Longitudinal characteristics of lymphocyte responses and cytokine profiles in the peripheral blood of SARS-CoV-2 infected patients

“…Although our findings concur with their observed clinical severity-based WBC differences, the discriminating power, early on during hospitalisation and thus value to determine prognosis, was insufficient. A previous report about the prognostic value of NLR (51) is also not supported by our data. Altogether, our findings indicate that new parameters, reflecting functional status of blood cells, are more frequently outside reference ranges in COVID-19 than classical parameters such as lymphocytes, neutrophils or platelets.…”

“…On the other hand, dysfunction of CD4 + and CD8 + T cells usually happens after viral infection and results in delayed viral clearance, viral persistence or even severe infectious tissue damage, such as substantial studies reported in chronic HBV and HIV infected patients 15, 16 . Different from the significant decrease of T lymphocytes reported in the symptomatic COVID-19 cases 2, 17 , the T cell count did not decrease in this asymptomatic individual. The CD4 + and CD8 + T cells experienced classical kinetics of T cell differentiation induced by viral infection and the proliferation of T cells especially Teff was even very active at the early stage of infection as we detected.…”

“…Most cell types were conserved among the PFMC, PBMC, and H-PBMC samples, including CD4 + /CD8 + T cell subsets, B cells, NK cells, monocytes and macrophages, to a much less extent dendritic cells (DC) and plasmacytoid DC (pDC) (Figures 1C-E, S1B). Consistent with the finding of lymphopenia reported in other COVID-19 patients (Diao et al, 2020; Liu et al, 2020a), absolute cell count assay showed that CD8 + T cell numbers in the patient’s blood dropped far below the normal range (Figure S1C), with only a slight decrease for CD4 + T cells and NK cells, and no significant change for B cells (Figure S1C), resulted in increased CD4 + /CD8 + T cell ratios in both PBMC and PFMC comparing to H-PBMC (Figure S1D). CCR7 + naïve CD4 + T cells were predominant in the patient’s PBMC, while PFMC contained more activated CD4 + T and CD8 + T cells by frequency (Figures 1C,1D, S1D and S1E).…”