Intravenous cyclophosphamide therapy for progressive interstitial pneumonia in patients with polymyositis/dermatomyositis

A Review of Myositis-Associated Interstitial Lung Disease

There is a well-established relationship between different subsets of idiopathic inflammatory myopathies (IIMs, myositis) and interstitial lung disease (ILD), with lung complications sometimes presenting prior to myopathic manifestations. The subtypes of myositis include those that are strongly associated with ILD, such as polymyositis (PM) and dermatomyositis (DM). Research has shown that in certain patients, these can then be further divided into subtypes using myositis-specific antibodies (MSAs), which are specific for myositis, and myositis-associated antibodies (MAAs), which can be found in myositis in overlap syndromes with other connective tissue diseases (CTDs). Notably, certain MSAs and MAAs are associated with ILD in patients with myositis. The clinical presentations of ILD in patients with myositis can vary widely and can be insidious in onset and difficult to diagnose. As ILD can progress rapidly in some cases, it is essential that clinicians are able to identify and diagnose ILD in patients with myositis. For this reason, the aim of this review is to highlight the clinical features, diagnostic criteria, important histopathologic, laboratory, and radiographic features, and treatment modalities for those patients with myositis-associated ILD.

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.

[Pulmonary involvement in idiopathic inflammatory myopathies]

Idiopathic inflammatory myopathies are rare systemic diseases with different types of pulmonary manifestations depending on the underlying aetiology; here, interstitial lung diseases (ILD) are the most frequently found patterns depending on the underlying disorder. There is a lack of sufficient prospective studies on this heterogeneous group of patients, particularly in case of ILD being involved. The diagnosis is based upon guideline recommendations for ILD and requires a multidisciplinary discussion within a team with specific expertise in this field. Myositis specific antibodies and myositis associated antibodies form an essential part of the diagnostic tools and may also be associated with a certain phenotype or disease progression. Anti-t-RNA-synthetase antibodies (Anti-ARS) and anti-melanoma differentiation-associated gene 5 antibodies (MDA5) play an important clinical role for treatment the estimation of response and prognosis. The most common ILD patterns are nonspecific interstitial pneumonia (NSIP) and organising pneumonia (OP) or a mixed pattern of both. Treatment is based on systemic steroids and early initiation of other immunosuppressant drugs. Evidence for this is, however, sparse, since most of the studies having investigated treatment modalities are of retrospective nature, even though some new prospective data may be useful for the establishment of treatment pathways in the future.

The prevalence and effects of treatments of rapidly progressive interstitial lung disease of dermatomyositis/polymyositis adults: A systematic review and meta-analysis

Rapidly progressive interstitial lung disease (RP-ILD) clearly harms the prognoses of dermatomyositis/polymyositis (DM/PM) patients, however there is a dearth of numerical prevalence and therapy comparison in this field. Therefore, the purpose of this study was to determine the prevalence of RP-ILD in DM/PM patients and compare prognoses, including remission rate and survival data, between treatments. Studies with reports of RP-ILD in DM/PM patients and studies with definite remission and/or survival data of DM/PM-RP-ILD were included in the study. Data sources were Pubmed, Embase, and Cochrane Library without language restrictions. Two authors (WHL and WWQ) extracted independently the data. Estimates of the pooled effects were calculated using the Mantel-Haenszel technique (random effects). The prevalence meta-analysis included 18 papers with 6058 DM/PM patients, and 31 papers were analyzed for treatment effects, including remission rate, 6-month survival rate, 1-year survival rate, and 5-year survival rate. Database search yielded 1816 articles. In the DM/PM population, the combined prevalence of RP-ILD was 8.9% (95% CI, 5.8% to 12.1%). Patients with RP-ILD have a remission rate of 58.4% (95% CI, 47.3% to 69.4%), with biologic treatment with the highest remission rate, followed by triple therapy (defined as adding a third intravenous medication, including cyclophosphamide and immunoglobulin). Biologics therapy had the highest overall survival rate at six months (95% CI, 49.8% to 73.9%), followed by cDMARDs, plasma exchange, and triple therapy. The 1-year survival rate was 77.4% (95% CI, 66.7% to 88.1%), and triple therapy and cDMARDs had the best survival rates. The 5-year survival rate was 40.0% (95% CI, 10.0% to 69.9%). The prevalence of RP-ILD in DM/PM was approximately 8.9%, with a poor long-term prognosis. The use of biological agents appears to provide the best therapeutic outcomes, providing RP-ILD management with a novel evidence-based therapy. The use of strong immunosuppressive treatments may result in life-threatening side effects, thus clinicians must closely monitor the condition.

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.

