Pulmonary Vascular Endothelialitis, Thrombosis, and Angiogenesis in Covid-19

Pathogenesis and virulence of coronavirus disease: Comparative pathology of animal models for COVID-19

Animal models that can replicate clinical and pathologic features of severe human coronavirus infections have been instrumental in the development of novel vaccines and therapeutics. The goal of this review is to summarize our current understanding of the pathogenesis of coronavirus disease 2019 (COVID-19) and the pathologic features that can be observed in several currently available animal models. Knowledge gained from studying these animal models of SARS-CoV-2 infection can help inform appropriate model selection for disease modelling as well as for vaccine and therapeutic developments.

Dialysis parameters associated with SARS-CoV-2 infection and prognosis in end-stage kidney disease

BACKGROUND

The Covid-19 pandemic has affected patients with end-stage kidney disease (ESKD). Whether dialysis parameters have a prognostic value in ESKD patients with Covid-19 remains unclear.

MATERIALS AND METHODS

We retrospectively evaluated clinical characteristics, blood pressure (BP) and dialysis parameters in ESKD patients undergoing maintenance outpatient hemodialysis, with (Covid-ESKD) and without (No-Covid-ESKD) Covid-19, at four Brazilian hemodialysis facilities. The Covid-ESKD (n = 107; 54% females; 60.8 ± 17.7 years) and No-Covid-ESKD (n = 107; 62% females; 58.4 ± 14.6 years) groups were matched by calendar time. The average BP and dialysis parameters were calculated during the pre-infection, acute infection, and post-infection periods. The main outcomes were Covid-19 hospitalization and all-cause mortality.

RESULTS

Covid-ESKD patients had greater intradialytic and postdialysis systolic BP and lower predialysis weight, postdialysis weight, ultrafiltration rate, and interdialytic weight gain during acute-illness compared to 1-week-before-illness, while these changes were not observed in No-Covid-ESKD patients. After 286 days of follow-up (range, 276-591), there were 18 Covid-19-related hospitalizations and 28 deaths among Covid-ESKD patients. Multivariable logistic regression analysis showed that increases in predialysis systolic BP from 1-week-before-illness to acute-illness (OR, 95%CI = 1.06, 1.02-1.10; p = .004) and Covid-19 vaccination (OR, 95%CI = 0.16, 0.04-0.69; p = .014) were associated with hospitalization in Covid-ESKD patients. Multivariable Cox-regression analysis showed that Covid-19-related hospitalization (HR, 95%CI = 5.17, 2.07-12.96; p < .001) and age (HR, 95%CI = 1.05, 1.01-1.08; p = .008) were independent predictors of all-cause mortality in Covid-ESKD patients.

CONCLUSION

Acute Covid-19 illness is associated with variations in dialysis parameters of volume status in patients with ESKD. Furthermore, increases in predialysis BP during acute Covid-19 illness are associated with an adverse prognosis in Covid-ESKD patients.

Ventilatory efficiency in long-term dyspnoeic patients following COVID-19 pneumonia

BACKGROUND

Long COVID is defined as persistency of symptoms, such as exertional dyspnea, twelve weeks after recovery from SARS-CoV-2 infection.

OBJECTIVES

To investigate ventilatory efficiency by the use of cardiopulmonary exercise testing (CPET) in patients with exertional dyspnea despite normal basal spirometry after 18 (T18) and 36 months (T36) from COVID-19 pneumonia.

METHODS

One hundred patients with moderate-critical COVID-19 were prospectively enrolled in our Long COVID program. Medical history, physical examination and lung high-resolution computed tomography (HRCT) were obtained at hospitalization (T0), 3 (T3) and 15 months (T15). All HRCTs were revised using a semi-quantitative CT severity score (CSS). Pulmonary function tests were obtained at T3 and T15. CPET was performed in a subset of patients with residual dyspnea (mMRC ≥ 1), at T18 and at T36.

RESULTS

Remarkably, at CPET, ventilatory efficiency was reduced both at T18 (V'E/V'CO2 slope = 31.4±3.9 SD) and T36 (V'E/V'CO2 slope = 31.28±3.70 SD). Furthermore, we identified positive correlations between V'E/V'CO2 slope at T18 and T36 and both percentage of involvement and CSS at HRCT at T0, T3 and T15. Also, negative linear correlations were found between V'E/V'CO2 slope at T18 and T36 and DLCO at T3 and T15.

CONCLUSIONS

At eighteen months from COVID-19 pneumonia, 20 % of subjects still complains of exertional dyspnea. At CPET this may be explained by persistently reduced ventilatory efficiency, possibly related to the degree of lung parenchymal involvement in the acute phase of infection, likely reflecting a damage in the pulmonary circulation.

Bioinformatics analysis of potential common pathogenic mechanisms for COVID-19 and venous thromboembolism

BACKGROUND

A growing body of research has shown that patients with coronavirus disease 2019 (COVID-19) have significantly higher rates of venous thromboembolism (VTE) than healthy. However, the mechanism remains incompletely elucidated. This study aimed to further investigate the molecular mechanisms underlying the development of this complication.

METHODS

The gene expression profiles of COVID-19 and VTE were downloaded from the Gene Expression Omnibus (GEO) database. After identifying the common differentially expressed genes (DEGs) for COVID-19 and VTE, functional annotation, a protein-protein interactions (PPI) network, module construction, and hub gene identification were performed. Finally, we constructed a transcription factor (TF)-gene regulatory network and a TF-miRNA regulatory network for hub genes.

RESULTS

A total of 42 common DEGs were selected for subsequent analyses. Functional analyses showed that biological function and signaling pathways collectively participated in the development and progression of VTE and COVID-19. Finally, 8 significant hub genes were identified using the cytoHubba plugin, including RSL24D1, RPS17, RPS27, HINT1, COX7C, RPL35, RPL34, and NDUFA4, which had preferable values as diagnostic markers for COVID-19 and VTE.

CONCLUSIONS

Our study revealed the common pathogenesis of COVID-19 and VTE. These common pathways and pivotal genes may provide new ideas for further mechanistic studies.

SARS-CoV-2-induced disruption of a vascular bed in a microphysiological system caused by type-I interferon from bronchial organoids

Blood vessels show various COVID-19-related conditions including thrombosis and cytokine propagation. Existing in vitro blood vessel models cannot represent the consequent changes in the vascular structure or determine the initial infection site, making it difficult to evaluate how epithelial and endothelial tissues are damaged. Here, we developed a microphysiological system (MPS) that co-culture the bronchial organoids and the vascular bed to analyze infection site and interactions. In this system, virus-infected organoids caused damage in vascular structure. However, vasculature was not damaged or infected when the virus was directly introduced to vascular bed. The knockout of interferon-related genes and inhibition of the JAK/STAT pathway reduced the vascular damage, indicating the protective effect of interferon response suppression. The results demonstrate selective infection of bronchial epithelial cells and vascular damage by cytokines and also indicate the applicability of MPS to investigate how the infection influences vascular structure and functions.

The mechanism of geniposide in patients with COVID-19 and atherosclerosis: A pharmacological and bioinformatics analysis

In patients with severe acute respiratory syndrome coronavirus 2 (which causes coronavirus disease 2019 [COVID-19]), oxidative stress (OS) is associated with disease severity and death. OS is also involved in the pathogenesis of atherosclerosis (AS). Previous studies have shown that geniposide has anti-inflammatory and anti-viral properties, and can protect cells against OS. However, the potential target(s) of geniposide in patients with COVID-19 and AS, as well as the mechanism it uses, are unclear. We combined pharmacology and bioinformatics analysis to obtain geniposide against COVID-19/AS targets, and build protein-protein interaction network to filter hub genes. The hub genes were performed an enrichment analysis by ClueGO, including Gene Ontology and KEGG. The Enrichr database and the target microRNAs (miRNAs) of hub genes were predicted through the MiRTarBase via Enrichr. The common miRNAs were used to construct the miRNAs-mRNAs regulated network, and the miRNAs' function was evaluated by mirPath v3.0 software. Two hundred forty-seven targets of geniposide were identified in patients with COVID-19/AS comorbidity by observing the overlap between the genes modulated by geniposide, COVID-19, and AS. A protein-protein interaction network of geniposide in patients with COVID-19/AS was constructed, and 27 hub genes were identified. The results of enrichment analysis suggested that geniposide may be involved in regulating the OS via the FoxO signaling pathway. MiRNA-mRNA network revealed that hsa-miR-34a-5p may play an important role in the therapeutic mechanism of geniposide in COVID-19/AS patients. Our study found that geniposide represents a promising therapy for patients with COVID-19 and AS comorbidity. Furthermore, the target genes and miRNAs that we identified may aid the development of new treatment strategies against COVID-19/AS.

Unfractionated Heparin Safety in COVID-19: Incidence and Risks of Bleeding Complications in Japan

AIM

Several studies have shown the efficacy and safety of low-molecular-weight heparin use in coronavirus disease 2019 (COVID-19), but that of unfractionated heparin (UFH) has not been investigated. We investigated the prevalence of bleeding complications during UFH administration, its impact on mortality, and the risk factors of bleeding outcomes associated with UFH.

