Role of Oxidative Stress in Pathogenesis and Severity of COVID-19 Infection: Case-Control Study in Iraq

Coronavirus disease 2019 (COVID-19) has presented a significant threat to public health and has rapidly spread across the globe since its outbreak in Wuhan, China, in 2019. Clinical evidence suggests higher oxidative stress in COVID-19 patients, and this worsening redox status may contribute to disease progression. The present study aimed to investigate oxidative stress in patients with mild and severe COVID-19. A case-control study was conducted from September 2021 to January 2022 among eighty-eight COVID-19 patients (male: female, 35:53) and eighty-eight healthy volunteers as the control group (male: female, 53:35) with ages ranging from (18-45) years in Duhok city, Kurdistan Region-Iraq. According to the severity of infection, patients were divided into two groups (mild and severe). Serum levels of malondialdehyde (MDA) and 8-isoprostaglandin F2 alpha (8-iso-PGF2) were assessed as oxidative stress markers. In addition, serum activity of two main antioxidant enzymes, superoxide dismutase (SOD) and catalase were measured. Furthermore, their correlation with the most frequently used laboratory parameters, C-reactive protein (CRP) and D-dimer, were investigated. Serum levels of 8-iso-PGF2 and MDA were considerably higher in patients with COVID-19 compared to healthy individuals (p <0.001) and between severe and mild patients (p<0.001). The activity of CAT was greater in COVID-19 group than in controls (p=0.011), but the difference between severe and mild diseases was statistically insignificant (p>0.05). However, SOD activity showed an insignificant difference between control and case groups (p>0.05), as well as between mild and severe groups (p>0.05). Also, a significant correlation was found between oxidative stress biomarkers and laboratory parameters CRP and D-dimer (p<0.001; and p=0.020), respectively. COVID-19 patients show significantly increased oxidative stress parameters. This may play a crucial role in the disease pathophysiology and could be considered as a predictive marker for COVID19 severity.