Diagnosis and Management of Myositis-Associated Lung Disease

Case report: Antisynthetase syndrome with positive anti-PL7/SSA/RO52 antibodies

Background

Antisynthetase syndrome (ASS) is a rare autoimmune disease characterized by the immune system attacking specific synthetase in the body. Due to the difficulty in clinical diagnosis, there is still a lack of effective treatment.

Methods

We report a case of a 50-year-old man who presented with progressive, symmetric limb weakness, starting from the lower limbs and gradually affecting the upper limbs. He was admitted to the intensive care unit (ICU) for treatment due to recurrent fever and coma. When he was admitted to the ICU, his limbs were almost unable to move, and the levels of creatine phosphokinase and muscle glycogen were significantly elevated (2449 u/l and 1857 ng/ml). The electromyogram showed myogenic injury, and the anti-PL7 antibody, anti-SSA antibody, and anti-Ro52 antibody were positive. Pathological biopsy of the left biceps brachii showed striated muscle necrosis and macrophage infiltration. He was finally diagnosed with ASS and received treatment with methylprednisolone (subsequently changed to prednisone) and traditional Chinese medicine (Buzhongyiqi Decoction and Shenlingbaizhu powder).

Results

After receiving 2 weeks of glucocorticoid and traditional Chinese medicine treatment, his muscle strength had basically recovered, reaching grade 5 in his limb muscles strength. During the 3-month follow-up period, his activity tolerance continued to improve.

Conclusion

We present a case of severe anti-PL7 positive ASS with positive anti-SSA/Ro52 antibody. The disease was relieved by glucocorticoid and traditional Chinese medicine treatment. This provides an effective approach for managing ASS.

Current efforts and historical perspectives on classification of idiopathic inflammatory myopathies

PURPOSE OF REVIEW

The classification of idiopathic inflammatory myopathies is challenging due to the large number of clinical, serological, histopathological and genetic findings, as well as the latest findings and developments in the field of myositis research. The latest official classification criteria are the 2017 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for adult and juvenile idiopathic inflammatory myopathies, which have been extensively reviewed in recent years for their applicability, sensitivity and specificity.

RECENT FINDINGS

The sensitivity and specificity of the 2017 ACR/EULAR criteria are sometimes performing better, but usually at the same level as the previous criteria. A large number of further suggestions for amendments to the criteria have been made. In particular there is a need to revise the criteria with regard to the addition of new myositis-specific autoantibodies, newly defined subgroups (especially antisynthetase syndrome, immune medicated necrotizing myopathy and overlap myositis) and possibly the addition of further diagnostic procedures (for instance, muscle MRI or PET CT) to improve the accuracy and timeliness of the criteria.

SUMMARY

Efforts to optimize the myositis classification criteria have been extensive in recent years and a new global interdisciplinary collaboration of clinicians is currently taking place based on the previous results with the aim of revising the 2017 EULAR/ACR classification criteria.

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.

HRCT findings predict 1-year mortality in patients with acute exacerbation of idiopathic inflammatory myopathies-associated interstitial lung disease

Background

Acute exacerbation of idiopathic inflammatory myopathies-associated interstitial lung disease (AE-IIM-ILD) is a significant event associated with increased morbidity and mortality. However, few studies investigated the potential prognostic factors contributing to mortality in patients who experience AE-IIM-ILD.

Objectives

The purpose of our study was to comprehensively investigate whether high-resolution computed tomography (HRCT) findings predict the 1-year mortality in patients who experience AE-IIM-ILD.

Methods

A cohort of 69 patients with AE-IIM-ILD was retrospectively created. The cohort was 79.7 % female, with a mean age of 50.7. Several HRCT features, including total interstitial lung disease extent (TIDE), distribution patterns, and radiologic ILD patterns, were assessed. A directed acyclic graph (DAG) was used to evaluate the statistical relationship between variables. The Cox regression method was performed to identify potential prognostic factors associated with mortality.

Results

The HRCT findings significantly associated with AE-IIM-ILD mortality include TIDE (HR per 10%-increase, 1.64; 95%CI, 1.29-2.1, p < 0.001; model 1: C-index, 0.785), diffuse distribution pattern (HR, 3.75, 95%CI, 1.5-9.38, p = 0.005; model 2: C-index, 0.737), and radiologic diffuse alveolar damage (DAD) pattern (HR, 6.37, 95 % CI, 0.81-50.21, p = 0.079; model 3: C-index, 0.735). TIDE greater than 58.33 %, diffuse distribution pattern, and radiologic DAD pattern correlate with poor prognosis. The 90-day, 180-day, and 1-year survival rates of patients who experience AE-IIM-ILD were 75.3 %, 66.3 %, and 63.3 %, respectively.

