Little is known about the time-dependent immune responses in severe COVID-19. Data of 15 consecutive patients were sequentially recorded from intensive care unit admission. Lymphocyte subsets and total monocyte and subsets counts were monitored as well as the expression of HLA-DR. For 5 patients, SARS-CoV-2–specific T-cell polyfunctionality was assessed against Spike and Nucleoprotein SARS-CoV-2 peptides. Non-specific inflammation markers were increased in all patients. Median monocyte HLA-DR expression was below the 8,000 AB/C threshold defining acquired immunodepression. A “V” trend curve for lymphopenia, monocyte numbers, and HLA-DR expression was observed with a nadir between days 11 and 14 after symptoms’ onset. Intermediate CD14 ++ CD16 + monocytes increased early with a reduction in classic CD14 ++ CD16 – monocytes. Polyfunctional SARS-Cov-2–specific CD4 T-cells were present and functional, whereas virus-specific CD8 T-cells were less frequent and not efficient. We report a temporal variation of both innate and adaptive immunity in severe COVID-19 patients, helpful in guiding therapeutic decisions (e.g. anti-inflammatory vs. immunostimulatory ones). We describe a defect in virus-specific CD8 T-cells, a potential biomarker of clinical severity. These combined data also provide helpful knowledge for vaccine design. Clinical Trial Registration https://clinicaltrials.gov/ , identifier NCT04386395
【저자키워드】 SARS-CoV-2, Immunity, monocyte HLA-DR, antigen-specific polyfunctional T-cells, intensive care unit, 【초록키워드】 Monocytes, immune response, Biomarker, adaptive, intensive care, severe COVID-19, Anti-inflammatory, spike, knowledge, Variation, Vaccine design, T-cells, Lymphocyte subsets, SARS-CoV-2 peptides, CD8, monocyte, lymphopenia, Registration, lymphocyte, clinical, immune responses, peptides, T-cell, nucleoprotein, threshold, expression, Admission, patients, HLA-DR, inflammation markers, intensive care unit admission, Clinical severity, CD16, classic, immunostimulatory, severe COVID-19 patients, CD14, defect, nadir, therapeutic decisions, intermediate, CD4 T-cell, functional, less, reduction in, subset, recorded, CD8 T-cell, consecutive patient, inflammation marker, therapeutic decision, 【제목키워드】 COVID-19, longitudinal,