanism of complement-dependent muscle and endothelial cell injury. A recent study using human muscle microvascular endothelial cells showed that Jo-1 antibodies from ASS induce complement-dependent cellular cytotoxicity in vitro. Based on both clinical and pathological observations, antibody- and complement-mediated microangiopathy may contribute to the development of DM and anti-Jo-1 ASS. Juvenile DM is characterized by the loss of capillaries, perivascular inflammation, and small-vessel angiopathies, which may be related to microinfarction and perifascicular atrophy. Several serum biomarkers that reflect the IFN1 signature and microangiopathy are elevated in patients with DM. The pathological observation of myxovirus resistance protein A (MxA), which suggests a type 1 interferon (IFN1) signature in DM, supports the diagnosis and further understanding of the pathomechanism of IIM. A recent report showed that an increase in triggering receptor expressed on myeloid cells (TREM-1) around perimysial blood vessels and muscles in patients with IIM plays a role in triggering inflammation and promoting the migration of inflammatory cells by secreting proinflammatory cytokines, such as tumor necrosis factor α. The deposition of complement in muscles and capillaries is a characteristic feature of DM, ASS, and IMNM. Microangiopathy plays a pathogenic role in DM, possibly resulting in perifascicular atrophy. Further understanding of the detailed pathomechanism regarding complement, microangiopathy, and inflammation may lead to novel therapeutic approaches for IIM.

Juvenile dermatomyositis with central nervous system involvement: two case reports from a retrospective single-center cohort, with literature review.

Juvenile dermatomyositis (JDM) is a systemic autoimmune disease primarily involving the muscles and skin; it can also affect the central nervous system (CNS). The relevant literature provides limited information regarding the characteristics of JDM with CNS involvement. We reviewed patients with JDM who were hospitalized at our center between January 2016 and August 2023, with a focus on those with CNS involvement. The aim was to provide detailed case reports on these patients, and to summarize the relevant literature about the characteristics of similar cases. Among 193 hospitalized patients with JDM, two (1.03%) had CNS involvement. Two patients, a 5.5-year-old girl and an 11-year-old boy, were admitted with severe proximal muscle weakness and seizures, and presented with active cutaneous vasculitis. Both were ultimately diagnosed with JDM, with CNS involvement. Both patients had confirmed presence of anti-NXP2 antibody through myositis-specific antibody analysis. Additionally, they all exhibited hyperferritinemia and thrombocytopenia. Salvage therapies like intravenous methylprednisolone (IVMP) pulse therapy and/or plasma exchange were administered successfully. At final follow-up, both patients had achieved complete clinical response and full neurological recovery. Our literature review identified nine similar case studies. CNS involvement usually occurred within the first 10 months of the disease course, and most of these patients had fatal outcomes, with a mortality rate of 66.6% (6/9). Including the two patients described herein, the median age for disease onset is 10.5 years (range 4-17 years), and the male: female ratio is 6:5. Seizures are the most common neurological symptom, accompanied by active cutaneous vasculitis. The brain biopsies showed two distinct pathological presentations: one was central nervous system vasculitis, and the other was cerebral macrophage activation syndrome. CNS involvement is a rare but life-threatening JDM complication. Herein, our cases and the literature indicate that it typically occurs within the first 10 months of the disease course and manifests as seizures, often accompanied by active cutaneous vasculitis, with fatal outcomes. Timely implementation of salvage therapies, like IVMP pulse therapy and plasma exchange, may significantly impact patient outcomes.

MDA5 Juvenile Dermatomyositis Misdiagnosed as Childhood Psoriasis: A Case Report

Juvenile Dermatomyositis (JDM) is a rare autoimmune disorder which mainly affects the skin and skeletal muscles. Characteristic features of this rare disorder include Gottron papules, heliotrope rashes and proximal muscle weakness. MDA5 positive JDM is usually associated with interstitial lung disease in later part of life. The authors report a case of an 11-year-old male child who presented to the Paediatric Department with complaints of rashes over extensor surfaces, Gottron papules and pain and weakness in all limbs. The child was on treatment from the Dermatology Department as a case of psoriasis for last six months. During hospital stay after detailed work-up, the child was diagnosed to have JDM. Anti-melanoma Differentiation-Associated gene 5 (Anti-MDA5) antibodies were positive in the present case. The child was treated with immunosuppressive drugs with supportive care and is currently on treatment for the last one and a half years and is largely asymptomatic. JDM requires meticulous clinical examination and specific investigations so that timely diagnosis can be made to ensure appropriate treatment. In the present index case, the authors describe the typical clinical presentation, newer investigative modalities like myositis specific antibody and treatment outcomes of this rare condition.

