Treatment in myositis

Tacrolimus personalized therapy based on CYP3A5 genotype in Chinese patients with idiopathic inflammatory myopathies

OBJECTIVE

Idiopathic inflammatory myopathies (IIM) are a heterogeneous and life-threatening group of diseases; in particular, anti-melanoma differentiation-associated gene 5 antibody positive DM (MDA5+ DM) is reportedly strongly associated with high mortality rate. Tacrolimus (TAC) provides an excellent therapeutic option, but the trough concentration (Cmin)-outcome relationship remains unexplored. This study was undertaken to identify optimal Cmin and individualized dose based on CYP3A5 genotype for IIM patients.

METHODS

A total of 134 IIM patients with 467 Cmin were enrolled. We examined the relationship between TAC Cmin and relapses. The receiver operating characteristic analysis was used to confirm the optimal Cmin. Analyses of factors influencing Cmin were conducted. The dose requirement based on CYP3A5 genotype was confirmed.

RESULTS

TAC Cmin is strongly associated with relapses. The optimal cutoff values were 5.30, 5.85, 4.85 and 5.35 ng/ml for acute, subacute, chronic and all-phase IIM patients (P = 0.001, 0.013, 0.002 and <0.001, respectively), as well as 5.35, 5.85, 5.55 and 5.85 ng/ml for acute, subacute, chronic and all-phase MDA5+ DM patients (P = 0.007, 0.001, 0.036 and <0.001, respectively). CYP3A5 genotype was one of the significant factors influencing TAC Cmin. CYP3A5 expressers required 0.059 mg/kg/day to attain the target Cmin, while nonexpressers required 0.046 mg/kg/day (P = 0.019).

CONCLUSION

TAC treatment may elicit favorable outcome in patients with IIM and MDA5+ DM when Cmin exceeded 5.35 and 5.85 ng/ml, which is crucial to a lower relapse rate. The individualized dose based on the CYP3A5 genotype provides a reference for TAC personalized therapy in IIM.

Peripheral nervous system immune-related adverse events due to checkpoint inhibition

Immune checkpoint inhibitors have revolutionized cancer therapy and are increasingly used to treat a wide range of oncological conditions, with dramatic benefits for many patients. Unfortunately, the resulting increase in T cell effector function often results in immune-related adverse events (irAEs), which can involve any organ system, including the central nervous system (CNS) and peripheral nervous system (PNS). Neurological irAEs involve the PNS in two-thirds of affected patients. Muscle involvement (immune-related myopathy) is the most common PNS irAE and can be associated with neuromuscular junction involvement. Immune-related peripheral neuropathy most commonly takes the form of polyradiculoneuropathy or cranial neuropathies. Immune-related myopathy (with or without neuromuscular junction involvement) often occurs along with immune-related myocarditis, and this overlap syndrome is associated with substantially increased mortality. This Review focuses on PNS adverse events associated with immune checkpoint inhibition. Underlying pathophysiological mechanisms are discussed, including antigen homology between self and tumour, epitope spreading and activation of pre-existing autoreactive T cells. An overview of current approaches to clinical management is provided, including cytokine-directed therapies that aim to decouple anticancer immunity from autoimmunity and emerging treatments for patients with severe (life-threatening) presentations.

ASM is a therapeutic target in dermatomyositis by regulating the differentiation of naive CD4 + T cells into Th17 and Treg subsets

BACKGROUND

This study aims to investigate the involvement of acid sphingomyelinase (ASM) in the pathology of dermatomyositis (DM), making it a potential therapeutic target for DM.

METHODS

Patients with DM and healthy controls (HCs) were included to assess the serum level and activity of ASM, and to explore the associations between ASM and clinical indicators. Subsequently, a myositis mouse model was established using ASM gene knockout and wild-type mice to study the significant role of ASM in the pathology and to assess the treatment effect of amitriptyline, an ASM inhibitor. Additionally, we investigated the potential treatment mechanism by targeting ASM both in vivo and in vitro.

RESULTS

A total of 58 DM patients along with 30 HCs were included. The ASM levels were found to be significantly higher in DM patients compared to HCs, with median (quartile) values of 2.63 (1.80-4.94) ng/mL and 1.64 (1.47-1.96) ng/mL respectively. The activity of ASM in the serum of DM patients was significantly higher than that in HCs. Furthermore, the serum levels of ASM showed correlations with disease activity and muscle enzyme levels. Knockout of ASM or treatment with amitriptyline improved the severity of the disease, rebalanced the CD4 T cell subsets Th17 and Treg, and reduced the production of their secreted cytokines. Subsequent investigations revealed that targeting ASM could regulate the expression of relevant transcription factors and key regulatory proteins.

CONCLUSION

ASM is involved in the pathology of DM by regulating the differentiation of naive CD4 + T cells and can be a potential treatment target.

Effectiveness of generic tofacitinib in idiopathic inflammatory myositis (IIM)-a retrospective analysis from Indian Myositis Registry (MyoIN)

OBJECTIVES

Determine domain-based-outcomes and steroid-sparing efficacy of generic tofacitinib in IIM.

METHODS

This is a multicenter retrospective study wherein clinical phenotype, autoantibody profile, prior immunosuppressives, and outcomes at 3, 6, and 12 months were retrieved for IIM patients prescribed tofacitinib. Overall clinical response was assessed as complete or partial remission as per physician judgment. Changes in cutaneous and calcinosis domain were recorded as per physician global assessment (PGA), lung domain as per medical research council (MRC) dyspnea scale, and muscle strength by Manual Muscle Testing-8 (MMT-8).

RESULTS

Forty-two patients of IIM with mean age 38.7 ± 16 years; (76.2% (N = 32) women), median duration of illness 48 (19;88) months were included. Commonest indication for initiating tofacitinib was either for refractory or as steroid sparing for cutaneous domain (N = 25/42, 59.5%) followed by calcinosis (N = 16/42, 38%). Overall complete and/or partial remission was achieved in 23/37 (64.8%), 30/35 (85.7%), and 29/30 (96.6%) patients at 3, 6, and 12 months, respectively. At 12-month follow-up, there was a reduction in prednisolone dose, with absolute decrease from a daily dose of 17.5 mg (IQR 5;50) to 2.5 mg (IQR 0;5) (p < 0.001). Individual domain assessments revealed improvement in cutaneous domain [16/25 (64%)] and calcinosis [6/15 (40%)]. Adverse effects included herpes zoster (N = 2/42, 4.8%) and dyslipidemia (N = 4/42, 9.5%).

CONCLUSIONS

Treatment with generic tofacitinib significantly reduces the daily dose of corticosteroids and is effective in cutaneous domain including calcinosis in IIM.

KEY POINTS

• This multicenter retrospective study is the first real-world data from India, elucidating steroid sparing efficacy of generic tofacitinib in patients with inflammatory myositis. • Domain-based outcome assessment suggests good clinical improvement especially in cutaneous domain, even those with refractory disease. • Modest benefits were evident in calcinosis, but its effect on the muscle and pulmonary domain appears limited.

IFNγ causes mitochondrial dysfunction and oxidative stress in myositis

Idiopathic inflammatory myopathies (IIMs) are severe autoimmune diseases with poorly understood pathogenesis and unmet medical needs. Here, we examine the role of interferon γ (IFNγ) using NOD female mice deficient in the inducible T cell co-stimulator (Icos), which have previously been shown to develop spontaneous IFNγ-driven myositis mimicking human disease. Using muscle proteomic and spatial transcriptomic analyses we reveal profound myofiber metabolic dysregulation in these mice. In addition, we report muscle mitochondrial abnormalities and oxidative stress in diseased mice. Supporting a pathogenic role for oxidative stress, treatment with a reactive oxygen species (ROS) buffer compound alleviated myositis, preserved muscle mitochondrial ultrastructure and respiration, and reduced inflammation. Mitochondrial anomalies and oxidative stress were diminished following anti-IFNγ treatment. Further transcriptomic analysis in IIMs patients and human myoblast in vitro studies supported the link between IFNγ and mitochondrial dysfunction observed in mice. These results suggest that mitochondrial dysfunction, ROS and inflammation are interconnected in a self-maintenance loop, opening perspectives for mitochondria therapy and/or ROS targeting drugs in myositis.

