COVSurfA Clinical Trial of Nebulized Surfactant for the Treatment of Moderate to Severe COVID-19

The hypothesis behind the proposed trial of surfactant therapy for COVID-19 infected patients requiring ventilator support is that endogenous surfactant is dysfunctional. This could be due to decreased concentration of surfactant phospholipid and protein, altered surfactant phospholipid composition, surfactant protein proteolysis and/or oedema protein inhibition of surfactant surface tension function and/or oxidative inactivation of surfactant proteins. Variations of these dysfunctional mechanisms have been reported in a range of lung diseases, including cystic fibrosis and severe asthma, and in child and adult patients with ARDS. Our studies of surfactant metabolism in adult ARDS patients showed altered percentage composition of surfactant PC, with decreased DPPC and increased surface tension-inactive unsaturated species, and decreased concentrations of both total PC and phosphatidylglycerol (PG) The SARS-CoV-2 virus binds to the angiotensin converting enzyme-2 (ACE2) receptor, which is preferentially expressed in the peripheral lung ATII cells. Consequent viral infection of ATII cells could reduce cell number and impair the capacity of the lungs to synthesise and secrete surfactant. This, however, has not yet been demonstrated empirically in COVID-19 patients. If this is the case, then exogenous surfactant administration to the lungs is potential one treatment option to mitigate disease severity in these patients.