Abatacept and sodium thiosulfate for treatment of recalcitrant juvenile dermatomyositis complicated by ulceration and calcinosis

A comprehensive review of dermatomyositis treatments - from rediscovered classics to promising horizons

INTRODUCTION

Dermatomyositis (DM) is a rare inflammatory disease with diverse cutaneous and systemic manifestations, often associated with myositis-specific antibodies. Managing patients with refractory DM, or individuals presenting pecific complications, like calcinosis or rapidly progressive interstitial lung disease, presents unique challenges.

AREAS COVERED

This review explores current and promising treatment options for DM, drawing from clinical studies, case series, and case reports that consider the underlying disease pathophysiology.

EXPERT OPINION

Recent advancements have improved our understanding and management of DM. The discovery of distinct DM autoantibodies and their correlation with specific clinical phenotypes has transformed patient categorization and enhanced our knowledge of the pathogenesis of the disease. Intravenous immunoglobulin, a well-established treatment in dermatomyositis, has regained prominence and a large randomized clinical trial has reaffirmed its efficacy, confirming it as an effective therapeutic option in this group of patients. Identification of the type I interferon pathway as a key pathogenic mechanism in DM has opened up new avenues for more effective treatment strategies. Blocking the JAK/STAT pathway offers potential for improved management of refractory patients and prevention of highly morbid complications. These recent advancements have significantly impacted the management and care of dermatomyositis patients, enabling tailored approaches, targeted interventions, and improved outcomes for individuals affected by this complex condition.

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.

Biologic drugs in the treatment of juvenile dermatomyositis: a literature review

There is no clear consensus in the literature regarding the choice of biologic therapies and efficacy in juvenile dermatomyositis (JDM). In this review, we aimed to examine previous studies regarding biologic drug use in JDM patients. We screened MEDLINE and Scopus for articles involving JDM patients treated with biologic drugs. We identified 74 articles describing 495 JDM patients treated with biologic drugs (538 biologic treatments) during our literature search. The median (min-max) age of these patients was 9.8 (1-17) years (F/M:1.8). The most frequently used biologic drugs were rituximab (RTX, 50%) and tumor necrosis factor (TNF) inhibitors (34.8%). In a few cases, abatacept (4.3%), anti-interleukin-1 agents (0.9%), tocilizumab (0.9%), bortezomib (0.4%), ustekinumab (0.2%), eculizumab (0.2%), and golimumab (0.2%) were used. RTX was most frequently preferred in patients with severe skin involvement (46.3%). Improvement with RTX was obtained in 60.1% of RTX treatments. Infliximab was most frequently preferred in calcinosis (43.3%), while adalimumab in skin involvement (50%) and etanercept in resistant/recurrent diseases (80%). Improvement was achieved in 44.4% of anti-TNF treatments. Adverse events were observed in 46.8% (58/124) of all treatments. Our results suggest that biologic agents may be a promising alternative for the treatment of particularly resistant JDM cases. Controlled studies are required to provide higher level of evidence for the timing of biologic use in JDM treatment. Key Points • There is no consensus on the choice and efficacy of biologic therapies in JDM. • RTX and TNF inhibitors are the most commonly used biologic drugs. • Biologics were especially preferred in severe skin involvement, calcinosis, and resistant diseases.

Systemic Sodium Thiosulfate as an Adjunct Treatment in Calcinosis: A Retrospective Study

(1) Background: Calcinosis of the skin mainly appears in connective tissue disorders (dystrophic subtype). It may cause inflammation, ulceration, pain, and restricted joint mobility. Management is difficult; sodium thiosulfate is one potential therapeutic agent with promising data on intralesional and topical formulation for smaller calcified lesions. There are very limited data on systemic administration. (2) Methods: A retrospective study was conducted at our department to assess the efficacy of oral and intravenous sodium thiosulfate in dystrophic calcinosis between 2003 and 2023. (3) Results: Seven patients were identified, who received systemic sodium thiosulfate (intravenous or oral). The mean duration of calcinosis at the time of administration was 3.8 ± 4 years (range 0-11). Intravenous sodium thiosulfate was administered in doses of 12.5-25 g two or three times during one week of the month for 4.5 ± 3.9 months on average. Orally, 1-8 g was administered daily for 29.1 ± 40.9 months on average. Four of seven patients had a partial response (57.1%). Despite no complete response, pain, ulceration and inflammation frequency decreased, and sodium thiosulfate prevented further progression in responsive patients. (4) Conclusions: Based on our experience and literature data, systemic sodium thiosulfate may be a potential adjunct therapy in calcinosis, especially if inflamed or ulcerating.

