Bernd Haditsch (Austria)
Gesundheitszentrum Graz, Austria Österreichische GesundheitskasseAuthor of 1 Presentation
IMPAIRED HOST ANTIVIRAL TH1 AND CD8 RESPONSE IN HIGHLY INFLAMMATORY SARS-COV-2 PATIENTS
Abstract
Background and Aims
Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, has become pandemic. A minority of patients exhibit an aberrant and excessive immune reaction, defined as cytokine release syndrome (CRS). As CRS is a major cause of disease severity and death, more information on the composition and activity of the T cell compartment is necessary.
Methods
We profiled the T cell composition, activation, and proliferation in patients with severe or critical COVID-19 and matched healthy controls by flow cytometry. 20 hospitalized COVID-19 patients, eight severe and twelve critical cases, were included. In addition, two healthy controls were age- and sex-matched to each COVID-19 patient.
Results
Beside lymphopenia we identified: reduced CXCR3+CCR4-CCR6- Th1 cell frequencies in critical COVID19 cases, elevated CXCR3-CCR6+ Th17 cells in both severe and critical, and higher CD8+ T cell frequencies in the severe group. Furthermore, frequencies of CD4+ central memory and CD8+CD28- differed significantly between healthy and SARS-COV-2 infected subjects. Compared to healthy controls patients suffering from severe COVID-19 had increased frequencies of activated and proliferating CD38+Ki67+ Th1 and CD8+ T cells suggesting active anti-viral T cell defense. In contrast, the frequencies of CD38+Ki67+ Th1 and CD8+ T cells correlated negatively with increasing plasma IL-6 in COVID-19 CRS.
Conclusions
Our data suggest that SARS-CoV-2-induced CRS may impair viral clearance by blunting the antiviral T-cell response.