Calcinosis Biomarkers in Adult and Juvenile Dermatomyositis

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

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Myofibrillar myopathies due to a novel mutation in exon 8 of the LDB3 gene

Myofibrillar myopathies (MFMs) are a group of genetically heterogeneous diseases affecting the skeletal and cardiac muscles. Myofibrillar myopathies are characterized by focal lysis of myogenic fibers and integration of degraded myogenic fiber products into inclusion bodies, which are typically rich in desmin and many other proteins. Herein, we report a case of a 54-year-old woman who experienced bilateral thigh weakness for over three years. She was diagnosed with MFMs based on muscle biopsy findings and the presence of a novel mutation in exon 8 of the LDB3 gene. Myofibrillar myopathies caused by a mutation in the LDB3 gene are extremely uncommon and often lack distinct clinical characteristics and typically exhibit a slow disease progression. When considering a diagnosis of MFMs, particularly in complex instances of autosomal dominant myopathies where muscle biopsies do not clearly indicate MFMs, it becomes crucial for clinicians to utilize genetic test as a diagnostic tool.

Autoimmune inflammatory myopathy biomarkers

The autoimmune inflammatory myopathy disease spectrum, commonly known as myositis, is a group of systemic diseases that mainly affect the muscles, skin and lungs. Biomarker assessment helps in understanding disease mechanisms, allowing for the implementation of precise strategies in the classification, diagnosis, and management of these diseases. This review examines the pathogenic mechanisms and highlights current data on blood and tissue biomarkers of autoimmune inflammatory myopathies.

Development of a computed tomography calcium scoring technique for assessing calcinosis distribution, pattern and burden in dermatomyositis

OBJECTIVES

To utilize whole-body CT imaging and calcium scoring techniques as tools for calcinosis assessment in a prospective cohort of patients with adult and juvenile dermatomyositis (DM and JDM, respectively).

METHODS

Thirty-one patients (14 DM and 17 JDM) who fulfilled Bohan and Peter Classification criteria as probable or definite DM, the EULAR-ACR criteria for definite DM, and with calcinosis identified by physical examination or prior imaging studies were included. Non-contrast whole-body CT scans were obtained using low-dose radiation procedures. Scans were read qualitatively and quantitated. We calculated the sensitivity and specificity of calcinosis detection of physician physical exam against CT. We quantified calcinosis burden using the Agatston scoring technique.

RESULTS

We identified five distinct calcinosis patterns: Clustered, Disjoint, Interfascial, Confluent and Fluid-filled. Novel locations of calcinosis were observed, including the cardiac tissue, pelvic and shoulder bursa, and the spermatic cord. Quantitative measures using Agatston scoring for calcinosis were used in regional distributions across the body. Physician physical exams had a sensitivity of 59% and a specificity of 90% compared with CT detection. A higher calcium score correlated with higher Physician Global Damage, Calcinosis Severity scores, and disease duration.

CONCLUSION

Whole-body CT scans and the Agatston scoring metric define distinct calcinosis patterns and provide novel insights relating to calcinosis in DM and JDM patients. Physicians' physical examinations underrepresented the presence of calcium. Calcium scoring of CT scans correlated with clinical measures, which suggests that this method may be used to assess calcinosis and follow its progression.

Local injection of infliximab into calcinosis lesions in patients with juvenile dermatomyositis (JDM): a clinical trial

BACKGROUND

Juvenile Dermatomyositis (JDM) is a rare autoimmune disorder that primarily affects muscles and skin. One of the severe complications associated with JDM is calcinosis, and treating this condition presents significant challenges. This study aimed to evaluate the efficacy and safety of local injection of infliximab into calcinosis lesions in patients with JDM.

METHODS

In this clinical trial, five patients diagnosed with JDM and calcinosis lesions were enrolled. The primary treatment consisted of weekly infliximab injections for 16 weeks, targeting all four sides of each lesion. Lesion dimensions, including length and width, were documented and monitored weekly. Before the intervention, patients underwent radiographic imaging. After the final injection in week 16, a follow-up radiographic assessment was performed. Data were analyzed using the Generalized Estimating Equation (GEE) method.

