ABSTRACT
The pathogenesis of severe coronavirus infection COVID-19 is associated with activation of immune system, cytokine storm, impaired blood clotting, microvascular thrombosis, organ ischemia and multiple organ dysfunction syndrome. The role of various lymphocyte subpopulations in COVID-19 is still debated. The aim of our study was to analyze the subpopulational profile of peripheral blood lymphocytes in COVID-19 patients as compared with healthy donors. The study included 20 COVID-19 patients (11 males and 9 females,) and 26 healthy donors. Average age of the patients was 52 and 56 years, respectively. Clinical examinations were performed by standard laboratory methods. Peripheral blood lymphocytes were isolated in the Ficoll gradient. The cells were stained with antibodies to specific antigens of main lymphocyte populations, endothelial cells, and apoptotic cell markers. The analysis was performed by flow cytometry. The results showed that all patients had elevated C-reactive protein (14- to 35-fold), ferritin (1.2- to 13-fold), D-dimers (1.2- to 90-fold). 55% of men had a decrease in the absolute number of lymphocytes, in women this index was at the low normal limit. Cytometric analysis showed that, among peripheral blood lymphocytes, the proportion of functional cells expressing the CD45 marker ranged from 2 to 12% in 70% of patients, as compared with 80-99% among the donors. The proportion of CD45+ lymphocytes significantly correlated with the level of hemoglobin, but not with the levels of inflammatory biochemical markers. Among the functional lymphocytes of patients, there was a decrease in the proportion of CD3+, CD4+, CD8+T cells, increased proportion of natural killer CD56+ and the apoptotic (AnnexinV+) cell contents, but the proportion of CD19 and HLA-DR+B cells was not changed. Analysis of the lymphocyte (LC) subpopulations that did not express CD45 marker showed that this fraction contained different lymphocyte subsets with reduced expression of CD4, CD8, CD19, CD56 etc. in the blood of patients and donors. Higher percentage of endothelial cells expressing CD62P marker made the difference between patients and donors. Laboratory determination of lymphocyte subsets in blood samples of COVID-19 patients does not reflect the real severity pattern of the disease, thus requiring studies of the CD45-expressing functional cell populations.Copyright © Svirshchevskaya E.V. et al., 2023 The article can be used under the Creative Commons Attribution 4.0 License.
ABSTRACT
The pathogenesis of severe coronavirus infection COVID-19 is associated with activation of immune system, cytokine storm, impaired blood clotting, microvascular thrombosis, organ ischemia and multiple organ dysfunction syndrome. The role of various lymphocyte subpopulations in COVID-19 is still debated. The aim of our study was to analyze the subpopulational profile of peripheral blood lymphocytes in COVID-19 patients as compared with healthy donors. The study included 20 COVID-19 patients (11 males and 9 females,) and 26 healthy donors. Average age of the patients was 52 and 56 years, respectively. Clinical examinations were performed by standard laboratory methods. Peripheral blood lymphocytes were isolated in the Ficoll gradient. The cells were stained with antibodies to specific antigens of main lymphocyte populations, endothelial cells, and apoptotic cell markers. The analysis was performed by flow cytometry. The results showed that all patients had elevated C-reactive protein (14- to 35-fold), ferritin (1.2- to 13-fold), D-dimers (1.2- to 90-fold). 55% of men had a decrease in the absolute number of lymphocytes, in women this index was at the low normal limit. Cytometric analysis showed that, among peripheral blood lymphocytes, the proportion of functional cells expressing the CD45 marker ranged from 2 to 12% in 70% of patients, as compared with 80-99% among the donors. The proportion of CD45+ lymphocytes significantly correlated with the level of hemoglobin, but not with the levels of inflammatory biochemical markers. Among the functional lymphocytes of patients, there was a decrease in the proportion of CD3+, CD4+, CD8+T cells, increased proportion of natural killer CD56+ and the apoptotic (AnnexinV+) cell contents, but the proportion of CD19 and HLA-DR+B cells was not changed. Analysis of the lymphocyte (LC) subpopulations that did not express CD45 marker showed that this fraction contained different lymphocyte subsets with reduced expression of CD4, CD8, CD19, CD56 etc. in the blood of patients and donors. Higher percentage of endothelial cells expressing CD62P marker made the difference between patients and donors. Laboratory determination of lymphocyte subsets in blood samples of COVID-19 patients does not reflect the real severity pattern of the disease, thus requiring studies of the CD45-expressing functional cell populations.Copyright © Svirshchevskaya E.V. et al., 2023 The article can be used under the Creative Commons Attribution 4.0 License.