"Management of myositis associated interstitial lung disease"

Idiopathic inflammatory myopathies (IIM) are rare disorders characterised by the presence of skeletal muscle inflammation, with interstitial lung disease (ILD) being the most frequent pulmonary manifestation. The spectrum of clinical presentations of myositis related ILD (M-ILD) encompasses a chronic process to a rapidly progressive ILD (RP-ILD); which is associated with a high mortality rate. The most effective treatments remain controversial and poses a unique challenge to both rheumatologists and respiratory physicians to manage. Given the rare heterogenous nature of M-ILD, there is a paucity of data to guide treatment. The cornerstone of existing treatments encompasses combinations of immunosuppressive therapies, as well as non-pharmacological therapies. In this review, we aim to summarize the current pharmacological therapies (including its dosing regimens and side effects profiles) and non-pharmacological therapies. Based on the existing literature to date, we propose a treatment algorithm for both chronic M-ILD and RP-ILD.

Intravenous cyclophosphamide improves functional outcomes in interstitial lung disease related to idiopathic inflammatory myopathies

OBJECTIVE

To compare the efficacy, toxicity and glucocorticoid (GC)-sparing effects of intravenous cyclophosphamide (iv CYC) with other immunosuppressive regimes as the induction treatment for Idiopathic Inflammatory Myopathy-Related Interstitial Lung Disease (IIM-ILD).

METHODS

Observational comparative study of patients with IIM-ILD from the EPIMAR and Cruces cohorts. The main efficacy outcome was a 6 to 12-month improvement >10% in the forced vital capacity (FVC) from baseline.

RESULTS

Overall, 47 patients were included: 22 (47%) in the CYC group and 25 (53%) in the non-CYC group (32% azathioprine, 28% GC alone, 20% mycophenolate, 16% calcineurin-inhibitors and methotrexate and 4% rituximab). 81% patients were female with a mean age of 50.4 years. FVC improvement was achieved by 64% patients in the CYC group vs. 32% in the non-CYC group (p = 0.03). In the logistic regression model, CYC was identified as the only independent predictor of FVC improvement (OR=3.97, 95% CI 1.07-14.75). Patients in the CYC group received more methyl-prednisolone pulses (MP) (59% vs. 28% in the non-CYC group, p = 0.03), less initial GCs doses >30 mg/d (19% vs. 77%, p = 0.001) and lower 6-month average doses of prednisone (11 mg/d vs. 31.1 mg/d, p = 0.001).

CONCLUSION

iv CYC showed better functional outcomes than other immunosuppressants in IIM-ILD. The additional use of MP is likely to potentiate the effects of CYC and allows lowering prednisone doses. Therefore, CYC in combination with MP could be considered as the first line induction therapy in IIM-ILD, without limiting its use to rapidly progressive, life-threatening or refractory disease.

Dermatomyositis: a comprehensive review of clinical manifestations, serological features, and therapeutic approaches

Dermatomyositis (DM) is an autoimmune disorder, which belongs to a group of rare autoimmune dermatoses characterized by different skin features and variable muscle involvement. We recognize four main variants of DM: classic DM, clinically amyopathic DM, paraneoplastic DM, and juvenile DM. Clinically, patients show several skin features, but heliotrope rash, and violaceous papules located at the interphalangeal or metacarpophalangeal joints (Gottron's papules) are the most frequently observed. Together with skin features, patients show muscle involvement, most commonly with symmetrical weakness of the proximal muscles. DM belongs to the facultative paraneoplastic dermatoses and a wide range of solid or hematologic malignancies can be detected in DM patients. Serologically, a wide range of autoantibodies can be detected in patients with DM. Indeed, distinct serotypes can be related to specific phenotypes with specific clinical features, carrying a different risk for systemic involvement and for malignancies. Systemic corticosteroids are still considered the first-line approach, but several steroid-sparing agents, such as methotrexate, azathioprine or mycophenolate mofetil, have been reported as effective in treating DM. Furthermore, new class of drugs, such as monoclonal antibodies, purified immunoglobulins or Janus kinase inhibitors are becoming more relevant in the clinical practice or are currently under investigation. In this work, we aim to offer a clinical overview of the diagnostic workout, the characteristics of DM variants, the role of autoantibodies in DM, and the management of this life-threatening systemic disorder.

Management of interstitial lung disease in patients with autoimmune disease-related interstitial lung disease

Interstitial lung disease (ILD) is a common manifestation of systemic autoimmune diseases. A proportion of patients with autoimmune disease associated-ILDs develop progressive pulmonary fibrosis. Regular monitoring of patients with pulmonary fibrosis is recommended to enable prompt detection of progression and initiation or escalation of therapy if needed. However, there is no established algorithm for the treatment of autoimmune disease associated-ILDs. In this article, we present three case studies that demonstrate the challenges in the diagnosis and management of patients with autoimmune disease associated-ILDs and the importance of taking a multidisciplinary approach to their care.

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).

