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Journal of Neuromuscular Diseases 2018Inflammatory disorders of the skeletal muscle include polymyositis (PM), dermatomyositis (DM), (immune mediated) necrotizing myopathy (NM), overlap syndrome with... (Review)
Review
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.
Topics: Biopsy; Dermatomyositis; Disease Management; Electromyography; Humans; Magnetic Resonance Imaging; Muscle, Skeletal; Myositis; Myositis, Inclusion Body; Polymyositis
PubMed: 29865091
DOI: 10.3233/JND-180308 -
Arquivos de Neuro-psiquiatria May 2022Idiopathic inflammatory myopathies (IIM) are a heterogenous group of treatable myopathies. Patients present mainly to the rheumatologist and neurologists, complaining of... (Review)
Review
Idiopathic inflammatory myopathies (IIM) are a heterogenous group of treatable myopathies. Patients present mainly to the rheumatologist and neurologists, complaining of acute or subacute onset of proximal weakness. Extramuscular manifestations may occur, including involvement of the lungs, skin, and joints. Classically, the diagnosis used to be made based on the creatine kinase level increase, abnormalities in electroneuromyography and presence of inflammatory infiltrates in the muscle biopsy. Recently, the importance of autoantibodies has increased, and now they may be identified in more than half of IIM patients. The continuous clinicoseropathological improvement in IIM knowledge has changed the way we see these patients and how we classify them. In the past, only polymyositis, dermatomyositis and inclusion body myopathy were described. Currently, immune-mediated necrotizing myopathy, overlap myositis and antisynthetase syndrome have been considered the most common forms of IIM in clinical practice, increasing the spectrum of classification. Patients previously considered to have polymyositis, in fact have these other forms of seropositive IIM. In this article, we reviewed the new concepts of classification, a practical way to make the diagnosis and how to plan the treatment of patients suffering from IIM.
Topics: Autoantibodies; Dermatomyositis; Humans; Muscular Diseases; Myositis; Neurologists; Polymyositis
PubMed: 35976321
DOI: 10.1590/0004-282X-ANP-2022-S131 -
Medicina (Kaunas, Lithuania) Nov 2022Polymyositis and dermatomyositis are autoimmune idiopathic systemic inflammatory diseases, characterized by various degrees of muscle inflammation and typical cutaneous... (Review)
Review
Polymyositis and dermatomyositis are autoimmune idiopathic systemic inflammatory diseases, characterized by various degrees of muscle inflammation and typical cutaneous lesions-the latter found in dermatomyositis. The underlying pathogenesis is characterized by a high level of uncertainty, and recent studies suggest diseases may have different immunopathological mechanisms. In polymyositis, components of the cellular immune system are involved, whereas in dermatomyositis, the pathogenesis is mainly mediated by the humoral immune response. The interstitial lung disease occurs in one-third of polymyositis and dermatomyositis patients associated with worse outcomes, showing an estimated excess mortality rate of around 40%. Lung involvement may also appear, such as a complication of muscle weakness, mainly represented by aspiration pneumonia or respiratory insufficiency. The clinical picture is characterized, in most cases, by progressive dyspnea and non-productive cough. In some cases, hemoptysis and chest pain are found. Onset can be acute, sub-acute, or chronic. Pulmonary involvement could be assessed by High Resolution Computed Tomography (HRCT), which may identify early manifestations of diseases. Moreover, Computed Tomography (CT) appearances can be highly variable depending on the positivity of myositis-specific autoantibodies. The most common pathological patterns include fibrotic and cellular nonspecific interstitial pneumonia or organizing pneumonia; major findings observed on HRCT images are represented by consolidations, ground-glass opacities, and reticulations. Other findings include honeycombing, subpleural bands, and traction bronchiectasis. In patients having Anti-ARS Abs, HRCT features may develop with consolidations, ground glass opacities (GGOs), and reticular opacities in the peripheral portions; nonspecific interstitial pneumonia or nonspecific interstitial pneumonia mixed with organizing pneumonia have been reported as the most frequently encountered patterns. In patients with anti-MDA5 Abs, mixed or unclassifiable patterns are frequently observed at imaging. HRCT is a sensitive method that allows one not only to identify disease, but also to monitor the effectiveness of treatment and detect disease progression and/or complications; however, radiological findings are not specific. Therefore, aim of this pictorial essay is to describe clinical and radiological features of interstitial lung diseases associated with polymyositis and dermatomyositis, emphasizing the concept that gold standard for diagnosis and classification-should be based on a multidisciplinary approach.
