Suppression of soluble T cell-associated proteins by an anti-interferon-α monoclonal antibody in adult patients with dermatomyositis or polymyositis

Advances in Juvenile Dermatomyositis: Pathophysiology, Diagnosis, Treatment and Interstitial Lung Diseases-A Narrative Review

Juvenile idiopathic inflammatory myopathy (JIIM) is a rare systemic autoimmune disease characterized by skeletal muscle weakness with or without a skin rash. Juvenile dermatomyositis (JDM) is the most common subtype of JIIM, accounting for 80% of JIIM. Recent studies identified several myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs). Each MSA or MAA is associated with distinct clinical features and outcomes, although there are several differences in the prevalence of MSA/MAA and autoantibody-phenotype relationships between age and ethnic groups. Histopathological studies have revealed critical roles of type I interferons and vasculopathy in the development of JDM. Serological classification mostly corresponds to clinicopathological classification. Novel therapeutic agents, such as biologics and Janus kinase inhibitors (JAKi), have been developed; however, to date, there is a lack of high-level evidence. As advances in treatment have reduced the mortality rate of JIIM, recent studies have focused on medium- and long-term outcomes. However, rapidly progressive interstitial lung disease (RP-ILD) remains a major cause of death in anti-melanoma differentiation gene 5 autoantibody-positive JDM. Early diagnosis and intervention using a multi-drug regimen is critical for the treatment of RP-ILD. Rituximab and JAKi may reduce mortality in patients with JDM-associated RP-ILD refractory to conventional therapy.

Type I Interferons in Systemic Autoimmune Rheumatic Diseases: Pathogenesis, Clinical Features and Treatment Options

Type I interferon (IFN) pathway dysregulation plays a crucial role in the pathogenesis of several systemic autoimmune rheumatic diseases (SARDs), including systemic lupus erythematosus (SLE), Sjögren's disease (SjD), systemic sclerosis (SSc), dermatomyositis (DM) and rheumatoid arthritis (RA). Genetic and epigenetic alterations have been involved in dysregulated type I IFN responses in systemic autoimmune disorders. Aberrant type I IFN production and secretion have been associated with distinct clinical phenotypes, disease activity, and severity as well as differentiated treatment responses among SARDs. In this review, we provide an overview of the role of type I IFNs in systemic autoimmune diseases including SLE, RA, SjD, SSc, and DM focusing on pathophysiological, clinical, and therapeutical aspects.

Atypical familial hemophagocytic lymphohistiocytosis type 3 in children: A report of cases and literature review

BACKGROUND

Familial hemophagocytic lymphohistiocytosis type 3 (FHL3) is caused by UNC13D variants. The clinical manifestations of FHL3 are highly diverse and complex. Some patients exhibit atypical or incomplete phenotypes, making accurate diagnosis difficult. Our study aimed to broaden the understanding of the atypical FHL3 clinical spectrum.

METHODS

In our study, we analyzed in detail the clinical features of four Chinese patients with UNC13D variants. Additionally, we conducted a comprehensive review of the existing literature on previously reported atypical manifestations and summarized the findings.

RESULTS

Two of our patients presented with muscle involvement, while the other two had hematological involvement; none of them met the diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH). However, protein expression and functional analysis ultimately confirmed diagnostic criteria for FHL3 in all patients. From the literature we reviewed, many atypical FHL3 patients had neurological involvement, especially isolated neurological manifestations. At the same time, arthritis and hypogammaglobulinemia were also prone to occur.

CONCLUSION

Our study highlights that the expression of the Munc13-4 protein may not fully indicate the pathogenicity of UNC13D variants, whereas CD107a analysis could be more sensitive for disease diagnosis. These findings contribute to a broader understanding of the FHL3 clinical spectrum and may offer new insights into the underlying pathogenesis of UNC13D variants. It is crucial to prioritize the timely and accurate diagnosis of atypical patients, as they may often be overlooked among individuals with rheumatic or hematological diseases.

Type I Interferons in Autoimmunity: Implications in Clinical Phenotypes and Treatment Response

Type I interferon (IFN-I) is thought to play a role in many systemic autoimmune diseases. IFN-I pathway activation is associated with pathogenic features, including the presence of autoantibodies and clinical phenotypes such as more severe disease with increased disease activity and damage. We will review the role and potential drivers of IFN-I dysregulation in 5 prototypic autoimmune diseases: systemic lupus erythematosus, dermatomyositis, rheumatoid arthritis, primary Sjögren syndrome, and systemic sclerosis. We will also discuss current therapeutic strategies that directly or indirectly target the IFN-I system.

