Cyclosporin A and intravenous immunoglobulin treatment in polymyositis/dermatomyositis

Pharmacological Strategies in Dermatomyositis: Current Treatments and Future Directions

Dermatomyositis (DM) is a complex and rare autoimmune disease characterized by muscle weakness and distinctive skin rashes. Its pathogenesis involves a combination of genetic susceptibility, environmental triggers, and immunological factors, with interferon pathways and specific gene upregulations playing crucial roles. Diagnosis is based on clinical presentation, laboratory findings, and imaging, with particular emphasis on myositis-specific antibodies and characteristic muscle and skin changes. The clinical heterogeneity of DM, including variants such as clinically amyopathic DM and DM-associated interstitial lung disease, necessitates a personalized diagnostic and therapeutic approach. Current pharmacological treatments for DM include glucocorticoids, which remain the first-line therapy despite their long-term adverse effects. Immunosuppressants, such as azathioprine, methotrexate, and mycophenolate mofetil, are commonly used in combination with glucocorticoids to enhance efficacy and reduce steroid dependence. Biologics, such as rituximab and intravenous immunoglobulin, have shown effectiveness in refractory cases. Emerging therapies, particularly Janus kinase inhibitors, offer promise for treatment-resistant DM, although they present significant safety concerns, including increased risks of infections and cardiovascular events. Despite significant advancements, managing DM remains challenging due to its rarity and variability. Future research should prioritize the development of precision medicine approaches tailored to individual genetic and pathological features. Additionally, integrated treatment strategies combining pharmacological and non-pharmacological interventions are crucial to improving patient outcomes and quality of life. Understanding the etiology and pathogenesis of DM more deeply will be vital for developing more effective and targeted treatments, ultimately leading to better disease management and prognosis.

Subcutaneous immunoglobulin for patients with idiopathic inflammatory myopathies: a real-world, single-centre experience

OBJECTIVES

Idiopathic inflammatory myopathies (IIMs) are heterogeneous diseases characterized by skeletal muscle inflammation associated with cutaneous, pulmonary and/or other visceral organ involvement. IVIG has been recommended as an adjunct therapy for IIM patients refractory to conventional therapy. However, IVIG has high resource needs and increased risk of adverse reactions. Subcutaneous immunoglobulin (SCIG) therapy has been used as an alternative to IVIG in primary immunodeficiencies and neuroinflammatory disorders. We assessed the satisfaction, patient preference and effectiveness in IIM patients who transitioned from IVIG to SCIG.

METHODS

We retrospectively reviewed consecutive 20 patients with IIM who were transitioned from IVIG to SCIG therapy for >12 months. Patient preference between IVIG and SCIG was surveyed using a questionnaire previously used in studies of neuroinflammatory conditions. In addition, disease flares, changes in immunosuppression, cumulative prednisone doses and global disease activity were evaluated using the Myositis Intention to Treat Index (MITAX) 12 months pre- and post-SCIG initiation.

RESULTS

Most patients (78.9%) preferred SCIG over IVIG and preferred home-based therapies to hospital-based therapies. There was no significant difference in global disease activity (MITAX 3.31 vs 3.02) or in cumulative steroid doses 12 months pre- or post-SCIG initiation. Three patients experienced disease flares, five escalated in immunosuppression, while four patients deescalated in immunosuppressive medications.

CONCLUSIONS

SCIG is preferred by most patients over IVIG without a substantial increased disease activity or need for additional CS. Future cost-effectiveness studies may provide an additional rationale for utilizing SCIG over IVIG for maintenance therapy for IIM.

Safety and tolerability of intravenous immunoglobulin in patients with active dermatomyositis: results from the randomised, placebo-controlled ProDERM study

BACKGROUND

Dermatomyositis is an idiopathic inflammatory myopathy characterised by rashes and progressive muscle weakness. The recent ProDERM (Progress in DERMatomyositis) study is the first large randomised, placebo-controlled trial to establish the efficacy and safety of intravenous immunoglobulin (IVIg) in adult patients with dermatomyositis. Objectives of this analysis were to closely examine the safety and tolerability of IVIg in patients from the ProDERM study.

METHODS

ProDERM was a double-blind, randomised, placebo-controlled, multicentre, phase 3 study. In the first period (weeks 0-16), adults with active dermatomyositis received 2.0 g/kg IVIg (Octagam 10%; Octapharma AG) or placebo every 4 weeks. In the open-label extension period (weeks 16-40), all patients received IVIg for 6 additional cycles; dose reduction (1.0 g/kg) was permitted if patients were stable. Treatment-emergent adverse events (TEAEs) were documented.

