RT Journal Article SR Electronic T1 In Vivo Visualization and Quantification of Neutrophil Elastase in Lungs of COVID-19 Patients: A First-in-Humans PET Study with 11C-NES JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 145 OP 148 DO 10.2967/jnumed.122.263974 VO 64 IS 1 A1 Gunnar Antoni A1 Mark Lubberink A1 Jens Sörensen A1 Elin Lindström A1 Mathias Elgland A1 Olof Eriksson A1 Michael Hultström A1 Robert Frithiof A1 Anders Wanhainen A1 Jonathan Sigfridsson A1 Paul Skorup A1 Miklos Lipcsey YR 2023 UL http://jnm.snmjournals.org/content/64/1/145.abstract AB Coronavirus disease 2019 (COVID-19) can cause life-threatening lung inflammation that is thought to be mediated by neutrophils. The aim of the present work was to evaluate a novel PET tracer for neutrophil elastase (NE). Methods: In this first-in-humans study, 4 patients with hypoxia due to COVID-19 and 2 healthy controls were investigated with PET using 11C-NES and 15O-water for visualization and quantification of NE and perfusion in the lungs, respectively. Results: 11C-NES accumulated selectively in lung areas with COVID-19 opacities on CT scans, suggesting high levels of NE there. In the same areas, perfusion was severely reduced in comparison to healthy lung tissue as measured with 15O-water. Conclusion: The data suggest that NE is associated with severe lung inflammation in COVID-19 patients and that inhibition of NE could potentially reduce the acute inflammatory process and improve the condition.