Inflammatory Myopathies

Clinically amyopathic dermatomyositis (CADM) is a unique subset of dermatomyositis, showing a high incidence of lung involvements. The aim of this study is to identify risk factors, other than melanoma differentiation-associated protein (MDA)-5, for developing rapidly progressive-interstitial lung disease (RP-ILD) in patients with CADM. Forty CADM patients, in whom 11 patients developed RP-ILD, were enrolled. Clinical features and laboratory findings were compared between the patients with and without RP-ILD...

BACKGROUND: Interstitial lung disease (ILD) is a common extra-muscular manifestation of antisynthetase (AS) syndrome. ILD prevalence is higher with anti-Jo-1 antibody positivity. Data on long-term outcomes in these patients are lacking. METHODS: Over 15 years, we identified subjects with anti-Jo-1 positive AS syndrome and ILD. Demographics, pulmonary function testing (PFT), high-resolution computed tomography (HRCT), histopathology, and long-term survival were analyzed...

The idiopathic inflammatory myopathies (IIMs) comprise a group of autoimmune disorders that target skeletal muscle. They are characterized by typical laboratory and clinical features including muscle weakness, elevated muscle enzymes, characteristic histopathology of muscle biopsies, as well as electromyography abnormalities. The IIMs are divided into polymyositis, dermatomyositis, inclusion body myositis, nonspecific myositis, and immune-mediated necrotizing myopathy (IMNM). IMNM is distinguished by the absence of primary inflammation on muscle biopsy...

OBJECTIVES: The aims of this study were to define the pattern of muscle involvement in patients with immune-mediated necrotising myopathy (IMNM) relative to those with other inflammatory myopathies and to compare patients with IMNM with different autoantibodies. METHODS: All Johns Hopkins Myositis Longitudinal Cohort subjects with a thigh MRI (tMRI) who fulfilled criteria for IMNM, dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) or clinically amyopathic DM (CADM) were included in the study...

Knowledge on idiopathic inflammatory myopathy (IIM) has evolved with the identification of myositis-associated and myositis-specific antibodies, development of histopathological classification and the recognition of how these correlate with clinical phenotype and response to therapy. In this paper, we outline key advances in diagnosis and histopathology, including the more recent identification of antibodies associated with immune-mediated necrotising myopathy (IMNM) and inclusion body myositis (IBM). Ongoing longitudinal observational cohorts allow further classification of these patients with IIM, their predicted clinical course and response to specific therapies...

OBJECTIVES: The aim was to compare standardized incidence ratios (SIRs) of cancers temporally related and unrelated to active myositis in patients with myositis. METHODS: Fifty-two cancer cases were identified in 281 myositis patients. SIRs of cancers having temporal overlap with the active phase of myositis [cancers concurrent with active myositis (CAM), n = 30] and cancers not having such temporal overlap [cancers non-concurrent with active myositis (CNM), n = 22] were compared in 281 patients...

Several uncontrolled studies have encouraged the use of rituximab (RTX) in patients with myositis. Unfortunately, the first placebo-phase trial to assess the efficacy of RTX in refractory myositis did not show a significant difference between the two treatment groups, and doubts have been expressed about its study design. In this review we present an up-to-date overview of the reported experiences of RTX therapy in myositis. A PubMed search was performed to find all the available cases of refractory myositis patients treated with RTX up to July 2015...

Interstitial lung disease (ILD) is a frequent pulmonary manifestation and an important cause of morbidity and mortality in patients with idiopathic inflammatory myopathy. Myositis-related ILD presents a therapeutic challenge for clinicians, as there are no available guidelines to help with management decisions. This review covers the existing evidence on the pharmacologic and nonpharmacologic management of myositis-related ILD, highlighting the lack of randomized controlled data to guide treatment. Given the absence of existing guidelines to inform treatment decisions, we provide a comprehensive summary, including dosing, side effects, and suggested monitoring of the commonly used immunosuppressive agents and a proposed treatment algorithm based on the existing literature...

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Salivary gland changes, characterised by a focal lymphocytic sialadenitits, play an important role in the diagnosis of primary Sjögren's syndrome (PSS) and were first described over 40 years ago. Recent evidence suggests that minor salivary gland biopsy may also provide information useful for prognostication and stratification, yet difficulties may arise in the histopathological interpretation and scoring, and evidence exists that reporting is variable. With the increasing number of actual and proposed clinical trials in PSS, we review the evidence that might support the role of histopathology as a biomarker for stratification and response to therapy and highlight areas where further validation work is required...

PURPOSE OF REVIEW: This review discusses the spectrum of diseases associated with a necrotizing muscle biopsy. Although patients with toxic myopathies, endocrine dysfunction, and heritable myopathies may have prominent necrosis on muscle biopsy, immune-mediated myopathies are emphasized here. RECENT FINDINGS: A decade ago, immune-mediated necrotizing myopathy was recognized as a distinct form of myositis. Recent evidence now suggests that immune-mediated necrotizing myopathy is not one disease, but can be divided on the basis of the presence of distinct autoantibodies recognizing either the signal recognition particle or 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase...

Autoantibodies are a hallmark in the diagnosis of many systemic autoimmune rheumatic diseases (SARD) including idiopathic inflammatory myopathies (IIM). Based on their specificity, autoantibodies in IIM are grouped into myositis specific (MSA) and myositis associated autoantibodies (MAA). Among the MSA, autoantibodies against aminoacyl-tRNA synthetases (ARS) represent the most common antibodies and can be detected in 25-35% of patients. The presence of ARS and other autoantibodies has become a key feature for classification and diagnosis of IIM and is increasingly used to define clinically distinguishable IIM subsets...

Systemic autoimmune diseases are becoming increasingly linked to accelerated risks of cardiovascular disease and events. What is apparent from the above review is that the IIM are not an exception to this growing pattern. Although not always clinically apparent, there seems to be a large percentage of patients who have subclinical CV involvement. Many of the traditional risk factors for CAD, such as hypertension and hyperlipidemia, are associated with developing cardiac involvement in patients with IIM. At this time, it is unclear how much of the atherosclerotic CV morbidity and mortality in IIM patients is driven by traditional CV risk factors versus the effects of chronic systemic inflammation from the underlying IIM...

Statin-induced necrotizing myositis is increasingly being recognised as part of the "statin-induced myopathy spectrum". As in other immune-mediated necrotizing myopathies, statin-induced myositis is characterised by proximal muscle weakness with marked serum creatinine kinase elevations and histological evidence of myonecrosis, with little or no inflammatory cell infiltration. Unlike other necrotizing myopathies, statin-induced myopathy is associated with the presence of autoantibodies directed against 3-hydroxy-3-methylglutaryl- coenzyme A reductase (the enzyme target of statin therapies), and with Human Leukocyte Antigen-DRB1*11...

PURPOSE OF REVIEW: Necrotizing autoimmune myopathy (NAM) is a relatively newly recognized subgroup of idiopathic inflammatory myopathies, which despite diverse causes, have the common histopathological features of myocyte necrosis without significant inflammation. Patients present with a subacute severe symmetrical proximal myopathy, associated with a markedly elevated creatine kinase level. These are most likely immune-mediated, as they respond to immunotherapy. The review aims to define this heterogeneous entity and summarize the salient clinical, laboratory, and muscle biopsy findings, in order to facilitate the diagnosis and treatment of this condition...