[Dermatomyositis and juvenile dermatomyositis]

Dermatomyositis (DM) is an inflammatory multisystem disease of unknown etiology, which can already occur in children but first onset can also be in older adulthood. Myalgia and muscle weakness can occur later in the course of the disease or even be completely absent in some forms. Classical signs on the skin include heliotrope rash, facial erythema, Gottron's papules and nailfold capillary abnormalities. For the diagnosis, screening for the presence of myositis-specific autoantibodies has become increasingly more relevant. Muscle enzymes may be elevated but not in approximately one third of patients. In the absence of typical clinical or serologic findings, additional examination methods such as nailfold capillaroscopy, magnetic resonance imaging, electromyography, skin or muscle biopsies may help to establish the diagnosis. Depending on the clinical and serological subtype, additional screening for gastrointestinal or cardiopulmonary involvement should be considered. In adults, an age-appropriate tumor screening should also be performed. Apart from corticosteroids as induction therapy, biologics and small molecule inhibitors are gaining in importance in addition to conventional disease-modifying anti-rheumatic drugs and intravenous immunoglobulins. The prognosis for DM and juvenile DM (JDM) has improved. Most patients recover at least to some extent; however, a few patients die and a minority develop persisting muscle atrophy or severe calcinosis.

A Man With Recurrent Pneumonitis: A Rare Case of Interstitial Lung Disease Associated With Anti-Mi-2 Beta-Specific Dermatomyositis

Dermatomyositis (DM) and polymyositis (PM) are idiopathic inflammatory myopathies. Interstitial lung disease (ILD) develops in most patients with DM and PM directly related to morbidity and mortality. Diagnosis requires a myositis panel and high-resolution computed tomography (HRCT). Prognosis depends on specific myositis-specific antibodies and the pattern of the interstitial lung changes. Anti-Mi-2 antibody-specific dermatomyositis has a lower prevalence of interstitial lung disease and has a favorable prognosis, responding well to steroids. Our patient is a 72-year old male who presented with recurrent episodes of pneumonitis, and ILD was found to have anti-Mi-2 beta-specific dermatomyositis and SLE overlap disease. He was responding well to high-dose steroids but was rebounding to similar symptoms whenever steroid weaning was attempted. He was started on azathioprine, but unfortunately, his disease rapidly progressed, and he died within a few months. This manuscript enhances the temporal relationship between dermatomyositis and ILD.

Idiopathic inflammatory myopathies

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

Pulmonary histopathology of interstitial lung disease associated with antisynthetase antibodies

BACKGROUND

We aimed to determine if antibody type is an indicator of pulmonary histopathology, using antisynthetase antibody positive interstitial lung disease (ILD) cases with lung biopsy or autopsy findings.

METHODS

We conducted a comprehensive review of the English language literature in PubMed to identify ILD histopathology results for cases with antibodies against anti-aminoacyl-transfer RNA (tRNA) synthetases (anti-ARS antibodies), including Jo1, PL-12, PL-7, KS, ES, and OJ. We additionally identified patients who had ILD, anti-ARS antibodies, and a lung biopsy between 2015 and 2020 at Beth Israel Deaconess Medical Center. For each case, we documented the specific anti-ARS antibody and major histopathologic patterns identified on biopsy or autopsy, including usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), and acute lung injury (ALI). To determine if histopathology varied by antibody type, we compared the proportion of each of four major patterns by antibody type using the Fisher's Exact test.

RESULTS

We identified 310 cases with pathology findings and anti-ARS antibody positivity, including 12 cases from our institution. The proportion of NSIP differed significantly across antibody type, found in 31% of Jo1 (p < 0.01), 67% of EJ (p < 0.01), and 63% of KS (p < 0.01) cases. OP was common in Jo1 (23%, p = 0.07), but rare in EJ (4%, p = 0.04) and KS (4%, p = 0.04). UIP was common in PL-12 alone (36%, p = 0.03).

CONCLUSION

The frequency of histopathologic findings in ILD with anti-ARS positivity varies significantly by antibody type, and NSIP occurs in less than half of all cases.

Detection and Management of Interstitial Lung Diseases Associated With Connective Tissue Diseases

Interstitial lung disease (ILD) is a common manifestation of connective tissue diseases (CTDs). A proportion of patients with CTD-ILDs develop progressive fibrosing ILD, which is characterized by worsening fibrotic abnormalities on high-resolution computed tomography scan, decline in lung function, worsening symptoms, and early mortality. Here, we review the impact of ILD in patients with CTDs, the importance of prompt diagnosis and close monitoring, and the evidence available to guide the management of CTD-ILDs. Management of patients with CTD-ILDs should be individualized and involve close collaboration between rheumatologists and pulmonologists. Immunosuppression is the mainstay of therapy for CTDs, but evidence for its effectiveness in slowing the progression of ILD is limited. Recently, nintedanib has been approved to slow decline in lung function in patients with systemic sclerosis-associated ILD and chronic fibrosing ILDs with a progressive phenotype. The results of ongoing clinical trials will help clinicians take a more evidence-based approach to the treatment of CTD-ILDs.