RESULTS

The lesions' size significantly decreased in both length and width during each visit. On average, the lesion length reduced by 2.66%, and the width shrank by 3.32% per visit. Based on radiographic findings, the average length and width of lesions at the initial visit were 12.09 ± 5.05 mm (range: 6.00-25.50 mm) and 6.35 ± 3.00 mm (range: 2.00-16.00 mm), respectively. The average length and width at the last visit were 5.59 ± 7.05 mm (range: 0-23.00 mm) and 3.41 ± 4.05 mm (range: 0-13.00 mm), respectively. No specific side effects related to the treatment were reported.

CONCLUSIONS

The results suggest that the direct administration of infliximab into the calcinosis lesions of patients with JDM could be a safe and effective treatment approach.

TRIAL REGISTRATION

Name of the registry: The effect of infliximab injection into calcinosis lesions on patients with juvenile dermatomyositis (JDM), Trial registration number: IRCT20210808052107N1, Registration date: 2022-07-22, URL of trial registry record: https://en.irct.ir/trial/58329 .

Risk factors for developing calcinosis in juvenile dermatomyositis: subcutaneous and myofascial edema in initial magnetic resonance imaging

Calcinosis is a sequela of Juvenile Dermatomyositis (JDM) with significant morbidity. A retrospective study observing risk factors for JDM calcinosis, including a possible association between higher intensity of subcutaneous and myofascial edema in initial magnetic resonance imaging (MRI) and development of calcinosis was performed at a tertiary pediatric medical center. Data from the past 20 years on JDM patients with MRIs at the time of JDM diagnosis were obtained. MRIs were individually evaluated by two pediatric musculoskeletal radiologists who blindly graded the intensity of edema on a 0-4 Likert scale. Clinical data and edema scores were compared between patients who developed calcinosis and who did not. Forty-three patients (14 with calcinosis and 29 without calcinosis) were identified. The calcinosis group contained more racial and ethnic minorities, younger ages of JDM onset and longer time to reach JDM diagnosis. Muscle enzyme levels at JDM diagnosis were lower in the calcinosis group, especially Creatinine Kinase (CK) (p = 0.047) and Alanine Aminotransferase (ALT) (p = 0.015). The median score for edema in both groups was 3 (p = 0.39) with an inter-rater reliability of 95%. There was no association between increased subcutaneous and myofascial edema in MRIs at the time of JDM diagnosis and development of calcinosis. Earlier age of JDM onset, racial and ethnic minority, and delay in JDM diagnosis could be risks for developing calcinosis. The calcinosis group presented with lower muscle enzyme levels at the time of JDM diagnosis, especially CK and ALT with statistical significance. This could reflect delay in diagnosis and treatment.

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.

Juvenile idiopathic inflammatory myositis: an update on pathophysiology and clinical care

The childhood-onset or juvenile idiopathic inflammatory myopathies (JIIMs) are a heterogenous group of rare and serious autoimmune diseases of children and young people that predominantly affect the muscles and skin but can also involve other organs, including the lungs, gut, joints, heart and central nervous system. Different myositis-specific autoantibodies have been identified that are associated with different muscle biopsy features, as well as with different clinical characteristics, prognoses and treatment responses. Thus, myositis-specific autoantibodies can be used to subset JIIMs into sub-phenotypes; some of these sub-phenotypes parallel disease seen in adults, whereas others are distinct from adult-onset idiopathic inflammatory myopathies. Although treatments and management have much improved over the past decade, evidence is still lacking for many of the current treatments and few validated prognostic biomarkers are available with which to predict response to treatment, comorbidities (such as calcinosis) or outcome. Emerging data on the pathogenesis of the JIIMs are leading to proposals for new trials and tools for monitoring disease.

Calcinosis Cutis and Calciphylaxis in Autoimmune Connective Tissue Diseases

Calcinosis represents a severe complication of several autoimmune disorders. Soft-tissue calcifications have been classified into five major types: dystrophic, metastatic, idiopathic, iatrogenic, and calciphylaxis. Autoimmune diseases are usually associated with dystrophic calcifications, including calcinosis cutis, occurring in damaged or devitalized tissues in the presence of normal serum levels of calcium and phosphate. In particular, calcinosis cutis has been described in dermatomyositis, polymyositis, juvenile dermatomyositis, systemic sclerosis, systemic lupus erythematosus, primary Sjögren's syndrome, overlap syndrome, mixed connective tissue disease, and rheumatoid arthritis. Calciphylaxis, a severe and life-threatening syndrome presenting with vascular calcifications and thrombosis, has also been associated with some autoimmune conditions. Due to the potentially disabling character of calcinosis cutis and calciphylaxis, physicians' awareness about the clinical presentation and management of these diseases should be increased to select the most appropriate treatment option and avoid long-term complications. In this review, we aim to analyze the clinical features of calcinosis cutis and calciphylaxis associated with autoimmune diseases, and the main treatment strategies evaluated up to now for treating this potentially disabling disease.