METHODS

This retrospective cohort study was conducted at a single-center tertiary care hospital, including hospitalized patients with COVID-19. The primary outcomes were measured as the prevalence of bleeding complications during hospitalization, and the secondary outcomes were thromboembolic events and 60-day mortality rates. Logistic regression analysis and propensity score matching were used to assess risk factors for bleeding complications and their impact on mortality.

RESULTS

Among 1035 included patients, 516 patients were treated with UFH. Twelve (2.3%) patients in the UFH group experienced major bleeding. The prevalence of major bleeding in patients treated with therapeutic-dose UFH was 9.2%. Logistic regression analysis showed that age ≥ 60 years (adjusted odds ratio [aOR], 3.89; 95% confidence interval [CI], 1.01-15.0; P＜.05) and COVID-19 severity (aOR, 35.9; 95% CI, 4.57-282; P＜.05) were associated with major bleeding complications. After propensity score matching, 11 major and 11 non-major bleeding cases (including minor bleeding) were matched. The 60-day cumulative mortality rate between the two groups did not differ significantly (P=.13, log-rank test).

CONCLUSIONS

The incidence of major bleeding in COVID-19 patients using therapeutic-dose UFH was relatively high. Critical COVID-19 and older age were risk factors for bleeding complications.

Exploring the underlying molecular mechanisms of acute myocardial infarction after SARS-CoV-2 infection

An increase in acute myocardial infarction (AMI)-related deaths has been reported during the COVID-19 pandemic. Despite evidence suggesting the association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and AMI, the underlying mechanisms remain unclear. Here, we integrated mRNA and microRNA expression profiles related to SARS-CoV-2 infection and AMI from public databases. We then performed transcriptomic analysis using bioinformatics and systems biology approaches to explore the potential molecular mechanisms of SARS-CoV-2 infection affects AMI. First, twenty-one common differentially expressed genes (DEGs) were identified from SARS-CoV-2 infection and AMI patients in endothelial cells datasets and then we performed functional analysis to predict the roles of these DEGs. The functional analysis emphasized that the endothelial cell response to cytokine stimulus due to excessive inflammation was essential in these two diseases. Importantly, the tumor necrosis factor and interleukin-17 signaling pathways appeared to be integral factors in this mechanism. Interestingly, most of these common genes were also upregulated in transcriptomic datasets of SARS-CoV-2-infected cardiomyocytes, suggesting that these genes may be shared in cardiac- and vascular-related injuries. We subsequently built a protein-protein interaction network and extracted hub genes and essential modules from this network. At the transcriptional and post-transcriptional levels, regulatory networks with common DEGs were also constructed, and some key regulator signatures were further identified and validated. In summary, our research revealed that a highly activated inflammatory response in patients with COVID-19 might be a crucial factor for susceptibility to AMI and we identified some candidate genes and regulators that could be used as biomarkers or potential therapeutic targets.

Autopsy Histopathologic Lung Findings in Patients Treated With Extracorporeal Membrane Oxygenation

CONTEXT.—

Extracorporeal membrane oxygenation (ECMO) is increasingly used in the treatment of respiratory and cardiac failure, but data describing lung histopathology in ECMO recipients are limited.

OBJECTIVE.—

To examine pulmonary histopathologic findings in patients who underwent venovenous (VV) ECMO for pulmonary reasons or venoarterial (VA) ECMO for cardiac indications shortly before death, and to determine if the pulmonary changes provided insights into therapy that may prevent complications and improve outcome.

DESIGN.—

We conducted a retrospective study of lung autopsies, from VV and VA ECMO recipients and patients with acute respiratory distress syndrome (ARDS) and non-ECMO treatment, between 2008 and 2020 in Silesia Center for Heart Diseases in Zabrze, Poland.

RESULTS.—

Among 83 ECMO patients (42-64 years; men, 57 [68.7%]), the most common histopathologic findings were bronchopneumonia (44 [53.0%]), interstitial edema (40 [48.2%]), diffuse alveolar damage (DAD; 32 [38.6%]), hemorrhagic infarct (28 [33.7%]), and pulmonary hemorrhage (25 [30.1%]). DAD was associated with longer ECMO treatment and longer hospital stay. The use of VV ECMO was a predictor of DAD in patients with ARDS and undergoing ECMO, but it also occurred in 21 of 65 patients (32.3%) in the VA ECMO group, even though VA ECMO was used for heart failure.

CONCLUSIONS.—

Although DAD was significantly more common in lung autopsies of VV ECMO patients, one-third of VA ECMO patients had histopathologic changes characteristic of ARDS. The presence of DAD in lung autopsies of patients treated with VA ECMO indicates that in these patients, protective lung ventilation should be considered.

HDL-based therapeutics: A promising frontier in combating viral and bacterial infections

Low levels of high-density lipoprotein (HDL) and impaired HDL functionality have been consistently associated with increased susceptibility to infection and its serious consequences. This has been attributed to the critical role of HDL in maintaining cellular lipid homeostasis, which is essential for the proper functioning of immune and structural cells. HDL, a multifunctional particle, exerts pleiotropic effects in host defense against pathogens. It functions as a natural nanoparticle, capable of sequestering and neutralizing potentially harmful substances like bacterial lipopolysaccharides. HDL possesses antiviral activity, preventing viruses from entering or fusing with host cells, thereby halting their replication cycle. Understanding the complex relationship between HDL and the immune system may reveal innovative targets for developing new treatments to combat infectious diseases and improve patient outcomes. This review aims to emphasize the role of HDL in influencing the course of bacterial and viral infections and its and its therapeutic potential.

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.

Has the Coronavirus Disease 2019 Pandemic Played a Role in the Early Detection of Pulmonary Embolism in Children?

OBJECTIVE

Pulmonary embolism (PE) poses a significant threat to children, and nonspecific symptoms lead to delayed diagnosis. The emergence of coronavirus disease 2019 (COVID-19) has increased the complexity as it is associated with similar symptoms and increased risk of thrombotic complications. This study aimed to assess the risk factors, clinical presentations, and diagnostic features of PE in pediatric patients and to examine the impact of the COVID-19 pandemic on children with PE.

MATERIALS AND METHODS

We conducted a retrospective descriptive study examining the clinical and diagnostic data of 44 pediatric patients with radiologically confirmed PE. The study compared and analyzed patients diagnosed before and during the COVID-19 pandemic.

RESULTS

In the study, 21 of 44 pediatric patients were diagnosed in the 4 years before the COVID-19 pandemic, and 23 were diagnosed with PE during the COVID-19 pandemic. The mean time to diagnosis was 8 (2 to 14) days before the pandemic and 1 (1 to 2) days during the pandemic ( P < 0.001). The most common associated condition in both groups was infection (65.9%). Dyspnea (65.9%) and tachypnea (50.0%) were common symptoms. Except for deep vein thrombosis, there were no significant differences according to associated conditions between the groups ( P = 0.001). Pulmonary emboli were anatomically detected using computed tomography angiography, showing bilateral involvement in 45.4% of patients, segmental artery involvement in 38.6%, and main artery involvement in 15.9%.

CONCLUSION

The COVID-19 pandemic heightened suspicion of pediatric PE and accelerated diagnosis. Standardized diagnostic guidelines are increasingly necessary to balance accurate diagnosis with avoiding excessive imaging.

The role of vasculature and angiogenesis in respiratory diseases

In European countries, nearly 10% of all hospital admissions are related to respiratory diseases, mainly chronic life-threatening diseases such as COPD, pulmonary hypertension, IPF or lung cancer. The contribution of blood vessels and angiogenesis to lung regeneration, remodeling and disease progression has been increasingly appreciated. The vascular supply of the lung shows the peculiarity of dual perfusion of the pulmonary circulation (vasa publica), which maintains a functional blood-gas barrier, and the bronchial circulation (vasa privata), which reveals a profiled capacity for angiogenesis (namely intussusceptive and sprouting angiogenesis) and alveolar-vascular remodeling by the recruitment of endothelial precursor cells. The aim of this review is to outline the importance of vascular remodeling and angiogenesis in a variety of non-neoplastic and neoplastic acute and chronic respiratory diseases such as lung infection, COPD, lung fibrosis, pulmonary hypertension and lung cancer.

Mutual regulation of CD4+ T cells and intravascular fibrin in infections

Innate myeloid cells especially neutrophils and their extracellular traps are known to promote intravascular coagulation and thrombosis formation in infections and various other conditions. Innate myeloid cell-dependent fibrin formation can support systemic immunity while its dysregulation enhances the severity of infectious diseases. Less is known about the immune mechanisms preventing dysregulation of fibrin homeostasis in infection. During experimental systemic infections local fibrin deposits in the liver microcirculation cause rapid arrest of CD4+ T cells. Arrested T-helper cells mostly represent Th17 cells that partially originate from the small intestine. Intravascular fibrin deposits activate mouse and human CD4+ T cells which can be mediated by direct fibrin-CD4+ T-cell interactions. Activated CD4+ T cells suppress fibrin deposition and microvascular thrombosis by directly counteracting coagulation activation by neutrophils and classical monocytes. T-cell activation, which is initially triggered by IL-12p40- and MHC-II-dependent mechanisms, enhances intravascular fibrinolysis via LFA-1. Moreover, CD4+ T cells disfavor the association of the thrombin-activatable fibrinolysis inhibitor (TAFI) with fibrin whereby fibrin deposition is increased by TAFI in the absence but not in the presence of T cells. In human infections thrombosis development is inversely related to microvascular levels of CD4+ T cells. Thus, fibrin promotes LFA-1-dependent T-helper cell activation in infections which drives a negative feedback cycle that rapidly restricts intravascular fibrin and thrombosis development.

