Increased NE-A1AT complexes were found in the plasma samples of COVID-19 patients:
Given the accumulation of neutrophils in COVID-19 patient lungs and the abundant evidence of NE expression and activity in the tissues, it was of interest to determine whether plasma from COVID-19 patients showed indications of increased NE. Because NE activity quickly dissipates, due to the high levels of the A1AT protease inhibitor that binds to NE and blocks its activity,47 an appealing alternative is to measure concentrations of NE-A1AT complexes that have an extended half-life. A sandwich ELISA was developed to determine levels of NE-A1AT complexes in the plasma samples of COVID-19 patients as well as healthy individuals. As shown in Figure 6, a significant increase in NE-A1AT complexes was observed in COVID-19 patients.