RESULTS

The 95 patients enrolled were randomised to receive IVIg (N = 47) or placebo (N = 48) in the first period, with 5 switching from placebo to IVIg. Overall, 664 IVIg infusion cycles were administered. During the first period, 113 TEAEs were possibly/probably related to treatment in 30/52 patients (57.7%) receiving IVIg and 38 in 11 patients (22.9%) on placebo. Eight patients discontinued therapy due to IVIg-related TEAEs. Eight thromboembolic events (TEEs) occurred in six patients on IVIg; six in five patients were deemed possibly/probably related to IVIg. Patients with TEEs exhibited more baseline TEE risk factors than those without TEEs (2.4-15.2-fold higher). Lowering infusion rate reduced the rate of TEEs, and none occurred at the lower IVIg dose. No haemolytic transfusion reactions or deaths occurred.

CONCLUSIONS

Results from this study demonstrate that IVIg has a favourable safety profile for treatment of adult dermatomyositis patients and provides evidence that will help to inform treatment choice for these patients. Dermatomyositis patients receiving high-dose IVIg should be monitored for TEEs, and a low rate of infusion should be used to minimise TEE risk, particularly in those with pre-existing risk factors.

TRIAL REGISTRATION

ProDERM study (NCT02728752).

Intravenous Immunoglobulin for Inflammatory Myositis: Experience in a Tertiary Medical Center

INTRODUCTION

Inflammatory myopathies are treated with glucocorticoids and other immunosuppressive medications. Intravenous immunoglobulin (IVIG) is increasingly used for refractory or severe cases; however, the evidence for their effectiveness is limited. We assessed effectiveness and safety of IVIG when used with other immunomodulatory agents in the treatment of inflammatory myopathies.

METHODS

This study reviewed records of patients diagnosed with dermatomyositis or polymyositis and treated with IVIG, from 2009 through 2016 in 1 tertiary medical center. Mixed-effects general linear regression models were applied to determine effectiveness of treatment on muscle strength, creatinine phosphokinase levels, and steroid dosage.

RESULTS

Twenty-three patients with dermatomyositis/polymyositis treated with IVIG were followed up for a mean of 31 (SD, ±25) months. During this period, a significant improvement in muscle strength was demonstrated, with a mean increase of 0.92 Medical Research Council scale points (β = 0.14; confidence interval [CI], 0.136-0.149; p < 0.0001), a significant reduction of creatinine phosphokinase levels and steroid dosage with a mean decrease of 1140 IU/L (β = -0.274; CI, -0.354 to -0.195; p < 0.0001), and 36 mg/d (β = -0.008; CI, -0.011 to -0.006; p < 0.0001), respectively. Overall, remission was observed in 10 patients (43.5%), and partial remission in 6 patients (26%), whereas 1 patient (17%) remained refractory to treatment, and 6 patients (27%) were lost to follow-up.

CONCLUSIONS

The majority of patients with inflammatory myopathies experienced a clinical and laboratory improvement during IVIG treatment. In addition, a steroid-sparing effect was noticed in most patients. These results encourage the use of IVIG as an alternative treatment option for patients with limited responsiveness to conventional methods.

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.

Long-term effects of early pulse methylprednisolone and intravenous immunoglobulin in patients with dermatomyositis and polymyositis

OBJECTIVE

To evaluate the long-term effects of pulse intravenous methylprednisolone (IVMP) or intravenous immunoglobulin (IVIG) administered during the first year of diagnosis in dermatomyositis (DM) and polymyositis (PM) patients.

METHODS

This is a retrospective single-center cohort study of patients with DM/PM followed for up to 4 years from 2001 to 2017. We used Cox regression models to estimate hazard ratios (HRs) and assess the effects of early pulse IVMP or IVIG on 3 outcomes: complete clinical response, corticosteroid discontinuation, and survival. Analysis was adjusted for clinical, laboratory, and treatment covariates.

RESULTS

A total of 204 patients were included and categorized into 4 initial treatment groups: pulse IVMP (n = 46), pulse IVMP+IVIG (n = 55), IVIG (n = 10), and without IVMP or IVIG (n = 93). The groups of early pulse IVMP and pulse IVMP+IVIG had a higher HR for complete clinical response in the multivariate models (HR = 1.56, 95% CI = 1.05-2.33, p = 0.029; and HR = 1.58, 95% CI = 1.02-2.45, p = 0.041, respectively). Only the group of pulse IVMP+IVIG had a significant association with corticosteroid discontinuation in the multivariate analysis (HR = 1.65, 95% CI = 1.02-2.68, p = 0.043). Early pulse IVMP or IVIG had no impact on mortality.