Crucial Roles of RSAD2/viperin in Immunomodulation, Mitochondrial Metabolism and Autoimmune Diseases

Autoimmune diseases are typically characterized by aberrant activation of immune system that leads to excessive inflammatory reactions and tissue damage. Nevertheless, precise targeted and efficient therapies are limited. Thus, studies into novel therapeutic targets for the management of autoimmune diseases are urgently needed. Radical S-adenosyl methionine domain-containing 2 (RSAD2) is an interferon-stimulated gene (ISG) renowned for the antiviral properties of the protein it encodes, named viperin. An increasing number of studies have underscored the new roles of RSAD2/viperin in immunomodulation and mitochondrial metabolism. Previous studies have shown that there is a complex interplay between RSAD2/vipeirn and mitochondria and that binding of the iron-sulfur (Fe-S) cluster is necessary for the involvement of viperin in mitochondrial metabolism. Viperin influences the proliferation and development of immune cells as well as inflammation via different signaling pathways. However, the function of RSAD2/viperin varies in different studies and a comprehensive overview of this emerging theme is lacking. This review will describe the characteristics of RSAD2/viperin, decipher its function in immunometabolic processes, and clarify the crosstalk between RSAD2/viperin and mitochondria. Furthermore, we emphasize the crucial roles of RSAD2 in autoimmune diseases and its potential application value.

The enchanting canvas of CAR technology: Unveiling its wonders in non-neoplastic diseases

Chimeric antigen receptor (CAR) T cells have made a groundbreaking advancement in personalized immunotherapy and achieved widespread success in hematological malignancies. As CAR technology continues to evolve, numerous studies have unveiled its potential far beyond the realm of oncology. This review focuses on the current applications of CAR-based cellular platforms in non-neoplastic indications, such as autoimmune, infectious, fibrotic, and cellular senescence-associated diseases. Furthermore, we delve into the utilization of CARs in non-T cell populations such as natural killer (NK) cells and macrophages, highlighting their therapeutic potential in non-neoplastic conditions and offering the potential for targeted, personalized therapies to improve patient outcomes and enhanced quality of life.

Review of Pulmonary Manifestations in Antisynthetase Syndrome

Antisynthetase syndrome (ASyS) is now a widely recognized entity within the spectrum of idiopathic inflammatory myopathies. Initially described in patients with a triad of myositis, arthritis, and interstitial lung disease (ILD), its presentation can be diverse. Additional common symptoms experienced by patients with ASyS include Raynaud's phenomenon, mechanic's hand, and fever. Although there is a significant overlap with polymyositis and dermatomyositis, the key distinction lies in the presence of antisynthetase antibodies (ASAs). Up to 10 ASAs have been identified to correlate with a presentation of ASyS, each having manifestations that may slightly differ from others. Despite the proposal of three classification criteria to aid diagnosis, the heterogeneous nature of patient presentations poses challenges. ILD confers a significant burden in patients with ASyS, sometimes manifesting in isolation. Notably, ILD is also often the initial presentation of ASyS, requiring pulmonologists to remain vigilant for an accurate diagnosis. This article will comprehensively review the various aspects of ASyS, including disease presentation, diagnosis, management, and clinical course, with a primary focus on its pulmonary manifestations.

Causality Assessment Between Idiopathic Inflammatory Myopathies and Lung Cancer: A Bidirectional 2-Sample Mendelian Randomization

BACKGROUND

Although observational studies have revealed associations between idiopathic inflammatory myopathies (IIMs) and lung cancer (LC), they have not established a causal relationship between these 2 conditions.

METHODS

We used a 2-sample Mendelian randomization approach to examine the bidirectional causal associations between IIMs and LC, using single-nucleotide polymorphisms selected from high-quality genome-wide association studies in the FinnGen database. Sensitivity analyses were conducted to assess potential heterogeneity and pleiotropy impacts on the Mendelian randomization results.

RESULTS

Our analysis demonstrated a positive causal effect of genetically increased IIM risk on LC (odds ratio, 1.114; 95% confidence interval, 1.057-1.173; p = 5.63 × 10 -5 ), particularly on the lung squamous cell carcinoma subtype (odds ratio, 1.168, 95% confidence interval, 1.049-1.300, p = 0.00451), but not on lung adenocarcinoma or small cell lung cancer. No causal effect of LC on IIMs was identified. Sensitivity analyses indicated that horizontal pleiotropy was unlikely to influence causality, and leave-one-out analysis confirmed that the observed associations were not driven by a single-nucleotide polymorphism.

CONCLUSION

Our findings offer compelling evidence of a positive causal relationship between IIMs and LC, particularly with regard to lung squamous cell carcinoma, in the European population. Conversely, there is no evidence of LC causing IIMs. We recommend that LC diagnosis consider the specific characteristics of IIMs.

Liver Involvement is Associated with Higher Risk of Rapidly Progressive Interstitial Lung Disease and Mortality in Anti-Melanoma Differentiation-Associated Gene 5 Antibody- Positive Dermatomyositis

Purpose

This study aimed to assess liver involvement and investigate its correlation with rapidly progressive interstitial lung disease (RP-ILD) and mortality in anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5 positive) DM patients.

Patients and Methods

This retrospective study included 159 patients diagnosed with anti-MDA5 positive DM or anti-synthetase syndrome (ASyS). Clinical features and laboratory findings were compared between patients with anti-MDA5 positive DM and patients with ASyS. In the anti-MDA5 positive DM cohort, clinical features and laboratory findings between patients with liver involvement and without liver involvement were further compared. The effects of liver involvement on the overall survival (OS) and development of RP-ILD were also analyzed using Kaplan-Meier method and Cox regression analysis.

Results

Levels of serum aspartate aminotransferase (AST), alanine transaminase (ALT), γ-glutamyl transferase (γGT) and alkaline phosphatase (ALP) were all significantly higher in patients with anti-MDA5 positive DM than those in patients with ASyS. In our cohort of anti-MDA5 positive DM patents, 31 patients (34.4%) were complicated with liver involvement. Survival analysis revealed that serum ferritin >1030.0 ng/mL (p<0.001), ALT >103.0 U/l (p<0.001), AST >49.0 U/l (p<0.001), γGT >82.0 U/l (p<0.001), ALP >133.0 U/l (p<0.001), lactate dehydrogenase (LDH)>474.0 U/l (p<0.001), plasma albumin (ALB) <35.7 g/l (p<0.001) and direct bilirubin (DBIL) >2.80 μmol/l (p=0.002) predicted poor prognosis. The incidence of RP-ILD increased remarkably in patients with liver involvement compared to patients without liver involvement (58.1% vs 22.0%, p=0.001). Multivariate analysis revealed that elevated serum ALT level was an independent risk factor for mortality (HR 6.0, 95% CI 2.3, 16.2, p<0.001) and RP-ILD (HR 5.9, 95% CI 2.2, 15.9, p<0.001) in anti-MDA5 positive DM patents.

Conclusion

Liver involvement is common in patients with anti-MDA5 positive DM. Elevated serum ALT level was an independent risk factor for RP-ILD and mortality in patients with anti-MDA5 positive DM.

Effect modification of cancer on the association between dysphagia and mortality in early idiopathic inflammatory myopathies

OBJECTIVE

The interplay between dysphagia, cancer, and mortality in idiopathic inflammatory myopathies (IIM) has not been carefully studied. The aim of this study was to investigate possible effect modification of cancer on the association between dysphagia and mortality in early IIM.

METHODS

A multi-center cohort of 230 adult IIM patients with dysphagia assessment within 6 months of disease onset was assembled. Crude mortality rates in IIM patients exposed or not to dysphagia were estimated for the 5-year period following cohort entry. To explore possible effect modification of cancer on the association between dysphagia and mortality, adjusted Cox models stratified on cancer status were performed as well as an interaction model.

RESULTS

Mortality rates per 100 person-years for IIM patients exposed to dysphagia were 2.3 (95 %CI 1.0 to 4.5) in those without cancer compared to 33.3 (95 %CI 16.6 to 59.5) in those with cancer. In stratified Cox models, the main effect of dysphagia was HR 0.5 (95 %CI 0.2 to 1.5) in non-cancer and 3.1 (95 %CI 1.0 to 10.2) in cancer patients. In the interaction model, the combination of dysphagia and cancer yielded a HR of 6.4 (1.2 to 35.1).