Effectiveness of topical sodium thiosulfate for ectopic calcifications and ossifications. Results of the CATSS-O study

INTRODUCTION

Ectopic calcifications (ECs) and heterotopic ossifications (HOs) form in non-mineralized tissues, most often in subcutaneous and muscular areas. Local and systemic complications can cause severe disability. Systemic administration of sodium thiosulfate (STS) gives promising results but is difficult to use in clinical practice.

OBJECTIVE

Evaluation of the efficacy and safety of topical STS in ECs and HOs.

METHODS

Retrospective analysis of the CATSS-O registry that included patients receiving topical STS 25 % prepared by the pharmacy of Limoges hospital during 2014-2020. The efficacy of STS was assessed by imaging (radiography or CT) after at least 6 months' treatment.

RESULTS

Among 126 patients who received STS 25 %, 35 had complete clinical and radiographic data for analysis (28 with ECs and 7 with HOs; 18 children [mean age 8.9 years, range 1.5-16], 17 adults [mean age 52.4 years, range 24-90]). Calcifications or ossifications were due to dermatomyositis (8 children, 6 adults), systemic scleroderma (6 adults) or pseudo-hypoparathyroidism 1A (7 children). They were single (37.1 %) or multiple (62.9 %). Treated regions were in the lower limbs (31.4 %), upper limbs (37.1 %) or both (28.6 %) and the axial region (2.9 %). Topical STS was clinically effective in 9/28 (32.1 %) patients with ECs and 2/7 (28.6 %) children with HOs. Three patients experienced complete disappearance of their calcifications. Response for ECs was better in children than adults (54.5% vs 17.6 %, p = 0.035). Topical STS was well tolerated.

CONCLUSION

Local STS seems effective for ossifications, particularly pediatric calcifications or ossifications. Randomized and experimental studies are needed to confirm this observation and to identify the underlying mechanisms.

Improvement in Disease Activity in Refractory Juvenile Dermatomyositis Following Abatacept Therapy

OBJECTIVE

This open-label, 24-week study was conducted to evaluate the safety and efficacy of abatacept in patients with refractory juvenile dermatomyositis (DM).

METHODS

Ten patients ≥7 years of age with moderate disease activity were enrolled in a 24-week study to examine the safety of subcutaneous abatacept and patient responses to the treatment. The primary endpoint was the International Myositis Assessment and Clinical Studies (IMACS) group Definition Of Improvement (DOI). Secondary endpoints included safety, changes in the core set activity measures (CSMs) of the IMACS group and the Pediatric Rheumatology International Trials Organization, and improvements in disease activity based on the American College of Rheumatology (ACR)/EULAR response criteria for juvenile DM. Radiologists blinded with regard to participant data assessed magnetic resonance images (MRIs) of patient thigh muscles. Interferon (IFN)-regulated gene score was performed on whole-blood RNA samples using a NanoString assay, and cytokines were assessed using a Luminex assay.

RESULTS

Five patients achieved DOI at week 12, and 9 patients achieved DOI at week 24, including 2 patients with minimal, 4 patients with moderate, and 3 patients with major improvement by the 2016 ACR/EULAR response criteria for juvenile DM when patients were assessed using the CSMs of the IMACS Group. Improvements from baseline were seen in all CSMs at weeks 12 and 24, except in muscle enzymes. Daily glucocorticoid doses decreased from a mean of 16.7 mg at baseline to 10.2 mg at week 24 (P = 0.002). Average MRI muscle edema scores decreased from a mean baseline score of 5.3 to 2.3 at week 24 (P = 0.01). Six patients had down-trending IFN-regulated gene scores and galectin-9 expression at week 24. Decreases in IFN-regulated gene scores and in levels of interferon-γ-inducible protein 10kDa, galectin-9, and interleukin-2 correlated with improvements in disease activity and in muscle edema shown on MRI. Eleven grade 2 or 3 treatment-emergent adverse events were observed.

CONCLUSION

This open-label study demonstrated that abatacept may be beneficial for patients with treatment-refractory juvenile DM.

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.