The role of NETosis in heart failure

The hallmark of heart failure (HF) is structural myocardial remodeling including cardiomyocyte hypertrophy, fibrosis, cardiomyocyte cell death, and a low-grade aseptic inflammation. The initiation and maintenance of persistent chronic low-grade inflammation in HF are not fully understood. Oxidative stress-mediated neutrophil extracellular traps (NETs) are the main immune defense mechanism against external bacterial infections. Furthermore, NETs play important roles in noninfectious diseases. In the settings of myocardial infarction, myocarditis, or cardiomyopathies, neutrophils infiltrate the cardiac tissue and undergo NETosis that further aggravate the inflammation. A number of stimuli may cause NETosis that is a form of programmed cell death of neutrophils that is different from apoptosis of these cells. Whether NETosis is directly involved in the pathogenesis and development of HF is still unclear. In this review, we analyzed the mechanisms and markers of NETosis, especially placing the accent on the activation of the neutrophil-specific myeloperoxidase (MPO), elastase (NE), and peptidylarginine deiminase 4 (PAD4). These conclusions are supported by the recent genetic and pharmacological studies which demonstrated that MPO, NE, and PAD4 inhibitors are effective at least in the settings of post-myocardial infarction adverse remodeling, cardiac valve diseases, cardiomyopathies, and decompensated left ventricular hypertrophy whose deterioration can lead to HF. This is essential for understanding NETosis as a contributor to pathophysiology of HF and developments of new therapies of HF.

The effect of long-term COVID-19 infection on maternal and fetal complications: a retrospective cohort study conducted at a single center in China

Investigate the effect of long-term COVID-19 on maternal and fetal complications. A retrospective cohort study was conducted. A total of 623 pregnant women who delivered in Kunming First People's Hospital from November 1, 2022 to July 31, 2023 were selected. By employing statistical methods, we compared the associations between maternal and fetal complications in pregnant women with acute COVID-19 during pregnancy, long-term COVID-19, and non-COVID-19 pregnant women. In the final 623 samples, there were 209 pregnant women with acute COVID-19, 72 pregnant women with long-term COVID-19, and 342 pregnant women without COVID-19. The epidemiological and clinical characteristics of all subjects were similar. Pregnant individuals who developed long-term COVID-19 during their pregnancy had an increased risk of experiencing gestational hypertension (OR 3.344, 95% CI 1.544-7.243), gestational diabetes mellitus (OR 2.301, 95% CI 1.290-4.102), and fetal intrauterine growth restriction (OR 2.817, 95% CI 1.385-5.952). Multivariate binary logistic regression analysis showed that this association remained consistent even after adjusting for confounders and performing subgroup analyses. Other maternal and fetal complications, such as premature rupture of membranes, preterm delivery, neonatal asphyxia, and transfer of neonates to NICU, did not exhibit statistically significant associations. After linear regression analysis, the platelet count (β: - 0.127, 95% CI - 0.001-0.000) of pregnant women with long-term COVID-19 was slightly lower than that of non-COVID-19 pregnant women, and the other coagulation parameters were not statistically significant. The incidence of gestational hypertension, gestational diabetes mellitus and fetal intrauterine growth restriction in pregnant women with long-term COVID-19 is significantly increased, but it does not further increase the coagulation status.

Accurate estimation of pathway activity in single cells for clustering and differential analysis

Inferring which and how biological pathways and gene sets change is a key question in many studies that utilize single-cell RNA sequencing. Typically, these questions are addressed by quantifying the enrichment of known gene sets in lists of genes derived from global analysis. Here we offer SiPSiC, a new method to infer pathway activity in every single cell. This allows more sensitive differential analysis and utilization of pathway scores to cluster cells and compute UMAP or other similar projections. We apply our method to COVID-19, lung adenocarcinoma and glioma data sets, and demonstrate its utility. SiPSiC analysis results are consistent with findings reported in previous studies in many cases, but SiPSiC also reveals the differential activity of novel pathways, enabling us to suggest new mechanisms underlying the pathophysiology of these diseases and demonstrating SiPSiC's high accuracy and sensitivity in detecting biological function and traits. In addition, we demonstrate how it can be used to better classify cells based on activity of biological pathways instead of single genes and its ability to overcome patient-specific artifacts.

Causal relationships between COVID-19 and venous thromboembolism: A mendelian randomization analysis

Objective: Observational studies show the correlation between COVID-19 and venous thromboembolism (VTE) risk. However, the causal effects remain uncertain. We aimed to explore the potential causal association between COVID-19 and VTE using Mendelian randomization (MR) design. Methods: Two-sample MR was used to evaluate the potential causality between COVID-19 and VTE by selecting single-nucleotide polymorphisms (SNPs) as instrumental variables (IVs) from genome-wide association studies (GWAS). The weighted median, MR-Egger, simple mode, and weighted mode were employed as supplementary methods for MR estimations, with the inverse-variance weighted (IVW) method serving as the principal analysis. In addition, we took sensitivity analyses, including Cochran's test, MR-Pleiotropy Residual Sum and Outlier (MR-PRESSO), and leave-one-out analysis to ensure that we obtained stable and reliable results. Results: Our study selected 26 COVID-19 severity, 31 COVID-19 hospitalization, and 13 COVID-19 susceptibility SNPs as instrumental variables. The IVW analysis results revealed that there was no causal relationship between COVID-19 severity, hospitalization, or susceptibility and VTE, with odds ratios of 0.974 (95%CI: 0.936-1.013, p = 0.19), 0.976 (95%CI: 0.918-1.039, p = 0.447), and 0.908 (95%CI: 0.775-1.065, p = 0.235), respectively. The IVW approach yielded consistent results with MR-Egger, Weighted Median simple mode, and weighted mode. MR-PRESSO and sensitivity analysis further confirmed the stability and consistency of the MR results. Conclusions: This study did not find evidence to support a causal relationship between COVID-19 and VTE at the genetic level. Further investigation is warranted to determine if the significant association reported in previous observational studies between the two is due to confounding factors.

Neuro-molecular perspectives on long COVID-19 impacted cerebrovascular diseases - a role for dipeptidyl peptidase IV

The coronavirus disease 2019 (COVID-19) has caused immense devastation globally with many outcomes that are now extending to its long-term sequel called long COVID. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects not only lungs, but also the brain and heart in association with endothelial cell dysfunction, coagulation abnormalities, and thrombosis leading to cardio-cerebrovascular health issues. Fatigue, cognitive decline, and brain fog are common neurological symptoms in persisting long COVID. Neurodegenerative processes and SARS-CoV-2 infection manifest overlapping molecular mechanisms, such as cytokine dysregulation, inflammation, protein aggregation, mitochondrial dysfunction, and oxidative stress. Identifying the key molecules in these processes is of importance for prevention and treatment of this disease. In particular, Dipeptidyl peptidase IV (DPPIV), a multifunctional peptidase has recently drawn attention as a potential co-receptor for SARS-CoV-2 infection and cellular entry. DPPIV is a known co-receptor for some other COVID viruses including MERS-Co-V. DPPIV regulates the immune responses, obesity, glucose metabolism, diabetes, and hypertension that are associated with cerebrovascular manifestations including stroke. DPPIV likely worsens persisting COVID-19 by disrupting inflammatory signaling pathways and the neurovascular system. This review highlights the neurological, cellular and molecular processes concerning long COVID, and DPPIV as a potential key factor contributing to cerebrovascular dysfunctions following SARS-CoV-2 infection.

The Impact of Pentraxin 3 Serum Levels and Angiotensin-Converting Enzyme Polymorphism on Pulmonary Infiltrates and Mortality in COVID-19 Patients

OBJECTIVES

The aim of this study was to examine the impact of the pentraxin 3 (PTX3) serum level and angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism on the severity of radiographic pulmonary infiltrates and the clinical outcomes of COVID-19.

METHODS

The severity of COVID-19 pulmonary infiltrates was evaluated within a week of admission by analyzing chest X-rays (CXR) using the modified Brixia (MBrixa) scoring system. The insertion (I)/deletion (D) polymorphism of the ACE gene and the serum levels of PTX3 were determined for all patients included in the study.

RESULTS

This study included 80 patients. Using a cut-off serum level of PTX3 ≥ 2.765 ng/mL, the ROC analysis (AUC 0.871, 95% CI 0.787-0.954, p < 0.001) showed a sensitivity of 85.7% and specificity of 78.8% in predicting severe MBrixa scores. Compared to ACE I/I polymorphism, D/D polymorphism significantly increased the risk of severe CXR infiltrates, OR 7.7 (95% CI: 1.9-30.1), and p = 0.002. Significant independent predictors of severe CXR infiltrates include hypertension (OR 7.71), PTX3 (OR 1.20), and ACE D/D polymorphism (OR 18.72). Hypertension (OR 6.91), PTX3 (OR 1.47), and ACE I/I polymorphism (OR 0.09) are significant predictors of poor outcomes.