CONCLUSION

In this IIM cohort, dysphagia in non-cancer patients was not associated with increased mortality, while it was in presence of cancer, supporting effect modification of cancer on the association between dysphagia and mortality. This suggests that IIM patients with and without cancer differ and separate analyses for the two groups should be conducted when the outcome of interest is mortality.

Hyperviscosity Syndrome in Undifferentiated Connective Tissue Disease: A Diagnostic and Therapeutic Challenge

Hyperviscosity is an uncommon manifestation of various underlying diseases. Rapid diagnosis and management of the underlying disease is crucial to prevent significant complications, including hypertension, cerebral vascular accidents, pulmonary embolism, bowel ischemia, and ophthalmologic pathologies. Although the acute management of complications arising from hyperviscosity is relatively straightforward, identifying and treating the underlying cause can prove difficult. This case highlights the difficulties of establishing a diagnosis and initiating appropriate management for a patient with hyperviscosity syndrome in a suspected rheumatologic disorder.

Idiopathic inflammatory myopathies: current insights and future frontiers

Idiopathic inflammatory myopathies are a group of autoimmune diseases with a broad spectrum of clinical presentations, primarily characterised by immune-mediated muscle injury. Until recently, there was little insight into the pathogenesis of idiopathic inflammatory myopathies, which challenged the recognition of the breadth of heterogeneity of this group of diseases as well as the development of new therapeutics. However, the landscape of idiopathic inflammatory myopathies is evolving. In the past decade, advances in diagnostic tools have facilitated an enhanced understanding of the underlying disease mechanisms in idiopathic inflammatory myopathies, enabling the expansion of therapeutic trials. The fields of transcriptomics, prot§eomics, and machine learning offer the potential to gain greater insights into the underlying pathophysiology of idiopathic inflammatory myopathies. Harnessing insights gained from these sophisticated tools could contribute to the identification of differences at a molecular level among patients, accelerating the development of targeted, tailored therapies. Bolstered by the validation and standardisation of robust outcome measures, many promising therapies are in clinical trial development. Although challenges remain, there is great optimism in the field due to the progress in innovative diagnostics, outcome measures, and therapeutic approaches. In this Review, we discuss the expanding landscape of idiopathic inflammatory myopathies as the frontier of precision medicine becomes imminent.

Quantitative interstitial lung disease scores in idiopathic inflammatory myopathies: longitudinal changes and clinical implications

OBJECTIVES

To investigate computer-aided quantitative scores from high-resolution CT (HRCT) images and determine their longitudinal changes and clinical significance in patients with idiopathic inflammatory myopathies (IIMs)-related interstitial lung disease (IIMs-ILD).

METHODS

The clinical data and HRCT images of 80 patients with IIMs who underwent serial HRCT scans at least twice were retrospectively analysed. Quantitative ILD (QILD) scores (%) were calculated as the sum of the extent of lung fibrosis, ground-glass opacity, and honeycombing. The individual time-estimated ΔQILD between two consecutive scans was derived using a linear approximation of yearly changes.

RESULTS

The baseline median QILD (interquartile range) scores in the whole lung were 28.1% (19.1-43.8). The QILD was significantly correlated with forced vital capacity (r = -0.349, P = 0.002) and diffusing capacity for carbon monoxide (r = -0.381, P = 0.001). For ΔQILD between the first two scans, according to the visual ILD subtype, QILD aggravation was more frequent in patients with usual interstitial pneumonia (UIP) than non-UIP (80.0% vs 44.4%, P = 0.013). Multivariable logistic regression analyses identified UIP was significantly related to radiographic ILD progression (ΔQILD >2%, P = 0.015). Patients with higher baseline QILD scores (>28.1%) had a higher risk of lung transplantation or death (P = 0.015). In the analysis of three serial HRCT scans (n = 41), dynamic ΔQILD with four distinct patterns (improving, worsening, convex and concave) was observed.

CONCLUSION

QILD changes in IIMs-ILD were dynamic, and baseline UIP patterns seemed to be related to a longitudinal progression in QILD. These may be potential imaging biomarkers for lung function, changes in ILD severity and prognosis in IIMs-ILD.

Necrotizing Autoimmune Myopathy: A Case Report on Statin-Induced Rhabdomyolysis

Statin-induced necrotizing myopathy (SINM) is an uncommon but severe complication associated with statin medication. SINM can develop at any point after a person starts taking steroids. It is now being acknowledged as a component of the broader category of "statin-induced myopathy." Like other immune-mediated necrotizing muscle diseases, statin-induced myositis is identified by weakness in proximal muscles, increased serum creatine kinase (CK) levels, and, in some cases, dysphagia and respiratory distress. In addition, there is evidence of muscle cell damage when examined under a microscope, occurring with minimal or no infiltration of inflammatory cells. Diagnosing SINM promptly is frequently challenging due to its unpredictable development over time, with symptoms sometimes emerging many years after the initial exposure to statins. One distinctive characteristic of SINM is the continued presence of muscle inflammation and elevated CK levels even after discontinuing statin treatment. Currently, no clinical trials are available to guide how to manage statin-induced immune-mediated necrotizing myopathy (IMNM). Here, we present a case of a 42-year-old woman diagnosed with SINM and was found to have persistently elevated CPK despite discontinuation of statins. Our case also suggests that intravenous (IV) immunoglobins and steroids are an effective and well-tolerated alternative to immunosuppressants.

Stromal vascular fraction in the treatment of myositis

Muscle regeneration is a physiological process that converts satellite cells into mature myotubes under the influence of an inflammatory environment progressively replaced by an anti-inflammatory environment, with precise crosstalk between immune and muscular cells. If the succession of these phases is disturbed, the immune system can sometimes become auto-reactive, leading to chronic muscular inflammatory diseases, such as myositis. The triggers of these autoimmune myopathies remain mostly unknown, but the main mechanisms of pathogenesis are partially understood. They involve chronic inflammation, which could be associated with an auto-reactive immune response, and gradually with a decrease in the regenerative capacities of the muscle, leading to its degeneration, fibrosis and vascular architecture deterioration. Immunosuppressive treatments can block the first part of the process, but sometimes muscle remains weakened, or even still deteriorates, due to the exhaustion of its capacities. For patients refractory to immunosuppressive therapies, mesenchymal stem cells have shown interesting effects but their use is limited by their availability. Stromal vascular fraction, which can easily be extracted from adipose tissue, has shown good tolerance and possible therapeutic benefits in several degenerative and autoimmune diseases. However, despite the increasing use of stromal vascular fraction, the therapeutically active components within this heterogeneous cellular product are ill-defined and the mechanisms by which this therapy might be active remain insufficiently understood. We review herein the current knowledge on the mechanisms of action of stromal vascular fraction and hypothesise on how it could potentially respond to some of the unmet treatment needs of refractory myositis.

The role of neutrophil extracellular traps and proinflammatory damage-associated molecular patterns in idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) are a group of systemic autoimmune diseases characterized by immune-mediated muscle injury. Abnormal neutrophil extracellular traps (NETs) can be used as a biomarker of IIM disease activity, but the mechanism of NET involvement in IIMs needs to be elucidated. Important components of NETs, including high-mobility group box 1, DNA, histones, extracellular matrix, serum amyloid A, and S100A8/A9, act as damage-associated molecular patterns (DAMPs) to promote inflammation in IIMs. NETs can act on different cells to release large amounts of cytokines and activate the inflammasome, which can subsequently aggravate the inflammatory response. Based on the idea that NETs may be proinflammatory DAMPs of IIMs, we describe the role of NETs, DAMPs, and their interaction in the pathogenesis of IIMs and discuss the possible targeted treatment strategies in IIMs.

