Mild Coronavirus Disease 2019 (COVID-19) Is Marked by Systemic Oxidative Stress: A Pilot Study

• Main Authors: Larissa E. van Eijk (Author), Adriana Tami (Author), Jan-Luuk Hillebrands (Author), Wilfred F. A. den Dunnen (Author), Martin H. de Borst (Author), Peter H. J. van der Voort (Author), Marian L. C. Bulthuis (Author), Alida C. M. Veloo (Author), Karin I. Wold (Author), María F. Vincenti González (Author), Bernardina T. F. van der Gun (Author), Harry van Goor (Author), Arno R. Bourgonje (Author)
• Format: Book
• Published: MDPI AG, 2021-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.
• Notes: 10.3390/antiox10122022; 2076-3921
• Keywords: oxidative stress; free thiols; COVID-19; redox; Therapeutics. Pharmacology; RM1-950
• Source: Antioxidants, Vol 10, Iss 12, p 2022 (2021)

Oxidative stress has been implicated to play a critical role in the pathophysiology of coronavirus disease 2019 (COVID-19) and may therefore be considered as a relevant therapeutic target. Serum free thiols (R-SH, sulfhydryl groups) comprise a robust marker of systemic oxidative stress, since they are readily oxidized by reactive oxygen species (ROS). In this study, serum free thiol concentrations were measured in hospitalized and non-hospitalized patients with COVID-19 and healthy controls and their associations with relevant clinical parameters were examined. Serum free thiol concentrations were measured colorimetrically (Ellman's method) in 29 non-hospitalized COVID-19 subjects and 30 age-, sex-, and body-mass index (BMI)-matched healthy controls and analyzed for associations with clinical and biochemical disease parameters. Additional free thiol measurements were performed on seven serum samples from COVID-19 subjects who required hospitalization to examine their correlation with disease severity. Non-hospitalized subjects with COVID-19 had significantly lower concentrations of serum free thiols compared to healthy controls (<i>p</i> = 0.014), indicating oxidative stress. Serum free thiols were positively associated with albumin (St. β = 0.710, <i>p <</i> 0.001) and inversely associated with CRP (St. β = −0.434, <i>p</i> = 0.027), and showed significant discriminative ability to differentiate subjects with COVID-19 from healthy controls (AUC = 0.69, <i>p</i> = 0.011), which was slightly higher than the discriminative performance of CRP concentrations regarding COVID-19 diagnosis (AUC = 0.66, <i>p</i> = 0.042). This study concludes that systemic oxidative stress is increased in patients with COVID-19 compared with healthy controls. This opens an avenue of treatment options since free thiols are amenable to therapeutic modulation.