Topics: Humans; Dermatomyositis; Lung; Polymyositis; Lung Diseases, Interstitial; Radiography; Autoimmune Diseases; Retrospective Studies
PubMed: 36556960
DOI: 10.3390/medicina58121757 -
Revista Medica de Chile Mar 2019Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of acquired immune-mediated diseases, which typically involve the striated muscle with a variable... (Review)
Review
Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of acquired immune-mediated diseases, which typically involve the striated muscle with a variable involvement of the skin and other organs. Clinically, they are characterized by proximal muscle weakness, elevation of muscle enzymes, myopathic changes on electromyography and an abnormal muscle biopsy. The different IIM have been classified according to their distinctive histopathologic features in dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and immune-mediated necrotizing myopathy (IMNM). Several myositis-specific antibodies are associated with the different phenotypes, as well as with different risk of neoplastic disease and systemic complications. The basis for the treatment of DM, PM, and IMNM is immunosuppression. For IBM there are only symptomatic treatments. Steroids, associated or not with other immunosuppressant drugs, are the first line of treatment. Biologic drugs will allow future individualized therapies. The 10-year survival of DM, PM and IMNM is 62 to 90%. The leading causes of death are neoplastic, lung and cardiac complications. IBM does not impair survival, although it affects the quality of life.
Topics: Antibodies; Dermatomyositis; Electromyography; Humans; Immunosuppressive Agents; Muscle, Skeletal; Myositis; Polymyositis
PubMed: 31344172
DOI: 10.4067/S0034-98872019000300342 -
Annals of the Rheumatic Diseases May 2017To develop response criteria for adult dermatomyositis (DM) and polymyositis (PM). Expert surveys, logistic regression, and conjoint analysis were used to develop 287...
2016 American College of Rheumatology/European League Against Rheumatism criteria for minimal, moderate, and major clinical response in adult dermatomyositis and polymyositis: An International Myositis Assessment and Clinical Studies Group/Paediatric Rheumatology International Trials Organisation...
To develop response criteria for adult dermatomyositis (DM) and polymyositis (PM). Expert surveys, logistic regression, and conjoint analysis were used to develop 287 definitions using core set measures. Myositis experts rated greater improvement among multiple pairwise scenarios in conjoint analysis surveys, where different levels of improvement in 2 core set measures were presented. The PAPRIKA (Potentially All Pairwise Rankings of All Possible Alternatives) method determined the relative weights of core set measures and conjoint analysis definitions. The performance characteristics of the definitions were evaluated on patient profiles using expert consensus (gold standard) and were validated using data from a clinical trial. The nominal group technique was used to reach consensus. Consensus was reached for a conjoint analysis-based continuous model using absolute per cent change in core set measures (physician, patient, and extramuscular global activity, muscle strength, Health Assessment Questionnaire, and muscle enzyme levels). A total improvement score (range 0-100), determined by summing scores for each core set measure, was based on improvement in and relative weight of each core set measure. Thresholds for minimal, moderate, and major improvement were ≥20, ≥40, and ≥60 points in the total improvement score. The same criteria were chosen for juvenile DM, with different improvement thresholds. Sensitivity and specificity in DM/PM patient cohorts were 85% and 92%, 90% and 96%, and 92% and 98% for minimal, moderate, and major improvement, respectively. Definitions were validated in the clinical trial analysis for differentiating the physician rating of improvement (p<0.001). The response criteria for adult DM/PM consisted of the conjoint analysis model based on absolute per cent change in 6 core set measures, with thresholds for minimal, moderate, and major improvement.
Topics: Adolescent; Adult; Child; Child, Preschool; Consensus; Dermatomyositis; Humans; Outcome Assessment, Health Care; Polymyositis; Randomized Controlled Trials as Topic; Sensitivity and Specificity; Severity of Illness Index
PubMed: 28385805
DOI: 10.1136/annrheumdis-2017-211400 -
Arthritis Care & Research Nov 2011
Review
Measures of adult and juvenile dermatomyositis, polymyositis, and inclusion body myositis: Physician and Patient/Parent Global Activity, Manual Muscle Testing (MMT), Health Assessment Questionnaire (HAQ)/Childhood Health Assessment Questionnaire (C-HAQ), Childhood Myositis Assessment Scale (CMAS),...
Topics: Adult; Child; Dermatology; Dermatomyositis; Health Status; Humans; Muscle Strength Dynamometer; Myositis, Inclusion Body; Parents; Patient Satisfaction; Physician's Role; Polymyositis; Quality of Life; Surveys and Questionnaires
PubMed: 22588740
DOI: 10.1002/acr.20532 -
Continuum (Minneapolis, Minn.) Dec 2013To discuss the clinical, laboratory, and histopathologic features and presumed pathogenic mechanisms of the four major categories of idiopathic inflammatory myopathy,... (Review)
Review
PURPOSE OF REVIEW
To discuss the clinical, laboratory, and histopathologic features and presumed pathogenic mechanisms of the four major categories of idiopathic inflammatory myopathy, namely dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and inclusion body myositis.