Treatment with add-on IVIg in Myositis Early In the diSease course May be sUperior to Steroids alone for reaching CLinical improvEment (TIME IS MUSCLE): study protocol of a phase-2 double-blind placebo-controlled randomised trial

INTRODUCTION

For idiopathic inflammatory myopathies (IIM) ('myositis') standard initial treatment is high-dosed glucocorticoids, which results in relatively slow improvement of muscle strength. Early immunosuppression or modulation by intensive treatment ('hit-early, hit-hard') may induce faster reduction of disease activity and prevent chronic disability due to disease-induced structural muscle damage. Intravenous immunoglobulin (IVIg) in addition to standard glucocorticoid treatment may be promising in this regard as was shown in various studies: add-on IVIg improved symptoms and muscle strength in refractory myositis patients and monotherapy IVIg improved outcomes after 9 weeks, in about half of treatment-naive patients.

HYPOTHESIS

We hypothesise that early add-on IVIg leads to a greater clinical response after 12 weeks in patients with newly diagnosed myositis, in comparison to prednisone monotherapy. Second, we expect that early treatment with add-on IVIg leads to a faster time to improvement and sustained positive effects on multiple secondary outcomes.

METHODS

The Time Is Muscle trial is a phase-2 double-blind placebo-controlled randomised trial. Forty-eight patients with IIM will be treated with IVIg or placebo at baseline (within 1 week after diagnosis) and after 4 and 8 weeks, in addition to standard therapy with prednisone. The primary outcome is the Total Improvement Score (TIS) of the myositis response criteria at 12 weeks. At baseline, and after 4, 8, 12, 26 and 52 weeks, relevant secondary outcomes will be assessed, including time to moderate improvement (TIS≥40), mean daily prednisone dosage, physical activity, health-related quality of life, fatigue and MRI muscle imaging parameters.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the medical ethics committee of the Academic Medical Centre, University of Amsterdam, the Netherlands (2020_180; including a first amendment approval at the 12 April 2023; A2020_180_0001). The results will be distributed through conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

EU Clinical trials register (2020-001710-37).

B-cell receptor profiling before and after IVIG monotherapy in newly diagnosed idiopathic inflammatory myopathies

OBJECTIVE

To unravel B-cell receptor (BcR) characteristics in muscle tissues and peripheral blood and gain more insight into BcR repertoire changes in peripheral blood in idiopathic inflammatory myopathies (IIMs), and study how this correlates to the clinical response to IVIG.

METHODS

Nineteen treatment-naive patients with newly diagnosed IIM were prospectively treated with IVIG monotherapy. RNA-based BcR repertoire sequencing was performed in muscle biopsies collected before, and in peripheral blood (PB) collected before and nine weeks after IVIG treatment. Results were correlated to patients' clinical improvement based on the total improvement score (TIS).

RESULTS

Prior to IVIG treatment, BcR clones found in muscle tissue could be retrieved in peripheral blood. Nine weeks after IVIG treatment, new patient-specific dominant BcR clones appeared in peripheral blood while pre-treatment dominant BcR clones disappeared. The cumulative frequency of all dominant BcR clones before treatment was significantly higher in individuals who responded to IVIG compared with those who did not respond to IVIG, and correlated with a higher CK. During follow-up, a decrease in the cumulative frequency of all dominant clones correlated with a higher TIS.

CONCLUSION

In treatment-naive patients with newly diagnosed IIM, muscle tissue and peripheral blood share expanded BcR clones. In our study a higher cumulative frequency of dominant BcR clones in blood before treatment was associated with a higher CK and better treatment response, suggesting that response to IVIG may depend on the composition of the pre-treatment BcR repertoire.

Clinical pearls and promising therapies in myositis

INTRODUCTION

Idiopathic inflammatory myopathies (IIMs) represent a diverse group of systemic autoimmune disorders with variable clinical manifestations and disease course. Currently, the challenges of IIMs are multifold, including difficulties in timely diagnosis owing to clinical heterogeneity, limited insights into disease pathogenesis, as well as a restricted number of available therapies. However, advances utilizing myositis-specific autoantibodies have facilitated the definition of subgroups as well as the prediction of clinical phenotypes, disease course, and response to treatment.

AREAS COVERED

Herein we provide an overview of the clinical presentations of dermatomyositis, anti-synthetase syndrome, immune-mediated necrotizing myopathy, and inclusion body myositis. We then provide an updated review of available and promising therapies for each of these disease groups. We synthesize current treatment recommendations in the context of case-based construct to facilitate application to patient care. Finally, we provide high-yield, clinical pearls relevant to each of the subgroups that can be incorporated into clinical reasoning.

EXPERT OPINION

There are many exciting developments on the horizon for IIM. As insights into pathogenesis evolve, the therapeutic armamentarium is expanding with many novel therapies in development, holding promise for more targeted treatment approaches.

Perspectives on Mycophenolate Mofetil in the Management of Autoimmunity

Before becoming a cornerstone in the treatment of numerous immune-mediated diseases, mycophenolate mofetil (MMF) was first introduced as an immunosuppressive agent in transplant immunology and later received the attention of rheumatologists and clinicians involved in the management of autoimmune diseases. MMF is now a widespread immunosuppressive drug for the treatment of several conditions, including lupus nephritis, interstitial lung disease associated with systemic sclerosis, and anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis while being efficacious also as rescue therapy in various orphan diseases, including dermatomyositis and IgA-associated nephropathy. Similarly, case reports or series support a possible use of MMF in other rare autoimmune diseases. Beyond modulating lymphocyte activation, MMF acts on other immune and non-immune cells and these effects may explain the therapeutic profile of this medication. The effects of MMF are broadly characterized by the impact on the immune system and the antiproliferative and antifibrotic changes induced. In this latter case, mechanistic data on fibroblasts may in the future allow to reevaluate the use of MMF in selected patients with inflammatory arthritis or systemic sclerosis. Attention must be paid towards the possible occurrence of adverse events, such as gastrointestinal complaints and teratogenicity, while the risk of infections and cancer related to MMF needs to be further investigated.

Rituximab as the first-line therapy in anti-synthetase syndrome-related interstitial lung disease

Anti-synthetase syndrome (ASS) is an idiopathic inflammatory myopathy (IIM). In comparison to interstitial lung disease (ILD) in polymyositis and dermatomyositis (PM/DM), ILD in ASS is more frequent, has a more aggressive phenotype, a greater involvement of the lungs, and a more rapid onset of pulmonary symptoms. Continuous declines in predicted forced vital capacity (FVC) and dyspnea were the main features of patients who developed end-stage ILD. The severity of ASS at diagnosis dictates when and which immunosuppressant will be started. There is an experience for the usage of RTX in the first, second, and subsequent lines, as well as for reintroduction and salvage therapies. Not all ASS patients will develop severe illness and require intense immunosuppression. Some features associated with poor prognosis include older age, acute or subacute onset, lack of response to steroids, and lower baseline values for FVC and DLCO. Here we hypothesize that RTX should be the first line of treatment for high-risk ILD in ASS to preserve lung function and then maintenance therapy should be continued with the same or another drug depending on the recovery of lung function.

Molecular signature of neutrophil extracellular trap mediating disease module in idiopathic inflammatory myopathy

The rarity and heterogeneity of idiopathic inflammatory myopathy (IIM) pose challenges for researching IIM in affected individuals. We analyzed integrated transcriptomic datasets obtained using muscle tissues from patients with five distinct IIM subtypes to investigate the shared and distinctive cellular and molecular characteristics. A transcriptomic dataset of muscle tissues from normal controls (n = 105) and patients with dermatomyositis (n = 89), polymyositis (n = 33), inclusion body myositis (n = 121), immune-mediated necrotizing myositis (n = 75), and anti-synthetase syndrome (n = 18) was used for differential gene-expression analysis, functional-enrichment analysis, gene set-enrichment analysis, disease-module identification, and kernel-based diffusion scoring. Damage-associated molecular pattern-associated pathways and neutrophil-mediated immunity were significantly enriched across different IIM subtypes, although their activities varied. Interferons-signaling pathways were differentially activated across all five IIM subtypes. In particular, neutrophil extracellular trap (NET) formation was significantly activated and correlated with Fcγ R-mediated signaling pathways. NET formation-associated genes were key for establishing disease modules, and FCGRs, C1QA, and SERPINE1 markedly perturbed the disease modules. Integrated transcriptomic analysis of muscle tissues identified NETs as key components of neutrophil-mediated immunity involved in the pathogenesis of IIM subtypes and, thus, has therapeutically targetable value.

