Sporadic inclusion body myositis: A review of recent clinical advances and current approaches to diagnosis and treatment

• Recent cohort studies have defined more fully the clinical phenotype and natural history of sporadic inclusion body myositis (IBM) and genetic susceptibility.
• Electrophysiology and muscle imaging can contribute to the diagnostic process in IBM and may be potential biomarkers for clinical trials.
• Novel disease-modifying therapies for IBM are under investigation.

Sporadic inclusion body myositis is the most frequent acquired myopathy of middle and later life and is distinguished from other inflammatory myopathies by its selective pattern of muscle involvement and slowly progressive course, and by the combination of inflammatory and degenerative muscle pathology and multi-protein deposits in muscle tissue. This review summarises the findings of recent studies that provide a more complete picture of the clinical phenotype and natural history of the disease and its global prevalence and genetic predisposition. Current diagnostic criteria, including the role of electrophysiological and muscle imaging studies and the recently identified anti-5′-nucleotidase (anti-cN1A) antibody in diagnosis are also discussed as well as current trends in the treatment of the disease.