CONCLUSION

PTX3 and ACE D/D polymorphism are significant predictors of the severity of COVID-19 pneumonia. PTX3 is a significant predictor of death.

Pulmonary function trajectories in COVID-19 survivors with and without pre-existing respiratory disease

A significant proportion of COVID-19 survivors still experience a reduced diffusion capacity three and twelve months after discharge. We aimed to compare pulmonary function trajectories between hospitalized COVID-19 patients with pre-existing respiratory disease (PRD) and patients without pre-existing respiratory disease (Non-PRD) at three and twelve months after hospital discharge. This single-centre retrospective cohort study included COVID-19 patients admitted to the VieCuri Medical Centre (Venlo, the Netherlands) between February and December 2020 that were invited to the outpatient clinic at three and twelve months after discharge. During this visit, pulmonary function tests were performed and impairments were based on lower limit of normal. Data of 239 patients were analysed (65% male, 66 ± 10 years, and 26% with a history of respiratory disease). Three months after discharge, 49% and 64% of the Non-PRD patients (n = 177) and PRD patients (n = 62) had a low diffusion capacity, respectively. This improved over time in Non-PRD patients (p = 0.003), but not in PRD patients (p = 0.250). A low diffusion capacity was still observed in 34% and 57% of the Non-PRD and PRD group, respectively, twelve months after discharge. Pulmonary function impairments, mainly a reduced diffusion capacity, are observed among hospitalized COVID-19 patients with PRD and Non-PRD, at three and twelve months follow-up. Although diffusion capacity impairments restore over time in Non-PRD patients, poor recovery was observed among PRD patients.

Deep Learning for 3D Vascular Segmentation in Phase Contrast Tomography

Automated blood vessel segmentation is critical for biomedical image analysis, as vessel morphology changes are associated with numerous pathologies. Still, precise segmentation is difficult due to the complexity of vascular structures, anatomical variations across patients, the scarcity of annotated public datasets, and the quality of images. Our goal is to provide a foundation on the topic and identify a robust baseline model for application to vascular segmentation using a new imaging modality, Hierarchical Phase-Contrast Tomography (HiP-CT). We begin with an extensive review of current machine learning approaches for vascular segmentation across various organs. Our work introduces a meticulously curated training dataset, verified by double annotators, consisting of vascular data from three kidneys imaged using Hierarchical Phase-Contrast Tomography (HiP-CT) as part of the Human Organ Atlas Project. HiP-CT, pioneered at the European Synchrotron Radiation Facility in 2020, revolutionizes 3D organ imaging by offering resolution around 20μm/voxel, and enabling highly detailed localized zooms up to 1μm/voxel without physical sectioning. We leverage the nnU-Net framework to evaluate model performance on this high-resolution dataset, using both known and novel samples, and implementing metrics tailored for vascular structures. Our comprehensive review and empirical analysis on HiP-CT data sets a new standard for evaluating machine learning models in high-resolution organ imaging. Our three experiments yielded Dice scores of 0.9523 and 0.9410, and 0.8585, respectively. Nevertheless, DSC primarily assesses voxel-to-voxel concordance, overlooking several crucial characteristics of the vessels and should not be the sole metric for deciding the performance of vascular segmentation. Our results show that while segmentations yielded reasonably high scores-such as centerline Dice values ranging from 0.82 to 0.88, certain errors persisted. Specifically, large vessels that collapsed due to the lack of hydro-static pressure (HiP-CT is an ex vivo technique) were segmented poorly. Moreover, decreased connectivity in finer vessels and higher segmentation errors at vessel boundaries were observed. Such errors, particularly in significant vessels, obstruct the understanding of the structures by interrupting vascular tree connectivity. Through our review and outputs, we aim to set a benchmark for subsequent model evaluations using various modalities, especially with the HiP-CT imaging database.

The relationship between Nuclear Factor-Kappa B and Inhibitor-Kappa B parameters with clinical course in COVID-19 patients

BACKGROUND

We aimed to investigate the serum Nuclear Factor Kappa B (NF-κB) p105, NF-κB p65 and Inhibitor Kappa B Alpha (IκBα) levels in patients with mild/moderate Coronavirus Disease 2019 (COVID-19) and their association with the course of the disease.

MATERIALS AND METHODS

Blood was drawn from 35 COVID-19 patients who applied to the Department of Emergency Medicine of Istanbul University-Cerrahpasa at the time of diagnosis and from 35 healthy individuals. The patients were evaluated to have mild/moderate degree of disease according to National Early Warning Score 2 (NEWS2) scoring and computed tomography (CT) findings. The markers were studied in the obtained serum samples, using enzyme-linked immunoassay (ELISA). Receiver Operating Characteristic (ROC) analysis was performed. Statistical significance was evaluated to be p < 0.05.

RESULTS

NF-κB p105 levels were significantly higher in the COVID-19 group compared to the control group. C-reactive protein (CRP), D-dimer, ferritin levels of the patients were significantly higher (p < 0.001) compared to the control group, while the lymphocyte count was found lower (p = 0.001). IκBα and NF-κB p65 levels are similar in both groups. Threshold value for NF-κB p105 was above 0.78 ng/mL, sensitivity was 71.4% and specificity was 97.1% (p < 0.05). NF-κB p105 levels at the time of diagnosis of the patients who required supplemental oxygen (O2), were significantly higher (p < 0.01).

CONCLUSIONS

The rise in serum NF-κB p105 levels during the early stages of infection holds diagnostic value. Besides its relation with severity might have a prognostic feature to foresee the requirement for supplemental O2 that occurs during hospitalization.

Lower or higher oxygenation targets in the intensive care unit: an individual patient data meta-analysis

PURPOSE

Optimal oxygenation targets for patients with acute hypoxemic respiratory failure in the intensive care unit (ICU) are not clearly defined due to substantial variability in design of previous trials. This study aimed to perform a pre-specified individual patient data meta-analysis of the Handling Oxygenation Targets in the ICU (HOT-ICU) and the Handling Oxygenation Targets in coronavirus disease 2019 (COVID-19) (HOT-COVID) trials to compare targeting a partial pressure of arterial oxygen (PaO2) of 8-12 kPa in adult ICU patients, assessing both benefits and harms.

METHODS

We assessed 90-day all-cause mortality and days alive without life support in 90 days using a generalised mixed model. Heterogeneity of treatment effects (HTE) was evaluated in 14 subgroups, and results graded using the Instrument to assess the Credibility of Effect Modification Analyses (ICEMAN).

RESULTS

At 90 days, mortality was 40.4% (724/1792) in the 8 kPa group and 40.9% (733/1793) in the 12 kPa group (risk ratio, 0.99; 95% confidence interval [CI] 0.92-1.07; P = 0.80). No difference was observed in number of days alive without life support. Subgroup analyses indicated more days alive without life support in COVID-19 patients targeting 8 kPa (P = 0.04) (moderate credibility), and lower mortality (P = 0.03) and more days alive without life support (P = 0.02) in cancer-patients targeting 12 kPa (low credibility).

CONCLUSION

This study reported no overall differences comparing a PaO2 target of 8-12 kPa on mortality or days alive without life support in 90 days. Subgroup analyses suggested HTE in patients with COVID-19 (moderate credibility) and cancer (low credibility).

Higher levels of IL-1ra, IL-6, IL-8, MCP-1, MIP-3α, MIP-3β, and fractalkine are associated with 90-day mortality in 132 non-immunomodulated hospitalized patients with COVID-19

INTRODUCTION

Immune dysregulation with an excessive release of cytokines has been identified as a key driver in the development of severe COVID-19. The aim of this study was to evaluate the initial cytokine profile associated with 90-day mortality and respiratory failure in a cohort of patients hospitalized with COVID 19 that did not receive immunomodulatory therapy.

METHODS

Levels of 45 cytokines were measured in blood samples obtained at admission from patients with confirmed COVID-19. Logistic regression analysis was utilized to determine the association between cytokine levels and outcomes. The primary outcome was death within 90 days from admission and the secondary outcome was need for mechanical ventilation.

RESULTS

A total of 132 patients were included during the spring of 2020. We found that one anti-inflammatory cytokine, one pro-inflammatory cytokine, and five chemokines were associated with the odds of 90-day mortality, specifically: interleukin-1 receptor antagonist, interleukin-6, interleukin-8, monocyte chemoattractant protein-1, macrophage inflammatory protein-3α, macrophage inflammatory protein-3β, and fractalkine. All but fractalkine were also associated with the odds of respiratory failure during admission. Monocyte chemoattractant protein-1 showed the strongest estimate of association with both outcomes.

CONCLUSION

We showed that one anti-inflammatory cytokine, one pro-inflammatory cytokine, and five chemokines were associated with 90-day mortality in patients hospitalized with COVID-19 that did not receive immunomodulatory therapy.