CONCLUSION

Despite having a more severe disease profile, patients with DM/PM submitted to pulse IVMP or pulse IVMP+IVIG during the first year of diagnosis had a higher HR for complete clinical response, whereas the combination of pulse IVMP+IVIG had an association with corticosteroid discontinuation. Prospective long-term studies are warranted to confirm these benefits of early pulse IVMP and IVIG on patients with DM/PM.

Real life picture of the use of intravenous immunoglobulins in idiopathic inflammatory myopathies: Results of a multicentric study

BACKGROUND

despite the absence of specific guidelines, the treatment with intravenous immunoglobulins (IvIg) is considered effective in patients with refractory idiopathic inflammatory myopathies (IIM). The aim of our study is to evaluate the effectiveness and the safety of IvIg and define the possible profile of IIM patients candidate to IvIg treatment.

METHODS

we performed a retrospective study of IIM pts. treated with IvIg (2 g/kg/month). We collected demographic, epidemiological, laboratory and clinical data. Additionally, to evaluate the toxicity, the adverse events occurred during the treatment were collected.

RESULTS

123 patients with IIM were included in the study. The main indications for the prescription of IvIg were muscle (83.7% of patients) and esophageal involvement (45.5% of patients). IvIg were started mainly for refractory disease. At the end of treatment (mean duration 14 months), muscular necrosis enzymes decreased significantly and dysphagia VAS decreased significantly (p < 0.001), while MMT value increased (104.6 ± 24.2 vs. 127.0 ± 22.2 p < 0.001). Ninety-six pts. (78%) responded to IvIg. They had a shorter disease duration (p < 0.001), higher creatine kinase levels (p < 0.001), and higher prevalence of myalgias at the baseline (p = 0.023) compared to non-responders. The presence of Raynaud's phenomenon (p = 0.023-odds ratio 0.28 [0.11-0.72]) and skin involvement (p = 0.004, odds ratio 0.18 [0.06-0.55]), were associated to a worse response. Adverse events were mostly mild and transitory.

CONCLUSIONS

Despite their high cost, IvIg confirmed their effectiveness in refractory IIM pts., particularly in muscular and esophageal manifestations. Specific clinical characteristics at the baseline may identify the patients with higher probability of response to the treatment.

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).

Recovering autonomy is a key advantage of home-based immunoglobulin therapy in patients with myositis: A qualitative research study

Immunoglobulins are 2nd or 3rd-line treatments in dermatomyositis (DM) or polymyositis (PM) refractory to high-dose corticosteroids and immunosuppressants. Immunoglobulins (2 g/kg/mo) are usually administered intravenously (IVIg) once a month and the patients stay at hospital for a few days. Recently, subcutaneous injections (SCIg) were proposed 2 to 3 times per week, in some dysimmune diseases. SCIg are administered at home preferably by the patient or by a nurse. We investigated the needs and attitudes of DM and PM patients with experience of IVIg and SCIg.Seven patients (6 PM and 1 DM) from a single center participated in a focus group (N = 6) or underwent in-depth interview (N = 1). Six had the experience of both IVIg at hospital and SCIg at home; 1 has received only IVIg at hospital. Verbatim was recorded and transcribed for further content analysis and computer-aided textual analysis.Clinical profiles and stories were heterogeneous. At diagnosis, muscle weakness, severe pain, and fatigue were at the forefront of patients' complaints impairing daily life. Patients reported considerable improvement with immunoglobulins. SCIg were described as easy, less disruptive for daily life, well tolerated, and less time-consuming. SCIg self-administration at home restored the feeling of autonomy and control.Interviews of DM and PM patients revealed that recovering autonomy and control was a central advantage of home-based SCIg that were efficient, well tolerated, and perceived as a good compromise between treatment burden and efficacy.

Immunoglobulin Treatment in Neuromuscular Medicine

Intravenous immunoglobulin (IVIg) is used in the treatment of autoimmune diseases, including immune-mediated central and peripheral nervous system disorders. This article will review the indications, proposed mechanism of actions, and administration of immunoglobulin treatment in various neuropathies, neuromuscular junction disorders, and myopathies. IVIg may have more than one mechanism of action to alter the pathogenesis of underlying neuromuscular disease. IVIg treatment has been used as a first-line treatment in Guillain-Barre syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy, and second-line off-label treatment in medically refractory cases of polymyositis, dermatomyositis, and myasthenia gravis. IVIg is a well-tolerated and effective treatment for these neuromuscular diseases. With this review article, we hope to increase clinicians' awareness of the indications and efficiencies of IVIg in a broad spectrum of neuromuscular diseases.

