Background: Oxidative stress may be a key player in COVID-19 pathogenesis due to its significant role in response
to infections. A defective redox balance has been related to viral pathogenesis developing a massive induction of
cell death provoked by oxidative stress. The aim of this study is to perform a complete oxidative stress profile
evaluation regarding antioxidant enzymes, total antioxidant capacity and oxidative cell damage in order to
characterize its role in diagnosis and severity of this disease.
Methods: Blood samples were obtained from 108 COVID-19 patients and 28 controls and metabolites representative of oxidative stress were assessed. The association between lipid peroxidation and 28-day intubation/death
risk was evaluated by multivariable regression analysis. Probability of intubation/death to day-28 was analyzed
by using Kaplan-Meier curves and tested with the log-rank test.
Results: Antioxidant enzymes (Superoxide dismutase (SOD) and Catalase) and oxidative cell damage (Carbonyl
and Lipid peroxidation (LPO)) levels were significantly higher in COVID-19 patients while total antioxidant
capacity (ABTS and FRAP) levels were lower in these patients. The comparison of oxidative stress molecules’
levels across COVID-19 severity revealed that only LPO was statistically different between mild and intubated/
death COVID-19 patients. COX multivariate regression analysis identified LPO levels over the OOP
(LPO>1948.17 μM) as an independent risk factor for 28-day intubation/death in COVID-19 patients [OR: 2.57;
95% CI: 1.10–5.99; p = 0.029]. Furthermore, Kaplan-Meier curve analysis revealed that COVID-19 patients
showing LPO levels above 1948.17 μM were intubated or died 8.4 days earlier on average (mean survival time
15.4 vs 23.8 days) when assessing 28-day intubation/death risk (p < 0.001).
Conclusion: These findings deepen our knowledge of oxidative stress status in SARS-CoV-2 infection, supporting
its important role in COVID-19. In fact, higher lipid peroxidation levels are independently associated to a higher
risk of intubation or death at 28 days in COVID-19 patients.
