A Unique Case of Myositis.

Keywords: ANCA-associated vasculitis; idiopathic inflammatory myopathy; myalgia; myositis; rituximab EN ANCA-associated vasculitis idiopathic inflammatory myopathy myalgia myositis rituximab 1 5 5 11/04/22 20221001 NES 221001 INTRODUCTION Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare systemic small-vessel disease, with heterogeneous clinical manifestations. Abbreviations AAV ANCA-associated vasculitis ANCA anti-neutrophil cytoplasmic antibodies CNS central nervous system CT computed tomography IIMs idiopathic inflammatory myopathies IMNM immune-mediated necrotizing myopathy MAC membrane attack complex MHC-I major histocompatibility complex-I MRI magnetic resonance imaging p perinuclear SRP signal recognition peptide. Fraser et al. found that signal intensity scores on short tau inversion recovery (STIR) were more sensitive in detecting myositis disease activity than was the presence of pathologic changes on muscle biopsy.[8] Anti-SRP antibody was positive in our patient. [Extracted from the article]