ABSTRACT
The pandemic caused by a new strain of the SARS-CoV-2 coronavirus has swept the whole world but effective methods for treating this severe pathology have not yet been created. It has now been established that a risk of a severe course of COVID-19 is not so much a patient's age itself, but so-called age-related diseases;the renin-angiotensin system (RAS) is directly or indirectly involved into their development. The SARS-CoV-19 virus interacts with one of the main regulatory elements of this system, ACE2, and disrupts the balance between the two RAS branches. This ultimately manifests itself in an increase in levels of angiotensin II, which, through binding to the angiotensin type 1 receptor (AT1R), causes a number of pathological conditions, including hypertension, atherosclerosis, and cardiovascular diseases, enhances cell proliferation, apoptosis, death of vascular endothelial cells, etc. This process has been described in many reviews by Russian and foreign authors. However, cells of innate and adaptive immunity are another less well-described but no less important target of angiotensin II. The consequences of this interaction are analyzed in detail in this review. With COVID-19, dendritic cells are activated, macrophage proliferation and neutrophil infiltration increase with further involvement of CD4-lymphocytes and other cellular elements of the adaptive immunity in this process. Hyperactivation of the immune system is accompanied with the release of a large amount of pro-inflammatory cytokines, which can lead to the occurrence of a cytokine storm. The picture is aggravated by the inhibitory effect produced by the virus itself on the synthesis of signaling interferons at initial stages in its internalization into the cell. A separate section in the review addresses the problem how to predict a risk of a developing serious condition and search for its predictors by analyzing the state of the RAS and ratios of key cellular elements in the immune system. This is extremely important for making decisions concerning the amount of necessary medical care and strategies for subsequent treatment. © Sadykov V.F., Poltavtseva R.A., Chaplygina A.V., Bobkova N.V., 2022
ABSTRACT
Background: Both myocardial infarction (MI) and COVID-19 are characterized by cytokine storm in blood. Purpose: The objective of this study was to compare the concentration of 39 cytokines, chemokines, and growth factors in blood sera of patients with MI, COVID-19 (COV), and healthy donors. Methods: Patients' blood was collected within 1-2 days after hospitalization in the cardiovascular or COVID intensive care units. All COV patients were in a severe condition;all had increased C reactive protein, 86 and 95% had increased ferritin and D-dimers levels accordingly, 8-10 times decreased lymphocyte numbers. The analysis of the humoral factors in blood serum of MI (n=22), COV (n=23) and donors (n=27) was performed using a 39-plex cytometric analysis. Results: Among all factors analyzed TGFa, IL-1b, 2, 3, 5, 9, 13, 17A were almost not detectable both in patient and donor sera. The concentrations of the other 31 humoral factors in normal sera differed significantly from 0 to 22000 pg/mL. We divided them into house-keeping factors HKF ranged from 1000 to 22000 pg/mL;sentinel innate immunity factors SIF (30-200 pg/mL), and acute phase factors APF (0-30 pg/mL). HKF were detected in all samples. Among SIF and APF IL-1a, G-CSF, IFNa2, IL-7, MIP-1a, IL- 12, and IFNg were detected in 56-80% donor blood while IL-1RA, MCP-3, IL-2, 6, 10, 12, 15, FLT-3F, GM-CSF, TNF-b - only in 10-55%. At the same time all MI patients were 100% positive in all these factors showing extensive activation of blood secretome. Among low incidence APF cytokines in COV patients, percentage of IL-1RA, MCP-3, IFNa2, IL-6, 10, 15, FLT-3L negative sera decreased 3-5 times;and all sera were positive for MIP-1a and IL-12. At the same time TNF-a level decreased significantly from 0 in control to 85% of negative sera in COV patients. Summarized results are shown as the ratios of factor concentrations in MI or COV sera to normal control (Fig). Blood secretome of MI changed more significantly than of COV patients. The major factors (shown in red) in MI were IL-6, IL-12, IFNg, FLT-3L, GM-CSF, and IL-15, which increased 12, 9, 6, 6, 6, and 5 times accordingly. In COV sera IL-6, IL-10, IP-10, and MCP-3 increased by 28, 12, 10, and 9 times accordingly. Less expressed however significant increases are marked with asterisks. Conclusions: Acute MI is characterized by severe disturbances in blood secretome with an increased level of 25 out of 39 factors studied. Contrary to it, in COV patients the levels of IL-6, 10, IP-10, and MCP-3 were more enhanced while only 15 out of 31 exceeded normal levels.
ABSTRACT
Aim. To investigate the immune status and compare immunological parameters in COVID-19 patients with different disease severity. Materials and methods. The prospective study included 62 patients with COVID-19. The patients were stratified into three groups based on the disease severity, including mild (group 1, n=29), moderate (group 2, n=17), and severe (group 3, n=16) forms of COVID-19. On days 3–7 from the onset of the disease, peripheral blood lymphocytes were phenotyped by flow cytometry. Cytokine concentrations were measured using a multiplex immunoassay-standard 48-plex Bio-Plex Pro™ Human Cytokine Screening test system (Bio-Rad, USA) on a flow-based laser immuno-analyzer Bio-Plex 200. Results. Patients with severe COVID-19 had higher levels of leukocytes, neutrophils, CRP, and lower relative and absolute lymphocyte counts. There were low counts of CD3+, CD3+CD4+, CD3+CD8+, and T-lymphocytes expressing the activation marker HLA-DR (CD3+HLA-DR+), NK-cells, and PAN. In group 3, changes in 39 of the 48 investigated soluble factors were observed. Conclusion. High levels of leukocytes, neutrophils, CRP, neutrophilic-leukocyte index, low levels of absolute and relative lymphocyte counts, pronounced changes in immunological parameters, a systemic inflammatory reaction associated with the release of mediators called cytokines ("cytokine storm") predispose to a severe course of COVID-19. © A group of authors, 2021.