Current Classification and Management of Inflammatory Myopathies

Abstract

Inflammatory disorders of the skeletal muscle include polymyositis (PM), dermatomyositis (DM), (immune mediated) necrotizing myopathy (NM), overlap syndrome with myositis (overlap myositis, OM) including anti-synthetase syndrome (ASS), and inclusion body myositis (IBM). Whereas DM occurs in children and adults, all other forms of myositis mostly develop in middle aged individuals. Apart from a slowly progressive, chronic disease course in IBM, patients with myositis typically present with a subacute onset of weakness of arms and legs, often associated with pain and clearly elevated creatine kinase in the serum. PM, DM and most patients with NM and OM usually respond to immunosuppressive therapy, whereas IBM is largely refractory to treatment. The diagnosis of myositis requires careful and combinatorial assessment of (1) clinical symptoms including pattern of weakness and paraclinical tests such as MRI of the muscle and electromyography (EMG), (2) broad analysis of auto-antibodies associated with myositis, and (3) detailed histopathological work-up of a skeletal muscle biopsy. This review provides a comprehensive overview of the current classification, diagnostic pathway, treatment regimen and pathomechanistic understanding of myositis.

Acute Exacerbation of Interstitial Lung Disease in Adult Patients With Idiopathic Inflammatory Myopathies: A Retrospective Case-Control Study

“…Multiple organs apart from muscle are often affected as well, leading to critical worsening of the life quality and outcome of these patients (5). Among the multiple extramuscular complications of IIM, interstitial lung disease (ILD) was identified as both the most frequent and severe involvement, leading to a significant elevation in mortality rate (6).…”

<p>Treatment with Repository Corticotropin Injection in Patients with Rheumatoid Arthritis, Systemic Lupus Erythematosus, and Dermatomyositis/Polymyositis</p>

“…[13][14][15][16][17] In the United States, DM has a prevalence of 1 to 6 per 100,000 persons, and PM ranges from the largest fraction with approximately 10 per 100,000 persons in the United States down to the rarest condition that should only be diagnosed by exclusion. 18 Glucocorticoids are used for first-line treatment of patients with DM/PM, followed by (or in conjunction with) immunosuppressive maintenance; in case of intolerance or insufficient response, oral cyclosporine or intravenous immunoglobulin G may be used and, upon relapse or interstitial lung disease, rituximab or cyclophosphamide may be considered. 18 Given that DM/PM is a rare disease, it is not surprising that there are a small number of published reports with results on the clinical efficacy and safety of RCI in patients with refractory DM/ PM.…”

The Changed Transcriptome of Muscular Dystrophy and Inflammatory Myopathy: Contributions of Non-Coding RNAs to Muscle Damage and Recovery

“…Idiopathic inflammatory myopathy represents a heterogeneous group of rare diseases characterized by autoimmune reactions within the skeletal muscle tissue [5]. Dermatomyositis (DM) presents with muscle weakness in the shoulders, upper arms, hips, thighs, and neck, often alongside typical skin lesions which include Gottron's sign (red scaly papules on finger joints), heliotrope rashes, and swelling around the eyes and on the upper chest or back (V-sign).…”