Current advances in the treatment of autoimmune-associated interstitial lung diseases

Autoimmune-associated interstitial lung disease (ILD) is a widespread and clinically significant form of autoimmune diseases. ILD can be present in most type of autoimmune diseases. Scleroderma, Sjogren syndrome, rheumatoid arthritis, inflammatory myositis, systemic lupus erythematosus, and mixed connective tissue disease are all examples of autoimmune disorders that can cause ILD. Treatment and prognosis vary from that of other forms of ILD depending on the etiology and pathogenesis of the autoimmune disease. As a result, glucocorticoids and immunosuppressive agents are the mainstays of treatment for autoimmune-associated ILD, despite the fact that there is little high-level evidence to guide the treatment owing to limited data from randomized controlled trials. Immunosuppressive agents including cyclophosphamide, tacrolimus, azathioprine, and mycophenolate mofetil can be used to reduce the dose of glucocorticoids and the inflammatory cascade and inhibit various pro-inflammatory cytokines. Studies have also started alternative therapeutic approaches, such as biological and antifibrotic agents, and traditional immunosuppressive agents. In this review, we summarize available treatment options and recent advances in therapeutic strategies for patients with autoimmune-associated ILD.

Management of Myositis-Associated Interstitial Lung Disease

Idiopathic inflammatory myopathies, including polymyositis (PM), dermatomyositis (DM), and clinically amyopathic DM (CADM), are a diverse group of autoimmune diseases characterized by muscular involvement and extramuscular manifestations. Interstitial lung disease (ILD) has major pulmonary involvement and is associated with increased mortality in PM/DM/CADM. The management of PM-/DM-/CADM-associated ILD (PM/DM/CADM-ILD) requires careful evaluation of the disease severity and clinical subtype, including the ILD forms (acute/subacute or chronic), because of the substantial heterogeneity of their clinical courses. Recent studies have highlighted the importance of myositis-specific autoantibodies’ status, especially anti-melanoma differentiation-associated gene 5 (MDA5) and anti-aminoacyl tRNA synthetase (ARS) antibodies, in order to evaluate the clinical phenotypes and treatment of choice for PM/DM/CADM-ILD. Because the presence of the anti-MDA5 antibody is a strong predictor of a worse prognosis, combination treatment with glucocorticoids (GCs) and calcineurin inhibitors (CNIs; tacrolimus (TAC) or cyclosporin A (CsA)) is recommended for patients with anti-MDA5 antibody-positive DM/CADM-ILD. Rapidly progressive DM/CADM-ILD with the anti-MDA5 antibody is the most intractable condition, which requires immediate combined immunosuppressive therapy with GCs, CNIs, and intravenous cyclophosphamide. Additional salvage therapies (rituximab, tofacitinib, and plasma exchange) should be considered for patients with refractory ILD. Patients with anti-ARS antibody-positive ILD respond better to GC treatment, but with frequent recurrence; thus, GCs plus immunosuppressants (TAC, CsA, azathioprine, and mycophenolate mofetil) are often needed in order to achieve favorable long-term disease control. PM/DM/CADM-ILD management is still a therapeutic challenge for clinicians, as evidence-based guidelines do not exist to help with management decisions. A few prospective clinical trials have been recently reported regarding the treatment of PM/DM/CADM-ILD. Here, the current knowledge on the pharmacologic managements of PM/DM/CADM-ILD was mainly reviewed.

Case Report: Rapidly Progressive Interstitial Lung Disease in A Pregnant Patient With Anti-Melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis

Dermatomyositis occurs extremely rarely during pregnancy. A number of studies in the published literature have documented how the outcome of pregnancy is poor for both mother and fetus. The present case study reports on a patient who was diagnosed with clinically amyopathic dermatomyositis complicated by interstitial lung disease during pregnancy, and was successfully treated with a combined immunosuppressant regimen. To the best of the authors' knowledge, this is the first case study detailing how a pregnant woman with clinically amyopathic dermatomyositis with positive anti-melanoma differentiation-associated gene 5 antibody achieved complete remission after early intervention of combined immunosuppressive therapy without residual pulmonary interstitial changes.

Efficacy of cyclophosphamide in treating connective tissue disease-related interstitial lung diseases

Interstitial lung diseases (ILDs) are some of the first and most serious complications of connective tissue diseases (CTDs). However, the pathogenesis of CTD-related ILDs (CTD-ILDs) is still unclear and their treatment often depends on functional and radiographic disease progression as well as on patient age and comorbidities. It can be difficult to manage CTD-ILDs due to their heterogeneous nature, the lack of robust therapeutic data, and the few well-defined outcome measures. This review focuses on cyclophosphamide due to its crucial role in the treatment of systemic sclerosis-related ILD, particularly in the case of patients with progressive ILD. This narrative review was performed using PubMed, Medline, and Cochrane Library databases to retrieve English language papers published between 2000 and April 2020 concerning the treatment of CTD-ILDs with cyclophosphamide.

