Systemic redox imbalance in severe COVID-19 patients

Area of Science:

• Biochemistry
• Immunology
• Critical Care Medicine

Background:

• Severe COVID-19 is characterized by systemic inflammation and oxidative stress.
• Understanding the redox state in critically ill COVID-19 patients is crucial for prognosis.

Purpose of the Study:

• To evaluate systemic redox and inflammatory markers in intensive care unit (ICU) and non-ICU severe COVID-19 patients.
• To assess changes in oxidative stress and inflammatory variables throughout hospitalization.

Main Methods:

• Blood samples analyzed at admission, T2 (5-7 days), and T3 (pre-discharge/death).
• Reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) measured in granulocytes and monocytes.
• THP-1 cell line incubated with patient plasma to assess viability and apoptosis.

Main Results:

• COVID-19 patients showed higher antioxidant capacity, protein oxidation, lipid peroxidation, and IL-6 at admission.
• ICU patients had elevated C-reactive protein, ROS, and protein oxidation compared to non-ICU patients.
• Granulocytes and monocytes displayed lower MMP and higher ROS in COVID-19 patients, particularly in the ICU group.

Conclusions:

• Disturbances in the redox state are a hallmark of severe COVID-19.
• Oxidative stress is associated with increased cell damage and death in severe COVID-19 patients.
• ICU patients experience a more severe redox imbalance and inflammatory response.