Aprotinin (I): Understanding the Role of Host Proteases in COVID-19 and the Importance of Pharmacologically Regulating Their Function

Proteases are produced and released in the mucosal cells of the respiratory tract and have important physiological functions, for example, maintaining airway humidification to allow proper gas exchange. The infectious mechanism of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), takes advantage of host proteases in two ways: to change the spatial conformation of the spike (S) protein via endoproteolysis (e.g., transmembrane serine protease type 2 (TMPRSS2)) and as a target to anchor to epithelial cells (e.g., angiotensin-converting enzyme 2 (ACE2)). This infectious process leads to an imbalance in the mucosa between the release and action of proteases versus regulation by anti-proteases, which contributes to the exacerbation of the inflammatory and prothrombotic response in COVID-19. In this article, we describe the most important proteases that are affected in COVID-19, and how their overactivation affects the three main physiological systems in which they participate: the complement system and the kinin-kallikrein system (KKS), which both form part of the contact system of innate immunity, and the renin-angiotensin-aldosterone system (RAAS). We aim to elucidate the pathophysiological bases of COVID-19 in the context of the imbalance between the action of proteases and anti-proteases to understand the mechanism of aprotinin action (a panprotease inhibitor). In a second-part review, titled "Aprotinin (II): Inhalational Administration for the Treatment of COVID-19 and Other Viral Conditions", we explain in depth the pharmacodynamics, pharmacokinetics, toxicity, and use of aprotinin as an antiviral drug.

Biomarkers of tissue remodelling are elevated in serum of COVID-19 patients who develop interstitial lung disease - an exploratory biomarker study

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a viral pneumonia that can result in serious respiratory illness. It is associated with extensive systemic inflammation, changes to the lung extracellular matrix, and long-term lung impairment such as interstitial lung disease (ILD). In this study, the aim was to investigate whether tissue remodelling, wound healing, and neutrophil activity is altered in patients with COVID-19 and how these relate to the development of post-COVID ILD.

METHOD

Serum samples were collected from 63 patients three months after discharge as part of the Research Evaluation Alongside Clinical Treatment study in COVID-19 (REACT COVID-19), 10 of whom developed ILD, and 16 healthy controls. Samples were quantified using neo-epitope specific biomarkers reflecting tissue stiffness and formation (PC3X, PRO-C3, and PRO-C6), tissue degradation (C1M, C3M, and C6M), wound healing (PRO-FIB and X-FIB), and neutrophil activity (CPa9-HNE and ELP-3).

RESULTS

Mean serum levels of PC3X (p < 0.0001), PRO-C3 (p = 0.002), C3M (p = 0.009), PRO-FIB (p < 0.0001), CPa9-HNE (p < 0.0001), and ELP-3 (p < 0.0001) were significantly elevated in patients with COVID-19 compared to healthy controls. Moreover, PC3X (p = 0.023) and PRO-C3 (p = 0.032) were significantly elevated in post-COVID ILD as compared to COVID-19.

CONCLUSION

Serological biomarkers reflecting type III collagen remodelling, clot formation, and neutrophil activity were significantly elevated in COVID-19 and type III collagen formation markers were further elevated in post-COVID ILD. The findings suggest an increased type III collagen remodelling in COVID-19 and warrants further investigations to assess the potential of tissue remodelling biomarkers as a tool to identify COVID-19 patients at high risk of developing ILD.

Emergency Presentations of Coronavirus Disease (COVID-19): A Review of the Literature and Radiologic Perspective

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the debilitating global pandemic known as Coronavirus disease (COVID-19). In this paper, we highlight the widespread manifestations and complications across disease systems. In addition, we present their relevant imaging findings to inform appropriate investigations and management in patients presenting to the Emergency Department with COVID-19 and its respective sequalae. Of note, we outline considerations for diagnosis of long COVID, an important medium to long term sequalae in patients with previous COVID-19 infections.

Endothelial biomarkers (Von willebrand factor, BDCA3, urokinase) as predictors of mortality in COVID-19 patients: cohort study

BACKGROUND

SARS-CoV-2 is a systemic disease that affects endothelial function and leads to coagulation disorders, increasing the risk of mortality. Blood levels of endothelial biomarkers such as Von Willebrand Factor (VWF), Thrombomodulin or Blood Dendritic Cell Antigen-3 (BDCA3), and uUokinase (uPA) increase in patients with severe disease and can be prognostic indicators for mortality. Therefore, the aim of this study was to determine the effect of VWF, BDCA3, and uPA levels on mortality.

METHODS

From May 2020 to January 2021, we studied a prospective cohort of hospitalized adult patients with polymerase chain reaction (PCR)-confirmed COVID-19 with a SaO2 ≤ 93% and a PaO2/FiO2 ratio < 300. In-hospital survival was evaluated from admission to death or to a maximum of 60 days of follow-up with Kaplan-Meier survival curves and Cox proportional hazard models as independent predictor measures of endothelial dysfunction.

RESULTS

We recruited a total of 165 subjects (73% men) with a median age of 57.3 ± 12.9 years. The most common comorbidities were obesity (39.7%), hypertension (35.4%) and diabetes (30.3%). Endothelial biomarkers were increased in non-survivors compared to survivors. According to the multivariate Cox proportional hazard model, those with an elevated VWF concentration ≥ 4870 pg/ml had a hazard ratio (HR) of 4.06 (95% CI: 1.32-12.5) compared to those with a lower VWF concentration adjusted for age, cerebrovascular events, enoxaparin dose, lactate dehydrogenase (LDH) level, and bilirubin level. uPA and BDCA3 also increased mortality in patients with levels ≥ 460 pg/ml and ≥ 3600 pg/ml, respectively.

CONCLUSION

The risk of mortality in those with elevated levels of endothelial biomarkers was observable in this study.

IgA Anti-β2-Glycoprotein I Antibodies as Markers of Thrombosis and Severity in COVID-19 Patients

Patients with COVID-19 may develop a hypercoagulable state due to tissue and endothelial injury, produced by an unbalanced immune response. Therefore, an increased number of thromboembolic events has been reported in these patients. The aim of this study is to investigate the presence of antiphospholipid antibodies (aPL) in COVID-19 patients, their role in the development of thrombosis and their relationship with the severity of the disease. In this retrospective study, serum samples from 159 COVID-19 patients and 80 healthy donors were analysed for the presence of aPL. A total of 29 patients (18.2%) and 14 healthy donors (17.5%) were positive for aPL. Nineteen COVID-19 patients (12%) but no healthy donor presented a positive percentage of the IgA isotype aPL. IgA anti-β2-glycoprotein I antibodies (anti-β2GPI) were the most frequent type (6.3%) in patients but was not detected in any healthy donor. The positivity of this antibody was found to be significantly elevated in patients with thromboembolic events (25% vs. 5%, p = 0.029); in fact, patients with positive IgA anti-β2GPI had an incidence of thrombosis over six times higher than those who had normal antibody concentrations [OR (CI 95%) of 6.67 (1.5-30.2), p = 0.014]. Additionally, patients with moderate-severe disease presented a higher aPL positivity than patients with mild disease according to the Brescia (p = 0.029) and CURB-65 (p = 0.011) severity scales. A multivariate analysis showed that positivity for IgA anti-β2GPI is significantly associated with disease severity measured by CURB-65 [OR (CI 95%) 17.8 (1.7-187), p = 0.0016]. In conclusion, COVID-19 patients have a significantly higher positive percentage of the IgA isotype aPL than healthy donors. IgA anti-β2GPI antibodies were the most frequently detected aPL in COVID-19 patients and were associated with thrombosis and severe COVID-19 and are thus proposed as a possible marker to identify high-risk patients.

Pott's puffy tumor: An unusual complication of rhino-orbito-cerebral mucormycosis

Objective

To describe clinicoradiological features and surgical outcomes in a series of nine patients with rhino-orbito-cerebral mucormycosis (ROCM) who presented with Pott's puffy tumor (ROCM-PPT).

Methods

The records of nine patients with ROCM-PPT seen between March 2020 and December 2021 were analysed. Clinical features, radiology, histopathology, operative findings, management and outcome were noted. Frontal sinus pneumatisation and outflow tract configuration was compared between patients and controls with ROCM and no PPT.

Results

ROCM-PPT was diagnosed in 9 of 284 (3.2 %) patients with ROCM seen during the study period. There were six (66.7 %) males and the median age was 54 (IQR 46-60) years. Eight (88.9 %) patients had diabetes mellitus and seven (77.8 %) had been COVID-19 positive. Radiological features of osteomyelitis, subperiosteal abscess formation and dural enhancement were seen in all patients. No significant differences in pneumatisation or frontal sinus outflow tract configuration were noted between patients and controls. All patients underwent a craniectomy with frontal bone debridement and frontal sinus exteriorisation. All patients were treated with anti-fungal agents for several months. All patients had symptomatic improvement at a median follow-up of 21 (IQR 18-23) months. Repeat CT/MRI scans showed disease regression/resolution in six out of eight (75 %) patients with follow-up imaging, and stable disease in two others.

Conclusions

ROCM-PPT is a rare, delayed complication of mucormycosis that was seen in larger numbers during the recent COVID-19 pandemic. Aggressive debridement of osteomyelitic bone and antifungal therapy results in a good outcome.

