SHM Converge Scientific Abstract ePoster Gallery-Statin Induced Immune Mediated Necrotizing Myopathy- Case Report

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This case report describes a 70-year-old Caucasian woman with dyslipidemia and lumbar degenerative disease who developed progressive proximal muscle weakness over 2 years, worsening over the last 6 months. She had difficulty climbing stairs, frequent falls, neck flexor weakness, and marked weakness in the deltoids and hip flexors, while distal strength remained intact. There were no skin findings or joint symptoms to suggest dermatomyositis or another connective tissue disease.<br /><br />Initial workup showed elevated creatine phosphokinase (CPK) and aldolase, but normal inflammatory markers and negative autoimmune serologies, including ANA, anti-Mi2, Jo-1, SRP, and others. Muscle biopsy of the deltoid revealed necrotizing myopathy without lymphocytic inflammation. Imaging and swallow evaluation did not suggest malignancy or interstitial lung disease. Importantly, HMG-CoA reductase antibody was positive, supporting a diagnosis of statin-induced immune-mediated necrotizing myopathy (SIANM).<br /><br />Her symptoms had persisted despite stopping statin therapy and a short prednisone course, which helped distinguish SIANM from typical statin myalgia or toxic statin myopathy, where symptoms usually resolve after discontinuation. She was treated with high-dose steroids and IVIG, followed by a steroid taper and prolonged IVIG therapy. Over time, her strength improved significantly, and by 2 years follow-up she had returned to normal strength with physical therapy and no further rheumatologic treatment.<br /><br />The report emphasizes that persistent proximal weakness and elevated CK levels after statin discontinuation should raise suspicion for SIANM. Early recognition, statin cessation, and prompt immunosuppressive treatment are important to improve remission and reduce morbidity.

Asset Subtitle

Khushboo Singh

Meta Tag

Author List Aleesha Kainat, Bedi Prabhjot, Ezza Fatima Tariq, Khushboo Singh, Tissa Bijoy George

Category Clinical Vignettes

Concept Statin-induced necrotizing autoimmune myopathy

Concept Proximal Muscle Weakness

Concept Creatine Kinase

Concept Anti-HMGCR Antibody

Concept Statin discontinuation

Distinguished Non-Finalist

Presenter Organization Upmc

Presenting Author Khushboo Singh

Track Adult

Keywords

statin-induced immune-mediated necrotizing myopathy

SIANM

proximal muscle weakness

elevated creatine phosphokinase

HMG-CoA reductase antibody

muscle biopsy

necrotizing myopathy

dyslipidemia

IVIG therapy

prednisone

Statin-induced necrotizing autoimmune myopathy

Proximal Muscle Weakness

Creatine Kinase

Anti-HMGCR Antibody

Statin discontinuation