Approach to Systemic Sclerosis Patient Assessment

Systemic sclerosis (SSc) is a heterogeneous disease comprising of a wide spectrum of ages of onset, sex-based differences, ethnic variations, disease manifestations, differential serologic profiles, and variable response to therapy resulting in reduced health-related quality of life, disability, and survival. The ability to subset groups of patients with SSc can assist with refining the diagnosis, guide appropriate monitoring, inform aggressiveness of immunosuppression, and predict prognosis. The ability to subset patients with SSc has several important practical implications for patient care.

Dermatomyositis-associated Calcinosis Cutis on Digital Breast Tomosynthesis

Supplemental material is available for this article.

Regression of calcinosis cutis after inkless tattoo in a patient with dermatomyositis: therapeutic potential of microneedling

Calcinosis cutis is defined as abnormal deposition of calcium salts in the skin and subcutaneous tissues. Dystrophic calcification, the most common form of calcinosis cutis, is associated with autoimmune connective tissue diseases. This condition is associated with severe pain and can affect the patient's quality of life and lead to long-term disability. Treatment is often challenging, and there is a very limited evidence base for potential treatments of calcinosis cutis associated with systemic sclerosis and dermatomyositis. Inkless tattoo is very similar to microneedling, a minimally invasive procedure stimulating the wound-healing cascade contributing to elastin and collagen formation as well as neovascularization. This technique has not been reported as a potential therapeutic option for calcinosis cutis. Here, we present a patient with calcinosis cutis in the setting of dermatomyositis that responded dramatically to inkless tattoo application. Our results support the need for future studies of microneedling in patients with this disorder.

Updated Role of High-frequency Ultrasound in Assessing Dermatological Manifestations in Autoimmune Skin Diseases

Autoimmune skin diseases are a group of disorders that arise due to the dysregulated immune system attacking self-antigens, causing multiple tissue and organ lesions. With disease progression, the physical and psychological health of patients may be seriously damaged. High-frequency ultrasound is non-invasive, reproducible, and suitable for visualizing the fine structure of external organs. The usage of high-frequency ultrasound has increased in recent years in the auxiliary diagnosis and monitoring of various skin diseases; it serves as a promising tool for dermatological disease assessment. This review summarizes the characteristics of high-frequency ultrasound imaging in common autoimmune skin diseases, including systemic lupus erythematosus, scleroderma, psoriasis, dermatomyositis, and pemphigus/pemphigoid. The objective of this review is to provide new ideas and strategies for dermatologists to diagnose and track the prognosis of autoimmune skin diseases.

Clinical Heterogeneity of Patients With Antinuclear Matrix Protein 2 Antibody-Positive Myositis: A Retrospective Cohort Study in China

OBJECTIVE

Heterogeneity exists among patients with myositis who have antinuclear matrix protein 2 (anti-NXP2) antibodies, although they usually present with severe muscle weakness. This study aimed to investigate the differences in phenotypes and prognoses among adult patients with myositis who have anti-NXP2 antibodies.

METHODS

Adult patients with myositis who have anti-NXP2 antibodies were enrolled from January 2010 to December 2019. Their clinical features and laboratory data were recorded retrospectively. We followed up on their survival status until June 30, 2020. A hierarchical cluster analysis, Kaplan-Meier curves, and classification and regression trees were used to analyze the data.

RESULTS

A total of 70 adult patients with myositis who have anti-NXP2 antibodies were enrolled. All patients experienced muscle weakness. A total of 11 patients did not present with rashes during disease progression, and 43 patients developed dysphagia. In total, 21 patients had interstitial lung disease (ILD), whereas no patients had rapidly progressive ILD. Hierarchical cluster analysis identified 2 clusters. Patients in cluster 1 were younger at disease onset, had a higher incidence of subcutaneous calcification, and had a lower incidence of V sign and shawl sign. Patients in cluster 2 had a higher frequency of ILD, accompanied by lower levels of lymphocytes and higher levels of serum ferritin. Moreover, patients in cluster 2 had worse prognoses.