Prednisolone and tacrolimus versus prednisolone and cyclosporin A to treat polymyositis/dermatomyositis-associated ILD: A randomized, open-label trial

BACKGROUND AND OBJECTIVE

The efficacy of combination therapy with corticosteroids and CNI, TAC and CsA, for PM/DM-ILD has been described retrospectively. However, it remains unknown which CNI treatment regimens, TAC or CsA regimens, are more effective as initial treatments for patients with PM/DM-ILD.

METHODS

We conducted a prospective multicentre, open-label, randomized, 52-week phase 2 trial. Patients with PM/DM-ILD were randomly allocated to receive PSL plus TAC (TAC group) or PSL plus CsA (CsA group). The primary endpoint was PFS rate in the intention-to-treat population at 52 weeks. The secondary endpoints were OS rate at 52 weeks, changes in pulmonary function tests from baseline to 52 weeks and AE.

RESULTS

Fifty-eight patients were randomly assigned to the TAC group (n = 30) and the CsA group (n = 28). The PFS rates at 52 weeks were 87% in the TAC group and 71% in the CsA group (P = 0.16). The OS rates at 52 weeks were 97% in the TAC group and 93% in the CsA group (P = 0.50). The %FVC at 52 weeks in the per-protocol populations significantly increased in both groups. None of the patients discontinued the treatment due to AE.

CONCLUSION

PSL plus TAC treatment may achieve a better short-term PFS rate compared with PSL plus CsA treatment. Further studies must be conducted to evaluate the long-term efficacy and safety of such treatment.

Antisynthetase syndrome: A distinct disease spectrum

The discovery of novel autoantibodies related to idiopathic inflammatory myopathies (collectively referred to as myositis) has not only advanced our understanding of the clinical, serological, and pathological correlation in the disease spectrum but also played a role in guiding management and prognosis. One group of the myositis-specific autoantibodies is anti-aminoacyl-tRNA synthetase (anti-ARS or anti-synthetase) which defines a syndrome with predominant interstitial lung disease, arthritis, and myositis. Autoantibodies to eight aminoacyl-tRNA synthetases have been identified with anti-Jo1 the most common in all of idiopathic inflammatory myopathies. Disease presentation and prognosis vary depending on which anti-aminoacyl-tRNA synthetase antibody is present. In this review, we will discuss the clinical characteristics, overlap features with other autoimmune diseases, prognostic factors, and management of the antisynthetase syndrome.

Promising and Upcoming Treatments in Myositis

PURPOSE OF REVIEW

To highlight new and emerging treatment targets in myositis.

RECENT FINDINGS

The landscape of novel therapeutics in myositis has vastly changed in the past 5 years. This is largely due to a greater understanding of the pathogenesis of myositis and validation of more robust outcome measures that standardize the ability to assess treatment response. Clinical trials in dermatomyositis are leading the way with ongoing multicenter, international phase 3 clinical trials. Proof-of-concept studies targeting the JAK/STAT pathway have also showed early promise in treating refractory dermatomyositis in adults and children. This review highlights that the future armamentarium of therapeutic drugs will likely be larger and more selective in treating different subgroups of myositis.

Insights into pathogenesis and clinical implications in myositis-associated interstitial lung diseases

PURPOSE OF REVIEW

Interstitial lung diseases (ILDs) have been reported to be associated with myositis (including polymyositis and dermatomyositis). These myositis-associated ILDs carry significant morbidity and mortality. This review summarizes recent findings on myositis-associated ILD with a focus on pathogenesis and emerging treatment.

RECENT FINDINGS

Recent advances in genetics have revealed 22 myositis-associated genome-wide loci, which were significantly enriched in regulatory regions in immune cells. An analysis of such disease-associated loci elucidated potential drug targets (e.g., TYK2 targeted by tofacitinib). In another study, an intronic variant in WDFY4 in association with clinically amyopathic dermatomyositis (CADM) had an effect for higher expression of a truncated WDFY4 isoform. Truncated WDFY4 markedly enhanced the MDA5-mediated NF-κB activation and cell apoptosis, indicating the dysregulated WDFY4-MDA5 pathway as a novel pathogenesis of CADM. As a novel strategy, tofacitinib treatment showed a promising improvement in survival and clinical features of CADM-associated ILD.

SUMMARY

The genetic differences in the myositis-susceptible loci may explain the heterogeneous phenotypes and treatment responses in myositis-associated ILD. The understanding of pathogenesis with the genetic background as well as autoantibodies will enable the practice of personalized treatment in the management of the disease.

Dermatomyositis: An Update on Diagnosis and Treatment

Dermatomyositis is a rare inflammatory disease with characteristic cutaneous findings and varying amounts of systemic involvement. Patients may present with skin disease alone, have concomitant muscle disease, or have extracutaneous manifestations such as pulmonary disease or an associated malignancy. Given such diverse presentations, dermatomyositis is both a diagnostic and therapeutic challenge. However, a prompt diagnosis is of utmost importance to institute adequate therapy and screen patients for an associated malignancy. Dermatologists should play a crucial role in the diagnosis and management of patients with dermatomyositis as cutaneous disease tends to be chronic, negatively impact quality of life, and be more recalcitrant to therapy. In this review, we discuss diagnosis, with a focus on myositis-specific antibodies and their associated phenotypes. We also review therapies available for this often refractory skin disease.