Clinical Outcomes With and Without Plasma Exchange in the Treatment of Rapidly Progressive Interstitial Lung Disease Associated With Idiopathic Inflammatory Myopathy

BACKGROUND/OBJECTIVE

A subset of patients with idiopathic inflammatory myopathy (IIM) develops highly fatal, rapidly progressive interstitial lung disease (RP-ILD). Treatment strategies consist of glucocorticoid and adjunctive immunosuppressive therapies. Plasma exchange (PE) is an alternative therapy, but its benefit is unclear. In this study, we aimed to determine whether PE benefited outcomes for patients with RP-ILD.

METHODS

In this medical records review study, we compared baseline characteristics and clinical outcomes for 2 groups of patients with IIM-related RP-ILD: those who received and did not receive PE.

RESULTS

Our cohort consisted of 15 patients, 9 of whom received PE. Baseline demographic characteristics and severity of lung, skin, and musculoskeletal disease between the 2 groups of patients were not significantly different. Five patients required mechanical ventilation (2, PE; 3, no PE). Plasma exchange was generally a third-line adjunctive treatment option. The PE group had a longer median (interquartile range) hospitalization (27.0 [23.0-36.0] days) than the non-PE group (12.0 [8.0-14.0] days) ( p = 0.02). There was a potential benefit in 30-day mortality improvement in those receiving PE (0% vs 33%, p = 0.14), with a statistically significant improvement in 2 important composite end points including 30-day mortality or need for lung transplant (0% vs 50%, p = 0.04) and 1-year mortality or need for lung transplant or hospital readmission for RP-ILD in those receiving PE (22% vs 83%, p = 0.04).

CONCLUSIONS

Plasma exchange may be an underutilized, safe salvage therapy for patients with IIM-related RP-ILD when other immunosuppressive therapies fail.

A Narrative Review of Acthar Gel for the Treatment of Myositis

Idiopathic inflammatory myopathies (IIMs) are autoimmune disorders characterized by symmetric proximal muscle weakness and chronic inflammation, with an increased risk of morbidity and mortality. The current standard of care includes traditional immunosuppressive pharmacotherapies; however, some patients cannot tolerate or do not adequately respond to these therapies, highlighting the need for alternative treatments for refractory disease. Acthar^® Gel (repository corticotropin injection) is a naturally sourced mixture of adrenocorticotropic hormone analogs and other pituitary peptides that has been approved by the US Food and Drug Administration since 1952 for use in patients with two subgroups of IIMs, dermatomyositis (DM) and polymyositis (PM). However, it has not been routinely used in the treatment of IIMs. While Acthar may induce steroidogenesis, it also has a steroid-independent mechanism of action by exerting immunomodulatory effects through the activation of melanocortin receptors on immune cells, such as macrophages, B cells, and T cells. Recent clinical trials, retrospective analyses, and case reports add to the growing evidence suggesting that Acthar may be effective in patients with DM and PM. Here we review the current evidence supporting the safety and efficacy of Acthar for the treatment of refractory DM and PM.

Targeting intracellular pathways in idiopathic inflammatory myopathies: A narrative review

In recent decades, several pieces of evidence have drawn greater attention to the topic of innate immunity, in particular, interferon (IFN) and Interleukin 6 in the pathogenesis of idiopathic inflammatory myopathies (IIM). Both of these molecules transduce their signal through a receptor coupled with Janus kinases (JAK)/signal transducer and activator of transcription proteins (STAT). In this review, we discuss the role of the JAK/STAT pathway in IIM, evaluate a possible therapeutic role for JAK inhibitors in this group of diseases, focusing on those with the strongest IFN signature (dermatomyositis and antisynthetase syndrome).

An observational study of clinical recurrence in patients with interstitial lung disease related to the antisynthetase syndrome

OBJECTIVE

To describe the clinical characteristics and risk factors of clinical recurrence in interstitial lung disease related to antisynthetase syndrome (ARS-ILD).

METHODS

Patients diagnosed as ARS-ILD in Nanjing Drum Tower Hospital between January 2015 and November 2020 were retrospectively analyzed. Clinical information and treatment course were reviewed. The primary endpoint was the disease recurrence, and the secondary point was mortality. Univariate and multivariable Cox regression analyses were performed to identify risk factors for recurrence.

RESULTS

Totally, 132 patients with ARS-ILD received immunomodulation treatment from diagnosis. During follow-ups, sixty-nine patients showed recurrence, with a recurrency rate yielding 52.3%. The median duration from treatment initiation to recurrence was 11 (5-18) months. The median tapering course in the recurrence group was 8 (3-12.5) months, which was significantly shorter than the 16 (10-32) months in the no-recurrence group (p < 0.001). Fifty-eight patients experienced recurrence when the glucocorticoids (GC) dose dropped to 10 (9.375-15) mg/day. Twelve patients discontinued GC with a median treatment course of 11.5 (8-16.75) months, and 11 patients developed recurrence after discontinuing GC for 3 (1-4) months. Twelve patients died, with a mortality rate of 9.1%, and recurrence was not associated with increased mortality. The adjusted multivariate analysis showed that age, increased serum lactate dehydrogenase (LDH) level, relatively shorter tapering duration, and inappropriate GC discontinuation were associated with recurrence.

CONCLUSION

Recurrence of ARS-ILD was common during medication intensity reduction. Age, LDH, medication tapering duration, and discontinuation were risk factors for recurrence. Further efforts to reduce recurrence should take into consideration of these factors. Key Points • Recurrence is observed commonly with a recurrency rate 52.3% in patients with interstitial lung disease related to antisynthetase syndrome (ARS-ILD) when glucocorticoids (GC) tapering or discontinuation. • Age, increased serum lactate dehydrogenase (LDH) level, medication tapering duration, and GC discontinuation were identified to be significantly associated with the recurrence of ARS-ILD.

A bibliometric analysis of idiopathic inflammatory myopathies from 1982 to 2021

OBJECTIVE

There has been an increasing number of literature related to idiopathic inflammatory myopathies (IIM) in the past few decades. However, there is a lack of intuitive and systematic analysis of research on IIM. Therefore, this study aimed to perform a bibliometric analysis to identify the current trends and hotspots of research on IIM.

METHODS

Articles and reviews on IIM published during 1982-2021 were acquired from the Web of Science Core Collection (WoSCC) database. VOSviewer application was applied to conduct a network analysis of the keywords, institutions, and countries. The top 100 most-cited publications regarding IIM were analyzed.

RESULTS

In total, 665 publications were included. Globally, the USA produced the most articles on IIM (144). Karolinska Institutet was the institution with the most outputs (47). Rheumatology ranked on top of journals, with 47 IIM-related documents collecting a total of 1420 citations. In the area of IIM documents, biomarkers were the most common research theme. According to the co-occurrence analysis of keywords, "cardiac involvement," "criteria," and "refractory adult" were identified as significant future research centers.

CONCLUSION

The scientific literature on IIM has advanced rapidly in the past 4 decades. The classification criteria, treatment, and extramuscular manifestations of IIM have been identified as promising research frontiers in the field. The global status and trends of the IIM literature from a bibliometric aspect can offer a helpful guidance and new insight for researchers and medical workers in the domain. Key Points • This study reveals the topic trends and knowledge structure of idiopathic inflammatory myopathies literature over the last 40 years. • This study identifies potential future research hotspots, including "cardiac involvement," "criteria," and "refractory adult."

Myositis in Germany: epidemiological insights over 15 years from 2005 to 2019

BACKGROUND

The medical care of patients with myositis is a great challenge in clinical practice. This is due to the rarity of these disease, the complexity of diagnosis and management as well as the lack of systematic analyses.

OBJECTIVES

Therefore, the aim of this project was to obtain an overview of the current care of myositis patients in Germany and to evaluate epidemiological trends in recent years.

METHODS

In collaboration with BARMER Insurance, retrospective analysis of outpatient and inpatient data from an average of approximately 8.7 million insured patients between January 2005 and December 2019 was performed using ICD-10 codes for myositis for identification of relevant data. In addition, a comparative analysis was performed between myositis patients and an age-matched comparison group from other populations insured by BARMER.