CSL362 potently and specifically depletes pDCs invitro and ablates SLE-immune complex-induced IFN responses

Systemic lupus erythematosus (SLE) is an autoimmune disease with significant morbidity and mortality. Type I interferon (IFN) drives SLE pathology and plasmacytoid dendritic cells (pDCs) are potent producers of IFN; however, the specific effects of pDC depletion have not been demonstrated. We show CD123 was highly expressed on pDCs and the anti-CD123 antibody CSL362 potently depleted pDCs in vitro. CSL362 pre-treatment abrogated the induction of IFNα and IFN-induced gene transcription following stimulation with SLE patient-derived serum or immune complexes. RNA transcripts induced in pDCs by ex vivo stimulation with TLR ligands were reflected in gene expression profiles of SLE blood, and correlated with disease severity. TLR ligand-induced protein production by SLE patient peripheral mononuclear cells was abrogated by CSL362 pre-treatment including proteins over expressed in SLE patient serum. These findings implicate pDCs as key drivers in the cellular activation and production of soluble factors seen in SLE.

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.

The Screening of Therapeutic Peptides for Anti-Inflammation through Phage Display Technology

For the treatment of inflammatory illnesses such as rheumatoid arthritis and carditis, as well as cancer, several anti-inflammatory medications have been created over the years to lower the concentrations of inflammatory mediators in the body. Peptides are a class of medication with the advantages of weak immunogenicity and strong activity, and the phage display technique is an effective method for screening various therapeutic peptides, with a high affinity and selectivity, including anti-inflammation peptides. It enables the selection of high-affinity target-binding peptides from a complex pool of billions of peptides displayed on phages in a combinatorial library. In this review, we will discuss the regular process of using phage display technology to screen therapeutic peptides, and the peptides screened for anti-inflammation properties in recent years according to the target. We will describe how these peptides were screened and how they worked in vitro and in vivo. We will also discuss the current challenges and future outlook of using phage display to obtain anti-inflammatory therapeutic peptides.

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.

IFN-α: A key therapeutic target for multiple autoimmune rheumatic diseases

Interferon (IFN)-α has emerged as a major therapeutic target for several autoimmune rheumatic diseases. In this review, we focus on clinical and preclinical advances in anti-IFN-α treatments in systemic lupus erythematosus (SLE), primary Sjögren syndrome (pSS), systemic sclerosis (SSc), and dermatomyositis (DM), for which a high medical need persists. Promising achievements were obtained following direct IFN-α neutralization, targeting its production through the cytosolic nucleic acid sensor pathways or by blocking its downstream effects through the type I IFN receptor. We further focus on molecular profiling and data integration approaches as crucial steps to select patients most likely to benefit from anti-IFN-α therapies within a precision medicine approach.

Interferon lambda in inflammation and autoimmune rheumatic diseases

Interferons are potent antiviral cytokines that modulate immunity in response to infection or other danger signals. In addition to their antiviral functions, type I interferons (IFNα and IFNβ) are important in the pathogenesis of autoimmune diseases. Type III interferons (IFNλs) were initially described as a specialized system that inhibits viral replication at epithelial barrier surfaces while limiting inflammatory damage. However, evidence now suggests that type III interferons have complex effects on both innate and adaptive immune responses and might also be pathogenic in systemic autoimmune diseases. Concentrations of IFNλs are increased in blood and tissues in a number of autoimmune rheumatic diseases, including systemic lupus erythematosus, and are further associated with specific clinical and laboratory parameters. This Review is aimed at providing a critical evaluation of the current literature on IFNλ biology and how type III interferons might contribute to immune dysregulation and tissue damage in autoimmunity. The potential effects of type III interferons on treatment strategies for autoimmune rheumatic diseases, such as interferon blockade, are also considered.

Biomarker profiles of endothelial activation and dysfunction in rare systemic autoimmune diseases: implications for cardiovascular risk

OBJECTIVES

Vasculopathy is an important hallmark of systemic chronic inflammatory connective tissue diseases (CICTD) and is associated with increased cardiovascular risk. We investigated disease-specific biomarker profiles associated with endothelial dysfunction, angiogenic homeostasis and (tissue) inflammation, and their relation to disease activity in rare CICTD.

