COVID-19, Endothelium and the Cardiometabolic Patient: A Possible Role for Capillary Leak Syndrome

Vascular endothelial growth factor A: friend or foe in the pathogenesis of HIV and SARS-CoV-2 infections?

This review article discusses the role of vascular endothelial growth factor A (VEGF-A) in the pathogenesis of SARS-CoV-2 and HIV infection, both conditions being renowned for their impact on the vascular endothelium. The processes involved in vascular homeostasis and angiogenesis are reviewed briefly before exploring the interplay between hypoxia, VEGF-A, neuropilin-1 (NRP-1), and inflammatory pathways. We then focus on SARS-CoV-2 infection and show how the binding of the viral pathogen to the angiotensin-converting enzyme 2 receptor, as well as to NRP-1, leads to elevated levels of VEGF-A and consequences such as coagulation, vascular dysfunction, and inflammation. HIV infection augments angiogenesis via several mechanisms, most prominently, by the trans-activator of transcription (tat) protein mimicking VEGF-A by binding to its receptor, VEGFR-2, as well as upregulation of NRP-1, which enhances the interaction between VEGF-A and VEGFR-2. We propose that the elevated levels of VEGF-A observed during HIV/SARS-CoV-2 co-infection originate predominantly from activated immune cells due to the upregulation of HIF-1α by damaged endothelial cells. In this context, a few clinical trials have described a diminished requirement for oxygen therapy during anti-VEGF treatment of SARS-CoV-2 infection. The currently available anti-VEGF therapy strategies target the binding of VEGF-A to both VEGFR-1 and VEGFR-2. The blocking of both receptors could, however, lead to a negative outcome, inhibiting not only pathological, but also physiological angiogenesis. Based on the examination of published studies, this review suggests that treatment targeting selective inhibition of VEGFR-1 may be beneficial in the context of SARS-CoV-2 infection.

The systemic capillary leak syndrome following COVID-19 vaccine

The COVID-19 outbreak has been declared the sixth Public Health Emergency of International Concern certified by the World Health Organization. With the extensive application of COVID-19 vaccines, rare but serious adverse reactions have gradually emerged, among which systemic capillary leak syndrome (SCLS) deserves our attention. SCLS is difficult to diagnose. Not only can it exacerbate various diseases, but also can lead to pulmonary edema, kidney failure, and even death. We summarized and discussed case reports of SCLS induced by COVID-19 vaccines to raise awareness of COVID-19 vaccine-associated rare diseases. We conducted a comprehensive search in Web of Science, PubMed and Embase and collected case reports of SCLS induced by COVID-19 vaccine before February 19, 2024. We identified and analyzed 12 articles, encompassing 15 cases. We synthesized the data to summerize possible mechanisms of SCLS, clinical manifestations, differential diagnoses, and therapeutic approaches. Most SCLS occurred after vaccination with the Pfe-Biontech mRNA vaccine (9/15) and following the second vaccination (10/15). Almost all patients experienced hypotension (13/15) and tachycardia (11/15). Most patients received intravenous fluids (9/15) and corticosteroids (9/15). 11 patients were recovered and were discharged, while 4 patients died. Inflammation and endothelial cell damage may be linked to SCLS and COVID-19 vaccines. These findings highlight the necessity of focusing on serious adverse reactions of COVID-19 vaccines and the urgency to reconsider the safety of COVID-19 vaccines.

Prognostic role of albumin, lactate-to-albumin ratio and C-reactive protein-to-albumin ratio in infected patients

INTRODUCTION

The prognostic evaluation of the septic patient has recently been enriched by some predictive indices such as albumin concentration, lactate/albumin ratio (LAR) and C-reactive protein/albumin ratio (CAR). The performance of these indices has been evaluated in septic patients in intensive care, but until now their performance in infected patients in the Emergency Department (ED) has not been evaluated.

AIM

To investigate the potential prognostic role of albumin, LAR and CAR in patients with infection in the ED.

METHODS

Single-centre prospective study performed between 1 January 2021 and 31 December 2021 at the ED of the Merano Hospital (Italy). All patients with infection were enrolled. The study outcome was death within 30 days. The predictive ability of albumin, LAR and CAR was assessed by area under the receiver operating characteristic curves (AUROCs). A multivariate logistic regression model was used to examine the association of the indices with 30-day mortality, with comorbidity, acute urgency and severity of infection as covariates.

