Immune-Mediated Necrotizing Myopathy (IMNM)
Also Known As: Necrotizing Autoimmune Myopathy (NAM) Immune-mediated necrotizing myopathy (IMNM) —also called necrotizing autoimmune myopathy (NAM) —is a rare but severe inflammatory muscle disease. It is characterized by rapidly progressive proximal muscle weakness , markedly elevated muscle enzymes, and extensive muscle fiber necrosis with minimal inflammatory cell infiltration on biopsy. Unlike inherited muscular dystrophies, IMNM is an acquired autoimmune condition in which the immune system mistakenly attacks muscle tissue. What Is IMNM? IMNM belongs to the group of idiopathic inflammatory myopathies , but it differs from other forms such as polymyositis or dermatomyositis because: Muscle cell death (necrosis) is prominent Inflammatory cells are sparse on biopsy Specific autoantibodies are commonly present The disease often progresses quickly Without treatment, IMNM can lead to significant disability. Is IMNM Genetic? IMNM is not a directly inherited genetic disor...