Potential long-term effects of SARS-CoV-2 infection on the pulmonary vasculature: a global perspective

Distinct type 1 immune networks underlie the severity of restrictive lung disease after COVID-19

The variable origins of persistent breathlessness after coronavirus disease 2019 (COVID-19) have hindered efforts to decipher the immunopathology of lung sequelae. Here we analyzed hundreds of cellular and molecular features in the context of discrete pulmonary phenotypes to define the systemic immune landscape of post-COVID lung disease. Cluster analysis of lung physiology measures highlighted two phenotypes of restrictive lung disease that differed according to their impaired diffusion and severity of fibrosis. Machine learning revealed marked CCR5+CD95+CD8+ T cell perturbations in milder lung disease but attenuated T cell responses hallmarked by elevated CXCL13 in more severe disease. Distinct sets of cells, mediators and autoantibodies distinguished each restrictive phenotype and differed from those of patients without substantial lung involvement. These differences were reflected in divergent T cell-based type 1 networks according to the severity of lung disease. Our findings, which provide an immunological basis for active lung injury versus advanced disease after COVID-19, might offer new targets for treatment.

Nasal Spray Disinfectant for Respiratory Infections Based on Functionalized Silver Nanoparticles: A Physicochemical and Docking Approach

Respiratory diseases have presented a remarkable challenge during modern history, contributing to important pandemics. The scientific community has focused its efforts on developing vaccines and blocking the transmission of viruses through the respiratory tract. In this study, we propose the use of stable silver nanoparticles (AgNPs) functionalized with tannic acid (TA) and sodium citrate (SC) as a nasal spray disinfectant (NSD). The non-ionic ethoxylated surfactant Tween 80 (T80) was added to enhance the wetting effect on nasal and oral tissues following spray application. We analyzed the physicochemical properties of the AgNPs and the NSD, including zeta potential, polarity, morphology, composition, particle size, and distribution. The results indicated spherical AgNPs ranging from 3 to 5 nm, stabilized by TA-SC. The addition of T80 resulted in particles with negative polarity, high stability, and improved coverage area. Furthermore, the colloidal stability was monitored over one year, showing no signs of degradation or precipitation. Interestingly, the interaction between the capped AgNP complex, the spike protein, and ACE2 was studied by molecular docking, indicating a strong and thermodynamically favorable complex interaction. These findings hold promise for the development of potential inhibitors, antagonist receptors, Ag-complex agonists (as observed here), and drug development for viral protection.

COVID-19 and Parasitic Co-Infection: A Hypothetical Link to Pulmonary Vascular Disease

Background/Objectives: Before the Coronavirus disease 2019 (COVID-19) era, the global prevalence of pulmonary arterial hypertension (PAH) was between 0.4 and 1.4 per 100,000 people. The long-term effects of protracted COVID-19 associated with pulmonary vascular disease (PVD) risk factors may increase this prevalence. According to preliminary data, the exact prevalence of early estimates places the prevalence of PVD in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection at 22%, although its predictive value remains unknown. PVD caused by COVID-19 co-infections is understudied and underreported, and its future impact is unclear. However, due to COVID-19/co-infection pathophysiological effects on pulmonary vascularization, PVD mortality and morbidity may impose a genuine concern-both now and in the near future. Based on reported studies, this literature review focused on the potential link between COVID-19, parasitic co-infection, and PVD. This review article also highlights hypothetical pathophysiological mechanisms between COVID-19 and parasitic co-infection that could trigger PVD. Methods: We conducted a systematic literature review (SLR) searching peer-reviewed articles, including link between COVID-19, parasitic co-infection, and PVD. Results: This review hypothesized that multiple pathways associated with pathogens such as underlying schistosomiasis, human immunodeficiency virus (HIV), pulmonary tuberculosis (PTB), pulmonary aspergillosis, Wuchereria bancrofti, Clonorchis sinensis, paracoccidioidomycosis, human herpesvirus 8, and scrub typhus coupled with acute or long COVID-19, may increase the burden of PVD and worsen its mortality in the future. Conclusions: Further experimental studies are also needed to determine pathophysiological pathways between PVD and a history of COVID-19/co-infections.

Genetics of Long COVID: Exploring the Molecular Drivers of Persistent Pulmonary Vascular Disease Symptoms

Background/ Objectives: Long COVID or post-acute sequelae of SARS-CoV-2 infection (PASC) are symptoms that manifest despite passing the acute infection phase. These manifestations encompass a wide range of symptoms, the most common being fatigue, shortness of breath, and cognitive dysfunction. Genetic predisposition is clearly involved in the susceptibility of individuals to developing these persistent symptoms and the variation in the severity and forms. This review summarizes the role of genetic factors and gene polymorphisms in the development of major pulmonary vascular disorders associated with long COVID. Methods: A comprehensive review of current literature was conducted to examine the genetic contributions to pulmonary complications following SARS-CoV-2 infection. Studies investigating genetic polymorphisms linked to pulmonary hypertension, pulmonary thromboembolism, and pulmonary vascular endothelialitis were reviewed and summarized. Results: Findings show that specific genetic variants contribute to increased susceptibility to pulmonary vascular complications in long COVID patients. Variants associated with endothelial dysfunction, coagulation pathways, and inflammatory responses have been implicated in the development of pulmonary hypertension and thromboembolic events. Genetic predispositions influencing vascular integrity and immune responses appear to influence disease severity and progression. Conclusions: Understanding these mechanisms and genetic predispositions could pave the way for targeted therapeutic interventions to alleviate the burden on patients experiencing long COVID.

Beyond the virus: ecotoxicological and reproductive impacts of SARS-CoV-2 lysate protein in C57Bl/6j female mice

Since the establishment of the COVID-19 pandemic, a range of studies have been developed to understand the pathogenesis of SARS-CoV-2 infection, vaccine development, and therapeutic testing. However, the possible impacts that these viruses can have on non-target organisms have been explored little, and our knowledge of the consequences of the COVID-19 pandemic for biota is still very limited. Thus, the current study aimed to address this knowledge gap by evaluating the possible impacts of oral exposure of C57Bl/6 J female mice to SARS-CoV-2 lysate protein (at 20 µg/L) for 30 days, using multiple methods, including behavioral assessments, biochemical analyses, and histopathological examinations. Although we did not have evidence of hematological, mutagenic, or genotoxic effects, we noted that the ingestion of SARS-CoV-2 lysate protein-induced behavioral disorders (hypoactivity, anxiety-like behavior, and short-term memory deficit), which were associated with oxidative stress and dopaminergic and cholinesterase imbalance in the animal brain. Furthermore, the elevation of bilirubin levels and lactate dehydrogenase levels in these animals suggests the occurrence of hepatic changes, and the redox imbalance, nitrosative stress, and elevated production of IFN-γ and inflammatory infiltration in the duodenum, disrupted follicular structure, and presence of vacuoles in granulosa cells, in ovarian, indicate that the SARS-CoV-2-exposed group showed significant toxicity. Principal component analysis (PCA) and cluster analysis confirmed that the groups were clearly separated and showed that the largest changes upon SARS-CoV-2 exposure were related to ROS, MDA, nitrite, IFN-γ/IL-10 levels and SOD and catalase activity in the ovary; IFN-γ/IL-10 production and SOD activity in the duodenum; BChE activity in the brain; bilirubin levels and lactate dehydrogenase activity in the serum; number of primary follicles in the ovary. In conclusion, our study provides new insights into the toxicity of SARS-CoV-2 lysate proteins in a non-target terrestrial organism of infection and, therefore, expands our understanding of the real extent of the ecological/environmental impact of the COVID-19 pandemic.