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

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

Autoimmune Myopathies: Updates on Evaluation and Treatment

The major forms of autoimmune myopathies include dermatomyositis (DM), polymyositis (PM), myositis associated with antisynthetase syndrome (ASS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). While each of these conditions has unique clinical and histopathological features, they all share an immune-mediated component. These conditions can occur in isolation or can be associated with systemic malignancies or connective tissue disorders (overlap syndromes). As more has been learned about these conditions, it has become clear that traditional classification schemes do not adequately group patients according to shared clinical features and prognosis. Newer classifications are now utilizing myositis-specific autoantibodies which correlate with clinical and histopathological phenotypes and risk of malignancy, and help in offering prognostic information with regard to treatment response. Based on observational data and expert opinion, corticosteroids are considered first-line therapy for DM, PM, ASS, and IMNM, although intravenous immunoglobulin (IVIG) is increasingly being used as initial therapy in IMNM related to statin use. Second-line agents are often required, but further prospective investigation is required regarding the optimal choice and timing of these agents.

Current Treatment for Myositis

PURPOSE OF REVIEW

The purpose of this review was to give an update on treatment modalities for patients with idiopathic inflammatory myopathies, or shortly myositis, excluding the subgroup inclusion body myositis, based on a literature survey on therapies used in myositis. Few controlled trials have been performed in patients with myositis; therefore, we also included a summary of open-label trials, case series, and case reports.

RECENT FINDINGS

Glucocorticoid (GC) in high doses is still the first-line treatment of patients with myositis. There is a general recommendation to combine GCs with another immunosuppressive agent in the early phase of disease to better control disease activity and possibly to reduce the risk for GC-related side effects. Furthermore, combining pharmacological treatment with individualized and supervised exercise can be recommended based on evidence. There is some evidence for the effect of rituximab in patients with certain myositis-specific autoantibodies, whereas other biologic agents are currently being tested in clinical trials.

SUMMARY

Immunosuppressive treatment in combination with exercise is recommended for patients with myositis to reduce disease activity and improve muscle performance. Subgrouping of patients into clinical and serological subtypes may be a way to identify biomarkers for response to specific immunosuppressive and biological agents and should be considered in future trials.

Treatment of inflammatory myopathies

INTRODUCTION

The idiopathic inflammatory myopathies (IIM) dermatomyositis (DM) and polymyositis (PM) are chronic diseases affecting the striated muscles with variable involvement of other organs. Glucocorticoids are considered the cornerstone of treatment, but some patients require adjunctive immunosuppressive agents because of insufficient response to glucocorticoids, flares upon glucocorticoid tapering, or glucocorticoid-related adverse events. Areas covered: The aim of this article was to review (PubMed search until February 2018) the evidence on established and new therapies derived from randomized controlled trials (RCTs) on adult DM and PM. In addition, key data from open-label trials, case reports, and abstracts were included where data from RCT were lacking. Expert commentary: Numerous synthetic and biological immunosuppressive agents are currently available to treat the IIM, sometimes in combination. The choice of the specific medication in the individual patient depends upon the disease phenotype and patient's characteristics. Exercise improves muscle performance without causing disease flares and should be an integral part of the treatment of the IIM. Prompt diagnosis and treatment can lead to better outcome.

Intravenous immunoglobulin: a biological corticosteroid-sparing agent in some autoimmune conditions

Intravenous immunoglobulin (IVIg) is increasingly used for the treatment of autoimmune and systemic inflammatory diseases. This compound is effective in a wide range of clinical conditions other than primary immunodeficiency, including autoimmune diseases, inflammatory disorders, infections, organ transplantation, and possibly supportive therapy for cancer. Systemic corticosteroids remain the gold standard treatment for many autoimmune diseases, but their long-term use is associated with complications in diverse organs and systems. Osteoporosis, osteonecrosis, cardiovascular disease, infections, and cancer have been associated with this treatment. Therefore, physicians are occasionally forced to withdraw the treatment with steroids. Biological agents may represent a good alternative, but in addition to being very expensive, these agents may have serious side effects. This review aimed to cover the major advances in the use of IVIg as a steroid-sparing agent in some relevant autoimmune diseases.