METHODS

A total of 38 serum proteins associated with endothelial (dys)function and inflammation were measured by multiplex-immunoassay in treatment-naive patients with localized scleroderma (LoS, 30), eosinophilic fasciitis (EF, 8) or (juvenile) dermatomyositis (34), 119 (follow-up) samples during treatment, and 65 controls. Data were analysed by unsupervised clustering, Spearman correlations, non-parametric t test and ANOVA.

RESULTS

The systemic CICTD, EF and dermatomyositis, had distinct biomarker profiles, with 'signature' markers galectin-9 (dermatomyositis) and CCL4, CCL18, CXCL9, fetuin, fibronectin, galectin-1 and TSP-1 (EF). In LoS, CCL18, CXCL9 and CXCL10 were subtly increased. Furthermore, dermatomyositis and EF shared upregulation of markers related to interferon (CCL2, CXCL10), endothelial activation (VCAM-1), inhibition of angiogenesis (angiopoietin-2, sVEGFR-1) and inflammation/leucocyte chemo-attraction (CCL19, CXCL13, IL-18, YKL-40), as well as disturbance of the Angiopoietin-Tie receptor system and VEGF-VEGFR system. These profiles were related to disease activity, and largely normalized during treatment. However, a subgroup of CICTD patients showed continued elevation of CXCL10, CXCL13, galectin-9, IL-18, TNFR2, VCAM-1, and/or YKL-40 during clinically inactive disease, possibly indicating subclinical interferon-driven inflammation and/or endothelial dysfunction.

CONCLUSION

CICTD-specific biomarker profiles revealed an anti-angiogenic, interferon-driven environment during active disease, with incomplete normalization under treatment. This warrants further investigation into monitoring of vascular biomarkers during clinical follow-up, or targeted interventions to minimize cardiovascular risk in the long term.

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).

Endothelial and Inflammation Biomarker Profiles at Diagnosis Reflecting Clinical Heterogeneity and Serving as a Prognostic Tool for Treatment Response in Two Independent Cohorts of Patients With Juvenile Dermatomyositis

Objective

Juvenile dermatomyositis (DM) is a heterogeneous systemic immune‐mediated vasculopathy. This study was undertaken to 1) identify inflammation/endothelial dysfunction–related biomarker profiles reflecting disease severity at diagnosis, and 2) establish whether such biomarker profiles could be used for predicting the response to treatment in patients with juvenile DM.

Methods

In total, 39 biomarkers related to activation of endothelial cells, endothelial dysfunction, and inflammation were measured using multiplex technology in serum samples from treatment‐naive patients with juvenile DM from 2 independent cohorts (n = 30 and n = 29). Data were analyzed by unsupervised hierarchical clustering, nonparametric tests with correction for multiple comparisons, and Kaplan‐Meier tests with Cox proportional hazards models for analysis of treatment duration. Myositis‐specific antibodies (MSAs) were measured in the patients’ serum using line blot assays.

Results

Severe vasculopathy in patients with juvenile DM was associated with low serum levels of intercellular adhesion molecule 1 (Spearman's rho [r_s] = 0.465, P = 0.0111) and high serum levels of endoglin (r_s = −0.67, P < 0.0001). In the discovery cohort, unsupervised hierarchical clustering analysis of the biomarker profiles yielded 2 distinct patient clusters, of which the smaller cluster (cluster 1; n = 8) exhibited high serum levels of CXCL13, CCL19, galectin‐9, CXCL10, tumor necrosis factor receptor type II (TNFRII), and galectin‐1 (false discovery rate <0.0001), and this cluster had greater severity of muscle disease and global disease activity (each P < 0.05 versus cluster 2). In the validation cohort, correlations between the serum levels of galectin‐9, CXCL10, TNFRII, and galectin‐1 and the severity of global disease activity were confirmed (r_s = 0.40–0.52, P < 0.05). Stratification of patients according to the 4 confirmed biomarkers identified a cluster of patients with severe symptoms (comprising 64.7% of patients) who were considered at high risk of requiring more intensive treatment in the first 3 months after diagnosis (P = 0.0437 versus other cluster). Moreover, high serum levels of galectin‐9, CXCL10, and TNFRII were predictive of a longer total treatment duration (P < 0.05). The biomarker‐based clusters were not evidently correlated with patients’ MSA serotypes.