Conclusion

HRCT findings, including TIDE, distribution pattern, and radiological pattern, are predictive of 1-year mortality in patients who experience AE-IIM-ILD.

Novel Therapeutic Approaches in Connective Tissue Disease-Associated Interstitial Lung Disease

Connective tissue diseases (CTD) comprise a group of autoimmune diseases that can affect multiple organs in the body including the lungs. The most common form of pulmonary involvement is interstitial lung disease (ILD). CTD-associated ILD (CTD-ILD) can take one of several courses including nonprogressive, chronically progressive, or rapidly progressive. Chronically and rapidly progressive patterns are associated with increased mortality. Limited randomized controlled trial data are available for treatment of CTD-ILD, with most data coming from systemic sclerosis-related ILD. The current first-line treatment for all CTD-ILD is immunosuppression with consideration of antifibrotics, stem cell transplant, and lung transplant in progressive disease. In this article, we review data for ILD treatment options in systemic sclerosis, rheumatoid arthritis, myositis, and primary Sjögren's syndrome-related ILDs.

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.

Interstitial Lung Disease: A Review

Importance

Interstitial lung disease (ILD) consists of a group of pulmonary disorders characterized by inflammation and/or fibrosis of the lung parenchyma associated with progressive dyspnea that frequently results in end-stage respiratory failure. In the US, ILD affects approximately 650 000 people and causes approximately 25 000 to 30 000 deaths per year.

Observations

The most common forms of ILD are idiopathic pulmonary fibrosis (IPF), which accounts for approximately one-third of all cases of ILD, hypersensitivity pneumonitis, accounting for 15% of ILD cases, and connective tissue disease (CTD), accounting for 25% of ILD cases. ILD typically presents with dyspnea on exertion. Approximately 30% of patients with ILD report cough. Thoracic computed tomography is approximately 91% sensitive and 71% specific for diagnosing subtypes of ILDs such as IPF. Physiologic assessment provides important prognostic information. A 5% decline in forced vital capacity (FVC) over 12 months is associated with an approximately 2-fold increase in mortality compared with no change in FVC. Antifibrotic therapy with nintedanib or pirfenidone slows annual FVC decline by approximately 44% to 57% in individuals with IPF, scleroderma associated ILD, and in those with progressive pulmonary fibrosis of any cause. For connective tissue disease-associated ILD, immunomodulatory therapy, such as tocilizumab, rituximab, and mycophenolate mofetil, may slow decline or even improve FVC at 12-month follow-up. Structured exercise therapy reduces symptoms and improves 6-minute walk test distance in individuals with dyspnea. Oxygen reduces symptoms and improves quality of life in individuals with ILD who desaturate below 88% on a 6-minute walk test. Lung transplant may improve symptoms and resolve respiratory failure in patients with end-stage ILD. After lung transplant, patients with ILD have a median survival of 5.2 to 6.7 years compared with a median survival of less than 2 years in patients with advanced ILD who do not undergo lung transplant. Up to 85% of individuals with end-stage fibrotic ILD develop pulmonary hypertension. In these patients, treatment with inhaled treprostinil improves walking distance and respiratory symptoms.

Conclusions and Relevance

Interstitial lung disease typically presents with dyspnea on exertion and can progress to respiratory failure. First-line therapy includes nintedanib or pirfenidone for IPF and mycophenolate mofetil for ILD due to connective tissue disease. Lung transplant should be considered for patients with advanced ILD. In patients with ILD, exercise training improves 6-minute walk test distance and quality of life.

Presenting clinical and imaging features of patients with clinically amyopathic interstitial lung disease associated with myositis-specific autoantibodies

Background

Lung involvement in the context of idiopathic inflammatory myopathies has significant impact on outcome; early and accurate diagnosis is important but can be difficult to achieve. In particular, patients without clinically evident muscle involvement pose a significant diagnostic challenge.

Methods

A computer-assisted search was conducted to identify patients with amyopathic interstitial lung disease associated with the presence of myositis-specific autoantibodies. Medical records and chest imaging studies were reviewed to identify clinical and radiologic features at presentation.

