Decreased Copper/Selenium Ratio Among Non-Responder Healthcare Workers to SARS-CoV-2: An Evidence of High Copper/Selenium Ratio Effects on the Immune Response to COVID-19 and Symptoms

Background: The relationship between strong immune response to infections and trace elements such as selenium (Se) and copper (Cu) is well documented. Furthermore, Se and Cu behave as negative and positive acute phase reactants under infectious conditions, respectively. Since SARS-CoV-2 causes systemic inflammation, this study was conducted to evaluate the association of Se and Cu serum levels with symptoms and immune response to SARS-CoV-2, and then assess the Cu/Se ratio in this matter.Methods: Blood samples and nasopharyngeal swabs were obtained from 126 SARS-CoV-2 participants with mild and severe clinical symptoms. The SARS-CoV-2 infection and immune response to the virus were confirmed by RT-PCR and anti-SARS-CoV-2 IgG, respectively. The measurement of Se and Cu serum levels were analyzed by atomic absorption spectrophotometry and colorimetric assay, respectively. Finally, data were analyzed and a P-value < 0.05 was considered statistically significant.Results: The mean Se levels were higher in patients with mild symptoms (108.73 ± 5.38 μg/L, P-value = 0.0012) and IgG non-responders (110.33 ± 3.38 μg/L, P-value < 0.001), whereas, the mean Cu was higher in participants with severe symptoms (111.055 ± 11.98 μg/dL, P-value = 0.045) and IgG responders (112 ± 9.98 μg/dL, P-value = 0.0058). The Cu/Se ratio was lower (ratio < 1) in participants with no immune responses to infection and mild symptoms versus immune responder patients with severe symptoms (P-value < 0.001).Conclusion: Our results suggest that Cu/Se ratio may be considered as a nutritional biomarker of severity and immune response in SARS-CoV-2-infected patients.