The systemic management of cutaneous dermatomyositis: Results of a stepwise strategy

Treatment of dermatomyositis (DM) is often achieved with a stepwise algorithm. However, the literature lacks quality evidence to support the use of this therapeutic strategy. The result of a stepwise therapeutic strategy in the management of skin-only DM is presented to better understand the clinical outcomes and allow for future studies. A cohort of 102 patients with DM, 41 of whom had skin-only disease, were seen between July 2009 and April 2013 at a referral-based connective tissue disease clinic. The Cutaneous Dermatomyositis Disease Area and Severity Index was used to prospectively assess disease severity and the outcomes in 41 adult patients with skin-only DM were analyzed. Of the 41 patients with skin-only DM, 23 patients (56.1%) received antimalarial medications alone and 18 patients (43.9%) received second- or third-line agents. Ten patients (24.4%) remained at the first level of the treatment algorithm and received only hydroxychloroquine. Prednisone was included in the treatment regimen for 11 patients with skin-only disease (26.8%). The results show that management of cutaneous DM often requires second-line agents because antimalarial medications alone are insufficient to treat most patients with skin-only disease.

The Clinical and Histological Spectrum of Idiopathic Inflammatory Myopathies

Idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of myositis, characterised by chronic muscle weakness, cutaneous features, different extra-muscular manifestations and circulating autoantibodies. IIMs included classical polymyositis (PM), dermatomyositis (DM) and other different types of myositis with a wide range of muscle involvement. A complete autoantibody profile and a muscle biopsy are mandatory to correctly diagnose different clinical entities and to define their different prognosis. Bohan and Peter's criteria included five items to diagnose adult onset PM and DM. The sensitivity was 74-100 %, while the specificity is low, due to a poor ability to differentiate PM from neuromuscular diseases. Other criteria included a more accurate histological definition of PM, DM or amyopathic DM, obtaining a higher specificity. Autoantibodies' association, interstitial lung disease and clinical cardiac involvement represent the main items that could define the prognosis of these patients. On the other hand, inclusion body myositis is a different myopathy characterised by a peculiar muscle mass involvement, muscle atrophy and progressive loss of function, due to complete failure to all immunosuppressive drugs used. Treatment of IIMs is based on corticosteroids (CS), which show rapid clinical response and functional improvement. Different immunosuppressant drugs are given to obtain a better control of the disease during CS tapering dose. No controlled double blind trials demonstrated the superiority of one immunesuppressant on another. The occurrence of interstitial lung involvement requires the immediate introduction of immunosuppressants in addiction to CS. Severe dysphagia seems to improve with intravenous immunoglobulins (Ig). Physical therapy could be started after the acute phase of diseases and seems to have a beneficial role in muscle strength recovery.

Critical review of the role of intravenous immunoglobulins in idiopathic inflammatory myopathies

OBJECTIVE

The aim of this review was to summarize key findings from the literature concerning the therapeutic role of intravenous immunoglobulins (IVIg) in idiopathic inflammatory myopathies (IIM), dissecting the evidence according to disease subtype and treatment indication, and to review the evidence relating to the mechanism of action of IVIg in IIM to ascertain rationale for continued research.

METHODS

Medline (Ovid) and Pubmed databases were searched from inception to July 2016 using relevant keywords. Original and review articles were retrieved for full-text review. Bibliographies of selected articles were also hand-searched for additional references. Data were summarized qualitatively and in tabular form.

RESULTS

The efficacy of IVIg in IIM is supported by 3 randomized controlled trials, involving dermatomyositis and polymyositis subjects, in refractory, relapsed, or steroid-dependent disease, as well as part of first-line therapy in elderly dermatomyositis subjects. Other indications for IVIg are supported by uncontrolled evidence only. Limitations of studies include open, uncontrolled or retrospective study designs, small and selected samples, short-term follow-up and ad hoc outcome measures. Despite the limited evidence, there is strong biological plausibility for the role of IVIg in IIM.

CONCLUSION

Robust, controlled evidence to support the use of IVIg using validated outcome measures is urgently required to guide therapeutic decision-making and maximize outcomes in IIM.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies (IIM) consist of rare heterogeneous autoimmune disorders that present with marked proximal and symmetric muscle weakness, except for distal and asymmetric weakness in inclusion body myositis. Despite many similarities, the IIM are fairly heterogeneous from the histopathologic and pathogenetic standpoints, and also show some clinical and treatment-response differences. The field has witnessed significant advances in our understanding of the pathophysiology and treatment of these rare disorders. This review focuses on dermatomyositis, polymyositis, and necrotizing myopathy, and examines current and promising therapies.

