Idiopathic inflammatory myopathies (IIMs) are a heterogenous group of complex muscle diseases of unknown cause. These diseases are characterized by muscle inflammation, progressive muscle weakness and damage, together with involvement of other organ systems. Conventionally, adaptive immune mechanisms (cell mediated and humoral) have been implicated in the pathogenesis of inflammatory myopathies. However, recent studies have provided evidence that not only adaptive immune pathways but also innate immune (e.g., TLR-NF-κB) signaling, and non-immune pathways such as endoplasmic reticulum stress response, autophagy, metabolic deficits in ATP generating pathways and hypoxia are involved in the disease pathogenesis. However, the relative contributions of each of these mechanisms to disease pathogenesis are currently unknown. Understanding the relative contributions of each of these pathways to disease pathogenesis would help to identify drugs that target these pathways to improve muscle weakness and quality of life for patients suffering from these debilitating muscle diseases.
Disclosure of Interest None declared