Rituximab and Cyclophosphamide in Antisynthetase Syndrome-related Interstitial Lung Disease: An Observational Retrospective Study

OBJECTIVE

Antisynthetase syndrome (AS)-related interstitial lung disease (ILD) has a poor prognosis. Intravenous cyclophosphamide (IV CYC) and rituximab (RTX) are the main treatments currently used for moderate to severe ILD. Here, we compare the efficacy of CYC followed by standard immunosuppressive treatment (IST) versus RTX in AS-related ILD.

METHODS

This observational retrospective study was conducted between 2003 and 2016 in 3 tertiary care centers. All patients with AS-related ILD and treated with CYC or RTX with at least 6 months of follow-up were included. Pulmonary progression-free survival (PFS), defined according to the American Thoracic Society guidelines, was assessed at 6 months and 2 years. All severe adverse events (AE) were recorded.

RESULTS

Sixty-two patients were included. Thirty-four patients received 2-12 monthly IV CYC pulses, followed by standard IST in 30 cases (88%). The RTX group included 28 patients. Following the initial Day 1 to Day 15 infusions, RTX was repeated every 6 months in 26 cases (93%) and 15 patients (54%) concomitantly received another IST. The median steroid dose was similar between both groups. Although RTX and CYC demonstrated similar PFS at 6 months (92% vs 85%, respectively), RTX was superior at 2 years (HR 0.263, 95% CI 0.094-0.732, P = 0.011). Interestingly, lower diffusing lung capacity for carbon monoxide (DLCO) at baseline was independently predictive of poor 2-year PFS [0.965 (0.936-0.995), P = 0.023]. Forced vital capacity and DLCO improved in both groups without significant differences. Serious AE were similar in both groups.

CONCLUSION

Despite similar PFS at 6 months, RTX was associated with a better 2-year PFS compared to CYC in patients with AS-related ILD.

Treatment of the Connective Tissue Disease-Related Interstitial Lung Diseases: A Narrative Review

Interstitial lung disease (ILD) is a frequent complication of patients with connective tissue disease (CTD) and significantly affects morbidity and mortality. Disease course may vary from stable or mildly progressive to more severe, with rapid loss of lung function. We conducted a search of PubMed (National Library of Medicine) and the Web of Science Core Collection using the key words lung, pulmonary, pneumonia, pneumonitis, and alveolar and subtypes of CTD. All clinical studies from January 1, 1980, through September 1, 2018, were reviewed for descriptions of specific therapies and their efficacy or safety and were categorized as controlled interventional trials, observational prospective or retrospective cohort studies, case series (>5 patients), and case reports (<5 patients). Low-quality reports (<5 patients) before 2000, reviews, editorials, popular science papers, and letters to the editor without complete descriptions of the therapies used or their outcomes were excluded. Directed therapy for CTD-ILD is dominated by empirical use of immunosuppressive agents, with the decision to treat, treatment choice, and treatment duration limited to cases and cohort observations. Only a few higher-level controlled studies were available specifically in scleroderma-related ILD. We summarize herein for the clinician the published treatment scope and experience, highlighted clinical response, and common adverse reactions for the management of CTD-ILD.

Recognition and Management of Myositis-Associated Rapidly Progressive Interstitial Lung Disease

Idiopathic inflammatory myopathies are autoimmune processes that are characterized by skeletal muscle inflammation. The lung is the most commonly involved extramuscular organ, and, when present, pulmonary disease drives morbidity and mortality. A subset of patients can present with rapidly progressive hypoxemic respiratory failure due to myositis-related interstitial lung disease. Confirmatory autoantibody testing requires sending samples to a reference laboratory; thus, diagnosis of rapidly progressive myositis-associated interstitial lung disease relies on a high index of suspicion and careful history and physical examination. Although the cornerstone of therapy for these patients remains multimodality immunosuppression, emerging data support a role for advanced therapies (including extracorporeal membrane oxygenation and lung transplantation) in appropriately selected patients. It is hoped that greater awareness of the clinical features of this syndrome will allow for appropriate diagnosis and treatment of these potentially treatable patients, as well as raise awareness of the need for multicenter collaboration to prospectively study how to manage this complex disease.

