Autoantibodies: Pathogenic or epiphenomenon.

Idiopathic inflammatory myopathies (IIM) are heterogeneous autoimmune diseases. There are distinct subgroups, including antisynthetase syndrome, dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and sporadic inclusion body myositis. In patients with IIM, autoantibodies are present in up to 80% of the patients. These autoantibodies are often characterized as myositis-specific autoantibodies (MSA) or myositis-associated autoantibodies (MAA). The recognition of the importance of autoantibodies, especially MSA, is increasing in recent years. In this chapter, we provide an overview of the MSAs, including some new autoantibodies of interest as they target mainly muscle-specific autoantigen, in clinical classification, the measurement of the disease activity, and a possible role in the pathogenesis in the patients with IIM.

Galindo-Feria AS ，Wang G ，Lundberg IE 《-》

Inflammatory muscle disease - An update.

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of inflammatory myopathies whose common feature is immune-mediated muscle injury. There are distinct subgroups including dermatomyositis (DM), polymyositis (PM), inclusion body myositis, and immune-mediated necrotizing myopathy. Antisynthetase syndrome is also emerging as a distinct subgroup with its unique muscle histopathological characteristic of perifascicular necrosis. While the newly updated EULAR/ACR Classification Criteria for IIM have brought advancements in diagnosis and the exclusion of mimickers, the use of only one autoantibody in the derivation of the schema limits its use. Similarly, while the advent of multiple novel therapeutics in the treatment of myositis has been exciting, it has also highlighted the scarcity of validated outcome measures. The purpose of our review is to highlight the updated classification criteria of myositis, newly reported clinical phenotypes associated with myositis autoantibodies, the measurement of outcomes, and emerging treatments in the field.

Baig S ，Paik JJ 《-》

Classification of idiopathic inflammatory myopathies: pathology perspectives.

Tanboon J ，Nishino I 《-》

Myositis autoantibody profiles and their clinical associations in Greek patients with inflammatory myopathies.

Zampeli E ，Venetsanopoulou A ，Argyropoulou OD ，Mavragani CP ，Tektonidou MG ，Vlachoyiannopoulos PG ，Tzioufas AG ，Skopouli FN ，Moutsopoulos HM ... -  《-》

Development of a New Classification System for Idiopathic Inflammatory Myopathies Based on Clinical Manifestations and Myositis-Specific Autoantibodies.

Mariampillai K ，Granger B ，Amelin D ，Guiguet M ，Hachulla E ，Maurier F ，Meyer A ，Tohmé A ，Charuel JL ，Musset L ，Allenbach Y ，Benveniste O ... -  《-》