Unraveling the pathogenesis of viral-induced pulmonary arterial hypertension: Possible new therapeutic avenues with mesenchymal stromal cells and their derivatives

Pulmonary hypertension (PH) is a severe condition characterized by elevated pressure in the pulmonary artery, where metabolic and mitochondrial dysfunction may contribute to its progression. Within the PH spectrum, pulmonary arterial hypertension (PAH) stands out with its primary pulmonary vasculopathy. PAH's prevalence varies from 0.4 to 1.4 per 100,000 individuals and is associated with diverse conditions, including viral infections such as HIV. Notably, recent observations highlight an increased occurrence of PAH among COVID-19 patients, even in the absence of pre-existing cardiopulmonary disorders. While current treatments offer partial relief, there's a pressing need for innovative therapeutic strategies, among which mesenchymal stromal cells (MSCs) and their derivatives hold promise. This review critically evaluates recent investigations into viral-induced PAH, encompassing pathogens like human immunodeficiency virus, herpesvirus, Cytomegalovirus, Hepatitis B and C viruses, SARS-CoV-2, and Human endogenous retrovirus K (HERKV), with a specific emphasis on mitochondrial dysfunction. Furthermore, we explore the underlying rationale driving novel therapeutic modalities, including MSCs, extracellular vesicles, and mitochondrial interventions, within the framework of PAH management.

Prolonged corticosteroid therapy and lung abnormalities in patients after severe COVID-19 pneumonia

BACKGROUND

Some of the hospitalized patients after severe COVID-19 pneumonia experience significant fall in peripheral saturation despite optimal treatment. Because of immune dysregulation in COVID-19 there are indications that prolonged corticosteroids could be considered in treating patients for persistent radiological sequelae and respiratory symptoms.

OBJECTIVES

to investigate lung function and lung sequelae on high-resolution CT (HRCT) im COVID-19 patients who were treated with glucocorticoid therapy in two dose regimens with a control group of patients who did not receive additional glucocorticoid therapy.

METHODS

In this prospective cohort research we studied patients who suffered from prolonged respiratory insufficiency after severe COVID-19 pneumonia. Patients received corticosteroid therapy in two dose regimens: for 14 days and for 3 months after discharge from the hospital. Control group of patients did not receive additional corticosteroid therapy. Lung function, post-COVID-19 symptoms, and lung abnormalities on CT scans were analyzed in three months follow-up and compared with the control group of patients.

RESULTS

Patients who received prolonged corticosteroid therapy for three months did not have better CT findings of lung abnormalities, lung function, or symptoms recovery in comparison to the patients with 14 days of therapy and control group of patients. Onwards, control group had significantly fewer dyspnea symptoms (Chi-square test, p=0,04) and higher DLCO (Kruskal Wallis test, p=0,03).

CONCLUSIONS

Supplementary corticosteroid therapy for patients after severe pneumonia and prolonged respiratory insufficiency with lung abnormalities after COVID-19 did not improve lung function or lung lesions on CT.

Increased risk of arrhythmias, heart failure, and thrombosis in SARS-CoV-2 positive individuals persists at one year post-infection

Risk of cardiovascular events is increased after COVID-19. However, information on cardiovascular risk trends after COVID-19 infection is lacking and estimates by sex are inconsistent. Our aim was to examine cardiovascular outcomes and mortality in a large cohort (164,346 participants) of SARS-CoV-2 positive individuals compared to non-positive individuals, stratified by sex. Data were obtained from the Spanish Health System's electronic medical records. Selected individuals were ≥ 45 years old with/without a positive SARS-CoV-2 test in the period March-May 2020. Follow-up was obtained until January 31, 2021, for cardiovascular events (angina/myocardial infarction, arrhythmias, bypass/revascularization, heart failure, peripheral artery disease, stroke/transient ischemic attack, and thrombosis), and until March 31, 2021, for mortality. Individuals were matched by propensity score. Incidence of cardiovascular events and mortality was compared with accelerated failure time models. The effect of matching and of COVID-19 severity was assessed with sensitivity analyses. In the first 3 months of follow-up, SARS-CoV-2 positive individuals had a higher risk of mortality and of all cardiovascular events. From 4-12 months, there was increased risk of mortality in SARS-CoV-2 positive individuals overall, of heart failure in SARS-CoV-2 positive females (HR= 1.26 [1.11-1.42]), and of arrhythmias and thrombosis in SARS-CoV-2 positive males (HR= 1.29 [1.14-1.47] and HR= 1.35 [1.03-1.77], respectively). When COVID-19 patients admitted to the ICU were excluded, incidence of thrombosis was similar in males regardless of positive/non-positive SARS-CoV-2 status. In the full year of follow-up, increased incidence of heart failure and of arrhythmias and thrombosis was observed in SARS-CoV-2 positive females and males, respectively.

Integrated analysis of microbiome and host transcriptome unveils correlations between lung microbiota and host immunity in bronchoalveolar lavage fluid of pneumocystis pneumonia patients

OBJECTIVE

The lung microbiota of patients with pulmonary diseases is disrupted and impacts the immunity. The microbiological and immune landscape of the lungs in patients with pneumocystis pneumonia (PCP) remains poorly understood.

METHODS

Multi-omics analysis and machine learning were performed on bronchoalveolar lavage fluid to explore interaction between the lung microbiota and host immunity in PCP. Then we constructed a diagnostic model using differential genes with LASSO regression and validated by qPCR. The immune infiltration analysis was performed to explore the landscape of lung immunity in patients with PCP.

RESULTS

Patients with PCP showed a low alpha diversity of lung microbiota, accompanied by the elevated abundance of Firmicutes, and the differential expressed genes (DEGs) analysis displayed a downregulation of MAPK signaling. The MAPK10, TGFB1, and EFNA3 indicated a potential to predict PCP (AUC = 0.86). The lung immune landscape in PCP showed the lower levels of naïve CD4+ T cells and activated dendritic cells. The correlation analysis of the MAPK signaling pathway-related DEGs and the differential microorganisms at the level of phylum showed that the Firmicutes was negatively correlated with these DEGs.

CONCLUSION

We profiled the characteristics of lung microbiota and immune landscape in PCP, which may contribute to elucidating the mechanism of PCP.

Infection and pulmonary vascular diseases consortium: United against a global health challenge

Leveraging the potential of virtual platforms in the post-COVID-19 era, the Infection and Pulmonary Vascular Diseases Consortium (iPVDc), with the support of the Pulmonary Vascular Research Institute (PVRI), launched a globally accessible educational program to highlight top-notch research on inflammation and infectious diseases affecting the lung vasculature. This innovative virtual series has already successfully brought together distinguished investigators across five continents - Asia, Europe, South and North America, and Africa. Moreover, these open global forums have contributed to a comprehensive understanding of the complex interplay among immunology, inflammation, infection, and cardiopulmonary health, especially concerning pulmonary hypertension and related pulmonary disorders. These enlightening discussions have not only heightened awareness about the impact of various pathogenic microorganisms, including fungi, parasites, and viruses, on the onset and development of pulmonary vascular diseases but have also cast a spotlight on co-infections and neglected illnesses like schistosomiasis - a disease that continues to impose a heavy socioeconomic burden in numerous regions worldwide. Thus, the overall goal of this review article is to present the most recent breakthroughs from infectious PVDs as well as bring to light the scientific and educational insights from the 2023 iPVDc/PVRI virtual symposium series, shaping our understanding of these crucial health issues in this more than ever interconnected world.

Portal hypertension-like pattern in coronavirus disease 2019 acute respiratory distress syndrome

OBJECTIVES

Although respiratory failure is the most common feature in coronavirus disease 2019 (COVID-19), abdominal organ involvement is likewise frequently observed. To investigate visceral and thoracic circulation and abdominal organ damage in COVID-19 patients.

MATERIALS AND METHODS

A monocentric observational study was carried on. In COVID-19 patients affected by acute respiratory distress syndrome (ARDS) (n = 31) or mild pneumonia (n = 60) thoracoabdominal circulation was evaluated using Doppler-ultrasound and computed tomography. The study also included non-COVID-19 patients affected by ARDS (n = 10) or portal hypertension (n = 10) for comparison of the main circulatory changes.

RESULTS

Patients affected by COVID-19 ARDS showed hyperdynamic visceral flow and increased portal velocity, hepatic artery resistance-index, and spleen diameter relative to those with mild-pneumonia (p = 0.001). Splanchnic circulatory parameters significantly correlated with the main respiratory indexes (p < 0.001) and pulmonary artery diameter (p = 0.02). The chest and abdominal vascular remodeling pattern of COVID-19 ARDS patients resembled the picture observed in the PH group, while differed from that of the non-COVID ARDS group. A more severe COVID-19 presentation was associated with worse liver dysfunction and enhanced inflammatory activation; these parameters both correlated with abdominal (p = 0.04) and chest imaging measures (p = 0.03).

