A retrospective cohort study of methylprednisolone therapy in severe patients with COVID-19 pneumonia

Dear Editor,Corona Virus Disease 2019(COVID-19)was first reported in late December 2019,in Wuhan,China.There are over 1,800,000 confirmed cases worldwide.1 The pathological process of severe COVID-19 pneumonia is an inflammation reaction characterized by the destruction of the deep airway and alveolar.2 It is currently considered that lung injury is not only associated with the direct virus-induced damage,but also the immune responses triggered by COVID-19 that lead to the activation of immune cells to release a large number of pro-and anti-inflammatory cytokines.Histologic examination has shown diffuse alveolar damage and mucinous exudate,which is similar to acute respiratory distress syndrome.2 Aggravation of symptoms always occurs during 5–7 days after onset in patients with COVID-19 pneumonia and severe cases develop rapidly to acute respiratory failure.3 Therefore,it is important to strengthen the treatment to suppress the proinflammatory response and control the cytokine storm at this stage.Methylprednisolone are the classical immunosuppressive drugs,which are important to stop or delay the progress of the pneumonia,and have been proved to be effective for the treatment of acute respiratory distress syndrome(ARDS).