Expanding the Clinical Spectrum of Statin-Naïve Anti-HMGCR Myopathy: Case Series and Literature Review

Anti-3-hydroxy-3-methylglutaryl-CoA reductase (anti-HMGCR) antibody-associated myopathy is a rare form of immune-mediated necrotizing myopathy most commonly reported in patients exposed to statins. However, its occurrence in statin-naïve individuals is increasingly recognized but remains underreported. We describe two unusual cases of statin-naïve anti-HMGCR myopathy presenting with severe rhabdomyolysis, leading to acute kidney injury in one patient and dropped head syndrome in another, emphasizing that anti-HMGCR IMNM should be suspected even in statin-naïve individuals presenting with unexplained myopathy, rhabdomyolysis-associated AKI, or axial muscle weakness such as dropped head syndrome, as early immunotherapy may significantly improve outcomes.