Immune-mediated necrotizing myopathy: clinical features and pathogenesis

Area of Science:

• Neurology
• Immunology
• Pathology

Background:

• Immune-mediated necrotizing myopathy (IMNM) is a distinct inflammatory myopathy characterized by rapid progression and severe muscle impairment.
• IMNM is classified into anti-SRP-positive, anti-HMGCR-positive, and seronegative subclasses, with autoantibodies playing a crucial role.

Purpose of the Study:

• To review the classification, pathogenesis, and therapeutic options for immune-mediated necrotizing myopathy (IMNM).
• To highlight the diagnostic and pathogenic significance of anti-SRP and anti-HMGCR autoantibodies in IMNM.

Main Methods:

• Literature review of IMNM classification, pathogenesis, and treatment.
• Analysis of the role of autoantibodies (anti-SRP, anti-HMGCR) in IMNM pathogenesis and diagnosis.
• Discussion of current and potential future therapeutic interventions.

Main Results:

• Anti-SRP and anti-HMGCR autoantibodies are significant biomarkers and pathogenic factors in IMNM, inducing muscle necrosis in experimental models.
• Seronegative IMNM may be associated with cancer.
• Effective treatments including rituximab and IVIG are available, with anticomplement therapies as a future prospect.

Conclusions:

• IMNM classification based on autoantibodies aids in understanding disease mechanisms.
• Autoantibodies are critical in IMNM pathogenesis and serve as diagnostic markers.
• Current and emerging therapies offer improved management options for IMNM patients.