CONCLUSION

Patients with myositis who have anti-NXP2 antibodies may present with different phenotypes that are characterized by unique features and prognoses.

Calcinosis in dermatomyositis: Origins and possible therapeutic avenues

Calcinosis, insoluble calcium compounds deposited in skin and other tissues, is a crippling sequela of dermatomyositis. Prolonged disease associated with ongoing inflammation, ischemia, repetitive trauma, and certain autoantibodies are associated with calcinosis. Herein, we describe potential pathogenic mechanisms including the role of mitochondrial calcification. There are no widely effective treatments for calcinosis. We review available pharmacologic therapies for calcinosis including those targeting calcium and phosphorus metabolism; immunosuppressive/anti-inflammatory therapies; and vasodilators. Mounting evidence supports the use of various formulations of sodium thiosulfate in the treatment of calcinosis. Although the early institution of aggressive immunosuppression may prevent calcinosis in juvenile dermatomyositis, only limited data support improvement once it has developed. Minocycline can be useful particularly for lesions associated with surrounding inflammation. Powerful vasodilators, such as prostacyclin analogs, may have promise in the treatment of calcinosis, but further studies are necessary. Surgical removal of lesions when amenable is our treatment of choice.

Innate Immunity in Calcinosis Cutis

Calcinosis cutis is the deposition of calcium salts in the skin and subcutaneous tissue, manifesting as variably shaped papules, nodules, and plaques that can substantially impair quality of life. The pathophysiology of calcinosis cutis involves dysregulation of proinflammatory cytokines, leukocytes, and other components of the innate immune system. In some conditions associated with calcinosis cutis, elevated serum calcium, phosphate, and vitamin D may also perturb innate immunity. The mechanisms by which these lead to cutaneous and subcutaneous calcification likely parallel those seen in vascular calcification. The role of aberrant innate immunity is further supported by the association between various autoantibodies with calcinosis cutis, such as anti-MDA5, anti-NXP2, anti-centromere, and anti-topoisomerase I. Treatments for calcinosis cutis remain limited and largely experimental, although mechanistically many therapies appear to focus on dampening innate immune responses. Further research is needed to better understand the innate immune pathophysiology and establish treatment options based on randomized-controlled trials.

Management of calcinosis cutis in rheumatic diseases

Calcinosis (hydroxyapatite and calcium phosphate crystal deposition) within the extracellular matrix of the dermis and subcutaneous tissue is a frequent manifestation of adult and pediatric systemic autoimmune rheumatic diseases, specifically systemic sclerosis, dermatomyositis, mixed connective tissue disease and systemic lupus erythematosus. In this article, we review classification of calcinosis, highlight mechanisms that may contribute to the pathogenesis of calcinosis and summarize the evidence evaluating non-pharmacologic and pharmacologic interventions for the treatment of calcinosis.

[Recent research on tofacitinib in the treatment of pediatric rheumatic diseases]

Tofacitinib is a Janus kinase inhibitor and can block the Janus kinase-signal transducer and activator of transcription signal transduction pathway and reduce the production and release of a variety of cytokines. It has great potential in the treatment of various rheumatic diseases with a rapid onset of action and can reduce corticosteroid dependence and related adverse events. The therapeutic effect of tofacitinib in adult patients has been confirmed, and it has been increasingly used in pediatric patients in recent years. This article reviews the clinical application of tofacitinib in the treatment of pediatric autoimmune diseases.

S1P defects cause a new entity of cataract, alopecia, oral mucosal disorder, and psoriasis-like syndrome

In this report, we discovered a new entity named cataract, alopecia, oral mucosal disorder, and psoriasis‐like (CAOP) syndrome in two unrelated and ethnically diverse patients. Furthermore, patient 1 failed to respond to regular treatment. We found that CAOP syndrome was caused by an autosomal recessive defect in the mitochondrial membrane‐bound transcription factor peptidase/site‐1 protease (MBTPS1, S1P). Mitochondrial abnormalities were observed in patient 1 with CAOP syndrome. Furthermore, we found that S1P is a novel mitochondrial protein that forms a trimeric complex with ETFA/ETFB. S1P enhances ETFA/ETFB flavination and maintains its stability. Patient S1P variants destabilize ETFA/ETFB, impair mitochondrial respiration, decrease fatty acid β‐oxidation activity, and shift mitochondrial oxidative phosphorylation (OXPHOS) to glycolysis. Mitochondrial dysfunction and inflammatory lesions in patient 1 were significantly ameliorated by riboflavin supplementation, which restored the stability of ETFA/ETFB. Our study discovered that mutations in MBTPS1 resulted in a new entity of CAOP syndrome and elucidated the mechanism of the mutations in the new disease.

