Humoral immunity is critically important to control COVID-19. Long-term antibody responses remain to be fully characterized in hospitalized patients who have a high risk of death. We compared specific Immunoglobulin responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between two groups, intensive care unit (ICU) and non-ICU hospitalized patients over several weeks. Plasma specific IgG, IgM, and IgA levels were assessed using a commercial ELISA and compared to an in-house cell-based ELISA. Among the patients analyzed (mean (SD) of age, 64.4 (15.9) years, 19.2% female), 12 (46.2%) were hospitalized in ICU. IgG levels increased in non-ICU cases from the second to the eighth week after symptom onset. By contrast, IgG response was blunted in ICU patients over the same period. ICU patients with hematological malignancies had very weak or even undetectable IgG levels. While both groups had comparable levels of specific IgM antibodies, we found much lower levels of specific IgA in ICU versus non-ICU patients. In conclusion, COVID-19 ICU patients may be at risk of reinfection as their specific IgG response is declining in a matter of weeks. Antibody neutralizing assays and studies on specific cellular immunity will have to be performed.
【저자키워드】 COVID-19, disease severity, intensive care unit, enzyme-linked immunosorbent assay, Immunoglobulin G, western blot, serological analyses, 【초록키워드】 antibodies, SARS-CoV-2, IgG, IgM, coronavirus, Hospitalized, intensive care, Immunity, Hematological malignancy, Antibody Response, risk, ELISA, ICU, Reinfection, cellular immunity, IgA, female, death, age, Neutralizing assay, high risk, IgG response, symptom onset, acute respiratory syndrome, two groups, IgG levels, non-ICU, non-ICU patients, specific IgM, while, ICU patient, analyzed, performed, the patient, characterized, hospitalized patient, comparable, responses against, IgA level, much lower, both group, declining, IgG level, undetectable, were assessed, 【제목키워드】 France, Specific, island, Revealed,