[Therapeutic strategy in inflammatory myopathies (polymyositis, dermatomyositis, overlap myositis, and immune-mediated necrotizing myopathy)]

Inflammatory myopathies (IM) are a heterogeneous group of autoimmune muscle disorders of unknown origin that share clinical symptoms such as muscle weakness and histological features with the presence in muscle of inflammatory infiltrate. Based on clinical, histological and serological characteristics, IM can be divided into polymyositis, dermatomyositis, overlap myositis, cancer-associated myositis, immune-mediated necrotizing myopathy, and inclusion-body myositis. Because of their resistance to corticosteroids and immunosuppressive drugs, inclusion-body myositis will be treated separately in this issue. Major obstacles in conducting high quality randomized controlled trials in inflammatory myopathies include the low prevalence and the heterogeneity of these diseases as well as the lack of international consensus on the outcome measures. In the absence of adequate controlled therapeutic trials, treatment of these disorders remains largely empirical. Corticosteroids are the cornerstone therapy. Due to the chronic course of the disease, there is a frequent need to use additional immunosuppressive treatment both to improve the disease response and to reduce the side effects of corticosteroids. Intravenous immunoglobulin infusion is a costly treatment option that is reserved in the presence of refractory dermatomyositis based on a trial showing superior efficacy against control in patients with impaired swallowing or with contraindications to immunosuppressive drugs. In patients who fail second-line therapy, which usually consists of methotrexate plus corticosteroids, the diagnosis should be carefully reassessed before considering other treatment options including methotrexate plus azathioprine or biological agents such as rituximab.

Cutaneous dermatomyositis: an updated review of treatment options and internal associations

Dermatomyositis is a specific type of inflammatory myopathy with characteristic cutaneous findings. Patients may have skin disease without clinically apparent muscle disease, but this disorder is best thought of as a systemic process. Therefore, all patients with dermatomyositis skin lesions need appropriate evaluation for muscle disease, esophageal dysfunction, cardiopulmonary disease, and potential internal malignancy. There are many therapies that have been used for patients with dermatomyositis, but most are based upon case series or expert opinion rather than meta-analyses or randomized, placebo-controlled trials. Even those therapies that have been subjected to randomized, blinded, placebo-controlled trials include a mixture of patients with idiopathic inflammatory myopathy and do not utilize a validated assessment tool for measuring cutaneous disease responses. In this review, we discuss the therapies available as well as the internal associations with dermatomyositis.

Therapeutic advances in myositis

PURPOSE OF REVIEW

To review the treatment advances of the inflammatory myopathies, a heterogeneous group of diseases that includes polymyositis, dermatomyositis, and inclusion body myositis.

RECENT FINDINGS

There are few clinical trials in myositis, making it difficult to provide clear recommendations on the treatment of these rare disorders. The current management for IIM includes the initial use of corticosteroids followed by various conventional second-line treatments such as methotrexate and azathioprine. Although these drugs have not been tested in rigorous randomized controlled trials, general expert consensus confirms their use. Intravenous immunoglobulin is a reasonable short-term treatment with proven benefit in one controlled trial, although the evidence for other immunosuppressive therapies has been derived mainly from uncontrolled studies. Cyclosporine or tacrolimus have shown efficacy in myositis including those patients with interstitial lung disease (ILD), whereas mycophenolate mofetil is effective in both polymyositis and refractory dermatomyosits (including recalcitrant rash) and ILD. Uncontrolled studies for rituximab are encouraging but results from the largest randomized controlled trial in myositis failed to meet the primary endpoint. Anti-tumor necrosis factor (TNF) agents have shown mixed results in small, randomized clinical trials with infliximab demonstrating no benefit and etanercept leading to encouraging results warranting further study. Some newer novel therapies such as ACTH analogues and tocilizumab require additional investigation.

SUMMARY

The balance of evidence suggests that traditional immunosuppressive and immunomodulatory drugs are certainly effective in polymyositis and dermatomyositis despite the lack of randomized controlled trials. Newer therapies are being studied but no major breakthroughs have been realized.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies are a group of rare disorders including polymyositis (PM), dermatomyositis (DM), and autoimmune necrotizing myopathies (NMs). The idiopathic inflammatory myopathies share many similarities. They present acutely, subacutely, or chronically with marked proximal and symmetric muscle weakness, except for associated distal and asymmetric weakness in inclusion body myositis. The idiopathic inflammatory myopathies also share a variable degree of creatine kinase (CK) elevation and a nonspecifically abnormal electromyogram demonstrating an irritative myopathy. The muscle pathology demonstrates inflammatory exudates of variable distribution within the muscle fascicle. Despite these similarities, the idiopathic inflammatory myopathies are a heterogeneous group. The overlap syndrome (OS) refers to the association of PM, DM, or NM with connective tissue disease, such as scleroderma or systemic lupus erythematosus. In addition to elevated antinuclear antibodies (ANA), patients with OS may be weaker in the proximal arms than the legs mimicking the pattern seen in some muscular dystrophies. In this review, we focus on DM, PM, and NM and examine current and promising therapies.

