Anti-SARS-CoV-2 Antibody Subclass Response and Cytokine Storm in Severe COVID-19 Patients Under Intensive Care Unit

Background SARS-CoV-2, the virus responsible for the COVID-19 pandemic, has diverse clinical presentations and varying degrees of severity, accounting for millions of deaths and the leading cause of intensive care unit (ICU) admissions during the pandemic. In this study, we sought to evaluate potential immunological biomarkers (antibodies, chemokines, cytokines, and growth factors) that predict clinical outcomes in circulating samples from patients with "Severe COVID" admitted to the ICU. Methods This is a prospective longitudinal study using peripheral blood samples from 30 patients admitted to the ICU with severe COVID-19 [with the outcomes discharge (DIS) and death (DEA)] and 30 healthy controls. Clinical and laboratory data were collected during patient evaluation. Furthermore, immunological molecules are being quantified using the Luminex methodology, a multiplex immunoassay. Results Males were the most common sex (70%), and 57% of patients had hypertension and diabetes mellitus. The circulating response profile differed between the study groups, with patients, regardless of outcome, presenting a heterogeneous profile of molecule production throughout the follow-up period. The DIS group showed greater control over the production of immune molecules, particularly IL-13, while the DEA group presented a profile consistent with a cytokine storm. Conclusions We suggest that IgM Anti-N and IgM Anti-RBD antibodies, along with molecules such as IFN-g (D0), TNF-a, and FGF-basic (D7), as well as CXCL8, CCL4, CXCL10, and G-CSF (D14), may be potential biomarkers of worsening clinical outcomes. Furthermore, IL-13 may play a protective role in these ICU patients.