ABSTRACT
Background: Although our understanding of immunopathology in the risk and severity of COVID-19 disease is evolving, a detail of immune response in long-term consequences of COVID-19 infection remains unclear. Recently, few studies have detailed the immune and cytokine profiles associated with PASC. However, dysregulation of immune system driving pulmonary PASC is still largely unknown. Method(s): To characterize the immunological features of PPASC, we performed droplet-based scRNA-sequencing using 10X genomics to study the transcriptomic profiles of peripheral blood mononuclear cells (PBMCs) from participants naive to SARS-CoV-2 (NP, n=2) and infected with SARS-CoV-2 with chronic pulmonary symptoms (PPASC, n=2). Result(s): Analysis of more than 34,000 PBMCs by integrating our dataset with previously reported control datasets generated cell distribution and identified 11 immune cell types based on canonical gene expression. The proportion of myeloid-lineage cells (CD14+monocyte, CD16+monocyte, and dendritic cells) and platelets were increased in PPASC compared with those of NP. Specifically, PPASC displayed up-regulation of VEGFA and transcription factors, such as ATF2, ELK, and SMAD in myeloid-lineage cells. Also, TGF-beta and WNT signaling pathways were up-regulated in these cell population. Cell-cell interaction analysis identified that myeloid-lineage cells in PPASC participated in regulation of fibrosis and immune response, such as VEGFA (increased) and MIF (decreased) interactions. Conclusion(s): Together, this study provides high-resolution insights into immune landscape in PPASC. Our results emphasize differences in myeloid lineage-mediated fibrosis and immunity between PPASC and NP, suggesting they could act as potential pathological drivers of PPASC. (Figure Presented).
ABSTRACT
Coronary artery disease (CAD) is widely considered a chronic inflammatory disorder, and dysfunction of epicardial adipose tissue could be an important source of the inflammation. Amino-terminal fragment of pro-B-type natriuretic peptide (NT-proBNP) is a known marker of cardiovascular disorders of cardiac origin. Recent studies show that inflammatory stimuli may influence its secretion. Our purpose was to evaluate NT-proBNP serum concentration in relation to immune cell ratios in epicardial adipose tissue (EAT), and cytokine levels in the patients with stable CAD. Patients with stable CAD and heart failure classified into classes II-III, according to the New York Heart Association (NYHA) scale, scheduled for the coronary artery bypass graft (CABG) surgery, were recruited into the study (n = 10;59.5 (53.0-65.0) y. o.;50% males). The EAT and subcutaneous adipose tissue (SAT) specimens were harvested in the course of CABG surgery. Immunostaining with anti-CD68, anti-CD45, anti-IL-1β and anti-TNFα monoclonal antibodies was performed to evaluate cell composition by differential counts per ten fields (400 magnification). Fasting venous blood was obtained from patients before CABG. Blood was centrifuged at 1500g, aliquots were collected and stored frozen at -40 °С until final analysis. Concentrations of NT-proBNP, IL-1β, IL-6, IL-10, TNFα were determined in serum samples by enzyme-linked immunosorbent assay (ELISA). We have found increased production of IL-1β and TNFα cytokines in EAT compared to SAT. Concentrations of NT-proBNP exceeded 125 pg/ml in 4 patients, and correlations between the CD68+ macrophage counts in both EAT and SAT samples (rs = 0.762;p = 0.010 and rs = 0.835;p = 0.003, respectively). NT-proBNP levels showed positive relations with CD45+ leukocyte counts (rs = 0.799;p = 0.006), and with IL-1β+ cell numbers (rs = 0.705;p = 0.023) in EAT samples only. As for the serum biomarkers, NT-proBNP levels showed negative correlation with fasting glucose levels (rs = -0.684;p = 0.029), and positive correlation with serum IL-6 concentrations (rs = 0.891;p = 0.001). Increased serum concentrations of NT-proBNP in CAD patients correlate with accumulation of macrophages in EAT, which is associated with increased production of IL-1β in EAT and correlates with some metabolic parameters.
ABSTRACT
INTRODUCTION/HYPOTHESIS: COVID-19 has been associated with distinct types of neuronal damage. We hypothesize that the progression of neurological damage will be related to an imbalance between neurodegeneration, neuroinflammatory, and neuroprotective markers, therefore suggesting a potential mechanism for the emergence of adverse, chronic outcomes. METHODS: 105 patients admitted to an urban, academic hospital with a diagnosis of COVID-19 were enrolled. Serum neuroprotective (clusterin, fetuin), neurodegenerative (τ, phosphorylated τ, amyloids, TDP43, NRGN, NCAM-1, and KLK6), and neuroinflammatory (CCL23, YKL40, MIF) markers were collected. These were analyzed longitudinally in conjunction with immune system activators (RAGE, IL-34) using the multiplex platform. Electronic medical records were used to collect demographic and clinical data. RESULTS: Of the 105 patients, 5 were diagnosed with stroke within 28 days of admission, followed by an additional 6 strokes occurring by 6 months, or a 9.5% occurrence of stroke overall. Serum levels of Amyloid β42 declined significantly for the general population 7 days after admission when compared to initial collections (p< 0.001), while Amyloid β40, KLK6, and MIF declined and recovered within the same 7 days (p< 0.001, p< 0.001, p=0.003). The neuroprotective markers fetuin and clusterin were particularly dynamic with fetuin decreasing and restoring in less than 7 days (p=0.02) and clusterin remaining low after admission (p< 0.001). Most patients had persistently elevated CCL23 levels, with the stroke patient cohort having the highest values (p=0.018). The IL-6 levels of stroke patients were significantly higher compared to their non-stroke counterparts one week after admission (p=0.001), while IL-8 levels fluctuated before declining (p< 0.001). CONCLUSIONS: Our data reveals elevations in neuronal damage in the 7 days following hospital admission for COVID-19 patients. The down-regulation of fetuin and clusterin is particularly compelling as their declines may be linked to the elevated neuronal injury seen with increased neuroinflammatory markers, specifically CCL23 and IL-6. Serum levels of neurodegeneration markers proved complex, therefore possibly suggesting a more dynamic relationship to the neural abnormalities seen in COVID-19 patients.