Molecular Markers of Blood Cell Populations Can Help Estimate Aging of the Immune System.

Aging of the immune system involves functional changes in individual cell populations, in hematopoietic tissues and at the systemic level. They are mediated by factors produced by circulating cells, niche cells, and at the systemic level. Age-related alterations in the microenvironment of the bone marrow and thymus cause a decrease in the production of naive immune cells and functional immunodeficiencies. Another result of aging and reduced tissue immune surveillance is the accumulation of senescent cells. Some viral infections deplete adaptive immune cells, increasing the risk of autoimmune and immunodeficiency conditions, leading to a general degradation in the specificity and effectiveness of the immune system in old age. During the COVID-19 pandemic, the state-of-the-art application of mass spectrometry, multichannel flow cytometry, and single-cell genetic analysis have provided vast data on the mechanisms of aging of the immune system. These data require systematic analysis and functional verification. In addition, the prediction of age-related complications is a priority task of modern medicine in the context of the increase in the aged population and the risk of premature death during epidemics. In this review, based on the latest data, we discuss the mechanisms of immune aging and highlight some cellular markers as indicators of age-related immune disbalance that increase the risk of senile diseases and infectious complications.

Blood Cell Parameters Combined with Inflammatory Markers in the Early Diagnosis of Pulmonary Embolism.

Venous thrombosis is a semi-solid formation of blood components that coalesce in the venous system, and the pathological process of its formation is called venous thrombosis. The deep veins of the lower extremities are a common site of prevalence, and the clinical diagnosis of lower extremity deep vein thrombosis can occur independently or as a complication of other diseases. There is a clear link between inflammation and coagulation/anticoagulation, with inflammatory mechanisms upregulating pro-inflammatory factors, downregulating natural anticoagulant substances, and inhibiting fibrinolytic activity; systemic inflammation is a strong pro-thrombotic stimulus; and in vivo, natural anticoagulant substances not only prevent thrombosis, but also deter inflammatory processes. The interconnection between inflammation and coagulation plays an important role in venous thrombosis. In this study, we analyzed the relationship between inflammatory markers CRP and Fg, FVIII:C and FIX:C by measuring plasma CRP concentration, Fg level, FVIII:C and FIX:C levels in patients with DVT diagnosed by ultrasound, and explored the role and mechanism of inflammatory response and coagulation factor abnormalities and the interaction between them in the development of DVT. In this paper, human blood DNA was extracted by phenol-chloroform-isoamyl alcohol extraction, and CRP 1059G/C gene polymorphism was detected by polymerase chain reaction-restriction enzyme segment length polymorphism (PCR-RFLP) nucleotide typing technique, and the genotypes of each subject were distinguished according to the bands seen by gel electrophoresis, and the frequency of each genotype was counted. Plasma CRP concentrations were measured by immunoturbidimetric assay, FVIII:C and FIX:C levels were measured by phase I assay, and plasma Fg levels were measured by coagulation assay in 59 cases (38 males and 21 females, aged 21-82 years, mean 49.67±11.12 years) and 26 controls (17 males and 9 females, aged 32-67 years, mean 50.13±8.96 years). The above indexes were compared between the two groups, and the correlation between CRP and FVIII:C, FIX:C and Fg was analyzed. Polymerase chain reaction-restriction enzyme segment length polymorphism nucleotide typing technique was used to detect the relationship between CRP 1059G/C gene polymorphism and DVT, to further search for risk factors of venous thrombosis, thus providing new ideas for the future prevention and treatment of this disease in clinical practice.

Targetting ferroptosis for blood cell-related diseases.