CONCLUSION

In COVID-19 ARDS patients there are abdominal and lung vascular modifications that depict a portal hypertension-like pattern. The correlation between visceral vascular remodeling, pulmonary artery enlargement, and organ damage in these critically ill patients is consistent with a portal hyperlfow-like syndrome that could contribute to the peculiar characteristics of respiratory failure in these patients.

CLINICAL RELEVANCE STATEMENT

our data suggest that the severity of COVID-19 lung involvement is directly related to the development of a portal hyperflow-like syndrome. These observations should help in defining the need for a closer monitoring, but also to develop dedicated therapeutic strategies.

A single-dose MCMV-based vaccine elicits long-lasting immune protection in mice against distinct SARS-CoV-2 variants

Current vaccines against COVID-19 elicit immune responses that are overall strong but wane rapidly. As a consequence, the necessary booster shots have contributed to vaccine fatigue. Hence, vaccines that would provide lasting protection against COVID-19 are needed, but are still unavailable. Cytomegaloviruses (CMVs) elicit lasting and uniquely strong immune responses. Used as vaccine vectors, they may be attractive tools that obviate the need for boosters. Therefore, we tested the murine CMV (MCMV) as a vaccine vector against COVID-19 in relevant preclinical models of immunization and challenge. We have previously developed a recombinant MCMV vaccine vector expressing the spike protein of the ancestral SARS-CoV-2 (MCMVS). In this study, we show that the MCMVS elicits a robust and lasting protection in young and aged mice. Notably, spike-specific humoral and cellular immunity was not only maintained but also even increased over a period of at least 6 months. During that time, antibody avidity continuously increased and expanded in breadth, resulting in neutralization of genetically distant variants, like Omicron BA.1. A single dose of MCMVS conferred rapid virus clearance upon challenge. Moreover, MCMVS vaccination controlled two variants of concern (VOCs), the Beta (B.1.135) and the Omicron (BA.1) variants. Thus, CMV vectors provide unique advantages over other vaccine technologies, eliciting broadly reactive and long-lasting immune responses against COVID-19.

Cardiopulmonary Complications after Pulmonary Embolism in COVID-19

Although pulmonary embolism (PE) is a frequent complication in COVID-19, its consequences remain unknown. We performed pulmonary function tests, echocardiography and computed tomography pulmonary angiography and identified blood biomarkers in a cohort of consecutive hospitalized COVID-19 patients with pneumonia to describe and compare medium-term outcomes according to the presence of PE, as well as to explore their potential predictors. A total of 141 patients (56 with PE) were followed up during a median of 6 months. Post-COVID-19 radiological lung abnormalities (PCRLA) and impaired diffusing capacity for carbon monoxide (DLCOc) were found in 55.2% and 67.6% cases, respectively. A total of 7.3% had PE, and 6.7% presented an intermediate-high probability of pulmonary hypertension. No significant difference was found between PE and non-PE patients. Univariate analysis showed that age > 65, some clinical severity factors, surfactant protein-D, baseline C-reactive protein, and both peak red cell distribution width and Interleukin (IL)-10 were associated with DLCOc < 80%. A score for PCRLA prediction including age > 65, minimum lymphocyte count, and IL-1β concentration on admission was constructed with excellent overall performance. In conclusion, reduced DLCOc and PCRLA were common in COVID-19 patients after hospital discharge, but PE did not increase the risk. A PCRLA predictive score was developed, which needs further validation.

Quantifying the impact of post-acute sequelae of coronavirus on the cardiopulmonary endurance of athletes

Post-acute sequelae of Coronavirus (PASC), or Long COVID, has emerged as a critical health concern. The clinical manifestations of PASC have been described, but studies have not quantified the cardiopulmonary effects. The goal of this study was to quantify PASC cardiopulmonary changes among endurance athletes. Endurance athletes were recruited via social media; 45 met inclusion criteria, 32 had PASC and 13 were asymptomatic at 3 months (control). Comprehensive interviews were conducted to assess: cardiopulmonary symptoms at 3 months; quantitative and qualitative changes in cardiovascular endurance; exercise hours per week at baseline and 3 months; and Modified Oslo, Dyspnea, and EQ-5D-5L scales. All collected data was based on self-reported symptoms. Wilcoxon rank sum compared PASC with control to distinguish the effects of PASC vs effects of COVID infection/lockdown. PASC subjects were more likely to be female (Table). The most common 3-month symptoms in PASC were fatigue and shortness of breath. Based on self-reported data, subjects endorsed a median decrease of 27% in cardiopulmonary endurance levels compared with 0% in controls (p = 0.0019). PASC subjects exercised less hours and had worse self-reported health as compared with controls. PASC subjects also had significantly worse Modified Oslo, Dyspnea, and EQ-5D-5L scores. Of the 32 PASC patients, 10 (31%) reported a complete inability to engage in any cardiovascular endurance exercise at 3 months. PASC leads to a significant, quantifiable decrease in cardiopulmonary health and endurance.

SARS-CoV2 Nsp3 protein triggers cell death and exacerbates amyloid β42-mediated neurodegeneration

Infection caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) virus, responsible for the coronavirus disease 2019 (COVID-19) pandemic, induces symptoms including increased inflammatory response, severe acute respiratory syndrome (SARS), cognitive dysfunction like brain fog, and cardiovascular defects. Long-term effects of SARS-CoV2 COVID-19 syndrome referred to as post-COVID-19 syndrome on age-related progressive neurodegenerative disorders such as Alzheimer’s disease remain understudied. Using the targeted misexpression of individual SARS-CoV2 proteins in the retinal neurons of the Drosophila melanogaster eye, we found that misexpression of nonstructural protein 3 (Nsp3), a papain-like protease, ablates the eye and generates dark necrotic spots. Targeted misexpression of Nsp3 in the eye triggers reactive oxygen species production and leads to apoptosis as shown by cell death reporters, terminal deoxynucleotidyl transferase (TdT) dUTP Nick-end labeling (TUNEL) assay, and dihydroethidium staining. Furthermore, Nsp3 misexpression activates both apoptosis and autophagy mechanism(s) to regulate tissue homeostasis. Transient expression of SARS-CoV2 Nsp3 in murine neuroblastoma, Neuro-2a cells, significantly reduced the metabolic activity of these cells and triggers cell death. Misexpression of SARS-CoV2 Nsp3 in an Alzheimer’s disease transgenic fly eye model (glass multiple repeats [GMR]>amyloid β42) further enhances the neurodegenerative rough eye phenotype due to increased cell death. These findings suggest that SARS-CoV2 utilizes Nsp3 protein to potentiate cell death response in a neurodegenerative disease background that has high pre-existing levels of neuroinflammation and cell death.

Proteomics of serum-derived extracellular vesicles are associated with the severity and different clinical profiles of patients with COVID-19: An exploratory secondary analysis

BACKGROUND AIMS

Coronavirus disease 2019 (COVID-19) is characterized by a broad spectrum of clinical manifestations with the potential to progress to multiple organ dysfunction in severe cases. Extracellular vesicles (EVs) carry a range of biological cargoes, which may be used as biomarkers of disease state.

METHODS

An exploratory secondary analysis of the SARITA-2 and SARITA-1 datasets (randomized clinical trials on patients with mild and moderate/severe COVID-19) was performed. Serum-derived EVs were used for proteomic analysis to identify enriched biological processes and key proteins, thus providing insights into differences in disease severity. Serum-derived EVs were separated from patients with COVID-19 by size exclusion chromatography and nanoparticle tracking analysis was used to determine particle concentration and diameter. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was performed to identify and quantify protein signatures. Bioinformatics and multivariate statistical analysis were applied to distinguish candidate proteins associated with disease severity (mild versus moderate/severe COVID-19).

RESULTS

No differences were observed in terms of the concentration and diameter of enriched EVs between mild (n = 14) and moderate/severe (n = 30) COVID-19. A total of 414 proteins were found to be present in EVs, of which 360 were shared while 48 were uniquely present in severe/moderate compared to mild COVID-19. The main biological signatures in moderate/severe COVID-19 were associated with platelet degranulation, exocytosis, complement activation, immune effector activation, and humoral immune response. Von Willebrand factor, serum amyloid A-2 protein, histone H4 and H2A type 2-C, and fibrinogen β-chain were the most differentially expressed proteins between severity groups.