RESULTS

45,800 BARMER-insured individuals received a diagnosis of myositis during the observation period, with a relatively stable prevalence throughout. With regard to comorbidities, a significantly higher rate of cardiovascular disease as well as neoplasm was observed compared to the control group within the BARMER-insured population. In addition, myositis patients suffer more frequently from psychiatric disorders, such as depression and somatoform disorders. However, the ICD-10 catalogue only includes the specific coding of "dermatomyositis" and "polymyositis" and thus does not allow for a sufficient analysis of all idiopathic inflammatory myopathies subtypes.

CONCLUSION

The current data provide a comprehensive epidemiological analysis of myositis in Germany, highlighting the multimorbidity of myositis patients. This underlines the need for multidisciplinary management. However, the ICD-10 codes currently still in use do not allow for specific analysis of the subtypes of myositis. The upcoming ICD-11 coding may improve future analyses in this regard.

Rehabilitation and Exercise in Dermatomyositis: A Case Report and Narrative Review of the Literature

Dermatomyositis (DM) is an idiopathic inflammatory myopathy most commonly characterized by proximal, progressive, symmetrical muscle weakness, as well as specific dermatological manifestations. The presence of nuclear matrix protein 2 (NXP-2) autoantibodies is predominantly associated with joint contractures and calcinosis. A 19-year-old female was diagnosed with DM with positive anti-NXP-2 autoantibodies. She had severe joint involvement of the shoulders, elbows, wrists, and ankles, and the presence of calcinosis was documented on radiographs. Concomitantly, she presented with heliotrope erythema on the eyelids and Grotton's papules on the interphalangeal joints of the hands. After performing a diagnostic investigation and beginning targeted therapy, the patient was transferred to an inpatient Physical Medicine and Rehabilitation Department to carry out a rehabilitation program. The patient had a favorable outcome, with improved range of motion and muscle strength, with a Manual Muscle Testing 8 at the time of admission of 73/150, and at discharge from the hospital of 94/150. Regarding the functional scales, she had a Functional Independence Measure at the time of admission of 87/126 and a Barthel Index of 50/100, with an objective improvement at the time of discharge to 118/126 and 90/100, respectively. DM is an insidious chronic disease with multisystemic involvement and can lead to a great loss of independence. Most patients with DM do not recover their previous muscle function, which leads to a negative impact on their quality of life. The institution of an early rehabilitation program seems to have beneficial effects on the functionality and independence of these patients. Its treatment is based on a multidisciplinary approach, and the established rehabilitation program must be individualized and directed to the deficits and limitations of each patient.

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.

The enigma of mixed connective tissue disease-challenges in routine care

OBJECTIVES

As a rare and heterogeneous disease, mixed connective tissue disease (MCTD) represents a challenge. Herein, we aimed to unravel potential pitfalls including correct referral diagnosis, distinction from other connective tissue diseases (CTD) and treatment modalities.

METHODS

We characterised the MCTD cohort at our tertiary referral centre. All patients were evaluated for fulfilment of classification criteria of various CTDs. SLEDAI-2 K and EUSTAR-AI were used in accordance with previous research to evaluate disease activity and treatment response.

RESULTS

Out of 85 patients initially referred as MCTD, only one-third (33/85, 39%) fulfilled the diagnostic MCTD criteria and the other patients had undifferentiated CTD (16/85, 19%), non-MCTD overlap syndromes (11/85, 13%) and other rheumatic diseases. In our final cohort of 33 MCTD patients, 16 (48%) also met the diagnostic criteria of systemic sclerosis, 13 (39%) these of systemic lupus erythematosus, 6 (18%) these of rheumatoid arthritis and 3 (9%) these of primary myositis. Management of MCTD required immunomodulating combination therapy in most cases (15/28, 54%), whereas monotherapy was less frequent (10/28, 36%), and only a few (3/28, 11%) remained without immune modulators until the end of the follow-up period. Treatment led to a significant decline in disease activity.

CONCLUSIONS

Our study showed a high risk for misdiagnosis for patients with MCTD. As a multi-organ disease, MCTD required prolonged immunomodulating therapy to achieve remission. The establishment of an international registry with longitudinal data from observational multi-centre cohorts might represent a first step to address the many unmet needs of MCTD.

High-Dimensional Cytometry Dissects Immunological Fingerprints of Idiopathic Inflammatory Myopathies

Chronic inflammation of skeletal muscle is the common feature of idiopathic inflammatory myopathies (IIM). Given the rarity of the disease and potential difficulty of routinely obtaining target tissue, i.e., standardized skeletal muscle, our understanding of immune signatures of the IIM spectrum remains incomplete. Further insight into the immune topography of IIM is needed to determine specific treatment targets according to clinical and immunological phenotypes. Thus, we used high-dimensional flow cytometry to investigate the immune phenotypes of anti-synthetase syndrome (ASyS), dermatomyositis (DM) and inclusion-body myositis (IBM) patients as representative entities of the IIM spectrum and compared them to healthy controls. We studied the CD8, CD4 and B cell compartments in the blood aiming to provide a contemporary overview of the immune topography of the IIM spectrum. ASyS was characterized by altered CD4 composition and expanded T follicular helper cells supporting B cell-mediated autoimmunity. For DM, unsupervised clustering identified expansion of distinct B cell subtypes highly expressing immunoglobulin G4 (IgG4) and CD38. Lastly, terminally differentiated, cytotoxic CD8 T cells distinguish IBM from other IIM. Interestingly, these terminally differentiated CD8 T cells highly expressed the integrin CD18 mediating cellular adhesion and infiltration. The distinct immune cell topography of IIM might provide the framework for targeted treatment approaches potentially improving therapeutic outcomes.

Trial of Intravenous Immune Globulin in Dermatomyositis

BACKGROUND

Intravenous immune globulin (IVIG) for the treatment of dermatomyositis has not been extensively evaluated.

METHODS

We conducted a randomized, placebo-controlled trial involving patients with active dermatomyositis. The patients were assigned in a 1:1 ratio to receive IVIG at a dose of 2.0 g per kilogram of body weight or placebo every 4 weeks for 16 weeks. The patients who received placebo and those without confirmed clinical deterioration while receiving IVIG could enter an open-label extension phase for another 24 weeks. The primary end point was a response, defined as a Total Improvement Score (TIS) of at least 20 (indicating at least minimal improvement) at week 16 and no confirmed deterioration up to week 16. The TIS is a weighted composite score reflecting the change in a core set of six measures of myositis activity over time; scores range from 0 to 100, with higher scores indicating greater improvement. Key secondary end points included at least moderate improvement (TIS ≥40) and major improvement (TIS ≥60), and change in score on the Cutaneous Dermatomyositis Disease Area and Severity Index.

RESULTS

A total of 95 patients underwent randomization: 47 patients were assigned to the IVIG group, and 48 to the placebo group. At 16 weeks, 79% of the patients in the IVIG group (37 of 47) and 44% of those in the placebo group (21 of 48) had a TIS of at least 20 (difference, 35 percentage points; 95% confidence interval, 17 to 53; P<0.001). The results with respect to the secondary end points, including at least moderate improvement and major improvement, were generally in the same direction as the results of the primary end-point analysis, except for the change in creatine kinase level (an individual core measure of the TIS), which did not differ meaningfully between the two groups. Over 40 weeks, 282 treatment-related adverse events occurred in the IVIG group, including headache (in 42% of patients), pyrexia (in 19%), and nausea (in 16%). A total of 9 serious adverse events that were considered to be related to IVIG occurred, including 6 thromboembolic events.

CONCLUSIONS

In this 16-week trial involving adults with dermatomyositis, the percentage of patients with a response of at least minimal improvement based on a composite score of disease activity was significantly greater among those who received IVIG than among those who received placebo. IVIG was associated with adverse events, including thromboembolism. (Funded by Octapharma Pharmazeutika; ProDERM ClinicalTrials.gov number, NCT02728752.).

The effect of immunosuppressive therapy on cardiac involvements in anti-mitochondrial antibody-positive myositis

AIMS

Anti-mitochondrial antibody (AMA)-positive myositis is frequently associated with various cardiac involvements, such as arrhythmia and left ventricular (LV) dysfunction. However, the efficacy of immunosuppressive therapy in these complications remains unknown. This study aimed to investigate the cardiac response to immunosuppressive therapy in patients with AMA-positive myositis.

