COVID-19 in three waves in a tertiary referral hospital in Belgium: a comparison of patient characteristics, management, and outcome.

Purpose: Few studies have compared patient characteristics, clinical management, and outcome of patients with COVID-19 between the different epidemic waves. In this study, we describe patient characteristics, treatment, and outcome of patients admitted for COVID-19 in the Antwerp University Hospital over the first three epidemic waves of 2020-2021.

Methods: Retrospective observational study of COVID-19 patients in a Belgian tertiary referral hospital.

Diagnosing Viral Infections Through T-Cell Receptor Sequencing of Activated CD8+ T Cells.

T-cell-based diagnostic tools identify pathogen exposure but lack differentiation between recent and historical exposures in acute infectious diseases. Here, T-cell receptor (TCR) RNA sequencing was performed on HLA-DR+/CD38+CD8+ T-cell subsets of hospitalized coronavirus disease 2019 (COVID-19) patients (n = 30) and healthy controls (n = 30; 10 of whom had previously been exposed to severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]). CDR3α and CDR3β TCR regions were clustered separately before epitope specificity annotation using a database of SARS-CoV-2-associated CDR3α and CDR3β sequences corresponding to >1000 SARS-CoV-2 epitopes.

Leveraging T-cell receptor - epitope recognition models to disentangle unique and cross-reactive T-cell response to SARS-CoV-2 during COVID-19 progression/resolution.

Despite the general agreement on the significance of T cells during SARS-CoV-2 infection, the clinical impact of specific and cross-reactive T-cell responses remains uncertain. Understanding this aspect could provide insights for adjusting vaccines and maintaining robust long-term protection against continuously emerging variants. To characterize CD8+ T-cell response to SARS-CoV-2 epitopes unique to the virus (SC2-unique) or shared with other coronaviruses (CoV-common), we trained a large number of T-cell receptor (TCR) - epitope recognition models for MHC-I-presented SARS-CoV-2 epitopes from publicly available data.

Symptomatic Severe Acute Respiratory Syndrome Coronavirus 2 Reinfection of a Healthcare Worker in a Belgian Nosocomial Outbreak Despite Primary Neutralizing Antibody Response.

Background: It is currently unclear whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection will remain a rare event, only occurring in individuals who fail to mount an effective immune response, or whether it will occur more frequently when humoral immunity wanes following primary infection.

Methods: A case of reinfection was observed in a Belgian nosocomial outbreak involving 3 patients and 2 healthcare workers. To distinguish reinfection from persistent infection and detect potential transmission clusters, whole genome sequencing was performed on nasopharyngeal swabs of all individuals including the reinfection case's first episode.

The Diagnostic Challenge of Extrapulmonary Tuberculosis: Esophageal Perforation, Mediastinitis, Pneumopericardium, and Pericardial Abscess Formation.

We describe the case of extrapulmonary tuberculosis complicated by esophageal perforation, pneumopericardium, and pericardial abscess formation. This case illustrates the difficulty in diagnosing extrapulmonary tuberculosis, as the occurrence of tuberculosis is rare in the developed world. The appropriate treatment strategy and 6-month follow-up results are discussed.

Endothelial dysfunction in acute brain injury and the development of cerebral ischemia.

Cerebral ischemia (CeI) is a major complicating event after acute brain injury (ABI) in which endothelial dysfunction is a key player. This study evaluates cellular markers of endothelial function and in vivo reactive hyperemia in patients with ABI and their relationship to the development of cerebral ischemia. We studied cellular markers of endothelial dysfunction and the peripheral reactive hyperemia index (RHI) in 26 patients with ABI at admission and after 6 and 12 days, and compared these with those of healthy volunteers (n = 15).

The endothelium, a protagonist in the pathophysiology of critical illness: focus on cellular markers.

The endotheliumis key in the pathophysiology of numerous diseases as a result of its precarious function in the regulation of tissue homeostasis. Therefore, its clinical evaluation providing diagnostic and prognostic markers, as well as its role as a therapeutic target, is the focus of intense research in patientswith severe illnesses. In the critically ill with sepsis and acute brain injury, the endothelium has a cardinal function in the development of organ failure and secondary ischemia, respectively.

Endothelium dependent vasomotion and in vitro markers of endothelial repair in patients with severe sepsis: an observational study.

Background: Outcome in sepsis is mainly defined by the degree of organ failure, for which endothelial dysfunction at the macro- and microvascular level is an important determinant. In this study we evaluated endothelial function in patients with severe sepsis using cellular endothelial markers and in vivo assessment of reactive hyperaemia.

Materials And Methods: Patients with severe sepsis (n = 30) and 15 age- and gender- matched healthy volunteers were included in this study.

TransFix® for delayed flow cytometry of endothelial progenitor cells and angiogenic T cells.

Endothelial progenitor cells (EPC) and angiogenic T cells have not been validated for use in studies that involve delayed sample processing and analysis. Here, we report our results for the flow cytometric enumeration of circulating EPC and angiogenic T cells using TransFix®-treated whole blood obtained from adult patients with cardiovascular disease and healthy volunteers. Both cell types promote neovascularization and vascular homeostasis.

Endothelial microparticles (EMP) for the assessment of endothelial function: an in vitro and in vivo study on possible interference of plasma lipids.

Background: Circulating endothelial microparticles (EMP) reflect the condition of the endothelium and are of increasing interest in cardiovascular and inflammatory diseases. Recently, increased numbers of EMP following oral fat intake, possibly due to acute endothelial injury, have been reported. On the other hand, the direct interference of lipids with the detection of EMP has been suggested.

Flow cytometric detection of endothelial microparticles (EMP): effects of centrifugation and storage alter with the phenotype studied.

Introduction: Endothelial microparticles (EMP) are released into the circulation in case of endothelial disturbance, and are therefore increasingly investigated as a biomarker reflecting disease activity. Numerous pre-analytic methods have been proposed for their flow cytometric enumeration, but standardization is still lacking. In this study we evaluated the influence of centrifugation and storage conditions on EMP quantification.