Transcriptomes of peripheral blood mononuclear cells from juvenile dermatomyositis patients show elevated inflammation even when clinically inactive

In juvenile dermatomyositis (JDM), the most common pediatric inflammatory myopathy, weakness is accompanied by a characteristic rash that often becomes chronic and is associated with vascular damage. We hoped to understand the molecular underpinnings of JDM, particularly when untreated, which would facilitate the identification of novel mechanisms and clinical targets that might disrupt disease progression. We studied the RNA-Seq data from untreated JDM peripheral blood mononuclear cells (PBMCs; n = 11), PBMCs from a subset of the same patients when clinically inactive (n = 8/11), and separate samples of untreated JDM skin and muscle (n = 4 each). All JDM samples were compared to non-inflammatory control tissues. The untreated JDM PBMCs showed a strong signature for type1 interferon response, along with IL-1, IL-10, and NF-κB. Surprisingly, PBMCs from clinically inactive JDM individuals had persistent immune activation that was enriched for IL-1 signaling. JDM skin and muscle both showed evidence for type 1 interferon activation and genes related to antigen presentation and decreased expression of cellular respiration genes. Additionally, we found that PBMC gene expression correlates with disease activity scores (DAS; skin, muscle, and total domains) and with nailfold capillary end row loop number (an indicator of microvascular damage). This included otoferlin, which was significantly increased in untreated JDM PBMCs and correlated with all 3 DAS domains. Overall, these data demonstrate that PBMC transcriptomes are informative of molecular disruptions in JDM and provide transcriptional evidence of chronic inflammation despite clinical quiescence.

Associations between cardiac and pulmonary involvement in patients with juvenile dermatomyositis—a cross-sectional study

This study aimed at exploring the association between detectable cardiac and pulmonary involvement in long-term juvenile dermatomyositis (JDM) and to assess if patients with cardiac and pulmonary involvement differ with regard to clinical characteristics. 57 JDM patients were examined mean 17.3 (10.5) years after disease onset; this included clinical examination, myositis specific/associated autoantibodies (immunoblot), echocardiography, pulmonary function tests and high-resolution computed tomography. Cardiac involvement was defined as diastolic and/or systolic left ventricular dysfunction and pulmonary involvement as low diffusing capacity for carbon monoxide, low total lung capacity and/or high-resolution computed tomography abnormalities. Patients were stratified into the following four groups: (i) no organ involvement, (ii) pulmonary only, (iii) cardiac only, and (iv) co-existing pulmonary and cardiac involvement. Mean age was 25.7 (12.4) years and 37% were males. One patient had coronary artery disease, seven had a history of pericarditis, seven had hypertension and three had known interstitial lung disease prior to follow-up. There was no association between cardiac (10/57;18%) and pulmonary (41/57;72%) involvement (p = 0.83). After stratifying by organ involvement, 21% of patients had no organ involvement; 61% had pulmonary involvement only; 7% had cardiac involvement only and 11% had co-existing pulmonary or cardiac involvement. Patients with co-existing pulmonary or cardiac involvement had higher disease burden than the remaining patients. Patients with either cardiac or pulmonary involvement only, differed in clinical and autoantibody characteristics. We found no increased risk of developing concomitant cardiac/pulmonary involvement in JDM. Our results shed light upon possible different underlying mechanisms behind pulmonary and cardiac involvement in JDM.

Clues to Disease Activity in Juvenile Dermatomyositis: Neopterin and Other Biomarkers

Easily accessible biomarkers are urgently needed to evaluate immune activation in Juvenile Dermatomyositis (JDM). The goal of this retrospective study is to define immunological and clinical differences between untreated JDM patients with either normal or elevated (>10 mmol/L) levels of neopterin, a biomarker of macrophage activation. We included all JDM with neopterin data obtained before initiating medical therapy. We assessed T, B, NK cell populations, muscle enzymes, and disease activity scores for skin (sDAS), muscle (mDAS), total (tDAS), the duration of untreated disease, disease course, and myositis-specific antibody (MSA). Seventy-nine percent of 139 untreated JDM patients had elevated serum neopterin. The group with elevated neopterin had significantly more active disease: tDAS 11.9 vs. 8.1 (p < 0.0001), mDAS 5.8 vs. 3.1 (p < 0.0001), sDAS 6.1 vs. 4.9 (p = 0.0002), aldolase 24.0 vs. 7.6 U/L (p < 0.0001), von Willebrand factor antigen (p < 0.0001), and ESR 19.8 vs. 11.5 mm/hr (p = 0.01). The flow cytometry documented both reduced T cells (1494 vs. 2278/mm3, p = 0.008) and NK cells (145 vs. 240/mm3, p = 0.003). TNFα-308AA/AG polymorphism was more common in children with elevated neopterin than TNFα-308GG (p 0.05). We conclude that the availability of neopterin data will contribute to the rapid assessment of untreated JDM disease activity.