CONCLUSION

Exploratory proteomic analysis of serum-derived EVs from patients with COVID-19 detected key proteins related to immune response and activation of coagulation and complement pathways, which are associated with disease severity. Our data suggest that EV proteins may be relevant biomarkers of disease state and prognosis.

Mechanisms of Pulmonary Vasculopathy in Acute and Long-Term COVID-19: A Review

Despite the end of the pandemic, coronavirus disease 2019 (COVID-19) remains a major public health concern. The first waves of the virus led to a better understanding of its pathogenesis, highlighting the fact that there is a specific pulmonary vascular disorder. Indeed, COVID-19 may predispose patients to thrombotic disease in both venous and arterial circulation, and many cases of severe acute pulmonary embolism have been reported. The demonstrated presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within the endothelial cells suggests that direct viral effects, in addition to indirect effects of perivascular inflammation and coagulopathy, may contribute to pulmonary vasculopathy in COVID-19. In this review, we discuss the pathological mechanisms leading to pulmonary vascular damage during acute infection, which appear to be mainly related to thromboembolic events, an impaired coagulation cascade, micro- and macrovascular thrombosis, endotheliitis and hypoxic pulmonary vasoconstriction. As many patients develop post-COVID symptoms, including dyspnea, we also discuss the hypothesis of pulmonary vascular damage and pulmonary hypertension as a sequela of the infection, which may be involved in the pathophysiology of long COVID.

Distinct Type 1 Immune Networks Underlie the Severity of Restrictive Lung Disease after COVID-19

The variable etiology of persistent breathlessness after COVID-19 have confounded efforts to decipher the immunopathology of lung sequelae. Here, we analyzed hundreds of cellular and molecular features in the context of discrete pulmonary phenotypes to define the systemic immune landscape of post-COVID lung disease. Cluster analysis of lung physiology measures highlighted two phenotypes of restrictive lung disease that differed by their impaired diffusion and severity of fibrosis. Machine learning revealed marked CCR5+CD95+ CD8+ T-cell perturbations in mild-to-moderate lung disease, but attenuated T-cell responses hallmarked by elevated CXCL13 in more severe disease. Distinct sets of cells, mediators, and autoantibodies distinguished each restrictive phenotype, and differed from those of patients without significant lung involvement. These differences were reflected in divergent T-cell-based type 1 networks according to severity of lung disease. Our findings, which provide an immunological basis for active lung injury versus advanced disease after COVID-19, might offer new targets for treatment.

Can adverse cardiac events of the COVID-19 vaccine exacerbate preexisting diseases?

INTRODUCTION

SARS-CoV-2 infection and COVID-19 vaccination can both lead to serious cardiac conditions such as myocarditis, arrhythmia, acute myocardial infarction, and coagulopathy. Further studies are needed to better understand the risks and benefits of COVID-19 vaccination, and to determine the best course of action for individuals with preexisting heart conditions.

AREAS COVERED

The current knowledge and challenges in understanding vaccine-associated heart issues concerning the COVID-19 pandemic are briefly summarized, highlighting similar cardiac conditions caused by either SARS-CoV-2 infection or COVID-19 vaccination and the potential clinical impacts.

EXPERT OPINION

The short-term risks of severe cardiovascular side effects following COVID-19 vaccination are relatively low. However, further studies are needed to determine whether adverse vaccination events outweigh the long-term benefits in specific groups of individuals. Since cardiac inflammation, blood pressure dysregulation, coagulopathy, acute myocardial infarction, or arrhythmia could be the consequences of either SARS-CoV-2 infection or COVID-19 vaccination, clinical questions should be asked whether the COVID-19 vaccine worsens the condition in persons with preexisting heart diseases. It is important to carefully assess the potential risks and benefits of COVID-19 vaccination, especially for individuals with preexisting heart conditions, and to continue monitoring and studying the long-term effects of vaccination on cardiovascular health.

The longitudinal association of stressful life events with depression remission among SHARP trial participants with depression and hypertension or diabetes in Malawi

Depressive disorders are leading contributors to morbidity in low- and middle-income countries and are particularly prevalent among people with non-communicable diseases (NCD). Stressful life events (SLEs) are risk factors for, and can help identify those at risk of, severe depressive illness requiring more aggressive treatment. Yet, research on the impact of SLEs on the trajectory of depressive symptoms among NCD patients indicated for depression treatment is lacking, especially in low resource settings. This study aims to estimate the longitudinal association of SLEs at baseline with depression remission achievement at three, six, and 12 months among adults with either hypertension or diabetes and comorbid depression identified as being eligible for depression treatment. Participants were recruited from 10 NCD clinics in Malawi from May 2019-December 2021. SLEs were measured by the Life Events Survey and depression remission was defined as achieving a Patient Health Questionaire-9 (PHQ-9) score <5 at follow-up. The study population (n = 737) consisted predominately of females aged 50 or higher with primary education and current employment. At baseline, participants reported a mean of 3.5 SLEs in the prior three months with 90% reporting ≥1 SLE. After adjustment, each additional SLE was associated with a lower probability of achieving depression remission at three months (cumulative incidence ratio (CIR) 0.94; 95% confidence interval: 0.90, 0.98, p = 0.002), six months (0.95; 0.92, 0.98, p = 0.002) and 12 months (0.96; 0.94, 0.99, p = 0.011). Re-expressed per 3-unit change, the probability of achieving depression remission at three, six, and 12 months was 0.82, 0.86, and 0.89 times lower per 3 SLEs (the median number of SLEs). Among NCD patients identified as eligible for depression treatment, recent SLEs at baseline were associated with lower probability of achieving depression remission at three, six, and 12 months. Findings suggest that interventions addressing SLEs during integrated NCD and depression care interventions (e.g., teaching and practicing SLE coping strategies) may improve success of depression treatment among adult patient populations in low-resource settings and may help identify those at risk of severe and treatment resistant depression.

Damage to endothelial barriers and its contribution to long COVID

The world continues to contend with COVID-19, fueled by the emergence of viral variants. At the same time, a subset of convalescent individuals continues to experience persistent and prolonged sequelae, known as long COVID. Clinical, autopsy, animal and in vitro studies all reveal endothelial injury in acute COVID-19 and convalescent patients. Endothelial dysfunction is now recognized as a central factor in COVID-19 progression and long COVID development. Different organs contain different types of endothelia, each with specific features, forming different endothelial barriers and executing different physiological functions. Endothelial injury results in contraction of cell margins (increased permeability), shedding of glycocalyx, extension of phosphatidylserine-rich filopods, and barrier damage. During acute SARS-CoV-2 infection, damaged endothelial cells promote diffuse microthrombi and destroy the endothelial (including blood-air, blood-brain, glomerular filtration and intestinal-blood) barriers, leading to multiple organ dysfunction. During the convalescence period, a subset of patients is unable to fully recover due to persistent endothelial dysfunction, contributing to long COVID. There is still an important knowledge gap between endothelial barrier damage in different organs and COVID-19 sequelae. In this article, we mainly focus on these endothelial barriers and their contribution to long COVID.

Sialylated Glycan Bindings from SARS-CoV-2 Spike Protein to Blood and Endothelial Cells Govern the Severe Morbidities of COVID-19

Consistent with well-established biochemical properties of coronaviruses, sialylated glycan attachments between SARS-CoV-2 spike protein (SP) and host cells are key to the virus's pathology. SARS-CoV-2 SP attaches to and aggregates red blood cells (RBCs), as shown in many pre-clinical and clinical studies, causing pulmonary and extrapulmonary microthrombi and hypoxia in severe COVID-19 patients. SARS-CoV-2 SP attachments to the heavily sialylated surfaces of platelets (which, like RBCs, have no ACE2) and endothelial cells (having minimal ACE2) compound this vascular damage. Notably, experimentally induced RBC aggregation in vivo causes the same key morbidities as for severe COVID-19, including microvascular occlusion, blood clots, hypoxia and myocarditis. Key risk factors for COVID-19 morbidity, including older age, diabetes and obesity, are all characterized by markedly increased propensity to RBC clumping. For mammalian species, the degree of clinical susceptibility to COVID-19 correlates to RBC aggregability with p = 0.033. Notably, of the five human betacoronaviruses, the two common cold strains express an enzyme that releases glycan attachments, while the deadly SARS, SARS-CoV-2 and MERS do not, although viral loads for COVID-19 and the two common cold infections are similar. These biochemical insights also explain the previously puzzling clinical efficacy of certain generics against COVID-19 and may support the development of future therapeutic strategies for COVID-19 and long COVID patients.

