Dynamic changes in radiological parameters, immune cells, selected miRNAs, and cytokine levels in peripheral blood of patients with severe COVID‑19

Abstract

The present study aimed to investigate the dynamic changes in peripheral blood leucocyte subpopulations, cytokine and miRNA levels, and changes in computed tomography (CT) scores in patients with severe coronavirus disease 2019 (COVID-19) (n=14) and age-matched non-COVID-19 volunteers (n=17), which were included as a reference control group. All data were collected on the day of patient admission (day 0) and on the 7th, 14th and 28th days of follow-up while CT of the lungs was performed on weeks 2, 8, 24 and 48. On day 0, lymphopenia and leucopenia were detected in most patients with COVID-19, as well as an increase in the percentage of banded neutrophils, B cells, and CD4⁺ Treg cells, and a decrease in the content of PD-1^low T cells, classical, plasmacytoid, and regulatory dendritic cells. On day 7, the percentage of T and natural killer cells decreased with a concurrent increase in B cells, but returned to the initial level after treatment discharge. The content of different T and dendritic cell subsets among CD45⁺ cells increased during two weeks and remained elevated, suggesting the activation of an adaptive immune response. The increase of PD-1-positive subpopulations of T and non-T cells and regulatory CD4 T cells in patients with COVID-19 during the observation period suggests the development of an inflammation control mechanism. The levels of interferon γ-induced protein 10 (IP-10), tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 decreased on day 7, but increased again on days 14 and 28. C-reactive protein and granulocyte colony-stimulating factor (G-CSF) levels decreased gradually throughout the observation period. The relative expression levels of microRNA (miR)-21-5p, miR-221-3p, miR-27a-3p, miR-146a-5p, miR-133a-3p, and miR-126-3p were significantly higher at the beginning of hospitalization compared to non-COVID-19 volunteers. The plasma levels of all miRs, except for miR-126-3p, normalized within one week of treatment. At week 48, CT scores were most prominently correlated with the content of lymphocytes, senescent memory T cells, CD127⁺ T cells and CD57⁺ T cells, and increased concentrations of G-CSF, IP-10, and macrophage inflammatory protein-1α.

Keywords: CD4 T cells; CD8 T cells; COVID-19; chest CT; cytokine; dynamic changes; immune cell subpopulations; microRNA.

Figure 1

Dynamic changes in hematological parameters in patients with COVID-19. (A) Dynamic profile of blood cell types. Blue rectangles denote the normal range. (B) Ratio of leukopenia and leukocytosis. (C) Ratio of lymphopenia. Data are presented as the median and interquartile range. Wilcoxon signed-rank test: ^*P≤0.05, ^**P≤0.01 and ^***P≤0.001. COVID-19, coronavirus disease 19; WBC, white blood cells; ESR, erythrocyte sedimentation rate; RBC, red blood cells.

Figure 2

Dynamic changes in lymphocyte subsets in patients with COVID-19. (A) Frequency of white blood cells, T cells, B cells, natural killer cells. (B) Frequency of double-positive CD4⁺CD8⁺ T cells, CD3⁺PD-1^low T cells, CD3^-PD-1^low non-T cells, CD25-expressing, and CD127-expressing T cells. Data are presented as the median and interquartile range. Wilcoxon signed-rank test was used for comparison of time-dependent events: ^*P≤0.05, ^**P≤0.01 and ^***P≤0.001. Mann-Whitney U test was used for comparing the values of the control and COVID-19 groups at each time point: ^#P≤0.05, ^##P≤0.01 and ^###P≤0.001. The blue line represents the COVID-19 group; and the black line represents the control group. COVID-19, coronavirus disease 19; WBC, white blood cells; NK, natural killer.

Figure 3

Dynamic changes in T-cell subsets in patients with COVID-19. (A) Different subsets of CD8 T cells. (B) Different subsets of CD4 T cells. Data are presented as the median and interquartile range. Wilcoxon signed-rank test was used for comparison of time-dependent events: ^*P≤0.05, ^**P≤0.01 and ^***P≤0.001. Mann-Whitney U test was used for comparing the values of the control and COVID-19 groups at each time point: ^#P≤0.05, ^##P≤0.01 and ^###P≤0.001. The blue line represents the COVID-19 group; and the black line represents the control group. COVID-19, coronavirus disease 19.

Figure 4

Dynamic changes in myeloid mononuclear cell subsets in patients with COVID-19. Data are presented as a median and interquartile range. Wilcoxon signed-rank test was used for comparison of time-dependent events: ^*P≤0.05, ^**P≤0.01 and ^***P≤0.001. Mann-Whitney U test was used for comparing the values of the control and COVID-19 groups at each time point: ^#P≤0.05, ^##P≤0.01 and ^###P≤0.001. The blue line represents the COVID-19 group; and the black line represents the control group. COVID-19, coronavirus disease 19.

Figure 5

Dynamic changes in cytokine levels in patients with COVID-19. Data are presented as a median and interquartile range. Wilcoxon signed-rank test was used for comparison of time-dependent events: ^*P≤0.05, ^**P≤0.01 and ^***P≤0.001. Mann-Whitney U test for comparing the control and COVID-19 groups at each time point: ^#P≤0.05, ^##P≤0.01 and ^###P≤0.001. The blue line represents the COVID-19 group; and the black line represents the control group. COVID-19, coronavirus disease 19; CRP, C-reactive protein; IP-10, interferon γ-induced protein 10; IL-6, interleukin 6; TNF-α, tumor necrosis factor-α; MIP-1α, macrophage inflammatory protein-1α; G-CSF, granulocyte colony-stimulating factor; IL-2, interleukin 2; MCP-1, monocyte chemoattractant protein-1.

Figure 6

Dynamic changes in miRNA expression levels in patients with COVID-19. Data are presented as a median and interquartile range. Wilcoxon signed-rank test was used for comparison of time-dependent events: ^*P≤0.05 and ^**P≤0.01. Mann-Whitney U test was used for comparing the values of the control and COVID-19 groups at each time point: ^#P≤0.05 and ^##P≤0.01. The blue line represents the COVID-19 group; and the black line represents the control group. miRNA or miR, microRNA; COVID-19, coronavirus disease 19; RU, relative units.

Figure 7

Dynamic changes in lung computed tomography scores in patients with COVID-19. Data are presented as a median and interquartile range. Paired t-test was used for comparison between related values of time-dependent events: ^*P≤0.05. The blue line represents the COVID-19 group. COVID-19, coronavirus disease 19; wk, week.