Association between the copper/selenium ratio and the immune response to SARS-CoV-2 infection

Aim: To assess the association serum levels of selenium (Se) and copper (Cu) with symptoms and IgG immune response to SARS-CoV-2. Patients & methods/materials: Blood samples and nasopharyngeal swabs were obtained from 126 COVID-19 patients with mild and severe symptoms. The serum levels of Cu and Se were measured by atomic-absorption spectrophotometry. Results & conclusion: Mean Se was higher in patients with mild symptoms and IgG nonresponders, whereas mean Cu was higher in patients with severe symptoms and IgG responders. The Cu/Se ratio was lower in patients with no IgG responses to infection and mild symptoms versus IgG responders with severe symptoms. These results suggest the Cu/Se ratio as a nutritional biomarker of severity and IgG immune response in COVID-19 patients.