Neutrophil-mediated oxidative stress and albumin structural damage predict COVID-19-associated mortality

This work reports that COVID-19-induced oxidative stress inflicts
structural damages to human serum albumin (HSA) and is linked with
mortality outcome in critically ill patients. Analyzing blood samples from
patients and healthy individuals, the paper provides evidence that
neutrophils are major sources of oxidative stress in blood and that
hydrogen peroxide is highly accumulated in plasmas of non-survivors. The
electron paramagnetic resonance spectra of spin-labeled fatty acids
(SLFAs) bound with HSA in whole blood of control, survivor, and
non-survivor subjects (n=10–11) were analyzed to probe structural damages
to the protein. Non-survivors’ HSA showed dramatically altered biophysical
parameters that reflect remarkably fluid protein microenvironments.
Following loading/unloading of 16-DSA, the results show that the transport
function of HSA may be impaired in severe patients. Stratified at the
means, Kaplan–Meier survival analysis indicated that lower values of S/W
ratio and accumulated H2O2 in plasma significantly predicted in-hospital
mortality.