Subcutaneous calcinosis: Is it different between systemic sclerosis and dermatomyositis?

Calcinosis cutis is the deposition of insoluble calcium in the skin and subcutaneous tissues. It is a manifestation of several autoimmune connective tissue diseases, most frequently with systemic sclerosis and juvenile dermatomyositis, followed by adult dermatomyositis. Autoimmune connective tissue disease-associated calcinosis is of the dystrophic subtype, which occurs at sites of damaged tissue in the setting of normal serum calcium and phosphate levels. In juvenile dermatomyositis, calcinosis is considered a marker of ongoing disease activity and possibly inadequate treatment, while in adult dermatomyositis, it is a hallmark of skin damage due to chronic rather than active disease. Calcinosis is associated with long disease duration in systemic sclerosis and dermatomyositis, anti-polymyositis/sclerosis autoantibodies in systemic sclerosis and NXP-2 and melanoma differentiation-associated gene 5 in dermatomyositis. Calcinosis in systemic sclerosis occurs most frequently in the hands, particularly the fingers, whereas in dermatomyositis, it affects mainly the trunk and extremities. The primary mineral component of calcinosis is hydroxyapatite in systemic sclerosis and carbonate apatite in dermatomyositis. Calcinosis in dermatomyositis and systemic sclerosis share some pathogenic mechanisms, but vascular hypoxia seems to play a more important role in systemic sclerosis, whereas the release of calcium from mitochondria in muscle cells damaged by myopathy may be a primary mechanism contributing to dermatomyositis-related calcinosis. Multiple treatment strategies for dermatomyositis and systemic sclerosis-related calcinosis have been used with variable results. Early aggressive treatment of underlying myositis in patients with dermatomyositis may improve long-term outcomes of calcinosis. A better understanding of the pathogenesis of calcinosis is needed to improve treatment options.

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.

Assessment of Treatment Response by Bone SPECT-CT in a Case of Dermatomyositis with Calcinosis Cutis

Calcinosis of soft tissue is a rare but known complication of dermatomyositis (DM), mostly associated with juvenile DM and rare in adult DM. Bone scan with Tc-99m Methylene diphosphonate is useful in disease mapping and has high sensitivity to know the extent of calcinosis. However, there is scanty literature available on the utility of bone scan in treatment response evaluation in DM. Rituximab has been found useful in adult DM with calcinosis unresponsive to conventional treatment. We describe an interesting case showing partial response to rituximab on bone scan with single-photon emission tomography-computed tomography.

Idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune disorders with varying clinical manifestations, treatment responses and prognoses. Muscle weakness is usually the classical clinical manifestation but other organs can be affected, including the skin, joints, lungs, heart and gastrointestinal tract, and they can even result in the predominant manifestations, supporting that these are systemic inflammatory disorders. Different myositis-specific autoantibodies have been identified and, on the basis of clinical, histopathological and serological features, IIMs can be classified into several subgroups — dermatomyositis (including amyopathic dermatomyositis), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis and overlap myositis. The prognoses, treatment responses and organ manifestations vary among these groups, implicating different pathophysiological mechanisms in each subtype. A deeper understanding of the molecular pathways underlying the pathogenesis and identifying the autoantigens of the immune reactions in these subgroups is crucial to improve outcomes. New, more homogeneous subgroups defined by autoantibodies may help define disease mechanisms, and will also be important in future clinical trials to develop targeted therapies and in identifying biomarkers to guide treatment decisions for the individual patient.

Idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM), also known as myositis, are a heterogeneous group of autoimmune disorders with varying clinical manifestations, treatment responses and prognoses. Muscle weakness is usually the classical clinical manifestation but other organs can be affected, including the skin, joints, lungs, heart and gastrointestinal tract, and they can even result in the predominant manifestations, supporting that IIM are systemic inflammatory disorders. Different myositis-specific auto-antibodies have been identified and, on the basis of clinical, histopathological and serological features, IIM can be classified into several subgroups - dermatomyositis (including amyopathic dermatomyositis), antisynthetase syndrome, immune-mediated necrotizing myopathy, inclusion body myositis, polymyositis and overlap myositis. The prognoses, treatment responses and organ manifestations vary among these groups, implicating different pathophysiological mechanisms in each subtype. A deeper understanding of the molecular pathways underlying the pathogenesis and identifying the auto-antigens of the immune reactions in these subgroups is crucial to improving outcomes. New, more homogeneous subgroups defined by auto-antibodies may help define disease mechanisms and will also be important in future clinical trials for the development of targeted therapies and in identifying biomarkers to guide treatment decisions for the individual patient.

Inflammatory myopathies in childhood

Myositis in childhood can occur under different conditions and with various aetiologies, juvenile dermatomyositis (jDM) being by far the most frequent entity. The exact diagnostic workup and precise assessment of muscular as well as extramuscular involvement of organs in these systemic autoimmune diseases are relevant for specific and adjunct treatment of complications. Many new insights have become available with respect to the pathophysiological concepts as well as modern diagnostic measures and therapeutic approaches. Autoantibody detection in the serum of children with myositis is one of the major novelties that has become widely used and that is indeed helpful for diagnostic and prognostic measures. The pathophysiological relevance of type I interferons in jDM has been studied intensively in the past years. jDM is now seen as an acquired interferonopathy and first therapeutic consequences have been drawn from this pathogenic finding with the use of Janus-kinase inhibitors for severe and not otherwise treatable children.

The chameleon rash: a review of the polyphenotypic dermatoses of dermatomyositis

Dermatomyositis (DM) is an autoimmune connective tissue disease that is included in the idiopathic inflammatory myopathies. Cutaneous manifestations are a prominent part of the condition: some skin signs in DM are common to most patients, while other signs are encountered infrequently. A number of features are pathognomic for DM. The demonstration of myositis-specific antibodies (MSAs) in DM has extended the ability to define phenotypic subgroups. It appears that the presence of certain MSAs confers susceptibility to specific clinical features, an association which reveals a serotype-phenotype relationship. In this review article we have provided a detailed summary of common and under-recognized cutaneous manifestations of DM.

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.

Juvenile Dermatomyositis: New Clues to Diagnosis and Therapy

PURPOSE OF REVIEW

To identify clues to disease activity and discuss therapy options.

RECENT FINDINGS

The diagnostic evaluation includes documenting symmetrical proximal muscle damage by exam and MRI, as well as elevated muscle enzymes-aldolase, creatine phosphokinase, LDH, and SGOT-which often normalize with a longer duration of untreated disease. Ultrasound identifies persistent, occult muscle inflammation. The myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA) are associated with specific disease course variations. Anti-NXP-2 is found in younger children and is associated with calcinosis; anti-TIF-1γ+ juvenile dermatomyositis has a longer disease course. The diagnostic rash-involving the eyelids, hands, knees, face, and upper chest-is the most persistent symptom and is associated with microvascular compromise, reflected by loss of nailfold (periungual) end row capillaries. This loss is associated with decreased bioavailability of oral prednisone; the bioavailability of other orally administered medications should also be considered. At diagnosis, at least 3 days of intravenous methyl prednisolone may help control the HLA-restricted and type 1/2 interferon-driven inflammatory process. The requirement for avoidance of ultraviolet light exposure mandates vitamin D supplementation.

SUMMARY

This often chronic illness targets the cardiovascular system; mortality has decreased from 30 to 1-2% with corticosteroids. New serological biomarkers indicate occult inflammation: ↑CXCL-10 predicts a longer disease course. Some biologic therapies appear promising.