The role of bDMARDs in idiopathic inflammatory myopathies: A systematic literature review

Idiopathic inflammatory myopathies (IIM) are a group of different conditions typically affecting striate muscle, lung, joints, skin and gastrointestinal tract. Treatment typically relies on glucocorticoids and synthetic immunosuppressants, but the occurrence of refractory, difficult to treat, manifestations, may require more aggressive treatment, borrowed from other autoimmune diseases, including biologic disease modifying drugs (bDMARDs). In this regard, we conducted a systemic literature review in order to depict the current evidence about the use of bDMARDs in IIM. A total of 78 papers, published during the last 21 years, were retrieved. The majority of patients was treated with TNF-α inhibitors, whose effectiveness was assessed particularly in recalcitrant striate muscle, skin and joints involvement. Rituximab, whose evidence is supported by a large number of real-life studies and trials, seems to be an excellent option in case of ILD and anti-synthetase syndrome, while Tocilizumab, despite not meeting primary and secondary endpoints in a recently published clinical trial, proved its effectiveness in rapidly progressing ILD. Similarly, Abatacept, studied in a phase IIb clinical trial with conflicting evidence, was reported to be effective in some case reports of refractory dermatomyositis. Less data exist for anti-IL1 and anti-IL23 agents, which were employed particularly for inclusion body myositis and severe skin disease, respectively. This study provides an organ-focused assessment of bDMARDs in IIM, which display encouraging results in the treatment of refractory subsets of disease.

Past, Present, and Future in Dermatomyositis Therapeutics

Purpose of review

This review highlights current and emerging pharmacologic therapies for the treatment of dermatomyositis (DM). Current clinical evidence, in addition to recently published and ongoing clinical trials for various drugs in development, are summarized in this review.

Recent findings

There has been significant progress in the research and development of potential treatments in DM. The FDA recently approved Octagam® 10% Immune Globulin Intravenous (IVIg) for the treatment of DM. Several drug targets are being explored as viable therapeutic options in phase 2 and phase 3 clinical trials; at the forefront of these are JAK inhibitors (tofacitinib and baricitinib) and T-cell co-stimulation blockers (i.e. abatacept). In addition, clinical trials are currently under way for therapeutics targeting novel molecular pathways, including immunoproteasome inhibitors, anti-B cell therapy, anti-interferon drugs, complement inhibitors, and phosphodiesterase-4 inhibitors.

Summary

With the large number of clinical trials, multiple novel therapeutics in development, and improved classification and outcome measures, the treatment landscape for DM will continue to rapidly evolve in the coming years as more options become available.

Possible future avenues for myositis therapeutics: DM, IMNM and IBM

Idiopathic inflammatory myopathies (IIMs) represent a heterogeneous group of systemic autoimmune diseases characterized by immune-mediated muscle injury. As insights into pathogenesis of IIM evolve, novel therapeutic strategies have become available to optimize outcomes. Herein, we summarize novel and emerging strategies in the management of dermatomyositis (DM), immunemediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM).

Current and new targets for treating myositis

As treatment of refractory idiopathic inflammatory myopathies (IIM) has been challenging, there is growing interest in assessing new therapies that target various pathways implicated in the pathogenesis of IIM. In the largest clinical trial to date, rituximab was studied in adult and juvenile myositis, but the primary outcome was not met despite 83 percent of subjects with refractory myositis meeting the definition of improvement. The U.S. Food and Drug Administration (FDA) has recently granted approval to Octagam 10% immune globulin intravenous (IVIg), for the treatment of adult dermatomyositis based on impressive results from a double-blind placebo-controlled trial. Anti-tumor necrosis factor (anti-TNF) utility in IIM is not recommended and recent reports suggest this therapy may induce systemic autoimmune disease including myositis. Further, anti-IL6 therapy cannot be recommended as a recent trial of tocilizumab failed to reach its primary endpoint. Further studies are needed to assess the role of newer therapies such as abatacept (inhibition of T cell co-stimulation), sifalimumab (anti-IFNα), Janus kinase [JAK] inhibitors, apremilast (phosphodiesterase 4 inhibitor), and KZR-616 (selective inhibitor of the immunoproteasome) given their biological plausibility and encouraging recent small-case series results. The future of IIM therapy will depend on exploring biomarkers implicated in the etiopathogenesis of IIM, improvements in myositis classification based on serological and histopathological features, and well-designed controlled clinical trials using validated consensus outcome measures.

Emerging Therapeutics in the Management of Connective Tissue Disease. Part II. Dermatomyositis and Scleroderma

The management of connective tissue diseases is dramatically evolving with the advent of biologics and novel oral systemic therapeutics. Despite involvement in the care of these complex patients, there is a knowledge gap in the field of dermatology regarding these emerging agents. The second article in this continuing medical education series discusses new and emerging therapeutics for dermatomyositis and scleroderma that target cells, intracellular signaling pathways, and cytokines.

Therapieoptionen und outcome bei idiopathischen entzündlichen Muskelerkrankungen

Die idiopathischen entzündlichen Muskelerkrankungen (IIM) sind eine sehr heterogene Gruppe, die sich immer besser differenzieren lässt. Damit eröffnen sich mehr Möglichkeiten für gezieltere Therapien, die zum einen auf die Veränderung pathogenetischer Faktoren gerichtet sind. Zum anderen sollen sie Krankheitsaktivität vermindern, Muskelaufbau fördern, Organschäden verhindern und Lebensqualität verbessern.