Comparison between computerised lung SPECT-CT and noncontrast thoracic HRCT for quantitative analysis of post-acute COVID-19 pulmonary vascular pruning

Computerised processing of images from routine noncontrast HRCT could be an efficient, costless and safe tool to investigate the vascular remodelling that occurs in the months after COVID-19 in a large number of patients https://bit.ly/3qAQZDW.

Long COVID Complicated by Fatal Cytomegalovirus and Aspergillus Infection of the Lungs: An Autopsy Case Report

After the acute phase of COVID-19, some patients develop long COVID. This term is used for a variety of conditions with a complex, yet not fully elucidated etiology, likely including the prolonged persistence of the virus in the organism and progression to lung fibrosis. We present a unique autopsy case of a patient with severe COVID-19 with prolonged viral persistence who developed interstitial lung fibrosis complicated by a fatal combination of cytomegalovirus and Aspergillus infection. SARS-CoV-2 virus was detected at autopsy in the lungs more than two months after the acute infection, although tests from the nasopharynx were negative. Immune dysregulation after COVID-19 and the administration of corticoid therapy created favorable conditions for the cytomegalovirus and Aspergillus infection that were uncovered at autopsy. These pathogens may represent a risk for opportunistic infections, complicating not only the acute coronavirus infection but also long COVID, as was documented in the presented case.

The vascular perspective on acute and chronic lung disease

The pulmonary vasculature has been frequently overlooked in acute and chronic lung diseases, such as acute respiratory distress syndrome (ARDS), pulmonary fibrosis (PF), and chronic obstructive pulmonary disease (COPD). The primary emphasis in the management of these parenchymal disorders has largely revolved around the injury and aberrant repair of epithelial cells. However, there is increasing evidence that the vascular endothelium plays an active role in the development of acute and chronic lung diseases. The endothelial cell network in the capillary bed and the arterial and venous vessels provides a metabolically highly active barrier that controls the migration of immune cells, regulates vascular tone and permeability, and participates in the remodeling processes. Phenotypically and functionally altered endothelial cells, and remodeled vessels, can be found in acute and chronic lung diseases, although to different degrees, likely because of disease-specific mechanisms. Since vascular remodeling is associated with pulmonary hypertension, which worsens patient outcomes and survival, it is crucial to understand the underlying vascular alterations. In this Review, we describe the current knowledge regarding the role of the pulmonary vasculature in the development and progression of ARDS, PF, and COPD; we also outline future research directions with the hope of facilitating the development of mechanism-based therapies.

SARS-CoV-2 spike protein receptor-binding domain perturbates intracellular calcium homeostasis and impairs pulmonary vascular endothelial cells

Exposure to the spike protein or receptor-binding domain (S-RBD) of SARS-CoV-2 significantly influences endothelial cells and induces pulmonary vascular endotheliopathy. In this study, angiotensin-converting enzyme 2 humanized inbred (hACE2 Tg) mice and cultured pulmonary vascular endothelial cells were used to investigate how spike protein/S-RBD impacts pulmonary vascular endothelium. Results show that S-RBD leads to acute-to-prolonged induction of the intracellular free calcium concentration ([Ca2+]i) via acute activation of TRPV4, and prolonged upregulation of mechanosensitive channel Piezo1 and store-operated calcium channel (SOCC) key component Orai1 in cultured human pulmonary arterial endothelial cells (PAECs). In mechanism, S-RBD interacts with ACE2 to induce formation of clusters involving Orai1, Piezo1 and TRPC1, facilitate the channel activation of Piezo1 and SOCC, and lead to elevated apoptosis. These effects are blocked by Kobophenol A, which inhibits the binding between S-RBD and ACE2, or intracellular calcium chelator, BAPTA-AM. Blockade of Piezo1 and SOCC by GsMTx4 effectively protects the S-RBD-induced pulmonary microvascular endothelial damage in hACE2 Tg mice via normalizing the elevated [Ca2+]i. Comparing to prototypic strain, Omicron variants (BA.5.2 and XBB) of S-RBD induces significantly less severe cell apoptosis. Transcriptomic analysis indicates that prototypic S-RBD confers more severe acute impacts than Delta or Lambda S-RBD. In summary, this study provides compelling evidence that S-RBD could induce persistent pulmonary vascular endothelial damage by binding to ACE2 and triggering [Ca2+]i through upregulation of Piezo1 and Orai1. Targeted inhibition of ACE2-Piezo1/SOCC-[Ca2+]i axis proves a powerful strategy to treat S-RBD-induced pulmonary vascular diseases.

Hydrogen Sulfide Ameliorates SARS-CoV-2-Associated Lung Endothelial Barrier Disruption

Recent studies have confirmed that lung microvascular endothelial injury plays a critical role in the pathophysiology of COVID-19. Our group and others have demonstrated the beneficial effects of H2S in several pathological processes and provided a rationale for considering the therapeutic implications of H2S in COVID-19 therapy. Here, we evaluated the effect of the slow-releasing H2S donor, GYY4137, on the barrier function of a lung endothelial cell monolayer in vitro, after challenging the cells with plasma samples from COVID-19 patients or inactivated SARS-CoV-2 virus. We also assessed how the cytokine/chemokine profile of patients' plasma, endothelial barrier permeability, and disease severity correlated with each other. Alterations in barrier permeability after treatments with patient plasma, inactivated virus, and GYY4137 were monitored and assessed by electrical impedance measurements in real time. We present evidence that GYY4137 treatment reduced endothelial barrier permeability after plasma challenge and completely reversed the endothelial barrier disruption caused by inactivated SARS-CoV-2 virus. We also showed that disease severity correlated with the cytokine/chemokine profile of the plasma but not with barrier permeability changes in our assay. Overall, these data demonstrate that treatment with H2S-releasing compounds has the potential to ameliorate SARS-CoV-2-associated lung endothelial barrier disruption.

Pulmonary embolism and deep venous thrombosis after COVID-19: long-term risk in a population-based cohort study

Background

Venous thromboembolism (VTE) (pulmonary embolism (PE) or deep venous thrombosis (DVT)) is common during acute COVID-19. Long-term excess risk has not yet been established.

Objective

To study long-term VTE risk after COVID-19.

Methods

Swedish citizens aged 18-84 years, hospitalized and/or testing positive for COVID-19 between January 1, 2020, and September 11, 2021 (exposed), stratified by initial hospitalization, were compared to matched (1:5) non-exposed population-derived subjects without COVID-19. Outcomes were incident VTE, PE or DVT recorded within 60, 60-<180, and ≥180 days. Cox regression was used for evaluation and a model adjusted for age, sex, comorbidities and socioeconomic markers developed to control for confounders.

Results

Among exposed patients, 48,861 were hospitalized for COVID-19 (mean age 60.6 years) and 894,121 were without hospitalization (mean age 41.4 years). Among patients hospitalized for COVID-19, fully adjusted hazard ratios (HRs) during 60-<180 days were 6.05 (95% confidence interval (CI) 4.80─7.62) for PE and 3.97 (CI 2.96─5.33) for DVT, compared to non-exposed with corresponding estimates among COVID-19 without hospitalization 1.17 (CI 1.01─1.35) and 0.99 (CI 0.86─1.15), based on 475 and 2,311 VTE events, respectively. Long-term (≥180 days) HRs in patients hospitalized for COVID-19 were 2.01 (CI 1.51─2.68) for PE and 1.46 (CI 1.05─2.01) for DVT while non-hospitalized had similar risk to non-exposed, based on 467 and 2,030 VTE events, respectively.

Conclusions

Patients hospitalized for COVID-19 retained an elevated excess risk of VTE, mainly PE, after 180 days, while long-term risk of VTE in individuals with COVID-19 without hospitalization was similar to the non-exposed.

