A recent eBioMedicine study identifies shared immunopathology between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and melanoma differentiation-associated protein-5 (MDA5) autoimmunity. Study: MDA5-autoimmunity and interstitial pneumonitis contemporaneous with the COVID-19 pandemic (MIP-C) . Image Credit: Light Studio Design / Shutterstock.
com Dermatomyositis (DM) is an autoimmune disease that is characterized by severe skin and muscle inflammation. Additionally, DM is associated with interstitial lung disease (ILD), which causes progressive pulmonary fibrosis. Anti-Mi-2, which targets the Mi-2 nuclear antigen , is the first autoantibody to be associated with DM.
Over time, multiple myositis-specific and related autoantibodies (MSA) have been identified for different phenotypic patterns. Clinically, amyopathic dermatomyositis (CADM) has been significantly associated with DM and leads to progressive ILD. CADM is expressed through retinoic acid-inducible gene 1 (RIG-1)-like receptor family gene, IFIH1, which encodes the MDA5 protein.
A recent study highlighted that MDA5+ cases predating the coronavirus disease 2019 (COVID-19) pandemic exhibited a significant manifestation of ILD. However, these patients did not develop the classical DM heliotropic rash and instead developed skin-based clinical symptoms, including tender palmar papules and skin ulceration. MDA5 is a RIG-1 helicase12 that functions as an RNA sensor and pattern recognition receptor for SA.