Conclusion

Results of this study confirm the heterogeneity of new‐onset juvenile DM based on serum biomarker profiles. Patients with high serum levels of galectin‐9, CXCL10, TNFRII, and galectin‐1 may respond suboptimally to conventional treatment, and may therefore benefit from more intensive monitoring and/or treatment.

Biologic therapy in the idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases resulting from inflammation of muscle and manifesting as weakness, though a range of extra-muscular manifestations are observed. These are often correlated closely with disease subtype and the presence of myositis-specific/myositis-associated antibodies. IIM are notoriously difficult to treat and often refractory to glucocorticoid therapy and synthetic immunosuppressants. Both the innate and adaptive immune systems are implicated in the pathogenesis of IIM. A growing understanding of the key cytokines as well as the cell-mediated and antibody effectors of disease has identified multiple potential targets for biologic therapy. The most widely used of these is B-cell depletion via rituximab though the tumour necrosis factor inhibitors and other biologic therapies used in diseases such as rheumatoid arthritis, systemic lupus erythematosus and multiple sclerosis have also been trialled. This review summarises the literature thus far on biologic therapy in IIM, highlighting both the significant trials that influence current treatment regimens and also the continuing need for further research to inform more effective therapies.

Recent Advances in Pharmacological Treatments of Adult Dermatomyositis

PURPOSE OF THE REVIEW

Dermatomyositis (DM) is an uncommon autoimmune disease that primarily affects the skin, muscle, and/or lungs, and remains a therapeutic challenge. We discuss recent studies evaluating efficacy of conventional treatments for clinically amyopathic DM (CADM), DM-associated interstitial lung (ILD) disease, and classic DM (CDM). We highlight several emerging new therapies with a focus on clinical trials, systematic reviews, and case series in the last 5 years.

RECENT FINDINGS

Recent studies report a significant number of patients remain refractory to antimalarials and require second- and third-line agents. Effective treatment for DM-associated ILD can vary based on patient specific antibodies. CDM requires oral glucocorticoids; recent studies have evaluated the benefits of adjunctive therapies including methotrexate and calcineurin inhibitors. New therapies target cell populations or cytokines thought to drive disease pathogenesis. Dermatomyositis is an autoimmune disease that remains challenging to treat. Many patients are refractory to conventional therapies, warranting the development and evaluation of new treatments.

Biologics in refractory myositis: experience in juvenile vs. adult myositis; part II: emerging biologic and other therapies on the horizon

The idiopathic inflammatory myopathies (IIM) until recently have been considered a heterogeneous broad group of six autoimmune muscle diseases. Initially, autoantibodies in IIM (including JDM) and CD8+ T cell-induced cytotoxicity (PM and IBM) were the predominant recognized etiopathology mechanisms used to classify myopathies. In the early late 1990's to 2000's, evolving understanding of the molecules such as interleukin (IL), tumor necrosis factor (TNF), interferon (IFN), and other cytokines as well as differences in response to therapies, has led IIM researchers to look beyond previous disease mechanisms. For decades the overexpression of Th1- associated cytokines (TNF-α, IFN-γ and IL-12) in the areas of inflammation in skin and muscle in IIM pointed to Th1 as the primary pathway for inflammation in myositis.However, in the last decade overexpression and elevated level of Th17-associated cytokines (IL-17, IL-22, and IL-6) were identified in the blood and the inflamed muscles of myositis patients. We also do not know how Th1 and Th2 cytokines work differently in diverse hosts, in different concentrations, in different inflammatory milieus, and in the presence or absence of each other or other adhesion/co-stimulatory molecules such as NF-κB. Also, several autoantibodies to intracellular organelles have been identified in myositis.In this review, we will discuss the most recent advances in IIM research and how that might bring new biologic therapies to market in the next 5-15 years to assist in the care of our most difficult IIM and JDM patients.