Therapeutic Options for the Treatment of Interstitial Lung Disease Related to Connective Tissue Diseases. A Narrative Review

Interstitial lung disease (ILD) is one of the most serious pulmonary complications of connective tissue diseases (CTDs) and it is characterized by a deep impact on morbidity and mortality. Due to the poor knowledge of CTD-ILD’s natural history and due to the difficulties related to design of randomized control trials, there is a lack of prospective data about the prevalence, follow-up, and therapeutic efficacy. For these reasons, the choice of therapy for CTD-ILD is currently very challenging and still largely based on experts’ opinion. Treatment is often based on steroids and conventional immunosuppressive drugs, but the recent publication of the encouraging results of the INBUILD trial has highlighted a possible effective and safe use of antifibrotic drugs as a new therapeutic option for these subjects. Aim of this review is to summarize the available data and recent advances about therapeutic strategies for ILD in the context of various CTD, such as systemic sclerosis, idiopathic inflammatory myopathy and Sjogren syndrome, systemic lupus erythematosus, mixed connective tissue disease and undifferentiated connective tissue disease, and interstitial pneumonia with autoimmune features, focusing also on ongoing clinical trials.

Inflammatory Myopathy-Related Interstitial Lung Disease: From Pathophysiology to Treatment

Inflammatory myopathies (IM) are auto-immune connective tissue diseases characterized by muscle involvement and by extramuscular manifestations. As such, pulmonary manifestations, which mainly include interstitial lung disease (ILD), often darken two out of four distinct IM, namely dermatomyositis and overlapping myositis. Being the initiation site of the disease and being the leading cause of morbidity and mortality, ILD is of major importance in this context. ILD has a heterogeneous expression among the patients, with various onset mode, various radiological pattern, various severity and finally with different prognoses, which are particularly difficult to predict at the time of IM diagnosis. Therefore, ILD is a challenging issue. Treatments are based on steroids and immunosuppressive or targeted therapies. Their respective place is yet poorly codified however and remains often based on clinician expertise. Dedicated clinical trials are lacking to date and are also difficult to build, due to difficulty of constituting large and homogeneous patient groups and to rigorously evaluate disease outcomes. Indeed, pulmonary function tests alone are being regularly defeated in IM, in which respiratory muscles are often involved. Composite scores, bringing together several lung parameters, should thus be developed and validated in the future, to better assess the disease response to treatment. This review aims to describe the current knowledge of IM immuno-pathogenesis, the clinical features associated with IM related-ILD, focusing of both severity and prognosis, and the actual therapeutic approaches.

Progressive fibrosing interstitial lung disease associated with systemic autoimmune diseases

Interstitial lung disease (ILD) is a common manifestation of systemic autoimmune diseases and a leading cause of death in these patients. A proportion of patients with autoimmune ILDs develop a progressive fibrosing form of ILD, characterized by increasing fibrosis on high-resolution computed tomography, worsening of lung function, and early mortality. Autoimmune disease-related ILDs have a variable clinical course and not all patients will require treatment, but all patients should be monitored for signs of progression. Apart from systemic sclerosis-associated ILD, the limited evidence to support the efficacy of immunosuppression as a treatment for ILDs is based mainly on small retrospective series and expert opinion. Non-clinical data suggest that there are commonalities in the mechanisms that drive progressive fibrosis in ILDs with an immunological trigger as in other forms of progressive fibrosing ILD. This suggests that nintedanib and pirfenidone, drugs known to slow disease progression in patients with idiopathic pulmonary fibrosis, may also slow the progression of ILD associated with systemic autoimmune diseases. In the SENSCIS® trial, nintedanib reduced the rate of ILD progression in patients with systemic sclerosis-associated ILD. The results of other large clinical trials will provide further insights into the role of anti-fibrotic therapies in the treatment of autoimmune disease-related ILDs.

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.

Interstitial Lung Disease and Pulmonary Fibrosis: A Practical Approach for General Medicine Physicians with Focus on the Medical History

Interstitial lung disease (ILD) and pulmonary fibrosis comprise a wide array of inflammatory and fibrotic lung diseases which are often confusing to general medicine and pulmonary physicians alike. In addition to the myriad of clinical and radiologic nomenclature used in ILD, histopathologic descriptors may be particularly confusing, and are often extrapolated to radiologic imaging patterns which may further add to the confusion. We propose that rather than focusing on precise histologic findings, focus should be on identifying an accurate etiology of ILD through a comprehensive and detailed medical history. Histopathologic patterns from lung biopsy should not be dismissed, but are often nonspecific, and overall treatment strategy and prognosis are likely to be determined more by the specific etiology of ILD rather than any particular histologic pattern. In this review, we outline a practical approach to common ILDs, highlight important aspects in obtaining an exposure history, clarify terminology and nomenclature, and discuss six common subgroups of ILD likely to be encountered by general medicine physicians in the inpatient or outpatient setting: Smoking-related, hypersensitivity pneumonitis, connective tissue disease-related, occupation-related, medication-induced, and idiopathic pulmonary fibrosis. Accurate diagnosis of these forms of ILD does require supplementing the medical history with results of the physical examination, autoimmune serologic testing, and chest radiographic imaging, but the importance of a comprehensive environmental, avocational, occupational, and medication-use history cannot be overstated and is likely the single most important factor responsible for achieving the best possible outcomes for patients.

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.

