A Review of Recent Advances in the Classification, Pathogenesis, Diagnosis, and Treatment of Idiopathic Inflammatory Myopathies

Review Article

Abstract

Idiopathic inflammatory myopathies (IIM) represent a heterogeneous group of rare autoimmune disorders affecting skeletal muscles. These conditions are traditionally classified into three main subtypes: polymyositis (PM), dermatomyositis (DM), and inclusion body myositis (IBM). Recent advances in understanding their pathogenesis have led to the identification of new subtypes and associated autoantibodies, revolutionizing disease classification and treatment approaches. The association between genetic susceptibility, particularly HLA associations, and environmental triggers contributes significantly to disease development. Myositis-specific autoantibodies have emerged as crucial tools for diagnosis, prognosis, and therapeutic decision-making. Advanced diagnostic techniques, including muscle biopsy, imaging, and serological testing, offer enhanced clinical utility in disease identification and monitoring. Contemporary treatment strategies encompass conventional immunosuppressive therapy and novel targeted biological agents. Emerging therapies targeting specific pathways, including B-cell depletion, interferon signaling, and complement inhibition, show promising results in clinical studies. Early diagnosis and personalized treatment approaches based on disease subtypes and biomarker profiles have become fundamental principles in managing these disorders. The integration of novel diagnostic tools and targeted therapies has significantly improved the potential for better outcomes in patients with IIM, though challenges in treatment optimization remain.