Mechanisms of action of intravenous immunoglobulin in inflammatory muscle disease

Intravenous immunoglobulin (IVIG) is a unique immune-modulating therapy that has a wide range of effects on the immune system at multiple levels. This allows it to be used successfully in a variety of immune-mediated, systemic, and neurological disorders, including the inflammatory myopathies. It is likely that the specific action of IVIG varies depending on the underlying pathogenesis of a given disease. In dermatomyositis (DM), IVIG has been shown to diminish the activity of complement and deposition of membrane attack complex on capillaries and muscle fibers, the expression of adhesion molecules, and cytokine production. IVIG also appears to modify gene expression in the muscle of DM patients. The mechanism by which IVIG affects muscle in polymyositis and inclusion body myositis has not been well-studied. However, it may work via suppression of T-cell activation (including cytotoxic T cells) and migration into muscle tissue and alterations in cytokine production. IVIG generally yields the greatest therapeutic benefit in DM and is often of marginal utility in inclusion body myositis. It is generally considered as second-line or adjunctive therapy in the inflammatory myopathies.

Therapeutic approaches in myositis

The inflammatory myopathies are a heterogeneous group of diseases including dermatomyositis, polymyositis, and inclusion body myositis. Few clinical trials have been conducted in myositis, making it difficult to provide clear recommendations on the treatment of these rare disorders. Although corticosteroids have not been tested in randomized controlled trials, the general expert consensus confirms their first-line use. However, in many patients, corticosteroid toxicity leads to significant disability, or these agents are ineffective, which then requires additional immunosuppression. Intravenous immunoglobulin is a reasonable short-term treatment with proven benefit in a controlled trial, but its long-term effectiveness remains unknown. The evidence for other immunosuppressive therapies has been derived mainly from case reports and open studies. These agents include methotrexate and/or azathioprine, followed by cyclosporine or tacrolimus (particularly for antisynthetase antibody-positive patients) and mycophenolate mofetil (for refractory rash). Newer therapies (eg, rituximab) are encouraging, but results from the largest randomized controlled trial studying this agent are soon to follow. The balance of evidence suggests that immunosuppressive drugs are effective in dermatomyositis and polymyositis, although randomized controlled trials are lacking.

[Intravenous IgG for treatment of neuromuscular diseases]

BACKGROUND

Highly purified IgG administered intravenously (IVIG) is used to treat many neurological diseases.

MATERIAL AND METHODS

This review is based on articles identified through a search in PubMed and the authors' knowledge and experience within the field.

RESULTS

The effect of IVIG has been best documented in the treatment of acute and chronic inflammatory demyelinating polyradiculoneuropathy, multifocal motor neuropathy and acute exacerbation of myasthenia gravis. Some smaller studies support explorative IVIG treatment in other neurological diseases such as Lambert-Eaton myasthenic syndrome, paraproteinemic neuropathy, neuropathy caused by vasculitis, inflammatory myopathies and stiff-person syndrome.

INTERPRETATION

IVIG affects the immune system in different ways. Documentation for the effect of such treatment in most neurological diseases remains sparse.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies are a group of systemic autoimmune syndromes characterized by striated muscle inflammation. Here, we discuss the clinical features of this group of conditions and review the recent developments in the understanding of the pathogenesis and immunogenetics of the idiopathic inflammatory myopathies. The role of myositis-specific autoantibodies and their clinical significance and an overview of management are also provided.

National registry of patients with juvenile idiopathic inflammatory myopathies in Hungary—Clinical characteristics and disease course of 44 patients with juvenile dermatomyositis