Ferroptosis is an iron-dependent cell death pathway and participates in various diseases. Current evidence suggests that ferroptosis can obviously affect the function of blood cells. This paper aims to elaborate the role of ferroptosis in blood cells and related diseases. First, abnormal ferroptosis damages the developing red blood cells by breaking systemic iron homeostasis, leading to erythropoiesis suppression and anaemia. Ferroptosis mediates neutrophils recruitment and neutrophil extracellular trap formation (NETosis). In T-cells, ferroptosis induces a novel point of synergy between immunotherapy and radiotherapy. Additionally, ferroptosis may mediate B cells differentiation, antibody responses and lymphoma. Nevertheless, increased ferroptosis can ameliorate acute myeloid leukaemia and T-cell leukaemia/lymphoma by inducing iron-dependent cancer cells death. Besides, ferroptosis activates platelets by increasing P-selectin, thus causing thromboembolism. Ferroptosis mediates virus infection and parasite infection by driving T-cell death and preventing T-cell immunity. Interestingly, ferroptosis is also considered as a critical player in COVID-19 infections, while targetting ferroptosis may also improve thromboembolism and prognosis in patients with COVID-19 infection. Overall, the crucial role of ferroptosis in blood cells will show a new therapeutic potential in blood cell-related diseases.HighlightsFerroptosis shows a new therapeutic potential for blood cell-related diseases.Ferroptosis damages erythropoiesis and thus induces anaemia.Ferroptosis induces platelet activation and leads to thromboembolism.Ferroptosis regulates T-cell and B-cell immunity, which participant in infectious diseases.Inversely, ferroptosis ameliorates acute myeloid leukaemia and T-cell leukaemia.

Cytokine producing ability of peripheral blood cells from COVID-19 patients after unspecific in vitro stimulation.

OBJECTIVE AND DESIGN: Perturbations of peripheral T cell homeostasis and dysregulation of the immune response to SARS-CoV-2, especially in severely ill patients, were observed. The aim of this study was to analyze the cytokine producing ability of peripheral blood cells from severely ill COVID-19 patients upon non-specific in vitro stimulation with phytohemagglutinin (PHA). Possible associations of cytokine levels with patients' age and gender, glucocorticosteroid therapy, as well as the trend of the inflammatory process at the time of sampling (increased or decreased) were also analyzed. SUBJECTS AND METHODS: The study included 23 COVID-19 patients and 17 healthy control subjects. The concentrations of selected Th1/Th2/Th9/Th17/Th22 cytokines were determined using a multi-analyte flow assay kit. RESULTS: Our results showed that peripheral blood cells from severely ill COVID-19 patients had a much reduced ability to produce cytokines in comparison to healthy controls. When inflammation was raised, blood cells produced more IL-6 and IL-17, which led to increases of some Th17/Th1 and Th17/Th2 ratios, skewing towards the Th17 type of response. The methylprednisolone used in the treatment of patients with COVID-19 influences the production of several cytokines in dose dependent manner. CONCLUSION: Our results indicate that the stage of the inflammatory process at the time of sampling and the dose of the applied glucocorticosteroid therapy might influence cytokine producing ability upon non-specific stimulation of T cells in vitro.

The clinical course of hospitalized moderately ill COVID-19 patients is mirrored by routine hematologic tests and influenced by renal transplantation.

Several studies of patients with COVID-19 have evaluated biological markers for predicting outcomes, most of them retrospectively and with a wide scope of clinical severity. We followed a prospective cohort of patients admitted in hospital wards with moderate COVID-19 disease, including those with a history of kidney transplantation, and examined the ability of changes in routine hematologic laboratory parameters to predict and mirror the patients' clinical course regarding the severity of their condition (classified as critical vs. non-critical) and in-hospital mortality or hospital discharge. Among the 68 patients, 20 (29%) were kidney transplanted patients (KT), and they had much higher mortality than non-kidney transplanted patients in this cohort (40% X 8.3%). Lymphocytes, neutrophils and neutrophils/lymphocytes ratio (NLR) at admission and platelets as well as the red blood cells parameters hemoglobin, hematocrit, and RDW by the time of hospital discharge or death clearly differentiated patients progressing to critical disease and those with clinical recovery. Patients with deteriorating clinical courses presented elevated and similar NLRs during the first week of hospitalization. However, they were dramatically different at hospital discharge, with a decrease in the survivors (NLR around 5.5) and sustained elevation in non-survivors (NLR around 21). Platelets also could distinguish survivors from non-survivors among the critical patients. In conclusion, routine hematologic tests are useful to monitor the clinical course of COVID-19 patients admitted with moderate disease. Unexpectedly, changes in hematologic tests, including lymphopenia, were not predictive of complicated outcomes among KT recipients.

