Spontaneously activated CD4+ and CD8+ T cells in COVID-19
We studied CD69 expression on T lymphocytes without any stimulation to measure spontaneous activation. In the severe group of patients with COVID-19, a significant increase has been found in the expression of CD69 on CD4+ (3.7% ±4.9 in the mild; 3.6% ±4 in the moderate; 9.4% ±6.8 in the severe group ; p<0.01 with severe group; Fig 5a, b) and on CD8+ cells (13.3% ±12.4; 30% ±35; 45% ±34.5 in the mild, moderate and severe groups respectively (p=0.01 between mild and severe group; Fig 5c, d).