Covert clues: the non-hallmark cutaneous manifestations of dermatomyositis

Dermatomyositis (DM) is a strikingly heterogenous disease characterized by a broad and ever-evolving spectrum of cutaneous manifestations that transcend the classic “hallmarks” defined by Peter and Bohan in 1975. Despite the increasing preponderance and ubiquity of autoantibody, radiologic, and electrophysiologic testing, the diagnosis of DM still hinges largely on prompt detection of cutaneous manifestations of this condition. While pathognomonic cutaneous features of DM are more readily recognizable, many patients present with subtle and/or atypical skin manifestations, and diagnosis of DM may require clinician identification of these cutaneous clues. In this review, we highlight several of the lesser-known skin manifestations of DM, specifically, panniculitis, diffuse subcutaneous edema, erythroderma, calcinosis, ulceration, flagellate erythema, Wong-type DM, gingival telangiectasias, and the ovoid palatal patch. We describe the clinical and histopathologic presentation of these cutaneous findings. While manifesting less frequently than the heliotrope rash, Gottron’s papules, and Gottron’s sign, these cutaneous clues are equally important for clinicians to recognize in order to facilitate timely diagnosis and early intervention.

Treatment of Calcinosis in Juvenile Dermatomyositis

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Is Anti-NXP2 Autoantibody a Risk Factor for Calcinosis and Poor Outcome in Juvenile Dermatomyositis Patients? Case Series

Juvenile dermatomyositis (JDM) has a wide spectrum of clinical presentations. In the last decade, several myositis-specific antibodies have been identified in patients with JDM and connected with specific organ involvement or specific clinical picture. It has been published that the presence of anti-NXP2 autoantibodies presents a risk for calcinosis in patients with JDM. We aimed to investigate the prevalence of calcinosis and response to the treatment in JDM patients with anti-NXP2. In a retrospective, multinational, multicenter study, data on 26 JDM (19 F, 7 M) patients with positive anti-NXP2 were collected. The mean age at disease presentation was 6.5 years (SD 3.7), the median diagnosis delay was 4 months (range 0.5-27 months). Patients were divided into two groups (A and B) based on the presence of calcinosis, which occurred in 42% of anti-NXP2 positive JDM patients (group A). Four patients already had calcinosis at presentation, one developed calcinosis after 4 months, and 6 developed calcinosis later in the disease course (median 2 years, range 0.8-7.8). The differences in laboratory results were not statistically significant between the groups. The mean age at disease presentation (5.2/7.5 years) trended toward being younger in group A. Children with calcinosis were treated with several combinations of drugs. In four cases, rituximab and, in one case, anti-TNF alpha agents were used successfully. Disease outcome (by evaluation of the treating physician) was excellent in four, good in two, stable in two, and poor in three patients. None of the patients from group B had a poor disease outcome. In conclusion, JDM patients with anti-NXP2 are prone to develop calcinosis, especially if they present with the disease early, before 5 years of age. The development of calcinosis is associated with worse disease outcomes. The combination of several immunomodulatory drugs and biologic drugs can stop calcinosis progression; however, there are no evidence-based therapies for treating calcinosis in JDM patients.

Juvenile Dermatomyositis: Advances in Pathogenesis, Assessment, and Management

BACKGROUND

Juvenile dermatomyositis is the most common inflammatory myopathy in the pediatric age group and a major cause of mortality and morbidity in individuals with childhood rheumatic diseases. Mounting evidence suggests that early diagnosis and timely aggressive treatment are associated with better outcomes.

OBJECTIVE

The purpose of this article is to provide readers with an update on the evaluation, diagnosis, and the treatment of juvenile dermatomyositis.

METHODS

A PubMed search was performed in Clinical Queries using the key term "juvenile dermatomyositis" in the search engine. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Juvenile dermatomyositis is a chronic autoimmune inflammatory condition characterized by systemic capillary vasculopathy that primarily affects the skin and muscles with possible involvement of other organs. In 2017, the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) developed diagnostic criteria for juvenile idiopathic inflammatory myopathies and juvenile dermatomyositis. In the absence of muscle biopsies which are infrequently performed in children, scores (in brackets) are assigned to four variables related to muscle weakness, three variables related to skin manifestations, one variable related to other clinical manifestations, and two variables related to laboratory measurements to discriminate idiopathic inflammatory myopathies from non-idiopathic inflammatory myopathies as follows: objective symmetric weakness, usually progressive, of the proximal upper extremities (0.7); objective symmetric weakness, usually progressive, of the proximal lower extremities (0.8); neck flexors relatively weaker than neck extensors (1.9); leg proximal muscles relatively weaker than distal muscles (0.9); heliotrope rash (3.1); Gottron papules (2.1); Gottron sign (3.3); dysphagia or esophageal dysmotility (0.7); the presence of anti-Jo-1 autoantibody (3.9); and elevated serum levels of muscle enzymes (1.3). In the absence of muscle biopsy, a definite diagnosis of idiopathic inflammatory myopathy can be made if the total score is ≥7.5. Patients whose age at onset of symptoms is less than 18 years and who meet the above criteria for idiopathic inflammatory myopathy and have a heliotrope rash, Gottron papules or Gottron sign are deemed to have juvenile dermatomyositis. The mainstay of therapy at the time of diagnosis is a high-dose corticosteroid (oral or intravenous) in combination with methotrexate.