Die folgende Übersichtsarbeit fasst die vorhandenen Daten zu bereits angewandten Behandlungen in der Praxis zusammen und gibt einen Ausblick auf zukünftige Alternativen.

Für die Polymyositis (PM) und Dermatomyositis (DM) sind Glukokortikoide weiter unverzichtbarer Therapiebestandteil. Eine frühe Kombination mit konventionellen DMARDs hat sich durchgesetzt. Die ProDerm- Studie stellt für die Immunglobulintherapie in der Praxis eine gute Basis dar. Rituximab (RTX) löst Cyclophosphamid (CYC) bei schweren Verlaufsformen immer mehr ab.

Für Abatacept, Jak-Kinase-Hemmer, Apremilast, Sifalimumab und Lenabasum müssen vielversprechende erste Ergebnisse durch weiter Studien untermauert werden. Anspruchsvoll ist die Behandlung bei extramuskulärer Beteiligung. Von großem Interesse ist der zukünftige Stellenwert von Nintedanib bei der interstitiellen Lungenerkrankung im Rahmen einer Myositis (IIM-ILD).

Die Therapie der Einschlusskörperchen- Myositis (IBM) ist immer noch eine große Herausforderung. Zahlreiche Studien haben bisher nicht überzeugend zu einer Besserung der Prognose führen können. Spätestens bei therapierefraktärem Verlauf sollte an eine Malignom- assoziierte Myositis gedacht werden. Gelegentlich verbirgt sich auch eine hereditäre Myopathie hinter einer, zum Beispiel durch einen Infekt oder Überlastung getriggerten, Myositis.

Komplikationen im Verlauf, wie Dysphagie, Infektionen, Myokardbeteiligung stellen keine Seltenheit dar. Häufig besteht Multimorbidität. Eine interdisziplinäre Zusammenarbeit in einem kompetenten Team, in dem erfahrene Physio-, Ergo- und Psychotherapeuten fester Bestandteil sind, ist unabdingbar für eine erfolgreiche Begleitung dieser Patienten.

Expert Perspective: Management of Refractory Inflammatory Myopathy

The idiopathic inflammatory myopathies (IIMs) are chronic disorders characterized by inflammation in skeletal muscle but also in other organs such as the skin, lungs, joints, gastrointestinal tract, and heart. The effect of immunosuppressive treatment varies between individual patients and between organ manifestations within the same individual. Many patients respond poorly to first-line treatment with glucocorticoids and other immunosuppressive agents such as methotrexate or azathioprine, with symptoms persisting in the muscles, skin, and lungs, leading to refractory disease. Management of refractory IIM is a clinical challenge, and a systematic approach is proposed to better understand the lack of treatment response, in order to guide disease management. The first step in the management of refractory IIM is to recognize whether remaining symptoms are caused by persistent inflammation in the affected tissue or whether the symptoms may be attributable to damage preceding inflammation. Thus, a second diagnostic examination is recommended. Second, in particular for patients with remaining muscle weakness, it is important to ascertain whether the diagnosis of myositis is correct or whether another underlying muscle disorder could explain the symptoms. Third, with confirmation of remaining inflammation in the tissues, a strategy to change treatment needs to be undertaken. Few controlled trials are available to guide our treatment strategies. Furthermore, different subgroups of patients may benefit from different therapies, and different organ manifestations may respond to different therapies. In this context, subgrouping of patients with IIM based on autoantibody profile may be helpful, as there are emerging data from open studies and case series to support the notion of a varying treatment response in different autoantibody-defined subgroups of IIM patients.

A review on applications of abatacept in systemic rheumatic diseases

Abatacept is a CTLA-4Ig fusion protein that selectively modulates the CD80/CD86:CD28 costimulatory pathway required for full T-cell activation. The FDA has approved it to be used to treat adult rheumatoid arthritis, juvenile idiopathic arthritis, and adult active psoriatic arthritis. Considering the vital pathogenic role of the CTLA-4 pathway in autoimmune diseases, abatacept could efficiently treat other systemic rheumatic diseases. Here we reviewed the published literature to profile the perspectives about the off-label uses of abatacept, especially in those refractory cases with inadequate responses to conventional therapies and biologic agents. Abatacept can be a promising therapeutic option and contribute to reducing hormone dependence and correlated adverse events.

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.

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.