Compartmentalization of the inflammatory response during bacterial sepsis and severe COVID-19

Acute infections cause local and systemic disorders which can lead in the most severe forms to multi-organ failure and eventually to death. The host response to infection encompasses a large spectrum of reactions with a concomitant activation of the so-called inflammatory response aimed at fighting the infectious agent and removing damaged tissues or cells, and the anti-inflammatory response aimed at controlling inflammation and initiating the healing process. Fine-tuning at the local and systemic levels is key to preventing local and remote injury due to immune system activation. Thus, during bacterial sepsis and Coronavirus disease 2019 (COVID-19), concomitant systemic and compartmentalized pro-inflammatory and compensatory anti-inflammatory responses are occurring. Immune cells (e.g., macrophages, neutrophils, natural killer cells, and T-lymphocytes), as well as endothelial cells, differ from one compartment to another and contribute to specific organ responses to sterile and microbial insult. Furthermore, tissue-specific microbiota influences the local and systemic response. A better understanding of the tissue-specific immune status, the organ immunity crosstalk, and the role of specific mediators during sepsis and COVID-19 can foster the development of more accurate biomarkers for better diagnosis and prognosis and help to define appropriate host-targeted treatments and vaccines in the context of precision medicine.

Thrombotic Microangiopathy as an Emerging Complication of Viral Vector-Based Gene Therapy

Gene therapy has brought tremendous hope for patients with severe life-threatening monogenic diseases. Although studies have shown the efficacy of gene therapy, serious adverse events have also emerged, including thrombotic microangiopathy (TMA) following viral vector-based gene therapy. In this review, we briefly summarize the concept of gene therapy, and the immune response triggered by viral vectors. We also discuss the incidence, presentation, and potential underlying mechanisms, including complement activation, of gene therapy-associated TMA. Further studies are needed to better define the pathogenesis of this severe complication of gene therapy, and the optimal measures to prevent it.

[Takayasu arteritis after COVID-19 infection in a 26-year-old female patient with Crohn's disease]

Extraintestinal manifestations, e.g. of the skin, joints or liver, are frequently found in Crohn's disease. We report about a 26-year-old female patient with longstanding Crohn's disease, who was admitted to our hospital with suspicion of an acute attack with suggestive symptoms and increased significantly inflammatory parameters. Shortly before, symptomatic COVID-19 disease (SARS-CoV-2 variant omicron) had been made. Comprehensive endoscopic and imaging diagnostics ruled out active Crohn's disease. However, inflammatory thickening of the aortic arch was seen, and a diagnosis of Takayasu arteritis (type II b) was made. Steroid therapy resulted in a rapid and sustained improvement of clinical symptoms. The occurrence of Takayasu arteritis is extremely rare outside Japan. An coincidence has been described in chronic inflammatory bowel diseases and is discussed as a possible extraintestinal manifestation. The occurrence of immune-mediated disease after COVID-19 disease has been described and may be triggered by the infection. Patients with inflammatory bowel disease may represent a special risk population.

Interventional Removal of Travelling Microthrombi Using Targeted Magnetic Microbubble

Microthrombus is one of the major causes of the sequelae of Corona Virus Disease 2019 (COVID-19 and leads to subsequent embolism and necrosis. Due to their small size and irregular movements, the early detection and efficient removal of microthrombi in vivo remain a great challenge. In this work, an interventional method is developed to identify and remove the traveling microthrombi using targeted-magnetic-microbubbles (TMMBs) and an interventional magnetic catheter. The thrombus-targeted drugs are coated on the TMMBs and magnetic nanoparticles are shelled inside, which allow not only targeted adhesion onto the traveling microthrombi, but also the effective capture by the magnetic catheter in the vessel. In the proof-of-concept experiments in the rat models, the concentration of microthrombus is reduced by more than 60% in 3 min, without damaging the organs. It is a promising method for treating microthrombus issues.

ECMO is associated with decreased hospital mortality in COVID-19 ARDS

This study determined whether compared to conventional mechanical ventilation (MV), extracorporeal membrane oxygenation (ECMO) is associated with decreased hospital mortality or fibrotic changes in patients with COVID-19 acute respiratory distress syndrome. A cohort of 72 patients treated with ECMO and 390 with conventional MV were analyzed (February 2020-December 2021). A target trial was emulated comparing the treatment strategies of initiating ECMO vs no ECMO within 7 days of MV in patients with a PaO2/FiO2 < 80 or a PaCO2 ≥ 60 mmHg. A total of 222 patients met the eligibility criteria for the emulated trial, among whom 42 initiated ECMO. ECMO was associated with a lower risk of hospital mortality (hazard ratio [HR], 0.56; 95% confidence interval [CI] 0.36-0.96). The risk was lower in patients who were younger (age < 70 years), had less comorbidities (Charlson comorbidity index < 2), underwent prone positioning before ECMO, and had driving pressures ≥ 15 cmH2O at inclusion. Furthermore, ECMO was associated with a lower risk of fibrotic changes (HR, 0.30; 95% CI 0.11-0.70). However, the finding was limited due to relatively small number of patients and differences in observability between the ECMO and conventional MV groups.

Mucorales: A systematic review to inform the World Health Organization priority list of fungal pathogens

The World Health Organization, in response to the growing burden of fungal disease, established a process to develop a fungal priority pathogens list (FPPL). This systematic review aimed to evaluate the epidemiology and impact of invasive fungal disease due to Mucorales. PubMed and Web of Science were searched to identify studies published between January 1, 2011 and February 23, 2021. Studies reporting on mortality, inpatient care, complications and sequelae, antifungal susceptibility, risk factors, preventability, annual incidence, global distribution, and emergence during the study time frames were selected. Overall, 24 studies were included. Mortality rates of up to 80% were reported. Antifungal susceptibility varied across agents and species, with the minimum inhibitory concentrations lowest for amphotericin B and posaconazole. Diabetes mellitus was a common risk factor, detected in 65%-85% of patients with mucormycosis, particularly in those with rhino-orbital disease (86.9%). Break-through infection was detected in 13.6%-100% on azole or echinocandin antifungal prophylaxis. The reported prevalence rates were variable, with some studies reporting stable rates in the USA of 0.094-0.117/10 000 discharges between 2011 and 2014, whereas others reported an increase in Iran from 16.8% to 24% between 2011 and 2015. Carefully designed global surveillance studies, linking laboratory and clinical data, are required to develop clinical breakpoints to guide antifungal therapy and determine accurate estimates of complications and sequelae, annual incidence, trends, and global distribution. These data will provide robust estimates of disease burden to refine interventions and better inform future FPPL.

Impact of intensive prone position therapy on outcomes in intubated patients with ARDS related to COVID-19

BACKGROUND

Previous retrospective research has shown that maintaining prone positioning (PP) for an average of 40 h is associated with an increase of survival rates in intubated patients with COVID-19-related acute respiratory distress syndrome (ARDS). This study aims to determine whether a cumulative PP duration of more than 32 h during the first 2 days of intensive care unit (ICU) admission is associated with increased survival compared to a cumulative PP duration of 32 h or less.

METHODS

This study is an ancillary analysis from a previous large international observational study involving intubated patients placed in PP in the first 48 h of ICU admission in 149 ICUs across France, Belgium and Switzerland. Given that PP is recommended for a 16-h daily duration, intensive PP was defined as a cumulated duration of more than 32 h during the first 48 h, whereas standard PP was defined as a duration equal to or less than 32 h. Patients were followed-up for 90 days. The primary outcome was mortality at day 60. An Inverse Probability Censoring Weighting (IPCW) Cox model including a target emulation trial method was used to analyze the data.

RESULTS

Out of 2137 intubated patients, 753 were placed in PP during the first 48 h of ICU admission. The intensive PP group (n = 79) had a median PP duration of 36 h, while standard PP group (n = 674) had a median of 16 h during the first 48 h. Sixty-day mortality rate in the intensive PP group was 39.2% compared to 38.7% in the standard PP group (p = 0.93). Twenty-eight-day and 90-day mortality as well as the ventilator-free days until day 28 were similar in both groups. After IPCW, there was no significant difference in mortality at day 60 between the two-study groups (HR 0.95 [0.52-1.74], p = 0.87 and HR 1.1 [0.77-1.57], p = 0.61 in complete case analysis or in multiple imputation analysis, respectively).

CONCLUSIONS

This secondary analysis of a large multicenter European cohort of intubated patients with ARDS due to COVID-19 found that intensive PP during the first 48 h did not provide a survival benefit compared to standard PP.

The TOX-RAGE axis mediates inflammatory activation and lung injury in severe pulmonary infectious diseases

Thymocyte selection-associated high-mobility group box (TOX) is a transcription factor that is crucial for T cell exhaustion during chronic antigenic stimulation, but its role in inflammation is poorly understood. Here, we report that TOX extracellularly mediates drastic inflammation upon severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by binding to the cell surface receptor for advanced glycation end-products (RAGE). In various diseases, including COVID-19, TOX release was highly detectable in association with disease severity, contributing to lung fibroproliferative acute respiratory distress syndrome (ARDS). Recombinant TOX-induced blood vessel rupture, similar to a clinical signature in patients experiencing a cytokine storm, further exacerbating respiratory function impairment. In contrast, disruption of TOX function by a neutralizing antibody and genetic removal of RAGE diminished TOX-mediated deleterious effects. Altogether, our results suggest an insight into TOX function as an inflammatory mediator and propose the TOX-RAGE axis as a potential target for treating severe patients with pulmonary infection and mitigating lung fibroproliferative ARDS.