CONCLUSION

For mild to moderate active muscle disease, early aggressive treatment with high-dose oral prednisone alone or in combination with methotrexate is the cornerstone of management. Pulse intravenous methylprednisolone is often preferred to oral prednisone in more severely affected patients, patients who respond poorly to oral prednisone, and those with gastrointestinal vasculopathy. Other steroid-sparing immunosuppressive agents such as cyclosporine and cyclophosphamide are reserved for patients with contraindications or intolerance to methotrexate and for refractory cases, as the use of these agents is associated with more adverse events. Various biological agents have been used in the treatment of juvenile dermatomyositis. Data on their efficacy are limited, and their use in the treatment of juvenile dermatomyositis is considered investigational.

Clinical features, muscle biopsy scores, myositis specific antibody profiles and outcome in juvenile dermatomyositis

INTRODUCTION

Juvenile dermatomyositis (JDM) is the most common inflammatory myopathy of childhood.

OBJECTIVE

To analyze clinical features, paraclinical examinations, MSAs, treatment response and long-term outcome in a JDM cohort METHODS: 58 patients (35F, 23 M) from a tertiary referral center in the last two decades are included.

RESULTS

Mean age at onset was 8.1 ± 4.3, with a mean follow-up period of 5.66±3.59 years. Dermatological manifestations (91%) and muscle weakness (76%) were the key diagnostic elements. Elevated serum creatine kinase levels (86%), electromyography (23/25), muscle MRI (12/15), and muscle biopsy (n = 35) were compatible with the diagnosis. Out of 46 patients tested, 34 (76%) had autoantibodies, with NXP2 (21.7%), followed by TIF1g (17.4%), MDA5 (8.7%), and Mi-2 (8.7%). Presence of TIF1g and NXP2 indicated a severe course; and Ku a much severe course compared to previous studies. Corticosteroids (100%) combined with methotrexate (93%) was the initial treatment. Biological disease modifying anti-rheumatic drugs (DMARDs) were used in 22% of the cohort. Calcinosis (36%) was the most common long-term complication, associated with disease onset ≤6 years, higher muscle biopsy scores and MDA5 positivity. Complete remission was achieved in 65.5% of the patients in a median 24 (IQR 11.8-42.5) months with a relapse rate of 26.3%. 43.9% of NXP2 and 33.3% of TIF-1 g positive patients had a relapse. Course was monophasic (31%), polyphasic (17.2%), chronic (51.8%) without mortality.

CONCLUSION

Integration of clinical features with laboratory and biopsy findings may help to predict prognosis and guide treatment in JDM. In our cohort calcinosis was associated with age, MDA5 autoantibodies, and muscle biopsy scores.

Monitoring disease activity and damage in adult and juvenile idiopathic inflammatory myopathy

PURPOSE OF REVIEW

We have reviewed the literature to identify significant advances related to disease activity and damage in the idiopathic inflammatory myopathies (IIMs) from January 2019 to July 2020.

RECENT FINDINGS

New observations in the field from 2019 to 2020 have resulted in a better understanding of the clinical association and pathogenic origins of IIM. The use of patient-reported outcome measures and perspectives, identifying biomarkers and making better use of autoantibody testing are summarized. Basic sciences have led to an improved understanding of the role of NETosis in calcinosis, and of interferon type 1, in IIM. Preliminary insights are offered into Covid-19 in the setting of IIM, and the use of potential tools for monitoring disease remotely, which may assume larger importance for optimal disease management during a global pandemic. The wider exploration of newer imaging modalities and the use of nailfold capillaroscopy is a further step in better management of the condition.

SUMMARY

The summarized research in IIM is a step forward in being able to further define, and to distinguish disease activity from damage, in order to potentially aid future clinical diagnosis and management in this challenging disease.