METHODS AND RESULTS

The clinical data of 15 AMA-positive myositis patients with cardiac involvement were retrospectively collected at our centre. To evaluate the effects of immunosuppressive therapy, echocardiographic and laboratory data of patients who received glucocorticoid therapy with additional immunosuppressants (n = 6) and those who did not (n = 6) were compared. Also, the characteristics of patients with or without >5% LV ejection fraction (LVEF) decline during the follow-up period (n = 5 vs. n = 7) were compared. Thirteen patients (87%) had arrhythmias, and eight patients (53%) had LV wall motion abnormalities. Although arrhythmias decreased after treatment, reduced LVEF and LV wall motion abnormalities persisted. Further investigation revealed an increased LV end-systolic dimension and reduced LVEF in patients without additional immunosuppressive therapy, while those in patients with additional immunosuppressive therapy were maintained. Six of seven patients (86%) without LVEF decline received additional immunosuppressive therapy, whereas no patients with LVEF decline had additional immunosuppressive therapy.

CONCLUSIONS

Cardiac involvement in AMA-positive myositis may worsen even with glucocorticoid monotherapy, and there might be some associations between the change of LV function and additional immunosuppressive therapy.

Severe Immune-Related Adverse Events: A Case Series of Patients Needing Hospital Admission in a Spanish Oncology Referral Center and Review of the Literature

Immune checkpoint inhibitors (ICI) have revolutionized the landscape of cancer treatment. Although several studies have shown that ICIs have a better safety profile than chemotherapy, some patients develop immune-related adverse events (irAEs), which require specialized and multidisciplinary management. Since ICI indications are rapidly increasing, it is crucial that clinicians involved in cancer care learn to identify irAEs and manage them properly. Here, we report a case series of 23 patients with severe irAEs requiring hospitalization over a period of 12 months and seize the opportunity to review and update different general features related to irAEs along with the management of the most frequent severe irAEs in our series.

Impaired physical function in patients with idiopathic inflammatory myopathies: results from the multicentre COVAD patient-reported e-survey

OBJECTIVES

The assessment of physical function is fundamental in the management of patients with idiopathic inflammatory myopathies (IIMs). We aimed to investigate the physical function of patients with IIMs compared with those with non-IIM autoimmune rheumatic diseases (AIRDs) utilizing Patient-Reported Outcome Measurement Information System (PROMIS) Physical Function (PF) data obtained in the COVAD study, an international self-reported e-survey assessing the safety of COVID-19 vaccines in AIRDs.

METHODS

Demographics, AIRD diagnosis, disease activity, and PROMIS PF short form-10a data were extracted from the COVAD database. PROMIS PF-10a scores were compared between disease categories and stratified by disease activity. Factors affecting PROMIS PF-10a scores other than disease activity were identified by multivariable regression analysis in patients with inactive disease.

RESULTS

A total of 1057 IIM patients, 3635 non-IIM AIRD patients and 3981 healthy controls (HCs) responded to the COVAD e-survey from April to August 2021. Using a binomial regression model, the predicted mean of PROMIS PF-10a scores was significantly lower in IIM patients compared with non-IIM AIRD patients or HCs [36.3 (95% CI 35.5, 37.1) vs 41.3 (95% CI 40.2, 42.5) vs 46.2 (95% CI 45.8, 46.6), P < 0.001], irrespective of disease activity. The independent factors for lower PROMIS PF-10a scores in patients with inactive disease were older age, female, longer disease duration, and a diagnosis of inclusion body myositis or polymyositis.

CONCLUSION

Physical function is significantly impaired in IIMs compared with non-IIM AIRDs or HCs, even in patients with inactive disease. Our study highlights a critical need for better strategies to minimize functional disability in patients with IIMs.

Skeletal muscle provides the immunological micro-milieu for specific plasma cells in anti-synthetase syndrome-associated myositis

Anti-synthetase syndrome (ASyS)-associated myositis is a major subgroup of the idiopathic inflammatory myopathies (IIM) and is characterized by disease chronicity with musculoskeletal, dermatological and pulmonary manifestations. One of eight autoantibodies against the aminoacyl-transferase RNA synthetases (ARS) is detectable in the serum of affected patients. However, disease-specific therapeutic approaches have not yet been established.To obtain a deeper understanding of the underlying pathogenesis and to identify putative therapeutic targets, we comparatively investigated the most common forms of ASyS associated with anti-PL-7, anti-PL-12 and anti-Jo-1. Our cohort consisted of 80 ASyS patients as well as healthy controls (n = 40), diseased controls (n = 40) and non-diseased controls (n = 20). We detected a reduced extent of necrosis and regeneration in muscle biopsies from PL-12⁺ patients compared to Jo-1⁺ patients, while PL-7⁺ patients had higher capillary dropout in biopsies of skeletal muscle. Aside from these subtle alterations, no significant differences between ASyS subgroups were observed. Interestingly, a tissue-specific subpopulation of CD138⁺ plasma cells and CXCL12⁺/CXCL13⁺CD20⁺ B cells common to ASyS myositis were identified. These cells were localized in the endomysium associated with alkaline phosphatase⁺ activated mesenchymal fibroblasts and CD68⁺MHC-II⁺CD169⁺ macrophages. An MHC-I⁺ and MHC-II⁺ MxA negative type II interferon-driven milieu of myofiber activation, topographically restricted to the perifascicular area and the adjacent perimysium, as well as perimysial clusters of T follicular helper cells defined an extra-medullary immunological niche for plasma cells and activated B cells. Consistent with this, proteomic analyses of muscle tissues from ASyS patients demonstrated alterations in antigen processing and presentation. In-depth immunological analyses of peripheral blood supported a B-cell/plasma-cell-driven pathology with a shift towards immature B cells, an increase of B-cell-related cytokines and chemokines, and activation of the complement system. We hypothesize that a B-cell-driven pathology with the presence and persistence of a specific subtype of plasma cells in the skeletal muscle is crucially involved in the self-perpetuating chronicity of ASyS myositis. This work provides the conceptual framework for the application of plasma-cell-targeting therapies in ASyS myositis.

Management of interstitial lung disease (ILD) in myositis syndromes: A practical guide for clinicians

Inflammatory myopathies are heterogeneous clinico-serological syndromes, with variable clinical manifestations. Interstitial lung disease (ILD) is a major cause of morbidity and mortality in patients with myositis. The clinical manifestation of myositis-ILD is heterogeneous, e.g., with acute-on-chronic presentations, as well as the chronic aftermath of acute disease. Here, we have largely divided myositis-ILD into three main prognostic groups which require different treatment approaches: mild-moderate (subacute), severe or progressive (acute or subacute) and rapidly progressive, life-threatening. In current clinical practice, the treatment of myositis-ILD involves immunomodulation in an induction-maintenance treatment paradigm. There is now an option to add antifibrotics to slow the progression of established fibrosis in selected cases with chronic progressive phenotype. Here, we describe current concepts in myositis-ILD and aim to provide a practical guide for clinicians on how to approach assessment, including early identification of ILD, phenotyping of patients according to clinical trajectory and likely prognosis and stratified management adopting multi-disciplinary cross-speciality expertise, with close collaboration between rheumatology and respiratory physicians.

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).

Anti-MDA5 Antibody Linking COVID-19, Type I Interferon, and Autoimmunity: A Case Report and Systematic Literature Review

Introduction

The SARS-CoV-2 infection has been advocated as an environmental trigger for autoimmune diseases, and a paradigmatic example comes from similarities between COVID-19 and the myositis-spectrum disease associated with antibodies against the melanoma differentiation antigen 5 (MDA5) in terms of clinical features, lung involvement, and immune mechanisms, particularly type I interferons (IFN).

Case Report

We report a case of anti-MDA5 syndrome with skin manifestations, constitutional symptoms, and cardiomyopathy following a proven SARS-CoV-2 infection.

Systematic Literature Review

We systematically searched for publications on inflammatory myositis associated with COVID-19. We describe the main clinical, immunological, and demographic features, focusing our attention on the anti-MDA5 syndrome.