Clinical trials and novel therapeutics in dermatomyositis

INTRODUCTION

Currently, there are no proven drugs that are FDA approved for the treatment of dermatomyositis (DM), even though multiple clinical trials are ongoing to evaluate safety and efficacy of novel therapeutics in DM. The purpose of this review is to highlight the biological plausibility, existing clinical evidence as well as completed and ongoing clinical trials for various drugs in pipeline for development for use in dermatomyositis.

AREAS COVERED

The drugs with the strongest evidence have been included in this review with a focus on the mechanism of their action pertaining to the disease process, clinical studies including completed and ongoing trials. With better understanding of the underlying pathophysiologic process, there are new molecular targets that have been identified that can be targeted by these novel drugs, predominantly biologic drugs.

EXPERT OPINION

There are various drugs being evaluated in phase II/III clinical trials that hold promise in DM. At the forefront of these are immunoglobulin, Lenabasum, and Abatacept for which phase III clinical trials are ongoing. In addition, promising clinical studies are ongoing or reported for KZR-616, anti-B cell therapy, anti-interferon drugs, and Repository Corticotrophin Injection (RCI).

Generalized Arterial Calcification of Infancy: New Insights, Controversies, and Approach to Management

PURPOSE OF REVIEW

This review summarizes current understanding of generalized arterial calcification of infancy (GACI), emphasizing pathophysiology, clinical presentation, and approaches and controversies in management.

RECENT FINDINGS

Identification of causative ENPP1 mutations revealed that GACI arises from deficiencies in inorganic pyrophosphate (leading to calcifications) and adenosine monophosphate (leading to intimal proliferation). Identification of genotypic and phenotypic overlap with pseudoxanthoma elasticum and autosomal recessive hypophosphatemic rickets further advanced understanding of GACI as a complex, multisystemic disease. Clinical data is limited to small, retrospective samples; it is therefore unknown whether commonly used medications, such as bisphosphonates and hypophosphatemia treatment, are therapeutic or potentially harmful. ENPP1-Fc replacement represents a promising approach warranting further study. Knowledge gaps in natural history place clinicians at high risk of assigning causality to interventions that are correlated with changes in clinical status. There is thus a critical need for improved natural history studies to develop and test targeted therapies.

Abatacept in the Treatment of Juvenile Dermatomyositis-Associated Calcifications in a 16-Year-Old Girl

Calcinosis is a feared complication of JDM that may be seen in up to 40% of children with JDM. It is associated with negative impact on the patients' quality of life due to weakness, functional disability, joint contractures, muscle atrophy, skin ulcers, and secondary infections. Calcinosis can present as superficial nodules or plaques, larger nodular deposits extending into deeper tissue layers, accumulation of calcifications along the fascial planes of muscles or tendons, or an exoskeleton of calcium leading to limitations in mobility and joint contractures. Currently, there are no known effective treatments for calcinosis and current therapy is based on anecdotal retrospective studies and cases series. We report the case of a child with JDM-associated calcinosis with extensive intramuscular calcifications who failed conventional therapies but demonstrated improvement as evident by decrease in calcinosis and improved physical function with use of abatacept. We found that use of abatacept was associated with improvement in functional outcome and recurrence did not occur. This case suggests use of abatacept as a safe and effective treatment option for calcinosis due to JDM. Furthermore, large-scale clinical studies are needed to validate our findings and to evaluate the long-term outcomes.

Co-expression network analysis reveals the pivotal role of mitochondrial dysfunction and interferon signature in juvenile dermatomyositis

Background

Juvenile dermatomyositis (JDM) is an immune-mediated disease characterized by chronic organ inflammation. The pathogenic mechanisms remain ill-defined.

Methods

Raw microarray data of JDM were obtained from the gene expression omnibus (GEO) database. Based on the GSE3307 dataset with 39 samples, weighted correlation network analysis (WGCNA) was performed to identify key modules associated with pathological state. Functional enrichment analyses were conducted to identify potential mechanisms. Based on the criteria of high connectivity and module membership, candidate hub genes were selected. A protein-protein interaction network was constructed to identify hub genes. Another dataset (GSE11971) was used for the validation of real hub genes. Finally, the real hub genes were used to screen out small-molecule compounds via the Connectivity map database.

Results

Three modules were considered as key modules for the pathological state of JDM. Functional enrichment analysis indicated that responses to interferon and metabolism were dysregulated. A total of 45 candidate hub genes were selected according to the pre-established criteria, and 20 genes could differentiate JDM from normal controls by validation of another external dataset (GSE11971). These real hub genes suggested the pivotal role of mitochondrial dysfunction and interferon signature in JDM. Furthermore, drug repositioning highlighted the importance of acacetin, helveticoside, lanatoside C, deferoxamine, LY-294002, tanespimycin and L01AD from downregulated genes with the potential to perturb the development of JDM, while betonicine, felodipine, valproic acid, trichostatin A and sirolimus from upregulated genes provided potentially therapeutic goals for JDM.

