Perfil Imunofenotípico e Inflamatório de Pacientes Graves e Convalescentes pela Infecção do SARS-CoV-2

Abstract

Background: COVID-19 is an acute respiratory disease, transmissible by airdrops from infected patients. Many cases were diagnosed in 2020 and evolved to severe conditions, with high number of deaths around the world, and it was seen before that parameters from immune response can act as biomarkers to clinical outcomes in severe and hospitalized. However, few studies focused on individuals cured from infection, without interferents, and less were related to antibody production, what highlighted the development of this study to establish new immunological strategies aiming the improvement of vaccines and management of patients with COVID-19. Aim: To evaluate the immunophenotypic and inflammatory profile from severe and convalescent patients with SARS-CoV-2 infection. Materials and methods: 51 healthy donors were recruited, 12 patients with COVID-19 in mild condition, 6 moderates and 9 severe, and 138 convalescents, who reached clinical recovery approximately 30 days after. Among these, 67 participants had a monthly follow-up for two months. Whole blood was obtained from all participants to evaluate by flow cytometry. Serum samples were also collected to measure cytokines, chemokines, and growth factors using Luminex, and dosage of anti-S and anti-N antibodies. Data analysis was done in Graph PadPrism v.9 and R Studio. All analyses were performed with a 95% confidence interval and a p-value < 0.05. Results: Severe patients COVID-19 demonstrated a decrease in NK and NKT cells number, also with inflammatory and non-classical monocytes. In serum, the concentration of IFN-y, CXCL10 and CXCL8 had potential to act as immunological biomarkers of clinical decision to patients with COVID-19. Among those under hospital attendance, those who evolved to death had high amounts on eosinophils. In convalescents, serum reactivity to anti-N decayed throughout the three months after clinical recovery, but not to anti-S. Markers, such as neutrophil-lymphocyte ratio, eosinophil count and IL-15 were increased during all convalescence, despite it was seen an initial cellular dynamic. Conclusion: With our findings, we observed that exacerbation of innate immunity in acute phase can increase the risk of death. A reparative effect can collaborate with IgG antibodies maintenance in convalescents. Comprehend the immune dynamics in seroconversion will allow the better approach of future pandemics, caused by viral respiratory agents, as establish more precise biomarkers to monitor and follow patients with COVID-19.