Discussion

MDA5 is a pattern recognition receptor essential in the immune response against viruses and this may contribute to explain the production of anti-MDA5 antibodies in some SARS-CoV-2 infected patients. The activation of MDA5 induces the synthesis of type I IFN with an antiviral role, inversely correlated with COVID-19 severity. Conversely, elevated type I IFN levels correlate with disease activity in anti-MDA5 syndrome. While recognizing this ia broad area of uncertainty, we speculate that the strong type I IFN response observed in patients with anti-MDA5 syndrome, might harbor protective effects against viral infections, including COVID-19.

Single-Cell Transcriptomics Reveals Peripheral Immune Responses in Anti-Synthetase Syndrome-Associated Interstitial Lung Disease

OBJECTIVE

Interstitial lung diseases (ILDs) secondary to anti-synthetase syndrome (ASS) greatly influence the prognoses of patients with ASS. Here we aimed to investigate the peripheral immune responses to understand the pathogenesis of this condition.

METHODS

We performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) from 5 patients with ASS-ILD and 3 healthy donors (HDs). Flow cytometry of PBMCs was performed to replenish the results of scRNA-seq.

RESULTS

We used scRNA-seq to depict a high-resolution visualization of cellular landscape in PBMCs from patients with ASS-ILD. Patients showed upregulated interferon responses among NK cells, monocytes, T cells, and B cells. And the ratio of effector memory CD8 T cells to naïve CD8 T cells was significantly higher in patients than that in HDs. Additionally, Th1, Th2, and Th17 cell differentiation signaling pathways were enriched in T cells. Flow cytometry analyses showed increased proportions of Th17 cells and Th2 cells, and decreased proportion of Th1 cells in patients with ASS-ILD when compared with HDs, evaluated by the expression patterns of chemokine receptors.

CONCLUSIONS

The scRNA-seq data analyses reveal that ASS-ILD is characterized by upregulated interferon responses, altered CD8 T cell homeostasis, and involvement of differentiation signaling pathways of CD4 T cells. The flow cytometry analyses show that the proportions of Th17 cells and Th2 cells are increased and the proportion of Th1 cells is decreased in patients with ASS-ILD. These findings may provide foundations of novel therapeutic targets for patients with this condition.

Pathophysiological Mechanisms and Treatment of Dermatomyositis and Immune Mediated Necrotizing Myopathies: A Focused Review

Idiopathic inflammatory myopathies (IIM), collectively known as myositis, are a composite group of rare autoimmune diseases affecting mostly skeletal muscle, although other organs or tissues may also be involved. The main clinical feature of myositis is subacute, progressive, symmetrical muscle weakness in the proximal arms and legs, whereas subtypes of myositis may also present with extramuscular features, such as skin involvement, arthritis or interstitial lung disease (ILD). Established subgroups of IIM include dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), overlap myositis (OM) and inclusion body myositis (IBM). Although these subgroups have overlapping clinical features, the widespread variation in the clinical manifestations of IIM suggests different pathophysiological mechanisms. Various components of the immune system are known to be important immunopathogenic pathways in IIM, although the exact pathophysiological mechanisms causing the muscle damage remain unknown. Current treatment, which consists of glucocorticoids and other immunosuppressive or immunomodulating agents, often fails to achieve a sustained beneficial response and is associated with various adverse effects. New therapeutic targets have been identified that may improve outcomes in patients with IIM. A better understanding of the overlapping and diverging pathophysiological mechanisms of the major subgroups of myositis is needed to optimize treatment. The aim of this review is to report on recent advancements regarding DM and IMNM.

Even if it looks like COVID-19, think again: the importance of differential diagnosis during a pandemic

INTRODUCTION

Antisynthetase syndrome (ASSD) is a rare auto-immune condition that can present as interstitial lung disease (ILD) and progress into Acute Respiratory Distress Syndrome (ARDS).

IMPORTANCE

The purpose of this clinical case is to highlight the importance of considering less prevalent causes of ARDS amid the COVID-19 pandemic.

CASE REPORT

We present a 56-year-old Belgian female of African descent without past medical history who demonstrated typical signs of COVID-19 at the start of the pandemic. Based on the disease course as well as CT-scan findings, a diagnosis of COVID-19 was made. She progressed to ARDS for which she got intubated and was started on venovenous membrane oxygenation (VV-ECMO). Despite initial negative screening for antinuclear antibodies, further analysis revealed anti-Jo-antibodies. Diagnosis of ASSD was eventually retained and immunosuppressive therapy was started. However, pulmonary fibrosis had evolved too far and therapy was halted shortly after.

Modification of Intestinal Microbiota Dysbiosis by Low-Dose Interleukin-2 in Dermatomyositis: A Post Hoc Analysis From a Clinical Trial Study

The microbiota has been observed altered in autoimmune diseases, including idiopathic inflammatory myopathies (IIMs), and associated with different treatments. Low-dose IL-2 treatment emerges as a new option for active IIMs. This study aims to explore the role of low-dose IL-2 in regulating intestinal dysbiosis involved in the IIMs. In this study, 13 patients with active IIMs were enrolled and received 1 ×10⁶ IU of IL-2 subcutaneously every other day for 12 weeks plus standard care. The clinical response and immune response were assessed. Stool samples were obtained to explore the structural and functional alterations of the fecal microbiota targeting the V3–V4 region of the 16S rRNA gene and analyze their associations with clinical and immunological characteristics. Our study demonstrated that diversity of microbiota decreased remarkably in patients with IIMs, compared to healthy controls. The inflammatory-related bacteria, such as Prevotellaceae increased, while some butyrate-producing bacteria, such as Pseudobutyrivibrio, Lachnospiraceae, Roseburia, and Blautia, decreased significantly. The alteration associated with disease activities in patients with IIMs. After low-dose IL-2 treatment, 92.31% (12/13) of patients achieved IMACS DOI at week 12. Proportion of Treg cells significantly increased at week 12 compared with that in baseline (15.9% [7.73, 19.4%] vs. 9.89% [6.02, 11.8%], P = 0.015). Interestingly, certain butyrate-producing bacteria increase significantly after IL-2 treatment, like Lachnospiraceae, Pseudobutyrivibrio, etc., and are associated with a rise in L-Asparagine and L-Leucine. The effects of low-dose IL-2 on gut microbiota were more apparent in NOD mice. Together, the data presented demonstrated that low-dose IL-2 was effective in active IIMs and highlighted the potential for modifying the intestinal microbiomes of dysbiosis to treat IIMs.

Role of Intravenous Immunoglobulin in Necrotizing Autoimmune Myopathy

BACKGROUND/OBJECTIVE

Immune-mediated necrotizing myopathy (IMNM) is a subtype of myositis that is associated with a refractory phenotype and poorer prognosis. The aim of the study was to provide single large center experience of outcomes of intravenous immunoglobulin (IVIg) for patients with IMNM using longitudinally collected data.

METHODS

This case series longitudinally evaluated 4 of the 6 myositis core set measures at baseline and at 3 and 6 months after IVIg on 20 adult IMNM patients from 2014 to 2019 at the University of Pittsburgh. We assessed patients for improvement in core set measures, prednisone dose, adverse effects, and by the "limited" ACR/EULAR 2016 myositis response criteria. The mean differences in CK and manual muscle testing (MMT-8) were compared using a paired t test. A clinically significant response was defined as a >10% absolute improvement in the MMT-8 and a >50% absolute reduction in serum CK at 6 months of IVIg.

RESULTS

Intravenous immunoglobulin treatment was associated with marked improvement in IMNM patients, with 85% of patient meeting clinically significant response. The median (interquartile range) relative percent improvement in CK level was 96% (85%-98%) and in MMT was 29% (14%-36%) at 6 months.There was a significant reduction in the mean (SD) dose of prednisone at 6 months and had minimal adverse effects. In addition, with IVIg, most (13/14) patients had at least minimal improvement as per ACR/EULAR 2016 myositis response criteria.

CONCLUSIONS

Based on objective, meaningful improvement in MMT-8 and CK as well as marked reduction in prednisone doses with acceptable tolerability, early implementation of IVIg should be considered in adult IMNM.