Conclusions

There are 20 real hub genes associated with the pathological state of JDM, suggesting the pivotal role of mitochondrial dysfunction and interferon signature in JDM. This analysis predicted several kinds of small-molecule compounds to treat JDM.

Clinical practice guidance for juvenile dermatomyositis (JDM) 2018-Update

Juvenile dermatomyositis is the most common type of juvenile idiopathic inflammatory myopathy mainly affecting the skin and proximal muscles. We have published the Japanese version of 'Clinical practice guidance for juvenile dermatomyositis (JDM) 2018 'consisting of a review of articles in the field and evidence-informed consensus-based experts' opinion on the treatment strategy in collaboration with The Pediatric Rheumatology Association of Japan and The Japan College of Rheumatology under the financial support by 'Research on rare and intractable diseases, Health and Labor Sciences Research Grants'. This article is a digest version of the Japanese guidance.

Juvenile dermatomyositis: advances in clinical presentation, myositis-specific antibodies and treatment

BACKGROUND

Juvenile dermatomyositis (JDM) is a chronic autoimmune disease characteristic by inflammation of small vessels within the skin, muscle and vital organs. But the clinical features and treatment of JDM have not been fully clarified.

DATA SOURCES

Databases underwent through PubMed for articles about the clinical features, myositis-specific antibodies of JDM and its treatment, and we selected publications written in English which were relevant to the topic of this review.

RESULTS

Clinical features and myositis-specific antibodies may predict the severity and prognosis of disease. Although the mortality rate has been lower with traditional treatments, such as corticosteroid, intravenous immunoglobulin, and disease-modifying anti-rheumatic drugs such as methotrexate, their usages are variable. Novel biological therapies seem to be effective for refractory JDM patients, but more clinical trials are necessary.

CONCLUSIONS

JDM is a sever disease of childhood. We need to better understand recent advances of JDM in the context of clinical features including skin manifestations, muscle weakness and organ damage, myositis-specific antibodies and their associated outcomes and the treatment of disease.

Linear amyopathic dermatomyositis with calcinosis cutis responsive to topical sodium thiosulfate

A case of a 15-year-old male patient with a 3-year history of linear, segmental amyopathic dermatomyositis with calcinosis cutis is presented. The calcinosis was recalcitrant to treatment with topical steroids and hydroxychloroquine. Topical 10% sodium thiosulfate use for 8 weeks resulted in improvement. The use of topical sodium thiosulfate for patients in whom surgical extraction is not an option is detailed.

B Cells as a Therapeutic Target in Paediatric Rheumatic Disease

B cells carry out a central role in the pathogenesis of autoimmune disease. In addition to the production of autoantibodies, B cells can contribute to disease development by presenting autoantigens to autoreactive T cells and by secreting pro-inflammatory cytokines and chemokines which leads to the amplification of the inflammatory response. Targeting both the antibody-dependent and antibody-independent function of B cells in adult rheumatic disease has led to the advent of B cell targeted therapies in clinical practice. To date, whether B cell depletion could also be utilized for the treatment of pediatric disease is relatively under explored. In this review, we will discuss the role of B cells in the pathogenesis of the pediatric rheumatic diseases Juvenile Idiopathic Arthritis (JIA), Juvenile Systemic Lupus Erythematosus (JSLE) and Juvenile Dermatomyositis (JDM). We will also explore the rationale behind the use of B cell-targeted therapies in pediatric rheumatic disease by highlighting new case studies that points to their efficacy in JIA, JSLE, and JDM.

Targeting Tregs in Juvenile Idiopathic Arthritis and Juvenile Dermatomyositis-Insights From Other Diseases

Regulatory T cells (Tregs) are believed to be dysfunctional in autoimmunity. Juvenile idiopathic arthritis (JIA) and juvenile dermatomyositis (JDM) result from a loss of normal immune regulation in specific tissues such as joints or muscle and skin, respectively. Here, we discuss recent findings in regard to Treg biology in oligo-/polyarticular JIA and JDM, as well as what we can learn about Treg-related disease mechanism, treatment and biomarkers in JIA/JDM from studies of other diseases. We explore the potential use of Treg immunoregulatory markers and gene signatures as biomarkers for disease course and/or treatment success. Further, we discuss how Tregs are affected by several treatment strategies already employed in the therapy of JIA and JDM and by alternative immunotherapies such as anti-cytokine or co-receptor targeting. Finally, we review recent successes in using Tregs as a treatment target with low-dose IL-2 or cellular immunotherapy. Thus, this mini review will highlight our current understanding and identify open questions in regard to Treg biology, and how recent findings may advance biomarkers and new therapies for JIA and JDM.

