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. 2021 Jun;7(2):150-160.
doi: 10.1007/s40674-021-00174-1. Epub 2021 Mar 29.

Therapeutic management of immune-mediated necrotizing myositis

Emma Weeding  1 , Eleni Tiniakou  1
Affiliations

Therapeutic management of immune-mediated necrotizing myositis

Emma Weeding et al. Curr Treatm Opt Rheumatol. 2021 Jun.

Abstract

Purpose of review: The idiopathic inflammatory myopathies are a heterogeneous group of autoimmune disorders characterized by skeletal muscle inflammation leading to chronic muscle weakness. Immune-mediated necrotizing myopathy (IMNM) is a distinct subgroup of inflammatory myopathy typically characterized by myofiber necrosis with minimal inflammatory infiltrates on muscle biopsy, highly elevated creatine kinase levels, and infrequent extra-muscular involvement. This review provides an overview of currently recommended treatment strategies for IMNM, including discussion of disease activity monitoring and recommended first-line immunomodulatory agents depending on clinical phenotype and autoantibody status.

Recent findings: IMNM can be divided into three subtypes based on autoantibody positivity: anti-3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) IMNM, anti-signal recognition particle (SRP) IMNM, and antibody negative IMNM. Autoantibody status in IMNM has considerable correlation with clinical phenotype, prognosis, and recommended choice of immunosuppressive agent. Patients with anti-HMGCR IMNM tend to respond well to intravenous immunoglobulin (IVIG), and IVIG monotherapy may be sufficient treatment for certain patients. In anti-SRP IMNM, early rituximab is commonly favored. More generally, prompt initiation of aggressive immunosuppression is often indicated, as both anti-SRP and anti-HMGCR IMNM can potentially cause debilitating weakness, and muscle atrophy and irreversible fatty replacement happen early in the disease course. Patients with IMNM frequently require combination therapy to achieve disease control, and have a high rate of relapse when tapering immunosuppression. Young age of onset is a poor prognostic factor.

Summary: IMNM can be severely disabling and often requires aggressive immunosuppression. For any given patient, the treatment strategy should be informed by the severity of their presenting features and autoantibody status. While our ability to treat IMNM has certainly improved, there remains a need for more prospective trials to inform optimal treatment strategies.

Keywords: HMGCR; Idiopathic inflammatory myopathies; Immunosuppression; Necrotizing myositis; Signal recognition particle; Treatment.

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Conflict of interest statement

Conflict of Interest Emma Weeding and Eleni Tiniakou declare that they have no conflict of interest

References

    1. Amato AA, Greenberg SA. Inflammatory Myopathies: CONTINUUM: Lifelong Learning in Neurology. 2013December;19:1615–33. - PMC - PubMed
    1. Dalakas MC. Inflammatory Muscle Diseases. Longo DL, editor. New England Journal of Medicine. 2015April30;372(18):1734–47. - PubMed
    1. De Bleecker JL, De Paepe B, Aronica E, de Visser M, Amato A, Aronica E, et al.205th ENMC International Workshop: Pathology diagnosis of idiopathic inflammatory myopathies Part II 28–30 March 2014, Naarden, The Netherlands. Neuromuscular Disorders. 2015March;25(3):268–72. - PubMed

    1. Allenbach Y, Mammen AL, Benveniste O, Stenzel W, Immune-Mediated Necrotizing Myopathies Working Group. 224th ENMC International Workshop:: Clinico-sero-pathological classification of immune-mediated necrotizing myopathies Zandvoort, The Netherlands, 14–16 October 2016. Neuromuscul Disord. 2018;28(1):87–99.

      ** This study includes the recommendation of the IMNM Working Group regarding definition, diagnosis and possible treatment of IMNM based on expert opinion and review of current literature.

    1. Allenbach Y, Keraen J, Bouvier A- M, Jooste V, Champtiaux N, Hervier B, et al.High risk of cancer in autoimmune necrotizing myopathies: usefulness of myositis specific antibody. Brain. 2016;139(Pt 8):2131–5. - PubMed

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