A trial of pirfenidone in hospitalized adult patients with severe coronavirus disease 2019

To the Editor:Coronavirus disease 2019(COVID-19),which broke out in 2019,has become a global pandemic.Similar to severe acute respiratory syndrome coronavirus(SARS-CoV)in 2003,SARS-CoV-2 could cause acute lung injury and cytokine storms characterized by the increased interleukin(IL)-8,IL-6,and tumor necrosis factorα(TNF-α).[1]Perspective studies in those survivors from the severe acute respiratory syndrome(SARS)epidemic in 2003 revealed that those SARS patients manifested varying degrees of pulmonary interstitial fibrosis.[2]Similarly,patients with severe COVID-19 are also featured by the diffuse alveolar damage along with alveolar interstitial fibrosis.[3]