Immune Checkpoints Receptors Expression of Macrophage/Monocytes in Response to Acute Viral Respiratory Infection.

Background: We aimed to monitor the phenotypic changes in macrophages and their polarization in patients with acute viral respiratory diseases, including coronavirus disease diagnosis, focusing on the variations in the percentages of macrophages and monocytes and their sub-populations in those patients compared to healthy control. Moreover, we defined the correlation between macrophage subtypes and some inflammatory indices. Methods: Twenty-seven patients with clinical and radiologic diagnosis of acute viral respiratory infection admitted in Al-Azhar and Assiut University hospitals were recruited. Fresh peripheral blood samples were collected from all patients and healthy controls for flow cytometric analysis using BD FACSCanto II analyzer equipped with three lasers. Results: Compared to healthy controls, accumulation of cluster of differentiation (CD)11B+CD68+ macrophages (M) (P = 0.018), CD274+ M1 (P = 0.01), CD274+ M2 (P < 0.001), and CD80-CD206+ M2 (P = 0.001) was more evident in patients. Moreover, CD273+ M2 (P = 0.03), CD80+CD206- M1 (P = 0.002), and CD80+CD86+ M1 (P = 0.002) were highly expressed in controls compared with patients. Conclusion: The examination of clinical specimens obtained from patients with signs of acute respiratory viral infection showed the role of the macrophage in the immune response. Dysfunction in macrophages results in heightened immune activity and inflammation, which plays a role in the progression of viral diseases and the emergence of accompanying health issues. This malfunction in macrophages is a common characteristic seen in various viruses, making it a promising focus for antiviral therapies with broad applicability. The immune checkpoint could be a target for immune modulation in patients with severe symptoms.

Phenotypical changes of hematopoietic stem and progenitor cells in COVID-19 patients: Correlation with disease status.

Hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) play a crucial role in the context of viral infections and their associated diseases. The link between HSCs and HPCs and disease status in COVID-19 patients is largely unknown. This study aimed to monitor the kinetics and contributions of HSCs and HPCs in severe and non-severe COVID-19 patients and to evaluate their diagnostic performance in differentiating between healthy and COVID-19 patients as well as severe and non-severe cases. Peripheral blood (PB) samples were collected from 48 COVID-19 patients, 16 recovered, and 27 healthy controls and subjected to deep flow cytometric analysis to determine HSCs and progenitor cells. Their diagnostic value and correlation with C-reactive protein (CRP), D-dimer, and ferritin levels were determined. The percentages of HSCs and common myeloid progenitors (CMPs) declined significantly, while the percentage of multipotent progenitors (MPPs) increased significantly in COVID-19 patients. There were no significant differences in the percentages of megakaryocyte-erythroid progenitors (MEPs) and granulocyte-macrophage progenitors (GMPs) between all groups. Severe COVID-19 patients had a significantly low percentage of HSCs, CMPs, and GMPs compared to non-severe cases. Contrarily, the levels of CRP, D-dimer, and ferritin increased significantly in severe COVID-19 patients. MPPs and CMPs showed excellent diagnostic performance in distinguishing COVID-19 patients from healthy controls and severe from non-severe COVID-19 patients, respectively. Collectively, our study indicated that hematopoietic stem and progenitor cells are significantly altered by COVID-19 and could be used as therapeutic targets and diagnostic biomarkers for severe COVID-19.

Regulatory T-lymphocyte subsets in children with chronic immune thrombocytopenia after high-dose of dexamethasone.

BACKGROUND: Immune thrombocytopenia (ITP) is an acquired autoimmune disease. This study's objective was to estimate the variations in the population of CD4+CD25+High FoxP3+ cells (CD4+ regulatory T-lymphocytes; Tregs) in previously untreated children with chronic ITP managed in Assiut University Hospitals, as well as to evaluate the efficacy of high-dose dexamethasone (HD-DXM) in these patients. METHODS: In this study, we investigated the frequencies of T-lymphocyte subsets in 27 untreated children with chronic ITP. RESULTS: Prior to treatment, the percentages of CD4+CD25High cells and Tregs were significantly lower in the chronic ITP group compared to the control group (p = 0.018 and p < 0.0001, respectively). After treatment with HD-DXM, Tregs and platelets were significantly increased in these patients (p < 0.0001 for both). CONCLUSIONS: Our results suggest that Tregs are deficient in children with chronic ITP and that HD-DXM immunosuppressive therapy can restore the levels of these cells. IMPACT: CD4+CD25High cells and Tregs were significantly lower in children chronic ITP compared to healthy control. HD-DXM treatment led to significantly increased Tregs and platelets in these patients. Our results suggest that Tregs are deficient in children with chronic ITP and that HD-DXM immunosuppressive therapy can restore the levels of these cells.

Association of serum fibroblast growth factor-23 with Doppler pulse wave velocity in hemodialysis patients.

We aimed to study the association of fibroblast growth factor-23 (FGF-23) as a novel cardiovascular risk factor with Doppler pulse wave velocity (PWV) as an arterial stiffness measuring tool in hemodialysis (HD) patients. We conducted a cross-sectional study in which blood samples from 86 HD patients were obtained to estimate FGF 23 and other parameters. Flow waveforms were obtained at two locations within right common carotid artery, and right femoral artery by Doppler ultrasound with ECG recorded in addition. The time differences between the R wave of the ECG signal and the onset of the flow waveforms at the two sites yield ΔT. Distances between sampling sites were measured using a tape measure. PWV was defined as (m/s) = D (m)/ ΔT (s). In the current study, we found significant positive correlations between Doppler PWV and both age (r = 0.401, P = 0.039) and systolic blood pressure (r = 0.602, P = 0.034), while no significant association between Doppler PWV and FGF-23 (r = 0.123, P = 0.259) could be detected. Serum FGF-23 levels are not significantly associated with Doppler PWV in HD patients.