P-selectin Facilitates SARS-CoV-2 Spike 1 Subunit Attachment to Vesicular Endothelium and Platelets

SARS-CoV-2 infection starts from the association of its spike 1 (S1) subunit with sensitive cells. Vesicular endothelial cells and platelets are among the cell types that bind SARS-CoV-2, but the effectors that mediate viral attachment on the cell membrane have not been fully elucidated. Herein, we show that P-selectin (SELP), a biomarker for endothelial dysfunction and platelet activation, can facilitate the attachment of SARS-CoV-2 S1. Since we observe colocalization of SELP with S1 in the lung tissues of COVID-19 patients, we perform molecular biology experiments on human umbilical vein endothelial cells (HUVECs) to confirm the intermolecular interaction between SELP and S1. SELP overexpression increases S1 recruitment to HUVECs and enhances SARS-CoV-2 spike pseudovirion infection. The opposite results are determined after SELP downregulation. As S1 causes endothelial inflammatory responses in a dose-dependent manner, by activating the interleukin (IL)-17 signaling pathway, SELP-induced S1 recruitment may contribute to the development of a "cytokine storm" after viral infection. Furthermore, SELP also promotes the attachment of S1 to the platelet membrane. Employment of PSI-697, a small inhibitor of SELP, markedly decreases S1 adhesion to both HUVECs and platelets. In addition to the role of membrane SELP in facilitating S1 attachment, we also discover that soluble SELP is a prognostic factor for severe COVID-19 through a meta-analysis. In this study, we identify SELP as an adhesive site for the SARS-CoV-2 S1, thus providing a potential drug target for COVID-19 treatment.

Veno-venous extracorporeal membrane oxygenation for perioperative management of infective endocarditis after COVID-19 with acute respiratory distress syndrome: a case report

BACKGROUND

Infective endocarditis (IE) is a rare cardiovascular complication in patients with coronavirus disease 2019 (COVID-19). IE after COVID-19 can also be complicated by acute respiratory distress syndrome (ARDS); however, the guidelines for the treatment of such cases are not clear. Here, we report a case of perioperative management of post-COVID-19 IE with ARDS using veno-venous extracorporeal membrane oxygenation (V-V ECMO).

CASE PRESENTATION

The patient was a 40-year-old woman who was admitted on day 18 of COVID-19 onset and was administered oxygen therapy, remdesivir, and dexamethasone. The patient's condition improved; however, on day 24 of hospitalization, the patient developed hypoxemia and was admitted to the intensive care unit (ICU) due to respiratory failure. Blood culture revealed Corynebacterium striatum, and transesophageal echocardiography revealed vegetation on the aortic and mitral valves. Valve destruction was mild, and the cause of respiratory failure was thought to be ARDS. Despite continued antimicrobial therapy, ARDS did not improve the patient's condition, and valve destruction progressed; therefore, surgical treatment was scheduled on day 13 of ICU admission. After preoperative consultation with the team, a decision was made to initiate V-V ECMO after the patient was weaned from CPB, with concerns about further worsening of her respiratory status after surgery. The patient returned to the ICU with transition to V-V ECMO, and her circulation remained stable. The patient was weaned off V-V ECMO on postoperative day 33 and discharged from the ICU on postoperative day 47.

CONCLUSIONS

ARDS may occur in patients with IE after COVID-19. Owing to concerns about further exacerbation of pulmonary damage, the timing of surgery should be comprehensively considered. Preoperatively, clinicians should discuss perioperative ECMO introduction and configuration.

Ocular manifestations of COVID-19

There is an increasing body of knowledge regarding how COVID-19 may be associated with ocular disease of varying severity and duration. This article discusses the literature on the ocular manifestations associated with COVID-19, including appraisal of the current evidence, suggested mechanisms of action, associated comorbidities and risk factors, timing from initial infection to diagnosis and clinical red flags. The current literature primarily comprises case reports and case series which inevitably lack control groups and evidence to support causality. However, these early data have prompted the development of larger population-based and laboratory studies that are emerging. As new data become available, a better appraisal of the true effects of COVID-19 on the eye will be possible. While the COVID-19 pandemic was officially declared no longer a "global health emergency" by the World Health Organization (WHO) in May 2023, case numbers continue to rise. Reinfection with different variants is predicted to lead to a growing cumulative burden of disease, particularly as more chronic, multi-organ sequelae become apparent with potentially significant ocular implications. COVID-19 ocular manifestations are postulated to be due to three main mechanisms: firstly, there is a dysregulated immune response to the initial infection linked to inflammatory eye disease; secondly, patients with COVID-19 have a greater tendency towards a hypercoagulable state, leading to prothrombotic events; thirdly, patients with severe COVID-19 requiring hospitalisation and are immunosuppressed due to administered corticosteroids or comorbidities such as diabetes mellitus are at an increased risk of secondary infections, including endophthalmitis and rhino-orbital-mucormycosis. Reported ophthalmic associations with COVID-19, therefore, include a range of conditions such as conjunctivitis, scleritis, uveitis, endogenous endophthalmitis, corneal graft rejection, retinal artery and vein occlusion, non-arteritic ischaemic optic neuropathy, glaucoma, neurological and orbital sequelae. With the need to consider telemedicine consultation in view of COVID-19's infectivity, understanding the range of ocular conditions that may present during or following infection is essential to ensure patients are appropriately triaged, with prompt in-person ocular examination for management of potentially sight-threatening and life-threatening diseases.

Mitochondria in COVID-19: from cellular and molecular perspective

The rapid development of the COVID-19 pandemic resulted in a closer analysis of cell functioning during β-coronavirus infection. This review will describe evidence for COVID-19 as a syndrome with a strong, albeit still underestimated, mitochondrial component. Due to the sensitivity of host mitochondria to coronavirus infection, SARS-CoV-2 affects mitochondrial signaling, modulates the immune response, modifies cellular energy metabolism, induces apoptosis and ageing, worsening COVID-19 symptoms which can sometimes be fatal. Various aberrations across human systems and tissues and their relationships with mitochondria were reported. In this review, particular attention is given to characterization of multiple alterations in gene expression pattern and mitochondrial metabolism in COVID-19; the complexity of interactions between SARS-CoV-2 and mitochondrial proteins is presented. The participation of mitogenome fragments in cell signaling and the occurrence of SARS-CoV-2 subgenomic RNA within membranous compartments, including mitochondria is widely discussed. As SARS-CoV-2 severely affects the quality system of mitochondria, the cellular background for aberrations in mitochondrial dynamics in COVID-19 is additionally characterized. Finally, perspectives on the mitigation of COVID-19 symptoms by affecting mitochondrial biogenesis by numerous compounds and therapeutic treatments are briefly outlined.

Association of dead space fraction to mortality in patients with COVID-19-related ARDS: A historical cohort observational study

OBJECTIVE

To assess the correlation of dead space fraction (VD/VT) measured through time capnography, corrected minute volume (CMV) and ventilation ratio (VR) with clinical outcomes in COVID-19 patients requiring invasive mechanical ventilation.

DESIGN

Observational study of a historical cohort.

SETTING

University hospital in Medellin, Colombia.

PARTICIPANTS

Patients aged 15 and above with a confirmed COVID-19 diagnosis admitted to the ICU and requiring mechanical ventilation.

INTERVENTIONS

Measurement of VD/VT, CMV, and VR in COVID-19 patients.

MAIN VARIABLES OF INTEREST

VD/VT, CMV, VR, demographic data, oxygenation indices and ventilatory parameters.

RESULTS

During the study period, 1047 COVID-19 patients on mechanical ventilation were analyzed, of whom 446 (42%) died. Deceased patients exhibited a higher prevalence of advanced age and obesity, elevated Charlson index, higher APACHE II and SOFA scores, as well as an increase in VD/VT ratio (0.27 in survivors and 0.31 in deceased) and minute ventilation volume on the first day of mechanical ventilation. The multivariate analysis revealed independent associations to in-hospital mortality, higher VD/VT (HR 1.24; 95%CI 1.003-1.525; p = 0.046), age (HR 1.024; 95%CI 1.014-1.034; p < 0.001), and SOFA score at onset (HR: 1.036; 95%CI: 1.001-1.07; p = 0.017).

CONCLUSIONS

VD/VT demonstrated an association with mortality in COVID-19 patients with ARDS on mechanical ventilation. These findings suggest that VD/VT measurement may serve as a severity marker for the disease.