Efficacy of Sildenafil in Patients with Severe COVID-19 and Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is common in severe coronavirus disease 2019 (COVID-19) and worsens the prognosis. Sildenafil, a phosphodiesterase-5 inhibitor, is approved for PAH treatment but little is known about its efficacy in cases of severe COVID-19 with PAH. This study aimed to investigate the clinical efficacy of sildenafil in patients with severe COVID-19 and PAH. Intensive care unit (ICU) patients were randomly assigned to receive sildenafil or a placebo, with 75 participants in each group. Sildenafil was administered orally at 0.25 mg/kg t.i.d. for one week in a placebo-controlled, double-blind manner as an add-on therapy alongside the patient's routine treatment. The primary endpoint was one-week mortality, and the secondary endpoints were the one-week intubation rate and duration of ICU stay. The mortality rate was 4% vs. 13.3% (p = 0.078), the intubation rate was 8% and 18.7% (p = 0.09), and the length of ICU stay was 15 vs. 19 days (p < 0.001) for the sildenafil and placebo groups, respectively. If adjusted for PAH, sildenafil treatment significantly reduced mortality and intubation risks: OR = 0.21 (95% CI: 0.05-0.89) and OR = 0.26 (95% CI: 0.08-0.86), respectively. Sildenafil demonstrated some clinical efficacy in patients with severe COVID-19 and PAH and should be considered as an add-on therapy in these patients.

Impact of aging on immune function in the pathogenesis of pulmonary diseases: potential for therapeutic targets

INTRODUCTION

Several immunological alterations that occur during pulmonary diseases often mimic alterations observed in the aged lung. From the molecular perspective, pulmonary diseases and aging partake in familiar mechanisms associated with significant dysregulation of the immune systems. Here, we summarized the findings of how aging alters immunity to respiratory conditions to identify age-impacted pathways and mechanisms that contribute to the development of pulmonary diseases.

AREAS COVERED

The current review examines the impact of age-related molecular alterations in the aged immune system during various lung diseases, such as COPD, IPF, Asthma, and alongside many others that could possibly improve on current therapeutic interventions. Moreover, our increased understanding of this phenomenon may play a primary role in shaping immunomodulatory strategies to boost outcomes in the elderly. Here, the authors present new insights into the context of lung-related diseases and describe the alterations in the functioning of immune cells during various pulmonary conditions altered with age.

EXPERT OPINION

The expert opinion provided the concepts on how aging alters immunity during pulmonary conditions, and suggests the associated mechanisms during the development of lung diseases. As a result, it becomes important to comprehend the complex mechanism of aging in the immune lung system.

Lung perfusion assessment in children with long-COVID: A pilot study

BACKGROUND

There is increasing evidence that chronic endotheliopathy can play a role in patients with Post-Covid Condition (PCC, or Long Covid) by affecting peripheral vascularization. This pilot study aimed at assessing lung perfusion in children with Long-COVID with ^99m Tc-MAA SPECT/CT.

MATERIALS AND METHODS

lung ^99m Tc-MAA SPECT/CT was performed in children with Long-COVID and a pathological cardiopulmonary exercise testing (CPET). Intravenous injections were performed on patients in the supine position immediately before the planar scan according to the EANM guidelines for lung scintigraphy in children, followed by lung SPECT/CT acquisition. Reconstructed studies were visually analyzed.

RESULTS

Clinical and biochemical data were collected during acute infection and follow-up in 14 children (6 females, mean age: 12.6 years) fulfilling Long-COVID diagnostic criteria and complaining of chronic fatigue and postexertional malaise after mild efforts, documented by CPET. Imaging results were compared with clinical scenarios during acute infection and follow-up. Six out of 14 (42.8%) children showed perfusion defects on ^99m Tc-MAA SPECT/CT scan, without morphological alterations on coregistered CT.

CONCLUSIONS

This pilot investigation confirmed previous data suggesting that a small subgroup of children can develop lung perfusion defects after severe acute respiratory syndrome coronavirus 2 infection. Larger cohort studies are needed to confirm these preliminary results, providing also a better understanding of which children may deserve this test and how to manage those with lung perfusion defects.

Human Endogenous Retrovirus, SARS-CoV-2, and HIV Promote PAH via Inflammation and Growth Stimulation

Pulmonary arterial hypertension (PAH) is a pulmonary vascular disease characterized by the progressive elevation of pulmonary arterial pressures. It is becoming increasingly apparent that inflammation contributes to the pathogenesis and progression of PAH. Several viruses are known to cause PAH, such as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), human endogenous retrovirus K(HERV-K), and human immunodeficiency virus (HIV), in part due to acute and chronic inflammation. In this review, we discuss the connections between HERV-K, HIV, SARS-CoV-2, and PAH, to stimulate research regarding new therapeutic options and provide new targets for the treatment of the disease.

Ovatodiolide inhibits SARS-CoV-2 replication and ameliorates pulmonary fibrosis through suppression of the TGF-β/TβRs signaling pathway

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues to pose threats to public health. The clinical manifestations of lung pathology in COVID-19 patients include sustained inflammation and pulmonary fibrosis. The macrocyclic diterpenoid ovatodiolide (OVA) has been reported to have anti-inflammatory, anti-cancer, anti-allergic, and analgesic activities. Here, we investigated the pharmacological mechanism of OVA in suppressing SARS-CoV-2 infection and pulmonary fibrosis in vitro and in vivo. Our results revealed that OVA was an effective SARS-CoV-2 3CLpro inhibitor and showed remarkable inhibitory activity against SARS-CoV-2 infection. On the other hand, OVA ameliorated pulmonary fibrosis in bleomycin (BLM)-induced mice, reducing inflammatory cell infiltration and collagen deposition in the lung. OVA decreased the levels of pulmonary hydroxyproline and myeloperoxidase, as well as lung and serum TNF-ɑ, IL-1β, IL-6, and TGF-β in BLM-induced pulmonary fibrotic mice. Meanwhile, OVA reduced the migration and fibroblast-to-myofibroblast conversion of TGF-β1-induced fibrotic human lung fibroblasts. Consistently, OVA downregulated TGF-β/TβRs signaling. In computational analysis, OVA resembles the chemical structures of the kinase inhibitors TβRI and TβRII and was shown to interact with the key pharmacophores and putative ATP-binding domains of TβRI and TβRII, showing the potential of OVA as an inhibitor of TβRI and TβRII kinase. In conclusion, the dual function of OVA highlights its potential for not only fighting SARS-CoV-2 infection but also managing injury-induced pulmonary fibrosis.

The Significance of Low Magnesium Levels in COVID-19 Patients

Magnesium is the fourth most common mineral in the human body and the second richest intracellular cation. This element is necessary for many physiological reactions, especially in the cardiovascular and respiratory systems. COVID-19 is an infectious disease caused by SARS-CoV-2. The majority of people who become ill as a result of COVID-19 have mild-to-moderate symptoms and recover without specific treatment. Moreover, there are people who develop severe forms of COVID-19, which require highly specialized medical assistance. Magnesium deficiency may play a role in the pathophysiology of infection with SARS-CoV-2. The primary manifestation of COVID-19 remains respiratory, but the virus can spread to other organs and tissues, complicating the clinical picture and culminating in multiorgan failure. The key mechanisms involved in the disease include direct viral cytotoxicity, endothelial dysfunction, and exaggerated release of inflammatory cytokines. The aim of this review was to summarize the available data regarding the role of magnesium in COVID-19 patients and its particularities in different clinical settings.