Juvenile Dermatomyositis Outcome Prediction Using Magnetic Resonance Imaging STIR Sequences

Background – Juvenile Dermatomyositis can have a unpredictable course after diagnosis, with no tools to prognosticate near-term outcomes. We explored a Short Tau Inversion Recovery (STIR) sequence Magnetic Resonance Imaging (MRI) protocol as a non-invasive baseline investigation to assess the present outcome in a cohort of JDM patients. Objectives – To determine the difference in baseline STIR-MRI parameters between children with JDM, who are currently in remission with medication and children in sustained remission off medications. Methods – We retrospectively reviewed the baseline MRI findings of 28 consecutive patients, evaluated and followed up for at least one year, by a senior paediatric rheumatologist. A radiologist reviewed the images of each child’s MRI thigh STIR Sequences, scored on four domains - STIR hyper-intensities, fatty infiltration of muscle, presence of skin and subcutaneous tissue involvement and muscle atrophy. We compared the median (inter quartile range) scores between children in remission with and without medication. Results – Median baseline age was 7 (7.5) years. At baseline, they reported a median CMAS of 17 (21), with STIR signal intensity of 2 (2), fatty infiltration grade of 0 (1). Twelve (42.9%) and four children (14.3%) showed evidence of skin and subcutaneous involvement and muscle atrophy, respectively. After being followed up for a median of 6 (6) years, eight children (28.6%) were in remission off medication. There was evidence that fatty infiltration differed between children in remission with medication vs off medication (p = 0.043). MRI Fatty infiltration grades predicted delayed treatment initiation ([Formula: see text] 6 months since symptom onset) in children, fairly accurately (AUC 0.731 ± 0.11, p = 0.036). Conclusions – Our study indicates that fatty infiltration in baseline STIR-MRI protocol may suggest a chronic disease course. Fatty infiltration, also suggests a history of inadequate/delayed diagnosis and treatment since symptom onset. Thus, early MRI may prognosticate the disease course in children with JDM. Further research is needed to exclude potential effect modifiers and confounders in the analysis.

Deep RNA sequencing of muscle tissue reveals absence of viral signatures in dermatomyositis.

Objective: To explore a possible connection between active viral infections and manifestation of dermatomyositis (DM). Methods: Skeletal muscle biopsies were analyzed from patients diagnosed with juvenile (n=10) and adult (n=12) DM. Adult DM patients harbored autoantibodies against either TIF-1γ (n=7) or MDA5 (n=5). Additionally, we investigated skeletal muscle biopsies from non-diseased controls (NDC, n=5). We used an unbiased high-throughput RNA sequencing (HTS) approach to detect viral sequences. To further increase sequencing depth, a host depletion approach was applied. Results: In this observational study, no relevant viral sequences were detected either by native sequencing or after host depletion. The absence of detectable viral sequences makes an active viral infection of the muscle tissue unlikely to be the cause of DM in our cohorts. Discussion: Type I interferons (IFN) play a major role in the pathogenesis of both juvenile and adult DM. The IFN response is remarkably conserved between DM subtypes classified by specific autoantibodies. Certain acute viral infections are accompanied by a prominent type I IFN response involving similar downstream mechanisms as in DM. Aiming to elucidate the pathogenesis of DM in skeletal muscle tissue, we used deep RNA sequencing and a host depletion approach to detect possible causative viruses.

Clinicoepidemiological Spectrum of Connective Tissue Diseases in the Pediatric Population in a Tertiary Care Center in North India: A Cross-sectional Observational Study

Abstract Background: Connective tissue diseases (CTDs) are chronic in nature and carry a high risk of morbidity, disability, and mortality if not recognized and treated promptly. Data on clinical spectrum of CTDs in the pediatric age group are sparse from developing countries such as India. Objective: To study the clinicoepidemiological spectrum of CTDs in the pediatric age group. Methodology: A hospital-based, cross-sectional, observational study was undertaken over a period of 16 months from January 2021 to June 2022 in the dermatology outpatient department and pediatric rheumatology clinic in a tertiary care hospital in North India. Clinical and laboratory findings were recorded. Results: A total of 100 children diagnosed with a CTD were included in the study. The mean age was 11.11 ± 4.20 years. Out of 100 children, 55% were female and 45% were male with a male-to-female ratio of 1:1.2. Our study included 63% juvenile idiopathic arthritis, 17% systemic lupus erythematosus, 7% juvenile dermatomyositis, 6% Kawasaki disease, 3% systemic sclerosis, and 2% Henoch–Schonlein purpura and mixed CTD patients each. Mucocutaneous features commonly seen were rash (40%), oral ulcers (22%), and photosensitivity (18%). Commonly seen systemic features were joint pain (77%), followed by fever (63%). Conclusion: Mucocutaneous manifestations are frequently seen in CTDs and constitute a frequent and an early manifestation of CTD. Early recognition of CTD in the pediatric age group will help in timely initiation of treatment to prevent disabilities and mortality.

Juvenile Dermatomyositis: Case Report from the Albert Royer National Children's Centre in Dakar (Senegal)

Juvenile Dermatomyositis: Case Report from the Albert Royer National Children's Centre in Dakar (Senegal)

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 amultisystemic 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 amultidisciplinary treatment (including physicians, physiotherapists, psychologists, social workers) is mandatory, especially in the first phases of the disease. Particularly important is aprofessionally correct treatment of the functional sequelae, which are aparticular focus of this article.