RESULTS

The study enrolled 962 patients with an infectious status. The overall 30-day mortality rate was 8.9% (86/962). The AUROC of albumin was 0.831 (95% CI 0.795-868), while for LAR this was 0.773 (CI95% 0.719-0.827) and for CAR 0.718 (CI95% 0.664-0.771). The odds ratio for 30-day mortality for albumin was 3.362 (95% CI 1.904-5.936), for ln(LAR) 2.651 (95% CI 1.646-4.270) and for ln(CAR) 1.739 (95% CI 1.326-2.281).

CONCLUSIONS

All three indices had a good discriminatory ability for the risk of short-term death in patients with infection, indicating their promising use in the ED as well as in the ICU. Further studies are needed to confirm the better performance of albumin compared to LAR and CAR.

Serum Albumin as Prognostic Marker for Older Adults in Hospital and Community Settings

Serum albumin, known for its multifaceted role in health, is hypothesized to serve as a prognostic marker for older adults, both in hospital and community settings. Nine studies were included in the review, revealing consistent associations between low serum albumin levels and increased mortality risk in hospitalized older individuals. In community settings, low serum albumin levels were linked to higher mortality rates compared to those with normal levels. The synthesis of evidence underscores the potential of serum albumin as a prognostic marker for older adults, offering valuable insights for risk stratification and targeted interventions. While robust evidence supports its utility in hospital settings, further research is warranted in community settings to address current limitations and enhance the applicability of serum albumin as a prognostic tool. This review merges existing knowledge of the prognostic significance of serum albumin in older adults across hospital and community settings. The findings emphasize the importance of serum albumin as a potential prognostic marker, urging continued research efforts to refine its application in diverse healthcare contexts and improve outcomes for the aging population.

COVID-19 Complications: Oxidative Stress, Inflammation, and Mitochondrial and Endothelial Dysfunction

SARS-CoV-2 infection, discovered and isolated in Wuhan City, Hubei Province, China, causes acute atypical respiratory symptoms and has led to profound changes in our lives. COVID-19 is characterized by a wide range of complications, which include pulmonary embolism, thromboembolism and arterial clot formation, arrhythmias, cardiomyopathy, multiorgan failure, and more. The disease has caused a worldwide pandemic, and despite various measures such as social distancing, various preventive strategies, and therapeutic approaches, and the creation of vaccines, the novel coronavirus infection (COVID-19) still hides many mysteries for the scientific community. Oxidative stress has been suggested to play an essential role in the pathogenesis of COVID-19, and determining free radical levels in patients with coronavirus infection may provide an insight into disease severity. The generation of abnormal levels of oxidants under a COVID-19-induced cytokine storm causes the irreversible oxidation of a wide range of macromolecules and subsequent damage to cells, tissues, and organs. Clinical studies have shown that oxidative stress initiates endothelial damage, which increases the risk of complications in COVID-19 and post-COVID-19 or long-COVID-19 cases. This review describes the role of oxidative stress and free radicals in the mediation of COVID-19-induced mitochondrial and endothelial dysfunction.

The importance of microvascular inflammation in ageing and age-related diseases: a position paper from the ESH working group on small arteries, section of microvascular inflammation

Microcirculation is pervasive and orchestrates a profound regulatory cross-talk with the surrounding tissue and organs. Similarly, it is one of the earliest biological systems targeted by environmental stressors and consequently involved in the development and progression of ageing and age-related disease. Microvascular dysfunction, if not targeted, leads to a steady derangement of the phenotype, which cumulates comorbidities and eventually results in a nonrescuable, very high-cardiovascular risk. Along the broad spectrum of pathologies, both shared and distinct molecular pathways and pathophysiological alteration are involved in the disruption of microvascular homeostasis, all pointing to microvascular inflammation as the putative primary culprit. This position paper explores the presence and the detrimental contribution of microvascular inflammation across the whole spectrum of chronic age-related diseases, which characterise the 21st-century healthcare landscape. The manuscript aims to strongly affirm the centrality of microvascular inflammation by recapitulating the current evidence and providing a clear synoptic view of the whole cardiometabolic derangement. Indeed, there is an urgent need for further mechanistic exploration to identify clear, very early or disease-specific molecular targets to provide an effective therapeutic strategy against the otherwise unstoppable rising prevalence of age-related diseases.