Molecular Basis for Surface-Initiated Non-Thrombin-Generated Clot Formation Following Viral Infection

In this paper, we propose a model that connects two standard inflammatory responses to viral infection, namely, elevation of fibrinogen and the lipid drop shower, to the initiation of non-thrombin-generated clot formation. In order to understand the molecular basis for the formation of non-thrombin-generated clots following viral infection, human epithelial and Madin-Darby Canine Kidney (MDCK, epithelial) cells were infected with H1N1, OC43, and adenovirus, and conditioned media was collected, which was later used to treat human umbilical vein endothelial cells and human lung microvascular endothelial cells. After direct infection or after exposure to conditioned media from infected cells, tissue surfaces of both epithelial and endothelial cells, exposed to 8 mg/mL fibrinogen, were observed to initiate fibrillogenesis in the absence of thrombin. No fibers were observed after direct viral exposure of the endothelium or when the epithelium cells were exposed to SARS-CoV-2 isolated spike proteins. Heating the conditioned media to 60 °C had no effect on fibrillogenesis, indicating that the effect was not enzymatic but rather associated with relatively thermally stable inflammatory factors released soon after viral infection. Spontaneous fibrillogenesis had previously been reported and interpreted as being due to the release of the alpha C domains due to strong interactions of the interior of the fibrinogen molecule in contact with hydrophobic material surfaces rather than cleavage of the fibrinopeptides. Contact angle goniometry and immunohistochemistry were used to demonstrate that the lipids produced within the epithelium and released in the conditioned media, probably after the death of infected epithelial cells, formed a hydrophobic residue responsible for fibrillogenesis. Hence, the standard inflammatory response constitutes the ideal conditions for surface-initiated clot formation.

Phase-Resolved Functional Lung (PREFUL) MRI May Reveal Distinct Pulmonary Perfusion Defects in Postacute COVID-19 Syndrome: Sex, Hospitalization, and Dyspnea Heterogeneity

BACKGROUND

Pulmonary perfusion defects have been observed in patients with coronavirus disease 2019 (COVID-19). Currently, there is a need for further data on non-contrast-enhanced MRI in COVID patients. The early identification of heterogeneity in pulmonary perfusion defects among COVID-19 patients is beneficial for their timely clinical intervention and management.

PURPOSE

To investigate the utility of phase-resolved functional lung (PREFUL) MRI in detecting pulmonary perfusion disturbances in individuals with postacute COVID-19 syndrome (PACS).

STUDY TYPE

Prospective.

SUBJECTS

Forty-four participants (19 females, mean age 64.1 years) with PACS and 44 healthy subjects (19 females, mean age 59.5 years). Moreover, among the 44 patients, there were 19 inpatients and 25 outpatients; 19 were female and 25 were male; 18 with non-dyspnea and 26 with dyspnea.

FIELD STRENGTH/SEQUENCE

3-T, two-dimensional (2D) spoiled gradient-echo sequence.

ASSESSMENT

Ventilation and perfusion-weighted maps were extracted from five coronal slices using PREFUL analysis. Subsequently, perfusion defect percentage (QDP), ventilation defect percentage (VDP), and ventilation-perfusion match healthy (VQM) were calculated based on segmented lung parenchyma ventilation and perfusion-weighted maps. Additionally, clinical features, including demographic data (such as sex and age) and serum biomarkers (such as D-dimer levels), were evaluated.

STATISTICAL TESTS

Spearman correlation coefficients to explore relationships between clinical features and QDP, VDP, and VQM. Propensity score matching analysis to reduce the confounding bias between patients with PACS and healthy controls. The Mann-Whitney U tests and Chi-squared tests to detect differences between groups. Multivariable linear regression analyses to identify factors related to QDP, VDP, and VQM. A P-value <0.05 was considered statistically significant.

RESULTS

QDP significantly exceeded that of healthy controls in individuals with PACS (39.8% ± 15.0% vs. 11.0% ± 4.9%) and was significantly higher in inpatients than in outpatients (46.8% ± 17.0% vs. 34.5% ± 10.8%). Moreover, males exhibited pulmonary perfusion defects significantly more frequently than females (43.9% ± 16.8% vs. 34.4% ± 10.2%), and dyspneic participants displayed significantly higher perfusion defects than non-dyspneic patients (44.8% ± 15.8% vs. 32.6% ± 10.3%). QDP showed a significant positive relationship with age (β = 0.50) and D-dimer level (β = 0.72).

DATA CONCLUSION

PREFUL MRI may show pulmonary perfusion defects in patients with PACS. Furthermore, perfusion impairments may be more pronounced in males, inpatients, and dyspneic patients.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 2.

Targeting GPVI with glenzocimab in COVID-19 patients: Results from a randomized clinical trial

BACKGROUND

Glenzocimab is a novel antithrombotic agent which targets platelet glycoprotein VI (GPVI) and does not induce haemorrhage. SARS-CoV-2 triggers a prothrombotic state and lung injury whose mechanisms include coagulopathy, endothelial dysfunction, and inflammation with dysregulated platelets.

METHODS AND PATIENTS

GARDEN was a randomised double-blind, exploratory phase II study of glenzocimab in SARS-CoV-2 respiratory failure (NCT04659109). PCR+ adults in Brazil and France (7 centres) were randomized to standard-of-care (SOC) plus glenzocimab (1000 mg/dayx3 days) or placebo, followed for 40 days. Primary efficacy endpoint was clinical progression at Day 4. All analyses concerned the intention-to-treat population.

RESULTS

Between December 2020 and August 2021, 61 patients received at least one dose (30 glenzocimab vs 32 placebo) and 58 completed the study (29 vs 29). Clinical progression of COVID-19 ARDS was not statistically different between glenzocimab and placebo arms (43.3% and 29.0%, respectively; p = 0.245). Decrease in the NEWS-2 category at D4 was statistically significant (p = 0.0290) in the glenzocimab arm vs placebo. No Serious Adverse Event (SAE) was deemed related to study drug; bleeding related events were reported in 6 patients (7 events) and 4 patients (4 events) in glenzocimab and placebo arms, respectively.

CONCLUSIONS

Therapeutic GPVI inhibition assessment during COVID-19 was conducted in response to a Public Health emergency. Glenzocimab in coagulopathic patients under therapeutic heparin was neither associated with increased bleeding, nor SAE. Clinical impact of glenzocimab on COVID-19 ARDS was not demonstrated. A potential role for GPVI inhibition in other types of ARDS deserves further experimentation. Glenzocimab is currently studied in stroke (ACTISAVE: NCT05070260) and cardiovascular indications.

Endothelial dysfunction and persistent inflammation in severe post-COVID-19 patients: implications for gas exchange

BACKGROUND

Understanding the enduring respiratory consequences of severe COVID-19 is crucial for comprehensive patient care. This study aims to evaluate the impact of post-COVID conditions on respiratory sequelae of severe acute respiratory distress syndrome (ARDS).

METHODS

We examined 88 survivors of COVID-19-associated severe ARDS six months post-intensive care unit (ICU) discharge. Assessments included clinical and functional evaluation as well as plasma biomarkers of endothelial dysfunction, inflammation, and viral response. Additionally, an in vitro model using human umbilical vein endothelial cells (HUVECs) explored the direct impact of post-COVID plasma on endothelial function.

RESULTS

Post-COVID patients with impaired gas exchange demonstrated persistent endothelial inflammation marked by elevated ICAM-1, IL-8, CCL-2, and ET-1 plasma levels. Concurrently, systemic inflammation, evidenced by NLRP3 overexpression and elevated levels of IL-6, sCD40-L, and C-reactive protein, was associated with endothelial dysfunction biomarkers and increased in post-COVID patients with impaired gas exchange. T-cell activation, reflected in CD69 expression, and persistently elevated levels of interferon-β (IFN-β) further contributed to sustained inflammation. The in vitro model confirmed that patient plasma, with altered levels of sCD40-L and IFN-β proteins, has the capacity to alter endothelial function.

CONCLUSIONS

Six months post-ICU discharge, survivors of COVID-19-associated ARDS exhibited sustained elevation in endothelial dysfunction biomarkers, correlating with the severity of impaired gas exchange. NLRP3 inflammasome activity and persistent T-cell activation indicate on going inflammation contributing to persistent endothelial dysfunction, potentially intensified by sustained viral immune response.

SARS-CoV-2: pathogenesis, therapeutics, variants, and vaccines

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in December 2019 with staggering economic fallout and human suffering. The unique structure of SARS-CoV-2 and its underlying pathogenic mechanism were responsible for the global pandemic. In addition to the direct damage caused by the virus, SARS-CoV-2 triggers an abnormal immune response leading to a cytokine storm, culminating in acute respiratory distress syndrome and other fatal diseases that pose a significant challenge to clinicians. Therefore, potential treatments should focus not only on eliminating the virus but also on alleviating or controlling acute immune/inflammatory responses. Current management strategies for COVID-19 include preventative measures and supportive care, while the role of the host immune/inflammatory response in disease progression has largely been overlooked. Understanding the interaction between SARS-CoV-2 and its receptors, as well as the underlying pathogenesis, has proven to be helpful for disease prevention, early recognition of disease progression, vaccine development, and interventions aimed at reducing immunopathology have been shown to reduce adverse clinical outcomes and improve prognosis. Moreover, several key mutations in the SARS-CoV-2 genome sequence result in an enhanced binding affinity to the host cell receptor, or produce immune escape, leading to either increased virus transmissibility or virulence of variants that carry these mutations. This review characterizes the structural features of SARS-CoV-2, its variants, and their interaction with the immune system, emphasizing the role of dysfunctional immune responses and cytokine storm in disease progression. Additionally, potential therapeutic options are reviewed, providing critical insights into disease management, exploring effective approaches to deal with the public health crises caused by SARS-CoV-2.