Treatment consensus for management of polymyositis and dermatomyositis among rheumatologists, neurologists and dermatologists

Although rheumatologists, neurologists and dermatologists see patients with polymyositis (PM) and dermatomyositis (DM), their management appears to vary depending on the physician's specialty. The aim of the present study was to establish the treatment consensus among specialists of the three fields to standardize the patient care. We formed a research team supported by a grant from the Ministry of Health, Labor and Welfare, Japan. Clinical questions (CQ) on the management of PM and DM were raised. A published work search on CQ was performed primarily using PubMed. Using the nominal group technique, qualified studies and results in the published work were evaluated and discussed to reach consensus recommendations. They were sent out to the Japan College of Rheumatology, Japanese Society of Neurology and Japanese Dermatological Association for their approval. We reached a consensus in 23 CQ and made recommendations and a decision tree for management was proposed. They were officially approved by the three scientific societies. In conclusion, a multidisciplinary treatment consensus for the management of PM and DM was established for the first time.

Update on the clinical management of juvenile dermatomyositis

INTRODUCTION

Juvenile dermatomyositis (JDM) is a rare, chronic autoimmune illness with primary features of symmetric, proximal muscle weakness and involvement of the skin with a number of identifiable rashes. Evidence to support treatment decisions is limited, given the paucity of clinical trials. Consensus based methods, informed by available data, play an important role in treatment recommendations. Areas covered: This review focuses on evidence and consensus opinion regarding therapeutic options in JDM and identifies gaps where future research is needed. Expert commentary: The combination of trial evidence (as limited as it is) and consensus opinion support standard initial management for children with JDM to consist of high-dose corticosteroids, either intravenous or oral, and methotrexate. Several other agents have preliminary support, either through clinical trials or case series for their use in patients who either fail to respond adequately, have severe disease or have contraindications to standard initial therapy. One of the important goals of management in JDM will be to reduce the corticosteroid exposure experienced by patients. To meet this goal, progress in a number of key areas is needed: increased international collaboration, advances in study design and increased translational research.

Biologics for idiopathic inflammatory myopathies

PURPOSE OF REVIEW

As treatment of refractory cases of idiopathic inflammatory myopathies (IIMs) has been challenging, there is growing interest in assessing novel biologics that target various pathways implicated in the pathogenesis of IIM.

RECENT FINDINGS

In the largest clinical trial in adult and juvenile IIM assessing the effectiveness of rituximab, the primary outcome was not met but 83% of this refractory group of IIM patients met a predefined definition of improvement and rituximab demonstrated a significant glucocorticoid-sparing effect. Antitumor necrosis factor utility in IIM is generally limited by uncertain efficacy data along with recent reports suggesting their potential for inducing systemic autoimmune disease including IIM.

SUMMARY

Further research is required to evaluate the role of newer therapies such as tocilizumab (anti-interleukin-6), abatacept (inhibition of T-cell costimulation), sifalimumab (anti-interferonα) and ruxolitinib, (Janus kinase inhibitor) given their biological plausibility and encouraging recent small case series results. Future clinical trials should consider the targeting of biomarkers implicated in the etiopathogenesis of IIM, predictive factors of treatment response, recent revisions in IIM classification criteria, as well as newly developed data-driven response criteria which employ validated core set measures.

Systemic sclerosis: Current concepts of skin and systemic manifestations

Systemic sclerosis is an uncommon autoimmune connective tissue disease with multiorgan system involvement and significant associated morbidity and mortality. Cutaneous signs and clinical manifestations are of particular importance, as they may be recognized before systemic manifestations, allowing earlier risk stratification into the limited and diffuse cutaneous subtypes, as well as earlier initiation of treatment. Important cutaneous manifestations include Raynaud's phenomenon, digital ulcers, cutaneous sclerosis, calcinosis cutis, telangiectasias, pruritus, and dyspigmentation. Despite investigation of a wide variety of treatments, no FDA-approved pharmacologic therapies exist for systemic sclerosis, and data from high-quality studies are limited. In the following review, we will discuss skin-directed therapies. Although there is evidence to support specific treatments for Raynaud's phenomenon, digital ulcers, and cutaneous sclerosis, there are limited rigorous studies evaluating the treatment of other cutaneous signs and clinical manifestations. Additional randomized-controlled trials and large observational studies are necessary to develop future evidence-based treatment options.