Vinorelbine-induced acute respiratory distress syndrome treated with non-invasive ventilation and immunosuppressive therapy

Severe drug-induced lung disease, resistant to steroids, is a dramatic situation due to the absence of therapeutic alternatives. We describe a case of vinorelbine-induced acute respiratory distress syndrome that did not respond to supportive care plus high-dose steroids. Cyclophosphamide pulse therapy was initiated with subsequent clinical and radiological improvement, allowing the patient to be discharged. We suggest that vinorelbine-induced lung toxicity is driven by a primarily immune-mediated mechanism and that it can respond favourably to immunosuppressive therapy.

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.

Mycophenolate mofetil treatment with or without a calcineurin inhibitor in resistant inflammatory myopathy

To evaluate the efficacy and tolerability of mycophenolate mofetil (MMF) with or without calcineurin inhibitors (CNIs) in patients with inflammatory myopathy taking prednisolone, but refractory to conventional immunosuppressive therapy. The records of patients with inflammatory myopathy who had previously failed treatment with at least one immunosuppressant were retrospectively evaluated. We selected patients treated with MMF and divided them into two groups depending on whether or not there was concomitant use of CNIs. We investigated the efficacy by changes in creatine kinase (CK) levels, forced vital capacity (%FVC), prednisolone dose, and high-resolution computed tomography (HRCT) findings. Interstitial lung disease (ILD) progression was defined by more than 10% decline of %FVC from baseline. We identified 19 patients on MMF treatment. There were seven (36.8%) patients on MMF and CNIs, including five on cyclosporine and two on tacrolimus. At baseline, no significant difference was seen in the prevalence of ILD between patients taking or not taking CNIs (85.7% vs. 75.0%, P = 0.68). Improvement in CK was seen in patients treated with CNIs (P = 0.04) but not in those without (P = 0.39). No significant improvement in %FVC and HRCT findings were found in patients with ILD in either group, and there were no differences in death or ILD progression. The combination of CNIs and MMF might be more effective for decreasing CK levels than MMF alone. Neither treatment arm had a beneficial effect on ILD over a variable observation period.

Oral cyclophosphamide in treatment of patients with refractory idiopathic inflammatory myopathies: a retrospective observational study

To describe the use of oral cyclophosphamide (PO CYC) in a single center longitudinal cohort of patients with idiopathic inflammatory myopathies (IIM). Patients using PO CYC were identified through a retrospective chart review of a myositis cohort at a single academic center. PO CYC dose, duration, adverse events, and disease activity measures before and after CYC were analyzed. Disease activity measures included muscle enzymes, manual muscle testing (MMT8), 100-mm visual analog scale (VAS), and 1-4 Likert scale for physician global assessment. Fourteen patients were treated with PO CYC within the cohort between 2008 and 2017; 9 dermatomyositis (DM), 3 polymyositis (PM), and 2 with immune-mediated necrotizing myopathy (IMNM). Age was 51.1 (40-72) years and the cumulative dose of PO CYC was 41 (2-131) grams over duration of 12.4 (0.5-43) months, mean (range) for all. All patients had severe refractory IIM, 10 (72%) with ILD, 3 (21%) with cardiac involvement and 4 (29%) were dependent in most activities of daily living. Median number of prior failed therapies was 4.5 (range 3-6) including intravenous CYC in 5 patients. Disease activity measures significantly improved following CYC use and concomitant daily prednisone dose decreased. The most common adverse events during CYC therapy were infections. We report the first cohort study of PO CYC use in IIM patients with severe, treatment refractory disease. Further trials are needed to verify these results as well as to evaluate long-term safety outcomes.

Current diagnosis and treatment of polymyositis and dermatomyositis

Idiopathic inflammatory myopathies (IIMs) are heterogeneous disorders that affect the skeletal muscles. Polymyositis, dermatomyositis, and inclusion body myositis are major IIM subsets. Immune-mediated necrotizing myopathy became recognized as a potentially new IIM subset. Since the new classification criteria published by the International Myositis Classification Criteria Project have higher sensitivity and specificity for IIM classification and subclassification than the previous criteria, they should help precise diagnosis. It should be noted that several tests available in current clinical practice, such as electromyography, magnetic resonance imaging, and other myositis-specific autoantibodies than anti-Jo-1 antibodies, were not included in the new criteria. As for treatment, glucocorticoids are used empirically as the first-line treatment despite their various adverse effects. Concomitant treatment with steroid-sparing immunosuppressive agents, including methotrexate, azathioprine, calcineurin inhibitors, mycophenolate mofetil, and cyclophosphamide, reduces successfully initial glucocorticoid doses for the remission induction, the relapse risk during glucocorticoid tapering, and adverse effects of glucocorticoids. Treatment with biologics, including rituximab and abatacept, seems promising in some IIM patients. Multi-target treatment with glucocorticoids and several steroid-sparing immunosuppressive agents is effective in refractory IIM patients. Considering proven steroid-sparing efficacy and tolerability of multi-target treatment in patients with other autoimmune diseases, it should be a good therapeutic option for IIMs.