Disclosures: James Fung, DO, MPH: No financial relationships or conflicts of interest

Case Diagnosis: A 52-year-old female with a past medical history of diabetes, hyperlipidemia and hypertension presents with two weeks of fatigue, myalgias and progressively worsening proximal weakness.

Case Description: Over a two-week period, the patient described progressive severe bilaterally posterior thigh and calf pain, increased difficulty brushing her hair, and the loss of ability to rise from a seated position. She also noticed dark urine despite increased oral hydration. On physical examination, manual muscle testing of all extremities showed proximal muscles to be 2/5 and distal muscles to be 4/5. Magnetic resonance imaging (MRI) of the lumbar spine was generally unremarkable except for some mild degenerative changes. MRI of the thigh/femur showed diffuse inflammatory changes. Her blood work showed elevated CPK (~26,000), ESR, and LFT derangement. Other lab findings showed +ANA.

Setting: Acute Care Community Hospital.Assessment/

Results: Further antibodies blood tests were positive for Hydroxy-3-Methylglutaryl-Coenzyme A Reductase (HMGCoR) and muscle pathology showing myonecrosis, consistent with Statin-induced necrotizing autoimmune myopathy (SINAM). Further history revealed she had been on Lipitor chronically. She received IV hydration, systemic steroids, IVIG, and cellcept. Over the next 3 months, patient has slowly regained muscle strength and is now able to ambulate with a rolling walker with good further prognosis.

Discussion: SINAM was identified and has led to identification of an autoantibody against 3-hydroxy-3-methylglutaryl coenzyme A reductase. Studies show sensitivity and specificity of the anti-HMGCR antibodies are 94.4% and 99.3%, respectively. PCSK-9 inhibitor may show a prudent alternative to statins for those whom suffer from SINAM.

Conclusion: Physiatrists should be aware of SINAM diagnosis with HMGCR antibodies and prompt immunosuppressive or intravenous immunoglobulin therapy can minimize physical debility. In addition, there is no temporal association with statin use relative to onset of SINAM . Our case report illustrates the importance of early recognition of SINAM, treatment of SINAM, and alternative medications to statins for the treatment of hyperlipidemia.

Level of Evidence: Level V

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PM&R Meeting Abstracts - https://pmrjabstracts.org/abstract/statin-induced-necrotizing-autoimmune-myositis-sinam-a-case-report/