Uncovering common pathobiological processes between COVID-19 and pulmonary arterial hypertension by integrating Omics data

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which led to the current pandemic. Many factors, including age and comorbidities, influence the severity and mortality of COVID-19. SARS-CoV-2 infection can cause pulmonary vascular dysfunction. The COVID-19 case-fatality rate in patients with pulmonary arterial hypertension (PAH) is higher in comparison with the general population. In this study, we aimed to identify pathobiological processes common to COVID-19 and PAH by utilizing the human protein-protein interactome and whole-genome transcription data from peripheral blood mononuclear cells (PBMCs) and from lung tissue. We found that there are significantly more interactions between SARS-CoV-2 targets and PAH disease proteins than expected by chance, suggesting that the PAH disease module is in the neighborhood of SARS-CoV-2 targets in the human interactome. In addition, SARS-CoV-2 infection-induced changes in gene expression significantly overlap with PAH-induced gene expression changes in both tissues, indicating SARS-CoV-2 and PAH may share common transcriptional regulators. We identified many upregulated genes and downregulated genes common to COVID-19 and PAH. Interestingly, we observed different co-regulation patterns and dysfunctional signaling pathways in PBMCs versus lung tissue. Endophenotype enrichment analysis revealed that genes regulating fibrosis, inflammation, hypoxia, oxidative stress, immune response, and thromboembolism are significantly enriched in the COVID-19-PAH co-expression modules. We examined the network proximity of the targets of repositioned drugs for COVID-19 to the co-expression modules in PBMCs and lung tissue, and identified 42 drugs that can be potentially used for COVID-19 patients with PAH as a comorbidity. The uncovered common pathobiological pathways are crucial for discovering therapeutic targets and designing tailored treatments for COVID-19 patients who also have PAH.

A role for Toll-like receptor 3 in lung vascular remodeling associated with SARS-CoV-2 infection

Cardiovascular sequelae of severe acute respiratory syndrome (SARS) coronavirus-2 (CoV-2) disease 2019 (COVID-19) contribute to the complications of the disease. One potential complication is lung vascular remodeling, but the exact cause is still unknown. We hypothesized that endothelial TLR3 insufficiency contributes to lung vascular remodeling induced by SARS-CoV-2. In the lungs of COVID-19 patients and SARS-CoV-2 infected Syrian hamsters, we discovered thickening of the pulmonary artery media and microvascular rarefaction, which were associated with decreased TLR3 expression in lung tissue and pulmonary artery endothelial cells (ECs). In vitro , SARS-CoV-2 infection reduced endothelial TLR3 expression. Following infection with mouse-adapted (MA) SARS-CoV-2, TLR3 knockout mice displayed heightened pulmonary artery remodeling and endothelial apoptosis. Treatment with the TLR3 agonist polyinosinic:polycytidylic acid reduced lung tissue damage, lung vascular remodeling, and endothelial apoptosis associated with MA SARS-CoV-2 infection. In conclusion, repression of endothelial TLR3 is a potential mechanism of SARS-CoV-2 infection associated lung vascular remodeling and enhancing TLR3 signaling is a potential strategy for treatment.

Management of COVID-19 in Patients with Pulmonary Arterial Hypertension

In this review, we discuss the evidence regarding the course and management of COVID-19 in patients with pulmonary arterial hypertension (PAH), the challenges in PAH management during the pandemic and, lastly, the long-term complications of COVID-19 in relation to pulmonary vascular disease. The inherent PAH disease characteristics, as well as age, comorbidities, and the patient's functional status act synergistically to define the prognosis of COVID-19 in patients with PAH. Management of COVID-19 should follow the general guidelines, while PAH-targeted therapies should be continued. The pandemic has caused a shift toward telemedicine in the chronic care of patients with PAH. Whether COVID-19 could predispose to the development of chronic pulmonary hypertension is a subject of future investigation.

From acute SARS-CoV-2 infection to pulmonary hypertension

As the world progressively recovers from the acute stages of the coronavirus disease 2019 (COVID-19) pandemic, we may be facing new challenges regarding the long-term consequences of COVID-19. Accumulating evidence suggests that pulmonary vascular thickening may be specifically associated with COVID-19, implying a potential tropism of severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) virus for the pulmonary vasculature. Genetic alterations that may influence the severity of COVID-19 are similar to genetic drivers of pulmonary arterial hypertension. The pathobiology of the COVID-19-induced pulmonary vasculopathy shares many features (such as medial hypertrophy and smooth muscle cell proliferation) with that of pulmonary arterial hypertension. In addition, the presence of microthrombi in the lung vessels of individuals with COVID-19 during the acute phase, may predispose these subjects to the development of chronic thromboembolic pulmonary hypertension. These similarities raise the intriguing question of whether pulmonary hypertension (PH) may be a long-term sequela of SARS-COV-2 infection. Accumulating evidence indeed support the notion that SARS-COV-2 infection is indeed a risk factor for persistent pulmonary vascular defects and subsequent PH development, and this could become a major public health issue in the future given the large number of individuals infected by SARS-COV-2 worldwide. Long-term studies assessing the risk of developing chronic pulmonary vascular lesions following COVID-19 infection is of great interest for both basic and clinical research and may inform on the best long-term management of survivors.

Unsupervised discovery of tissue architecture in multiplexed imaging

Multiplexed imaging and spatial transcriptomics enable highly resolved spatial characterization of cellular phenotypes, but still largely depend on laborious manual annotation to understand higher-order patterns of tissue organization. As a result, higher-order patterns of tissue organization are poorly understood and not systematically connected to disease pathology or clinical outcomes. To address this gap, we developed an approach called UTAG to identify and quantify microanatomical tissue structures in multiplexed images without human intervention. Our method combines information on cellular phenotypes with the physical proximity of cells to accurately identify organ-specific microanatomical domains in healthy and diseased tissue. We apply our method to various types of images across healthy and disease states to show that it can consistently detect higher-level architectures in human tissues, quantify structural differences between healthy and diseased tissue, and reveal tissue organization patterns at the organ scale.

["Guiding lights" for the diagnosis of chronic thromboembolic pulmonary hypertension in the flow of patients with pulmonary embolism]

On December 13, 2021, an expert council was held to determine the position of experts of different specialties regarding the reasons for the low level of diagnosis of chronic thromboembolic pulmonary hypertension (CTEPH) in real clinical practice in a pandemic of a new coronavirus infection and possible ways to improve detection in patients with pulmonary embolism (PE) ) in history. The reasons for the low level of diagnosis of CTEPH are the insufficient level of knowledge of specialists, especially primary care physicians; lack of clear regulatory documents and expert centers for the management of this category of patients. Primary diagnosis of CTEPH in a pandemic can be strengthened through the widespread use of telemedicine for consultations of primary care physicians with specialists from expert centers; to maximize the role of echocardiography and computed tomography (CT) as differential diagnostic tools for dyspnea, in particular in patients with COVID-19. To increase the detection rate of CTEPH, diagnostic vigilance is required in patients with risk factors and episodes of venous thromboembolism. To improve the screening of CTEPH, it is necessary to create an algorithm for monitoring patients who have had PE; provide educational activities, including through the media; create materials for patients with accessible information. The regulatory documents should designate the circle of responsible specialists who will be engaged in long-term monitoring of patients with PE. Educational programs are needed for primary care physicians, cardiologists, and other physicians who come into the field of view of patients with CTEPH; introduction of a program to create expert centers for monitoring and managing patients with the possibility of performing ventilation-perfusion lung scintigraphy, cardiopulmonary stress test, CT, right heart catheterization. It seems important to build cooperation with the Ministry of Health of Russia in order to create special protocols, procedures for managing patients with PE and CTEPH.

Co-infection associated with SARS-CoV-2 and their management

SARS-CoV-2 was discovered in Wuhan, China and quickly spread throughout the world. This deadly virus moved from person to person, resulting in severe pneumonia, fever, chills and hypoxia. Patients are still experiencing problems after recovering from COVID-19. This review covers COVID-19 and associated issues following recovery from COVID-19, as well as multiorgan damage risk factors and treatment techniques. Several unusual illnesses, including mucormycosis, white fungus infection, happy hypoxia and other systemic abnormalities, have been reported in recovered individuals. In children, multisystem inflammatory syndrome with COVID-19 (MIS-C) is identified. The reasons for this might include uncontrollable steroid usage, reduced immunity, uncontrollable diabetes mellitus and inadequate care following COVID-19 recovery.

The impact of COVID-19 pandemic on pulmonary hypertension: What have we learned?