Systemic and Tissue Inflammation in Juvenile Dermatomyositis: From Pathogenesis to the Quest for Monitoring Tools

Juvenile Dermatomyositis (JDM) is a systemic immune-mediated disease of childhood, characterized by muscle weakness, and a typical skin rash. Other organ systems and tissues such as the lungs, heart, and intestines can be involved, but may be under-evaluated. The inflammatory process in JDM is characterized by an interferon signature and infiltration of immune cells such as T cells and plasmacytoid dendritic cells into the affected tissues. Vasculopathy due to loss and dysfunction of endothelial cells as a result of the inflammation is thought to underlie the symptoms in most organs and tissues. JDM is a heterogeneous disease, and several disease phenotypes, each with a varying combination of affected tissues and organs, are linked to the presence of myositis autoantibodies. These autoantibodies have therefore been extensively studied as biomarkers for the disease phenotype and its associated prognosis. Next to identifying the JDM phenotype, monitoring of disease activity and disease-inflicted damage not only in muscle and skin, but also in other organs and tissues, is an important part of clinical follow-up, as these are key determinants for the long-term outcomes of patients. Various monitoring tools are currently available, among which clinical assessment, histopathological investigation of muscle and skin biopsies, and laboratory testing of blood for specific biomarkers. These investigations also give novel insights into the underlying immunological processes that drive inflammation in JDM and suggest a strong link between the interferon signature and vasculopathy. New tools are being developed in the quest for minimally invasive, but sensitive and specific diagnostic methods that correlate well with clinical symptoms or reflect local, low-grade inflammation. In this review we will discuss the types of (extra)muscular tissue inflammation in JDM and their relation to vasculopathic changes, critically assess the available diagnostic methods including myositis autoantibodies and newly identified biomarkers, and reflect on the immunopathogenic implications of identified markers.

Type I interferon receptor blockade with anifrolumab corrects innate and adaptive immune perturbations of SLE

Objective

Anifrolumab is a fully human immunoglobulin G₁ κ monoclonal antibody specific for subunit 1 of the type I interferon (IFN) α receptor. In a phase IIb study of adults with moderate to severe SLE, anifrolumab treatment demonstrated substantial reductions in multiple clinical endpoints. Here, we evaluated serum proteins and immune cells associated with SLE pathogenesis, type I interferon gene signature (IFNGS) test status and disease activity, and how anifrolumab affected these components.

Methods

Whole blood samples were collected from patients enrolled in MUSE (NCT01438489) for serum protein and cellular assessments at baseline and subsequent time points. Data were parsed by IFNGS test status (high/low) and disease activity. Protein expression and immune cell subsets were measured using multiplex immunoassay and flow cytometry, respectively. Blood samples from healthy donors were analysed for comparison.

Results

Baseline protein expression differed between patients with SLE and healthy donors, IFNGS test-high and -low patients, and patients with moderate and severe disease. Anifrolumab treatment lowered concentrations of IFN-induced chemokines associated with B, T and other immune cell migration in addition to proteins associated with endothelial activation that were dysregulated at baseline. IFNGS test-high patients and those with high disease activity were characterised by low baseline numbers of lymphocytes, circulating memory T-cell subsets and neutrophils. Anifrolumab treatment reversed lymphopenia and neutropenia in the total population, and normalised multiple T-cell subset counts in IFNGS test-high patients compared with placebo.

Conclusions

Anifrolumab treatment reversed IFN-associated changes at the protein and cellular level, indicating multiple modes of activity.

Trial registration number

NCT01438489.

Myositis-specific autoantibodies in Japanese patients with juvenile idiopathic inflammatory myopathies

OBJECTIVES

The aim of our study is to clarify the association of myositis-specific autoantibodies (MSAs) with clinical and laboratory features in Japanese patients with juvenile idiopathic inflammatory myopathies (JIIMs).

METHODS

We retrospectively analyzed the frequency of MSAs and their association with clinical or laboratory findings in 25 Japanese patients with JIIMs in Hokkaido district.

RESULTS

Eighteen of the 25 patients (72%) were positive for MSAs; seven with anti-melanoma differentiation associated gene (MDA) 5 (28%), five with anti-transcriptional intermediary factor (TIF)-1γ (20%), four with anti-MJ/nuclear matrix protein (NXP)-2 (16%), two with anti-Jo-1 (8%), one with anti- HMG-CoA reductase, one with anti-signal recognition peptide (SRP) antibodies (4% each), including co-existence and transition of MSAs in one patient each. Anti-MDA5 antibodies were related to interstitial lung disease (ILD) and arthritis but not to amyopathic juvenile dermatomyositis. Drug-free remission was achieved, once ILD was overcome in this group. Anti-TIF-1γ antibodies were associated with typical rashes and mild myositis. Anti-MJ/NXP2 and anti-SRP antibodies were associated with severe muscle weakness. No patient was complicated with malignancy.