Changes in peripheral blood in SARS CoV-2 patients and its clinico-pathological correlation: A prospective cross-sectional study.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) caused by SARS-CoV2 can present from mild flu-like symptoms to acute respiratory distress syndrome. There is multi-organ involvement; particularly, hematopoietic system can be associated with morphological changes in blood cells of COVID-19 patients. METHOD: We conducted a cross-sectional study on a cohort of 50 COVID-19 patients, confirmed on RT-PCR with documented cycle threshold (Ct) value. Peripheral blood sample of these patients was collected and examined for complete blood counts (CBC) on automated haematological analyser as well as Leishman-stained blood smears to look for morphological changes in blood cells. Morphological changes were evaluated with reference to clinical severity and Ct value. Additionally, association between Ct value and clinical severity was also performed. Statistical tests were performed, and P value <.05 was considered significant. RESULTS: Mean age of our study group was 42.16 ± 15.55 years, with male preponderance. Most commonly observed peripheral blood changes were hypolobation (P value = .002) and toxic granules (P value = .005) in neutrophils, atypical granules with nucleolar prominence in lymphocytes, cytoplasmic granulation with clumped nuclear chromatin in monocytes, giant platelets and thrombocytopenia and normocytic normochromic anaemia. CONCLUSION: No association was found between clinical severity and Ct value as well as peripheral blood morphological changes with Ct value. We conclude that examination of peripheral smear coupled with complete blood count (CBC) is only partially supportive of disease pathogenesis and to assess the viral load other parameters should be utilised instead of relying solely on Ct value.

Blood fibrocytes are associated with severity and prognosis in COVID-19 pneumonia.

Increased blood fibrocytes are associated with a poor prognosis in fibrotic lung diseases. We aimed to determine whether the percentage of circulating fibrocytes could be predictive of severity and prognosis during coronavirus disease 2019 (COVID-19) pneumonia. Blood fibrocytes were quantified by flow cytometry as CD45+/CD15-/CD34+/collagen-1+ cells in patients hospitalized for COVID-19 pneumonia. In a subgroup of patients admitted in an intensive care unit (ICU), fibrocytes were quantified in blood and bronchoalveolar lavage (BAL). Serum amyloid P (SAP), transforming growth factor-ß1 (TGF-ß1), CXCL12, CCL2, and FGF2 concentrations were measured. We included 57 patients in the hospitalized group (median age = 59 yr [23-87]) and 16 individuals as healthy controls. The median percentage of circulating fibrocytes was higher in the patients compared with the controls (3.6% [0.2-9.2] vs. 2.1% [0.9-5.1], P = 0.04). Blood fibrocyte count was lower in the six patients who died compared with the survivors (1.6% [0.2-4.4] vs. 3.7% [0.6-9.2], P = 0.02). Initial fibrocyte count was higher in patients showing a complete lung computed tomography (CT) resolution at 3 mo. Circulating fibrocyte count was decreased in the ICU group (0.8% [0.1-2.0]), whereas BAL fibrocyte count was 6.7% (2.2-15.4). Serum SAP and TGF-ß1 concentrations were increased in hospitalized patients. SAP was also increased in ICU patients. CXCL12 and CCL2 were increased in ICU patients and negatively correlated with circulating fibrocyte count. We conclude that circulating fibrocytes were increased in patients hospitalized for COVID-19 pneumonia, and a lower fibrocyte count was associated with an increased risk of death and a slower resolution of lung CT opacities.

Differences of blood cells, lymphocyte subsets and cytokines in COVID-19 patients with different clinical stages: a network meta-analysis.