Results

Of the 35 patients with amyopathic interstitial lung disease associated with myositis-specific autoantibodies, the median age was 65 years (range 43-78) and 20 were women (57%). Of the patients, 34% had previously visited the rheumatology department. Presenting symptoms consisted of dyspnea (94%), cough (43%), and arthritis (23%). Raynaud phenomenon, "mechanic hands," Gottron papules, and inspiratory crackles were present in 23, 31, 9, and 74% of patients, respectively. After a detailed history, none of the patients reported muscle weakness, while four (11%) exhibited increased CK levels; of these four, two had a concomitant increase in aldolase levels. Median FVC was 79% predicted (range: 49-135) and median DLco was 50% predicted (range: 17-103). HRCT pattern was suggestive of an alternative to UIP pattern in 31/33 (94%) patients; the most common imaging patterns were NSIP (49%) and NSIP/OP (39%).

Conclusion

In patients with NSIP and NSIP/OP pattern, the presence of amyopathic interstitial lung disease associated with myositis-specific autoantibodies should be considered even in the absence of clinical evident myositis.

A Review of Antisynthetase Syndrome-Associated Interstitial Lung Disease

Our objective in this review article is to present a clinical case of a patient with antisynthetase syndrome (ASyS) and provide an overview of the pathogenesis, classification criteria, antibody profiles, clinical features, and current knowledge of treatment options, focusing on interstitial lung disease (ILD). ASyS is an uncommon autoimmune disease with a heterogenous clinical presentation characterized by the presence of autoantibodies against an aminoacyl-tRNA synthetase and manifested by myositis, fever, inflammatory arthritis, Raynaud's phenomenon, mechanics hands, and ILD. ASyS-associated ILD (ASyS-ILD) is the most serious complication of ASyS, which may evolve to rapidly progressive ILD; therefore, it often requires thorough clinical and radiologic evaluation including recognition of a specific clinical phenotype associated with the antisynthetase antibodies (ASAbs) to guide therapeutic interventions.

Effectiveness and safety of mycophenolate mofetil and rituximab combination therapy for immune idiopathic myopathies

INTRODUCTION

Idiopathic inflammatory myopathies (IIM) represent a rare and heterogenous group diseases, and their treatment is not fully defined yet. According to previous small case series, the combination of mycophenolate mofetil (MMF) and rituximab (RTX) may be effective in controlling difficult-to-treat patients. Our aim was to further explore the efficacy and safety of this combined approach in patients with IIM.

METHODS

Patients with IIM treated with the RTX/MMF combination in our Center were retrospectively identified. After the start of combination therapy, the efficacy was evaluated at 12 months (T12) according the 2016 ACR/EULAR response criteria for IIM. Cardiac imaging and pulmonary function tests were used to monitor disease activity in patients with myocarditis and interstitial lung disease, respectively. Adverse events were recorded over the follow-up period.

RESULTS

Among the 20 patients (median age 61 years; 70% female) included in the study, anti-synthetase syndrome was the most prevalent IIM subgroup (60%). At treatment start, muscle, heart, and lung were the most commonly actively affected organs. After 12 months, a moderate or major response was observed in all patients, and creatine kinase was significantly decreased (p-value = 0.012). Cardiac imaging and enzymes monitoring showed a reduction of heart inflammation, while pulmonary function tests improved in patients with lung involvement. No severe side effects were observed.

CONCLUSION

Our data show that combination of RTX and MMF is effective and safe in patients with severe and refractory IIM. Therefore, this combined treatment might represent a feasible approach for difficult-to-treat IIM cases.

Spontaneous pneumomediastinum: An extra muscular manifestation of anti-MDA5 dermatomyositis. Report of 2 cases

The use of specific antibodies in inflammatory myopathies has improved the characterization of this disease, identifying different clinical phenotypes. Patients with dermatomyositis (DM) and anti-MDA5 antibodies display typical skin symptoms, lesser muscular involvement, and a prevalence of interstitial lung disease (ILD) of up to 91%. Beyond ILD, spontaneous pneumomediastinum (SN) has been identified as a rare but potentially fatal pulmonary manifestation. Two cases of this complication in patients with anti-MDA5 DM are reported.

Clinical Features and Outcomes of Patients with Idiopathic Inflammatory Myositis-Associated Interstitial Lung Disease in Rural Appalachia: A Cross-Sectional Study

BACKGROUND

Idiopathic inflammatory myopathies (IIMs) are a group of autoimmune disorders often complicated by interstitial lung disease (ILD). The clinical characteristics and outcomes of IIM-associated ILD have been reported variably, but the literature on rural populations is scarce.

