COVID-19 pneumonia is induced by the newly emerging pandemic Severe acute respiratory Syndrome (SARS) coronavirus 2 and results in progression to the acute respiratory distress syndrome (ARDS). Apart from protective ventilation, fluid restriction, prone positioning and extracorporeal membrane oxygenation (ECMO), no specific therapeutic options exist to treat this devastating disease with a mortality rate of up to 50%. The growth factor granulocyte-macrophage colony-stimulating factor (GM-CSF) is widely recognized to promote differentiation and mobilization of different myeloid leukocyte subsets including neutrophils, tissue macrophages/dendritic cells or their circulating precursors. GM-CSF was found to be crucial for alveolar epithelial repair following hyperoxic and inflammatory lung injury.The aim of the current trial is to prevent progression to ARDS in COVID-19 pneumonia patients by preemptive GM-CSF Inhalation