The coronavirus 2019 disease (COVID-19) pandemic threatened the Spanish health-care system. Patients with demanding conditions such as precapillary pulmonary hypertension (PH) faced a potentially severe infection, while their usual access to medical care was restricted. This prospective, unicentric study assessed the impact of COVID-19 on PH patients' outcomes and the operational changes in the PH network. Sixty-three PH patients (41 pulmonary arterial hypertension [PAH]; 22 chronic thromboembolic pulmonary hypertension [CTEPH]) experienced COVID-19. Overall mortality was 9.5% without differences when stratifying by hemodynamics or PAH-risk score. Patients who died were older (73.6 ± 5 vs. 52.2 ± 15.4; p = 0.001), with more comorbidities (higher Charlson index: 4.17 ± 2.48 vs. 1.14 ± 1.67; p = 0.0002). Referrals to the PH expert center decreased compared to the previous 3 years (123 vs. 160; p = 0.002). The outpatient activity shifted toward greater use of telemedicine. Balloon pulmonary angioplasty activity could be maintained after the first pandemic wave and lockdown while pulmonary thromboendarterectomy procedures decreased (19 vs. 36; p = 0.017). Pulmonary transplantation activity remained similar. The COVID-19 mortality in PAH/CTEPH patients was not related to hemodynamic severity or risk stratification, but to comorbidities. The pandemic imposed structural changes but a planned organization and resource reallocation made it possible to maintain PH patients' care.

Clinical Features and Burden of Postacute Sequelae of SARS-CoV-2 Infection in Children and Adolescents

Importance

The postacute sequelae of SARS-CoV-2 infection (PASC) has emerged as a long-term complication in adults, but current understanding of the clinical presentation of PASC in children is limited.

Objective

To identify diagnosed symptoms, diagnosed health conditions, and medications associated with PASC in children.

Design, Setting and Participants

This retrospective cohort study used electronic health records from 9 US children's hospitals for individuals younger than 21 years who underwent antigen or reverse transcriptase-polymerase chain reaction (RT-PCR) testing for SARS-CoV-2 between March 1, 2020, and October 31, 2021, and had at least 1 encounter in the 3 years before testing.

Exposures

SARS-CoV-2 positivity by viral test (antigen or RT-PCR).

Main Outcomes and Measures

Syndromic (symptoms), systemic (conditions), and medication PASC features were identified in the 28 to 179 days following the initial test date. Adjusted hazard ratios (aHRs) were obtained for 151 clinically predicted PASC features by contrasting viral test-positive groups with viral test-negative groups using proportional hazards models, adjusting for site, age, sex, testing location, race and ethnicity, and time period of cohort entrance. The incidence proportion for any syndromic, systemic, or medication PASC feature was estimated in the 2 groups to obtain a burden of PASC estimate.

Results

Among 659 286 children in the study sample, 348 091 (52.8%) were male, and the mean (SD) age was 8.1 (5.7) years. A total of 59 893 (9.1%) tested positive by viral test for SARS-CoV-2, and 599 393 (90.9%) tested negative. Most were tested in outpatient testing facility settings (322 813 [50.3%]) or office settings (162 138 [24.6%]). The most common syndromic, systemic, and medication features were loss of taste or smell (aHR, 1.96; 95% CI, 1.16-3.32), myocarditis (aHR, 3.10; 95% CI, 1.94-4.96), and cough and cold preparations (aHR, 1.52; 95% CI, 1.18-1.96), respectively. The incidence of at least 1 systemic, syndromic, or medication feature of PASC was 41.9% (95% CI, 41.4-42.4) among viral test-positive children vs 38.2% (95% CI, 38.1-38.4) among viral test-negative children, with an incidence proportion difference of 3.7% (95% CI, 3.2-4.2). A higher strength of association for PASC was identified in those cared for in the intensive care unit during the acute illness phase, children younger than 5 years, and individuals with complex chronic conditions.

Conclusions and Relevance

In this large-scale, exploratory study, the burden of pediatric PASC that presented to health systems was low. Myocarditis was the most commonly diagnosed PASC-associated condition. Acute illness severity, young age, and comorbid complex chronic disease increased the risk of PASC.

The COVID-19 pandemic and pulmonary arterial hypertension in Italy: adaptation, outcomes and valuable lessons learned

This editorial summarises the key findings of R. Badagliacca and co-workers regarding the changes in care and clinical outcomes of PAH patients during the initial COVID-19 pandemic in Italy https://bit.ly/3ytgIjk

Proteomic Profile of Procoagulant Extracellular Vesicles Reflects Complement System Activation and Platelet Hyperreactivity of Patients with Severe COVID-19

Background

Extracellular vesicles (EVs) are a valuable source of biomarkers and display the pathophysiological status of various diseases. In COVID-19, EVs have been explored in several studies for their ability to reflect molecular changes caused by SARS-CoV-2. Here we provide insights into the roles of EVs in pathological processes associated with the progression and severity of COVID-19.

Methods

In this study, we used a label-free shotgun proteomic approach to identify and quantify alterations in EV protein abundance in severe COVID-19 patients. We isolated plasma extracellular vesicles from healthy donors and patients with severe COVID-19 by size exclusion chromatography (SEC). Then, flow cytometry was performed to assess the origin of EVs and to investigate the presence of circulating procoagulant EVs in COVID-19 patients. A total protein extraction was performed, and samples were analyzed by nLC-MS/MS in a Q-Exactive HF-X. Finally, computational analysis was applied to signify biological processes related to disease pathogenesis.

Results

We report significant changes in the proteome of EVs from patients with severe COVID-19. Flow cytometry experiments indicated an increase in total circulating EVs and with tissue factor (TF) dependent procoagulant activity. Differentially expressed proteins in the disease groups were associated with complement and coagulation cascades, platelet degranulation, and acute inflammatory response.

Conclusions

The proteomic data reinforce the changes in the proteome of extracellular vesicles from patients infected with SARS-CoV-2 and suggest a role for EVs in severe COVID-19.

Long-term mortality following SARS-CoV-2 infection: A national cohort study from Estonia

BACKGROUND

The objective of this study was to describe 12-month mortality following SARS-CoV-2 infection compared with a reference population with no history of SARS-CoV-2.

METHODS

Nationwide cohort study using electronic health care data on SARS-CoV-2 RNA positive cases (n= 66,287) and reference group subjects (n=254,969) with linkage to SARS-CoV-2 testing and death records.

FINDINGS

People infected with SARS-COV-2 had more than three times the risk of dying over the following year compared with those who remained uninfected (aHR 3·1, 95%CI 2·9-3·3). Short-term mortality (up to 5 weeks post-infection) was significantly higher among COVID-19 group (1623·0/10 000) than in the reference group (118/10 000). For COVID-19 cases aged 60 years or older, increased mortality persisted until the end of the first year after infection, and was related to increased risk for cardiovascular (aHR 2·1, 95%CI 1·8-2·3), cancer (aHR 1·5, 95%CI 1·2-1·9), respiratory system diseases (aHR 1·9, 95%CI 1·2-3·0), and other causes of death (aHR 1·8, 95%CI 1·4-2·2).

INTERPRETATION

Increased risk of death from SARS-CoV-2 is not limited to the acute illness: SARS-CoV-2 infection carries a substantially increased mortality in the following 12 months. This excess death mainly occurs in older people and is driven by broad array of causes of death.

FUNDING

Research was carried out with the support of Estonian Research Council (grants PRG1197, PRG198), European Regional Development Fund (RITA 1/02-120) and European Social Fund via IT Academy program.

Two Cases of COVID-19-Related Deaths Unaccounted for: A Call for Action

Coronavirus disease 2019 (COVID-19) high-risk survivors experience long-term COVID-19 symptoms. Hence, these individuals require early and ubiquitous respiratory rehabilitation to avoid malnutrition. We report the case of a 93-year-old woman who recovered from moderate II severity (pneumonia requiring oxygen). The patient, after prolonged hospitalization, demonstrated low severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity and showed no COVID-19 respiratory symptoms for more than 72 hours. Subsequently, the patient became debilitated and lost her appetite without dysphagia, dysgeusia, and smell disorder, developed nosocomial pneumonia as a sequela of acute COVID-19 and died. We also report the second case of an 84-year-old man diagnosed with moderate II COVID-19 severity. After recovery, the patient was frail due to the previous onset of COVID-19 and worsened during his stay at home, losing appetite without dysphagia, dysgeusia, and smell disorder, and dying of senility as the official cause. Recovered COVID-19 appears to be a health risk by malnutrition without anorexia and depression, among other conditions. A proven rehabilitation program for each phase of the disease is required for better lung function and nutritional status.