METHODS

A retrospective cross-sectional study was conducted at a rural tertiary academic medical center. Twenty-nine patients met the final inclusion criteria. The primary outcome was to assess the disease state and immunological and radiographic features of IIM-associated ILD. Secondary outcomes included disease progression, ILD exacerbation, mortality rate, and factors associated with poor outcome.

RESULTS

Dermatomyositis (n = 15, 51.72%) followed by polymyositis (n = 8, 27.58%) were predominant myopathies. The most common autoantibodies were anti-Jo1 antibodies (n = 11, 37.93%). Indeterminate usual interstitial pneumonitis (41.30%, n = 12) was the most common radiographic pattern followed by non-specific interstitial pneumonia (n = 5, 17.24%). ILD exacerbation (n = 14, 66.66%) and mortality rate (n = 6, 20.69%) were high. Albumin levels were significantly lower in patients who died.

CONCLUSIONS

The clinical characteristics of patients with IIM-associated ILD in rural Appalachia exhibit notable distinctions, and outcomes are worse compared to other populations. Larger studies are needed to investigate other prognostics factors and longitudinal trends of clinical characteristics and outcomes of IIM-associated ILD in rural populations.

Progressive pulmonary fibrosis in myositis-specific antibody-positive interstitial pneumonia: a retrospective cohort study

Objectives

Idiopathic inflammatory myopathy (IIM) frequently coexists with interstitial pneumonia (IP) and is commonly the initial or sole manifestation accompanied by positive myositis-specific autoantibodies (MSAs), even in the absence of meeting diagnostic criteria. This study aims to evaluate the proportion of progressive pulmonary fibrosis (PPF) and identify potential predictors influencing the progression of pulmonary fibrosis in patients with MSA-IP.

Methods

This descriptive study employed a retrospective cohort design, enrolling patients diagnosed with interstitial pneumonia and positive MSAs at Beijing Chao-Yang Hospital in a sequential manner. Clinical data were systematically collected from the patients' medical records during regular follow-up visits conducted every 3 to 6 months. Cox regression analysis was utilized to identify independent predictors of PPF in patients with positive MSAs and interstitial pneumonia.

Results

A total of 307 patients were included in the study, with 30.6% of them developing PPF during a median follow-up period of 22 months. Kaplan-Meier survival curves demonstrated a significantly lower survival in the PPF patients compared to the non-PPF patients (median 11.6 months vs. 31 months, p = 0.000). An acute/subacute onset of interstitial pneumonia (HR 3.231, 95%CI 1.936-5.392, p = 0.000), lower diffusing capacity of the lungs for carbon monoxide (DLCO) % predicted (HR 6.435, 95%CI 4.072-10.017, p = 0.001), and the presence of diffuse alveolar damage (DAD) on high-resolution computed tomography (HRCT) (HR 8.679, 95%CI 1.974-38.157, p = 0.004) emerged as independent predictors of PPF. Notably, the implementation of triple therapy comprising glucocorticoids, immunosuppressants, and antifibrotic drugs was associated with a reduced risk of developing PPF (HR 0.322, 95%CI 0.115-0.899, p = 0.031).

Conclusion

Approximately 30.6% of patients with MSA-IP may develop PPF within the follow-up period. Patients presenting with an acute/subacute onset of interstitial pneumonia, lower predicted DLCO SB% and evidence of DAD on HRCT are more susceptible to developing PPF. Conversely, the administration of triple therapy appears to serve as a protective factor against the development of PPF in patients with MSA-IP.

The Lack of a Durable Response to Tofacitinib in Anti-PL-12 Anti-synthetase Syndrome With Progressive Interstitial Pneumonitis

We discuss a case of a 48-year-old female with anti-PL-12 anti-synthetase syndrome. She presented with dermatitis and myositis and developed rapidly progressive interstitial lung disease (ILD) while on prednisone and azathioprine, which responded dramatically to the addition of tofacitinib. However, the patient later developed arthritis, worsening skin disease, cutaneous vasculitis, and worsening ILD with corticosteroid reduction. The response to a standard dose of tofacitinib, although dramatic in the subacute phase of ILD, was not durable in terms of preventing a flare-up of skin disease, cutaneous vasculitis, arthritis, and the slow progression of pulmonary fibrosis as corticosteroids were tapered. Rituximab and nintedanib were then sequentially added to her therapy. Our experience suggests that rather than sequential addition, targeted triple therapy with tofacitinib, rituximab, and an antifibrotic should be considered early in the disease course in patients with dermatomyositis and severe ILD.