Lack of response to intravenous sodium thiosulfate in three cases of extensive connective tissue disease-associated calcinosis cutis

Dystrophic calcinosis cutis is a debilitating condition of calcium salt deposition in the skin often occurring in association with connective tissue disease (CTD). Available treatments for calcinosis cutis are unsatisfactory, but given the recent use of topical and intralesional sodium thiosulfate (STS) to treat calcifying disorders, we sought to describe the use of intravenous (IV) STS for CTD-associated dystrophic calcinosis cutis. We report three patients with long-standing and extensive CTD-associated calcinosis cutis treated with IV STS after having failed multiple prior therapies. All three patients experienced fatigue and nausea with STS infusions, and none of the patients had notable clinical or symptomatic improvement of calcinosis. It remains to be seen whether the administration of IV STS earlier in the onset of calcinosis might be of benefit given that these patients all had long-standing and refractory CTD-associated calcinosis. Given the small number of patients in this series, further investigation into the use of IV STS in calcinosis cutis is warranted.

The Vasculopathy of Juvenile Dermatomyositis

Juvenile dermatomyositis (JDM) is a rare autoimmune disease mainly characterized by muscle and skin involvement. Vasculopathy is considered central to the pathogenesis of the disease. The exact nature of vasculopathy is not yet understood but it is a complex process with both an inflammatory and a non-inflammatory, occlusive component. Impaired function of JDM vasculature includes immune complex deposition, altered expression of cell adhesion molecules predominantly inducing Th17 cell infiltration, and endothelial cell dysfunction. Development of vasculopathy is associated with the severe extra-muscular manifestations of JDM, such as gastrointestinal and cardiac manifestations, interstitial lung disease, ulcerative skin disease or development of calcinosis, and portends a poor prognosis. Correlation of histopathological findings, autoantibodies, and extensive diagnostic workup represent key elements to the early detection of vasculopathic features and early aggressive treatment. Monitoring of vasculopathy remains challenging due to the lack of non-invasive biomarkers. Current treatment approaches provide variable benefit, but better understanding of the essential pathogenic mechanisms should help lead to improved outcomes. Whilst acknowledging that evidence is limited, this review aims to describe the vasculopathy of JDM in the context of pathophysiology, clinical features, and treatment of disease.

Abatacept in the treatment of adult dermatomyositis and polymyositis: a randomised, phase IIb treatment delayed-start trial

OBJECTIVES

To study the effects of abatacept on disease activity and on muscle biopsy features of adult patients with dermatomyositis (DM) or polymyositis (PM).

METHODS

Twenty patients with DM (n=9) or PM (n=11) with refractory disease were enrolled in a randomised treatment delayed-start trial to receive either immediate active treatment with intravenous abatacept or a 3 month delayed-start. The primary endpoint was number of responders, defined by the International Myositis Assessment and Clinical Studies Group definition of improvement (DOI), after 6 months of treatment. Secondary endpoints included number of responders in the early treatment arm compared with the delayed treatment arm at 3 months. Repeated muscle biopsies were investigated for cellular markers and cytokines.

RESULTS

8/19 patients included in the analyses achieved the DOI at 6 months. At 3 months of study, five (50%) patients were responders after active treatment but only one (11%) patient in the delayed treatment arm. Eight adverse events (AEs) were regarded as related to the drug, four mild and four moderate, and three serious AEs, none related to the drug. There was a significant increase in regulatory T cells (Tregs), whereas other markers were unchanged in repeated muscle biopsies.

CONCLUSIONS

In this pilot study, treatment of patients with DM and PM with abatacept resulted in lower disease activity in nearly half of the patients. In patients with repeat muscle biopsies, an increased frequency of Foxp3⁺ Tregs suggests a positive effect of treatment in muscle tissue.

Treatment of Juvenile Dermatomyositis: An Update

The idiopathic inflammatory myopathies of childhood consist of a heterogeneous group of autoimmune diseases characterised by proximal muscle weakness and pathognomonic skin rashes. The overall prognosis of juvenile myositis has improved significantly over recent years, but the long-term outcome differs substantially from patient to patient, suggestive of distinct clinical phenotypes with variable responses to treatment. High doses of corticosteroids remain the cornerstone of therapy along with other immunosuppressant therapies depending on disease severity and response. The advent of biological drugs has revolutionised the management of various paediatric rheumatologic diseases, including inflammatory myopathies. There are few data from randomised controlled trials to guide management decisions; thus, several algorithms for the treatment of juvenile myositis have been developed using international expert opinion. The general treatment goals now include elimination of active disease and normalisation of physical function, so as to preserve normal growth and development, and to prevent long-term damage and deformities. This review summarises the newer and possible future therapies of juvenile inflammatory myopathies, including evidence supporting their efficacy and safety.