An 8-year-old-girl with juvenile dermatomyositis and autoimmune thyroiditis in Tanzania: a case report

Background Juvenile dermatomyositis is an inflammatory disease of muscles, skin, and blood vessels of unknown cause affecting all age and ethnic groups, with a reported incidence of 1.9–4.1 per million. It manifests with weakness in axial and proximal muscles and typical skin lesions. Historically, the Bohan and Peter classification schema has been used to diagnose juvenile dermatomyositis. Case presentation We report an 8-year-old African female child, who presented with features of juvenile dermatomyositis and a rare association with subclinical autoimmune thyroiditis. This case illustrates the typical presentation, diagnosis, and treatment outcomes of this highly misdiagnosed condition. Conclusion Due to the limited resources and knowledge about this under-reported disease in resource-constrained settings, the characteristic manifestations of juvenile dermatomyositis can be easily missed and thus requires a high index of suspicion for earlier diagnosis and management.

Juvenile Dermatomyositis: Endothelschaden, Hyperkoagulabilität, Arterien steifigkeit

Die Pathogenese der juvenilen Dermatomyositis basiert im Wesentlichen auf einer Vaskulopathie, die insbesondere für schwere extramuskuläre Krankheitsmanifestationen prädisponiert. Wie gut lassen sich die vaskulopathischen Veränderungen nicht invasiv – durch Biomarker des Endothelschadens, der subklinischen Inflammation und der Hyperkoagulabilität sowie durch die Arteriensteifigkeit – abbilden? Dieser Frage ging ein britisches Forscherteam nach.

Challenges in Diagnosing COVID-19 Related Disease in Pediatric Patients With Rheumatic Disease

Objectives Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe condition associated with coronavirus disease 2019 (COVID-19). Here we aimed to raise awareness for the symptoms of MIS-C in patients with rheumatic diseases, emphasizing the challenges of the differential features. Methods We retrospectively evaluated the demographic and clinical characteristics, laboratory and imaging findings, treatments, and outcomes of six MIS-C patients with previous rheumatic disease. Results Three of the patients had familial Mediterranean fever (FMF), one had juvenile dermatomyositis (JDM), one had systemic juvenile idiopathic arthritis (JIA), and another patient had oligoarticular JIA. All FMF patients presented with fever and abdominal pain, two also had chest pain. The patient with systemic JIA presented with fever, rash, and myalgia. All patients had elevated inflammatory markers and high d-dimer levels. Chest imaging of two FMF patients showed infiltrations compatible with pneumonia. One FMF patient had mildly decreased systolic functions with a shortening fraction of 48% in his echocardiography. Intravenous immunoglobulin and methylprednisolone were administered to all patients. Anakinra was given to four patients. Conclusions Clinical and laboratory signs of MIS-C may overlap with the findings of various rheumatic diseases, and this may cause a delay in diagnosis.

Immunoglobulin-Induced Aseptic Meningitis in Juvenile Dermatomyositis: A Case Report

Background: Aseptic meningitis is a known but unusual serious adverse effect of intravenous immunoglobulin (IVIG). It usually resembles infectious meningitis which makes diagnosis challenging. Case presentation: We report a five-and-a-half-year-old Chinese girl with juvenile dermatomyositis presented with signs of meningismus 21 hours after the initiation of IVIG infusion. Her blood work at diagnosis showed neutrophilia and lymphopenia. The cerebrospinal fluid analysis demonstrated neutrophilic pleocytosis, hyperproteinorrachia and normoglycorrhachia. All microbiological tests were negative. The child recovered fully within 72hours without neurological sequelae.Conclusion: IVIG-induced aseptic meningitis remains a diagnosis of exclusion. Although it is rare, paediatricians should be aware of this complication and avoid unnecessary investigation or treatment.