CONCLUSION

Anti-MDA5 antibodies are prevalent and closely associated with ILD in our series compared with other countries. There was no apparent difference in clinical features associated with other MSAs among races.

Skeletal muscle cells actively shape (auto)immune responses

Histopathological analyses of muscle specimens from myositis patients indicate that skeletal muscle cells play an active role in the interaction with immune cells. Research over the last few decades has shown that skeletal muscle cells exhibit immunobiological properties that perfectly define them as non-professional antigen presenting cells. They are able to present antigens via major histocompatibility complex molecules, exhibit costimulatory molecules and secrete soluble molecules that actively shape the immune response in an either pro- or anti-inflammatory manner. Skeletal muscle cells regulate both innate and adaptive immune responses and are essentially involved in the pathophysiological processes of idiopathic inflammatory myopathies. Understanding the role of skeletal muscle cells might help to identify new therapeutic targets for these devastating diseases. This review summarizes the immunobiological features of skeletal muscle cells, especially in the context of idiopathic inflammatory myopathies, and discusses shortcomings and limitations in skeletal muscle related research providing potential perspectives to overcome them in the future.

Guidelines on dermatomyositis--excerpt from the interdisciplinary S2k guidelines on myositis syndromes by the German Society of Neurology

The present guidelines on dermatomyositis (DM) represent an excerpt from the interdisciplinary S2k guidelines on myositis syndromes of the German Society of Neurology (available at www.awmf.org). The cardinal symptom of myositis in DM is symmetrical proximal muscle weakness. Elevated creatine kinase, CRP or ESR as well as electromyography and muscle biopsy also provide important diagnostic clues. Pharyngeal, respiratory, cardiac, and neck muscles may also be affected. Given that approximately 30% of patients also develop interstitial lung disease, pulmonary function tests should be part of the diagnostic workup. Although the cutaneous manifestations in DM are variable, taken together, they represent a characteristic and crucial diagnostic criterion for DM. Approximately 5-20% of individuals exhibit typical skin lesions without any clinically manifest muscle involvement (amyopathic DM). About 30% of adult DM cases are associated with a malignancy. This fact, however, should not delay the treatment of severe myositis. Corticosteroids are the therapy of choice in myositis (1-2 mg/kg). Additional immunosuppressive therapy is frequently required (azathioprine, for children methotrexate). In case of insufficient therapeutic response, the use of intravenous immunoglobulins is justified. The benefit of rituximab has not been conclusively ascertained yet. Acute therapeutic management is usually followed by low-dose maintenance therapy for one to three years. Skin lesions do not always respond sufficiently to myositis therapy. Effective treatment for such cases consists of topical corticosteroids and sometimes also calcineurin inhibitors. Systemic therapies shown to be effective include antimalarial agents (also in combination), methotrexate, and corticosteroids. Intravenous immunoglobulins or rituximab may also be helpful. UV protection is an important prophylactic measure.

Dysregulated innate immune function in the aetiopathogenesis of idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of systemic muscle conditions that are believed to be autoimmune in nature. They have distinct pathological features, but the aetiopathogenesis of each subtype remains largely unknown. Recently, there has been increased interest in the complex role the innate immune system plays in initiating and perpetuating these conditions, and how this may differ between subtypes. This article summarises the traditional paradigms of IIM pathogenesis and reviews the accumulating evidence for disturbances in innate immune processes in these rare, but debilitating chronic conditions.

Cytokine Therapies in Neurological Disease

Cytokines are a heterogeneous group of glycoproteins that coordinate physiological functions. Cytokine deregulation is observed in many neurological diseases. This article reviews current research focused on human clinical trials of cytokine and anticytokine therapies in the treatment of several neurological disease including stroke, neuromuscular diseases, neuroinfectious diseases, demyelinating diseases, and neurobehavioral diseases. This research suggests that cytokine therapy applications may play an important role in offering new strategies for disease modulation and treatment. Further, this research provides insights into the causal link between cytokine deregulation and neurological diseases.

