The Role of Myositis-Specific and Myositis-Associated Autoantibodies and the Activation of Type I Interferon Pathway in the Generation of Clinical Phenotypes of Inflammatory Myopathies

Charalampos Skarlis; Nikolaos Michalakeas; Maria Gerochristou; Sylvia Raftopoulou; Nikolaos Marketos; Kyriaki Boki; Dimitrios Vassilopoulos; Alexandros Panayiotis Stratigos; Dimitrios Boumpas; Clio Mavragani

doi:10.31138/mjr.34.2.275

The Role of Myositis-Specific and Myositis-Associated Autoantibodies and the Activation of Type I Interferon Pathway in the Generation of Clinical Phenotypes of Inflammatory Myopathies

Mediterr J Rheumatol. 2023 Jun 30;34(2):275-278. doi: 10.31138/mjr.34.2.275. eCollection 2023 Jun.

Authors

Affiliations

¹ Department of Physiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
² First Department of Dermatology and Venereology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
³ Sismanogleio General Hospital, Athens, Greece.
⁴ Clinical Immunology-Rheumatology, Hippokration General Hospital, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
⁵ Joint Academic Rheumatology Program, Athens, Greece.
⁶ Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
⁷ Fourth Department of Internal Medicine, University Hospital Attikon, National and Kapodistrian University of Athens, Athens, Greece.

Abstract

Idiopathic inflammatory myopathies (IIMs) are a group of heterogeneous autoimmune diseases with a prevalence of 20 cases per 100000 of population. Despite their diversity, IMMs are characterised by several common clinical features such as muscle inflammation, proximal muscle weakness, abnormal electromyography and/or muscle biopsy. Over the last years, it has been increasingly recognised that an array of autoantibodies known as myositis-specific antibodies (MSAs) and myositis-associated antibodies (MAAs) are associated with distinct clinical phenotypes and diverse prognosis. Although the exact underlying mechanism of IIMs is not fully understood, accumulating data suggest that the activation of type I interferon pathway plays a central role in disease development. Previous studies have reported the upregulation of type I interferon (IFN) induced genes in peripheral blood and muscle biopsies derived from myositis patients. Given the heterogeneity of inflammatory myopathies along with the central role of type I IFN pathway in disease pathogenesis, the aim of the current study is to elucidate the link between distinct clinical phenotypes of inflammatory myopathies with the presence of serum MSAs or MAAs, as well as with type I IFN activation.

Keywords: autoantibodies; inflammatory myositis; type I interferons.