BACKGROUND: Due to the rapid spread of coronavirus disease 2019 (COVID-19) worldwide, it is necessary to ascertain essential immune inflammatory parameters that describe the severity of the disease and provide guidance for treatment. We performed network meta-analyses to determine differences in blood cells, lymphocyte subsets, and cytokines in COVID-19 patients with different clinical stages. METHODS: Databases were systematically searched to May 2, 2020, and updated on June 1, 2020. Network meta-analyses were conducted via Stata 15.0, and the mean difference (MD) and its 95% CI were used as the effect values of the pooled analysis. RESULTS: Seventy-one studies were included involving 8647 COVID-19 patients, White blood cell (WBC), neutrophil (NEUT), IL-6, and IL-10 counts increased significantly with worsening of the COVID-19, while lymphocyte (LYM) counts decreased. The levels of platelet (PLT), CD3+, CD4+, CD8+, and CD19+ cells in severe and critical patients were significantly lower than those in mild patients. IL-1ß count was significantly elevated in critical patients. CONCLUSIONS: Immune suppression and inflammatory injury play crucial roles in the progression of COVID-19, and the identification of susceptible cells and cytokines provide guidance for the early and accurate treatment of COVID-19 patients.

Hemocytometric characteristics of COVID-19 patients with and without cytokine storm syndrome on the sysmex XN-10 hematology analyzer.

OBJECTIVES: COVID-19 is an ongoing global pandemic. There is an urgent need for identification and understanding of clinical and laboratory parameters related to progression towards a severe and fatal form of this illness, often preceded by a so-called cytokine-storm syndrome (CSS). Therefore, we explored the hemocytometric characteristics of COVID-19 patients in relation to the deteriorating clinical condition CSS, using the Sysmex XN-10 hematology analyzer. METHODS: From March 1st till May 16th, 2020, all patients admitted to our hospital with respiratory complaints and suspected for COVID-19 were included (n=1,140 of whom n=533 COVID-19 positive). The hemocytometric parameters of immunocompetent cells in peripheral blood (neutrophils [NE], lymphocytes [LY] and monocytes [MO]) obtained upon admission to the emergency department (ED) of COVID-19 positive patients were compared with those of the COVID-19 negative ones. Moreover, patients with CSS (n=169) were compared with COVID-19 positive patients without CSS, as well as with COVID-19 negative ones. RESULTS: In addition to a significant reduction in leukocytes, thrombocytes and absolute neutrophils, it appeared that lymphocytes-forward scatter (LY-FSC), and reactive lymphocytes (RE-LYMPHO)/leukocytes were higher in COVID-19-positive than negative patients. At the moment of presentation, COVID-19 positive patients with CSS had different neutrophils-side fluorescence (NE-SFL), neutrophils-forward scatter (NE-FSC), LY-FSC, RE-LYMPHO/lymphocytes, antibody-synthesizing (AS)-LYMPHOs, high fluorescence lymphocytes (HFLC), MO-SSC, MO-SFL, and Reactive (RE)-MONOs. Finally, absolute eosinophils, basophils, lymphocytes, monocytes and MO-FSC were lower in patients with CSS. CONCLUSIONS: Hemocytometric parameters indicative of changes in immunocompetent peripheral blood cells and measured at admission to the ED were associated with COVID-19 with and without CSS.

Clinical study using mesenchymal stem cells for the treatment of patients with severe COVID-19.

The Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 was identified in December 2019. The symptoms include fever, cough, dyspnea, early symptom of sputum, and acute respiratory distress syndrome (ARDS). Mesenchymal stem cell (MSC) therapy is the immediate treatment used for patients with severe cases of COVID-19. Herein, we describe two confirmed cases of COVID-19 in Wuhan to explore the role of MSC in the treatment of COVID-19. MSC transplantation increases the immune indicators (including CD4 and lymphocytes) and decreases the inflammation indicators (interleukin-6 and C-reactive protein). High-flow nasal cannula can be used as an initial support strategy for patients with ARDS. With MSC transplantation, the fraction of inspired O2 (FiO2) of the two patients gradually decreased while the oxygen saturation (SaO2) and partial pressure of oxygen (PO2) improved. Additionally, the patients' chest computed tomography showed that bilateral lung exudate lesions were adsorbed after MSC infusion. Results indicated that MSC transplantation provides clinical data on the treatment of COVID-19 and may serve as an alternative method for treating COVID-19, particularly in patients with ARDS.