Musculoskeletal adverse events induced by immune checkpoint inhibitors: a large-scale pharmacovigilance study

Background: The musculoskeletal toxicity of immune checkpoint inhibitors (ICIs) is receiving increasing attention with clinical experience. Nevertheless, the absence of a systematic investigation into the musculoskeletal toxicity profile of ICIs currently results in the under-recognition of associated adverse events. Further and more comprehensive investigations are warranted to delineate the musculoskeletal toxicity profile of ICIs and characterize these adverse events. Material and methods: The present study employed the FDA Adverse Event Reporting System database to collect adverse events between January 2010 and March 2021. We utilized both the reporting odds ratio and the Bayesian confidence propagation neural network algorithms to identify suspected musculoskeletal adverse events induced by ICIs. Subsequently, the clinical characteristics and comorbidities of the major musculoskeletal adverse events were analyzed. The risk of causing these events with combination therapy versus monotherapy was compared using logistic regression model and Ω shrinkage measure model. Results: The musculoskeletal toxicity induced by ICIs primarily involves muscle tissue, including neuromuscular junctions, fascia, tendons, and tendon sheaths, as well as joints, spine, and bones, including cartilage. The toxicity profile of PD-1/PD-L1 and CTLA-4 inhibitors varies, wherein the PD-1 inhibitor pembrolizumab exhibits a heightened overall risk of inducing musculoskeletal adverse events. The major ICIs-induce musculoskeletal adverse events, encompassing conditions such as myositis, neuromyopathy (including myasthenia gravis, Lambert-Eaton myasthenic syndrome, Guillain-Barré syndrome, and Chronic inflammatory demyelinating polyradiculoneuropathy), arthritis, fractures, myelitis, spinal stenosis, Sjogren's syndrome, fasciitis, tenosynovitis, rhabdomyolysis, rheumatoid myalgia, and chondrocalcinosis. Our study provides clinical characteristics and comorbidities of the major ICIs-induced musculoskeletal adverse events. Furthermore, the combination therapy of nivolumab and ipilimumab does not result in a statistically significant escalation of the risk associated with the major musculoskeletal adverse events. Conclusion: Immune checkpoint inhibitors administration triggers a range of musculoskeletal adverse events, warranting the optimization of their management during clinical practice.

Anti-Ro52/Anti-nuclear Matrix Protein 2 Positive Clinically Amyopathic Dermatomyositis Presented Only With Interstitial Lung Disease

This report contemplates a unique case of clinically amyopathic dermatomyositis (CADM) that presented as interstitial lung disease. The patient was a 55-year-old woman who showed up with progressive exercise intolerance and a dry cough without muscular or dermatological clinical manifestations. Diagnostic workup and imaging revealed the presence of interstitial lung disease, and further evaluation led to a positive autoimmune panel for anti-nuclear matrix protein 2 (anti-NXP2) and anti-Ro52 antibodies, establishing the diagnosis of anti-NXP2 plus anti-Ro52 antibodies-positive amyopathic idiopathic inflammatory dermatomyositis. The patient was started on intravenous corticosteroids. She showed improvement on her chest X-ray (CXR) and was then switched to oral corticosteroids. After six months of steroid treatment, corticosteroids were stopped, and the patient was re-evaluated one month later disease relapse.

Rapidly progressive respiratory failure due to antisynthetase syndrome related interstitial lung disease

A 65-year-old female was admitted with rapidly progressive respiratory failure requiring intubation and mechanical ventilation. She was considered to have an infective exacerbation of underlying interstitial lung disease (ILD). She improved on antibiotics, but the interstitial process progressed rapidly, and she could not be weaned. An antimyositis antibody panel yielded a strongly positive anti-Jo-1 and anti-Ro 52. A diagnosis of antisynthetase syndrome (ASS) associated ILD, a very rare disease with high mortality, was made. She was managed with high-dose corticosteroids and intravenous immunoglobulin therapy and was eventually liberated from mechanical ventilation. This case highlights the importance of considering ASS in an otherwise unexplained rapidly progressive ILD requiring mechanical ventilation.