Similarities and differences between severe COVID 19 pneumonia and anti MDA 5 positive dermatomyositis associated rapidly progressive interstitial lung diseases: a challenge for the future.

We read with great interest the article by Megremis et al ,1 who identified three immunogenic linear epitopes with high sequence identity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins in patients with dermatomyositis (DM). Speculatively, this finding could indicate that latent exposure to the Coronaviridae family might contribute to musculoskeletal autoimmune disease development.1 Consequently, SARS-CoV-2 infection might mimic myositis and could also lead to catastrophic results in patients with DM with prior interstitial lung disease (ILD) manifestation.\n\nCOVID-19, caused by SARS-CoV-2, has rapidly spread to the whole world. Lung involvement is the hallmark of the disease, significantly associated with worse prognosis and higher mortality. The mechanism leading to acute lung injury in COVID-19 has not yet been completely elucidated. Nevertheless, immune dysfunction and cytokine dysregulation seem to play a pivotal role in this process. It is speculated that SARS-CoV-2 binds to target host cells through ACE 2, which is expressed in the airway and on type 2 pneumocytes in the lung. Subsequently, the virus triggers a storm of innate and adaptive immune response, resulting in the aberrant release of a large number of cytokines, including interleukin (IL)-1, IL-6, IL-10, granulocyte-macrophage colony stimulating factor (GM-CSF), monocyte chemotactic …