Abstract
Background: COVID-19 pandemic has generated a million deaths worldwide. The efficiency of the immune system can modulate individual vulnerability with variable outcomes. However, the relationships between disease severity and the titer of antibodies produced against SARS-CoV-2 in non-vaccinated, recently infected subjects need to be fully elucidated.
Methods: A total of 99 patients admitted to a COVID-unit underwent clinical assessment and measurement of serum levels of anti-spike protein (S1) IgM, and anti-nucleocapsid protein IgG. Patients were stratified according to the clinical outcome (i.e., discharged at home or in-hospital death).
Results: Following hospitalization, 18 died during the hospital stay. They were older, had lymphopenia, a higher co-morbidity rate, and longer hospital stay than 81 patients who were discharged after healing. Patients in this latter group had, at hospital admittance, 7.9-fold higher serum concentration of IgM, and 2.4-fold higher IgG levels. Multivariate Cox regression models indicated age and anti-nucleocapsid protein IgG concentration at admission as independently associated with the risk of in-hospital death.
Conclusions: An efficient immunological response during the early phase of COVID-19 protects from mortality, irrespective of age. Advanced age is a critical risk factor for poor outcome in infected subjects. Further studies must explore potential therapeutic strategies able to restore a valid functional humoral immunity in elderly patients with poor antibody response during the early stage of COVID-19 infection.
Keywords: COVID-19; Elderly; IgG; IgM; SARS-Cov-2; mortality.
【저자키워드】 COVID-19, SARS-CoV-2, IgG, IgM, Mortality, elderly, 【초록키워드】 Mortality, Hospitalization, antibody, COVID-19 pandemic, disease severity, hospital, Antibody Response, risk, immune system, outcome, risk factor, elderly patients, Clinical outcome, lymphopenia, outcomes, Protein, serum, Humoral immunity, COVID-19 infection, titer, Patient, death, co-morbidity, age, Admission, Critical, early stage, therapeutic strategy, Anti-spike, Immunological response, Concentration, Efficiency, Elderly patient, Hospital stay, In-hospital death, clinical assessment, Cox regression model, healing, Older, Serum level, subject, serum levels, early phase, Multivariate Cox regression models, advanced age, IgG levels, multivariate, PROTECT, produced, died, indicated, functional, subjects, modulate, discharged, stratified, 【제목키워드】 antibody, age, COVID-19 mortality,