Current pharmacological treatment of idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies are uncommon and heterogeneous disorders. Their classification is based on distinct clinicopathologic features. Although idiopathic inflammatory myopathies share some similarities, different subtypes may have variable responses to therapy, so it is very important to distinguish the correct subtype. There are few randomised, double blind placebo controlled studies to support the current treatment. High dose corticosteroids continue to be the first-line therapy and other immunosupressive drugs are used in refractory cases, as well as steroid-sparing agents. Some novel therapeutic approaches have emerged as potential treatment including tacrolimus, intravenous immunoglobulin and rituximab, following good outcomes reported in case studies. However, more randomised controlled trials are needed. This review considers the current and the potential future therapies for inflammatory myopathies.

Progress with the use of monoclonal antibodies for the treatment of systemic lupus erythematosus

In recent years, significant progress has been made in the use of monoclonal antibodies in the treatment of systemic lupus erythematosus (SLE). Advances in our understanding of the complexity of SLE immunopathogenesis have led to the testing of several biologic agents in clinical trials. Monoclonal therapies currently emerging or under development include B-cell depletion therapies, agents targeting B-cell survival factors, blockade of T-cell co-stimulation and anticytokine therapies. Issues remain, however, regarding clinical trial design and outcome measures in SLE which need to be addressed to optimize translation of these promising therapies into clinical practice.

Therapy of myositis: biological and physical

PURPOSE OF REVIEW

To give an update on reported use and effects of biological and physical therapies in patients with myositis.

RECENT FINDINGS

The most promising biological treatment in polymyositis, dermatomyositis and juvenile dermatomyositis is B-cell blockade by rituximab. Anti-Jo or anti-Mi-2 antibodies were predictors of response suggesting different molecular pathways in different subsets of myositis. T-cell blockade with abatacept is a new possibility, as is blockade of interleukin-1, interleukin-6 or type I interferon, but controlled studies are needed. Metabolic abnormalities may contribute to muscle impairment, lending support to combine pharmacological therapy with exercise in patients with polymyositis and dermatomyositis. Exercise improved the aerobic milieu in the muscle, along with improved aerobic capacity, and reduced disability. Support is also provided for the safety of exercise in patients with recent-onset polymyositis and dermatomyositis and exercise is well tolerated in patients with juvenile dermatomyositis.

SUMMARY

There is a strong need to develop new therapies in patients with myositis. To achieve this, more knowledge is needed on the molecular pathogenesis. Targeted therapies using biologics or exercise can be employed to achieve an improved understanding of molecular pathways, provided that clinical outcome measures are combined with molecular studies on muscle and blood.

Cytokines in immune-mediated inflammatory myopathies: cellular sources, multiple actions and therapeutic implications

The idiopathic inflammatory myopathies are a heterogeneous group of disorders characterised by diffuse muscle weakness and inflammation. A common immunopathogenic mechanism is the cytokine-driven infiltration of immune cells into the muscle tissue. Recent studies have further dissected the inflammatory cell types and associated cytokines involved in the immune-mediated myopathies and other chronic inflammatory and autoimmune disorders. In this review we outline the current knowledge of cytokine expression profiles and cellular sources in the major forms of inflammatory myopathy and detail the known mechanistic functions of these cytokines in the context of inflammatory myositis. Furthermore, we discuss how the application of this knowledge may lead to new therapeutic strategies for the treatment of the inflammatory myopathies, in particular for cases resistant to conventional forms of therapy.

Type I IFNs as biomarkers in rheumatoid arthritis: towards disease profiling and personalized medicine

RA (rheumatoid arthritis) is a chronic rheumatic condition hallmarked by joint inflammation and destruction by self-reactive immune responses. Clinical management of RA patients is often hampered by its heterogeneous nature in both clinical presentation and outcome, thereby highlighting the need for new predictive biomarkers. In this sense, several studies have recently revealed a role for type I IFNs (interferons), mainly IFNα, in the pathogenesis of a subset of RA patients. Genetic variants associated with the type I IFN pathway have been linked with RA development, as well as with clinical features. Moreover, a role for IFNα as a trigger for RA development has also been described. Additionally, a type I IFN signature has been associated with the early diagnosis of RA and clinical outcome prediction in patients undergoing biological drug treatment, two challenging issues for decision-making in the clinical setting. Moreover, these cytokines have been related to endothelial damage and vascular repair failure in different autoimmune disorders. Therefore, together with chronic inflammation and disease features, they could probably account for the increased cardiovascular disease morbidity and mortality of these patients. The main aim of the present review is to provide recent evidence supporting a role for type I IFNs in the immunopathology of RA, as well as to analyse their possible role as biomarkers for disease management.