Idiopathic inflammatory myopathies (IIMs) are systemic autoimmune diseases characterized by chronic muscle inflammation resulting in progressive weakness and frequent involvement of internal organs, mainly the pulmonary, gastrointestinal and cardiac systems which considerably contribute to the morbidity and mortality of the IIMs. Aim of this study was to present clinical characteristics, disease course, frequency of relapses and survival in patients with juvenile dermatomyositis (DM). A national registry of patients with juvenile IIMs was elaborated by the authors in Hungary. We have summarized data of the register according to signs and symptoms, disease course, frequency of relapses and survival of patients with juvenile IIM. Analysis was performed using data of 44 patients with juvenile DM diagnosed between 1976 and 2004 according to Bohan and Peter's criteria. Survival probability was calculated by Kaplan-Meier method. Data of patients with juvenile DM were compared with data of 66 patients with adult DM. The most frequent cutaneous features were facial erythema and heliotrope rash. Extramuscular and extraskeletal manifestations of the disease were more frequent in adult patients. The most common extramuscular feature was arthralgia in both groups of patients with juvenile or adult DM. Cardiac manifestation of the disease was not observed in juvenile patients. Respiratory muscle involvement and interstitial lung disease (ILD) were more frequent among adult DM patients than cardiac manifestation of the myositis. In view of the disease course, the authors found that frequency of polycyclic and monophasic subtypes of the disease were mainly similar. The hazard of relapse was found higher during the first year after the remission. None of the juvenile patients died. Among adult patients four disease-specific deaths occurred. There was no correlation between relapse free survival and initial therapeutic regimen. Many of our patients had polycyclic or chronic disease. As relapses can occur after a prolonged disease-free interval, patients should be followed up for at least 2 years. Although we found favourable survival probability, further investigations are needed to assess functional outcome.

Intravenous immunoglobulin therapy for refractory interstitial lung disease associated with polymyositis/dermatomyositis

Interstitial lung disease (ILD) associated with polymyositis/dermatomyositis (ILD-PM/DM), including amyopathic dermatomyositis (ADM), is recognized as an important condition because it frequently causes death, despite intensive therapy with high-dose corticosteroid and immunosuppressive agents, such as cyclosporine A and cyclophosphamide. Intravenous immunoglobulin therapy (IVIG) has shown efficacy for myopathy associated with PM/DM, but its usefulness for ILD-PM/DM is unclear. This study was designed to investigate the efficacy of IVIG for refractory ILD-PM/DM. A review was made of medical charts of five patients (2 men and 3 women) who were treated with IVIG for refractory ILD-PM/DM resistant to high-dose corticosteroid and cyclosporine A and/or cyclophosphamide. One patient had acute ILD-PM and four patients had acute ILD-ADM. Of the five patients, one patient with ILD-PM and one patient with ILD-ADM survived. No adverse reactions were seen due to IVIG treatment. There were no critical differences in the clinical parameters and clinical courses between survivors and nonsurvivors. IVIG treatment is safe and could be an effective salvage therapy for refractory ILD-PM/DM in certain cases, suggesting that further controlled trials are worthwhile.

Intravenous immunoglobulin as add on treatment with mycophenolate mofetil in severe myositis

OBJECTIVES

To report the use of intravenous immunoglobulin (IVIg) and mycophenolate mofetil (MMF) in polymyositis (PM) and dermatomyositis (DM).

METHODS

We performed an open study in PM and DM with active disease. Indications for treatment were: steroid-dependency, refractoriness to steroid and/or immunosuppressants, and life-threatening disease. IVIg was used at 2 g/kg in monthly cycles for six months and then each other month for other three cycles. MMF was slowly titrated to 30 mg/kg/day orally. Parameters employed to follow patients were the Medical Research Council (MRC) scale, the modified Rankin score, CK serum levels and daily prednisone dose.

RESULTS

Seven patients were studied (4PM, 3DM). All were females, with a mean age of 49 years. All of them achieved a complete remission and, at the last follow-up visit, significant differences in MRC score, modified Rankin score, CK levels, and the daily maintenance prednisone dose were documented. No relevant side effects were observed.

CONCLUSION

IVIg as add on treatment with MMF is effective in severe and refractory myositis, moreover as safe and steroid-sparing agent.

The treatment and prognosis of dermatomyositis: an updated review

Dermatomyositis (DM) is an idiopathic inflammatory myopathy. The mainstay of treatment for DM is oral corticosteroids. However, the dose and length of treatment is debated. Adding to the confusion, there have been no randomized controlled studies comparing the use of various corticosteroid doses and taper rates, and no controlled long-term studies assessing the hypothesis that, unlike systemic lupus erythematous, patients with DM can often achieve long-term remission off therapy. This literature review supports an approach that prednisone should be started at about 1 mg/kg/d, which is then tapered slowly based on the response. As patients respond differently to prednisone, additional therapies may be necessary. When to initiate these therapies requires clinical judgment. In addition, as we learn more about the pathophysiology of DM, newer medications that target specific mechanisms in the immune response may help us better treat the disease. Evidence-based data with long-term follow-up will allow for selection of the best treatment to maximize long-term remission, not simply short-term lowering of the systemic corticosteroid dose.