Background: The immunological changes associated with COVID-19 are largely unknown. Methods: Patients with COVID-19 showing moderate ( n = 18; SpO2 > 93%, respiratory rate > 22 per minute, CRP > 10 mg/L) and severe ( n = 23; SpO 2 < 93%, respiratory rate >30 per minute, PaO 2 /FiO 2 ≤ 300 mmHg, permanent oxygen therapy, qSOFA > 2) infection, and 37 healthy donors (HD) were enrolled. Circulating T- and B-cell subsets were analyzed by flow cytometry. Results: CD4+Th cells were skewed toward Th2-like phenotypes within CD45RA+CD62L− (CM) and CD45RA–CD62L− (EM) cells in patients with severe COVID-19, while CM CCR6+ Th17-like cells were decreased if compared with HD. Within CM Th17-like cells “classical” Th17-like cells were increased and Th17.1-like cells were decreased in severe COVID-19 cases. Circulating CM follicular Th-like (Tfh) cells were decreased in all COVID-19 patients, and Tfh17-like cells represented the most predominant subset in severe COVID-19 cases. Both groups of patients showed increased levels of IgD-CD38++ B cells, while the levels of IgD+CD38− and IgD–CD38− were decreased. The frequency of IgD+CD27+ and IgD–CD27+ B cells was significantly reduced in severe COVID-19 cases. Conclusions: We showed an imbalance within almost all circulating memory Th subsets during acute COVID-19 and showed that altered Tfh polarization led to a dysregulated humoral immune response.
【저자키워드】 COVID-19, T-cell subsets, B-cell subsets, imbalanced immune response, multicolor flow cytometry, 【초록키워드】 severe COVID-19, Th17, Infection, B cells, CRP, oxygen, flow cytometry, memory, B cell, Patient, Oxygen therapy, phenotype, humoral immune response, group, moderate, CD38, COVID-19 patients, Tfh, B-cell, CD27, Frequency, immunological changes, respiratory rate, Ccr6, qSOFA, Phenotypes, Imbalance, SpO2, both groups, minute, circulating, acute COVID-19, CD45, CD45RA, Th cells, Cell, healthy donor, enrolled, analyzed, significantly, reduced, predominant, dysregulated, subset, follicular, immunological change, PaO, skewed, with COVID-19, 【제목키워드】 response,