Conclusions
Patients with HMGCR antibody-associated myopathies present with weakness and muscle discomfort and often have damage to both perimysial connective tissue and muscle fibers, with necrosis and myonuclear pathology. Only a minority of patients with HMGCR antibody-associated myopathies have a history of statin exposure.
Methods
Retrospective review of records and myopathologic features of 49 consecutive patients with myopathies and serum HMGCR antibodies.
Objective
To analyze clinical features and myopathology changes in muscle fibers, connective tissue, and vessels in 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) antibody-associated myopathies.
Results
Clinical features included onset age from 12 to 83 years, female predominance (67%), proximal, symmetric weakness (84%), muscle discomfort (78%), dysphagia (35%), systemic features, including skin rash and interstitial lung disease (37%), statin use (38%), and a high serum creatine kinase (83%). Myopathology included muscle fiber necrosis or regeneration (66%), myonuclear pathology (43%), perimysial connective tissue damage (61%), and lymphocytic foci (27%). Conclusions: Patients with HMGCR antibody-associated myopathies present with weakness and muscle discomfort and often have damage to both perimysial connective tissue and muscle fibers, with necrosis and myonuclear pathology. Only a minority of patients with HMGCR antibody-associated myopathies have a history of statin exposure.