RECENT FINDINGS
Dermatomyositis, polymyositis, necrotizing myopathy, and inclusion body myositis are clinically, histologically, and pathogenically distinct. Polymyositis is a T cell-mediated disorder directed against muscle fibers. The pathogenesis of dermatomyositis, necrotizing myopathy, and inclusion body myositis are unknown. Dermatomyositis, polymyositis, and necrotizing myopathy are generally, but not always, responsive to immunosuppressive therapy, in contrast to inclusion body myositis, which is generally refractory to therapy.
SUMMARY
The pattern of muscle weakness, other clinical features (eg, rash, concurrent interstitial lung disease), laboratory features (creatine kinase, autoantibodies), and muscle biopsies are useful in distinguishing subtypes of inflammatory myopathy and in guiding treatment. More research is necessary to unravel the exact pathogenic bases of these myopathies and identify better treatments.
Topics: Dermatomyositis; Humans; Myositis; Myositis, Inclusion Body; Polymyositis
PubMed: 24305450
DOI: 10.1212/01.CON.0000440662.26427.bd -
Internal Medicine (Tokyo, Japan) 2023
Topics: Humans; Dermatomyositis; Polymyositis; Myositis; Edema
PubMed: 37532512
DOI: 10.2169/internalmedicine.1199-22 -
Journal of Veterinary Internal Medicine 2004A retrospective study was performed on 200 randomly selected cases of inflammatory myopathy in dogs from diagnostic muscle biopsies received at the Comparative...
A retrospective study was performed on 200 randomly selected cases of inflammatory myopathy in dogs from diagnostic muscle biopsies received at the Comparative Neuromuscular Laboratory, University of California, San Diego. The most common clinical signs in dogs diagnosed with an inflammatory myopathy were generalized weakness, stilted gait, dysphagia, masticatory or generalized muscle atrophy, inability to open the jaw, megaesophagus, and dysphonia. Myalgia was rarely described. Age of onset ranged from 0.25 to 14 years. Genders were equally represented. Breed distribution approximated the 2002 American Kennel Club registration statistics (r = .85) with the notable exception of Boxers and Newfoundlands. From the results of muscle biopsies, clinical signs, and presence or absence of antibodies against type 2M fibers, dogs were classified as a generalized inflammatory myopathy (gIM)--including immune-mediated polymyositis; infectious and preneoplastic myositis; and, rarely, dermatomyositislike or overlap syndromes or unclassified myositis-or a focal inflammatory myopathy (flM)--including masticatory muscle and extraocular myositis. Average creatine kinase (CK) and aspartate aminotransferase (AST) concentrations in gIMs were significantly higher than those with fIMs (P < .05). Neoplasia developed in 12 of 200 dogs within 12 months of diagnosis of polymyositis, with lymphoma diagnosed in 6 of 32 Boxers. Inflammatory myopathy was associated with antibody titers against infectious diseases in 38 dogs. Neospora caninum and Hepatozoon americanum cysts were found in tissues of 2 dogs not serologically tested. Antibodies against an unidentified sarcolemmal antigen were found in 9 of 19 Newfoundlands with polymyositis. The spectrum of canine inflammatory myopathies can be broad, with infectious etiologies relatively common, and can include preneoplastic and uncharacterized syndromes.
Topics: Animals; Aspartate Aminotransferases; Creatine Kinase; Dermatomyositis; Dog Diseases; Dogs; Female; Male; Masticatory Muscles; Muscle Fibers, Fast-Twitch; Myositis; Polymyositis; Retrospective Studies; Serologic Tests
PubMed: 15515585
DOI: 10.1892/0891-6640(2004)18<679:cimacr>2.0.co;2 -
Neurologic Clinics Aug 2014The idiopathic inflammatory myopathies (IIM) consist of rare heterogeneous autoimmune disorders that present with marked proximal and symmetric muscle weakness, except... (Review)
Review
The idiopathic inflammatory myopathies (IIM) consist of rare heterogeneous autoimmune disorders that present with marked proximal and symmetric muscle weakness, except for distal and asymmetric weakness in inclusion body myositis. Despite many similarities, the IIM are fairly heterogeneous from the histopathologic and pathogenetic standpoints, and also show some clinical and treatment-response differences. The field has witnessed significant advances in our understanding of the pathophysiology and treatment of these rare disorders. This review focuses on dermatomyositis, polymyositis, and necrotizing myopathy, and examines current and promising therapies.
Topics: Autoimmune Diseases; Dermatomyositis; Female; Humans; Male; Muscle Weakness; Myositis; Myositis, Inclusion Body
PubMed: 25037081
DOI: 10.1016/j.ncl.2014.04.007