Evaluation of the associations between endothelial dysfunction, inflammation and coagulation in Crimean-Congo hemorrhagic fever patients

Vascular dysfunction in hemorrhagic viral fevers: opportunities for organotypic modeling

The hemorrhagic fever viruses (HFVs) cause severe or fatal infections in humans. Named after their common symptom hemorrhage, these viruses induce significant vascular dysfunction by affecting endothelial cells, altering immunity, and disrupting the clotting system. Despite advances in treatments, such as cytokine blocking therapies, disease modifying treatment for this class of pathogen remains elusive. Improved understanding of the pathogenesis of these infections could provide new avenues to treatment. While animal models and traditional 2D cell cultures have contributed insight into the mechanisms by which these pathogens affect the vasculature, these models fall short in replicatingin vivohuman vascular dynamics. The emergence of microphysiological systems (MPSs) offers promising avenues for modeling these complex interactions. These MPS or 'organ-on-chip' models present opportunities to better mimic human vascular responses and thus aid in treatment development. In this review, we explore the impact of HFV on the vasculature by causing endothelial dysfunction, blood clotting irregularities, and immune dysregulation. We highlight how existing MPS have elucidated features of HFV pathogenesis as well as discuss existing knowledge gaps and the challenges in modeling these interactions using MPS. Understanding the intricate mechanisms of vascular dysfunction caused by HFV is crucial in developing therapies not only for these infections, but also for other vasculotropic conditions like sepsis.

Exploring free amino acid profiles in Crimean-Congo hemorrhagic fever patients: Implications for disease progression

This study investigated the intricate interplay between Crimean-Congo hemorrhagic fever virus infection and alterations in amino acid metabolism. The primary aim is to elucidate the impact of Crimean-Congo hemorrhagic fever (CCHF) on specific amino acid concentrations and identify potential metabolic markers associated with viral infection. One hundred ninety individuals participated in this study, comprising 115 CCHF patients, 30 CCHF negative patients, and 45 healthy controls. Liquid chromatography-tandem mass spectrometry techniques were employed to quantify amino acid concentrations. The amino acid metabolic profiles in CCHF patients exhibit substantial distinctions from those in the control group. Patients highlight distinct metabolic reprogramming, notably characterized by arginine, histidine, taurine, glutamic acid, and glutamine metabolism shifts. These changes have been associated with the underlying molecular mechanisms of the disease. Exploring novel therapeutic and diagnostic strategies addressing specific amino acids may offer potential means to mitigate the severity of the disease.

Predictive epidemiological, clinical and laboratory parameters in the diagnosis of Crimean-Congo hemorrhagic fever

Background: The aim of this study is to determine predictive parameters that can be used in the differential diagnosis of Crimean-Congo Hemorrhagic Fever (CCHF) and other diseases with similar clinical and laboratory findings. Materials & methods: In this study, epidemiological, clinical and laboratory parameters of 107 CCHF-positive and 71 CCHF-negative patients were compared. Results: Alanine amino transferase, aspartate aminotransferase, creatine kinase, lactate dehydrogenase, red blood cell, hemoglobin and hematocrit were significantly higher in CCHF-positive patients, whereas total and direct bilirubin, alkaline phosphatase, prothrombin time, international normalization ratio, white blood cell, C-reactive protein and procalcitonin were higher in CCHF-negative patients. In binary logistic regression analysis, an increase in activated partial thromboplastin time level was identified as an independent predictor of having CCHF, while alanine amino transferase, white blood cell and C-reactive protein elevations were identified as independent predictors of not having CCHF. Conclusion: In endemic areas where PCR and serological tests are delayed, knowing the predictive parameters may be of vital importance in the early diagnosis of CCHF.

Crimean-Congo Hemorrhagic Fever Case Series: a Chronology of Biochemical and Hematological Parameters

Introduction

Crimean-Congo hemorrhagic fever (CCHF) is a widespread tick-borne zoonotic disease. Sporadic outbreaks of CCHF occur in endemic regions, including Pakistan. The clinical spectrum of the illness varies from asymptomatic seroconversion to severe disease which may end in death. The treatment is supportive, including blood and blood products. There is multi-organ involvement in CCHF including acute hepatitis, thrombocytopenia, coagulopathy, acute kidney injury (AKI), and encephalopathy. Hematological and biochemical parameters may identify patients at substantial risk of worse outcomes. Early detection of the disease and forecasting the clinical course may be helpful. This case series aims to evaluate the trends of hematological and biochemical parameters among the survivors and non-survivors of CCHF.

Methods

All consecutive patients aged 16 years and above admitted to the isolation unit of Hayatabad Medical Complex, Peshawar, Pakistan between 1^st July and 30^th July 2022 with the diagnosis of CCHF were included in this case series. The diagnosis of CCHF was made by detecting viral ribonucleic acid by a polymerase chain reaction. For all patients, age, gender, address, occupation, clinical presentation, history of contact with animals, and travel history were recorded. All the vitals were taken regularly. The hematological (complete blood count) and biochemical parameters (serum creatinine, alanine aminotransferase (ALT), and C-reactive protein (CRP)) were documented daily. The blood group was determined for all the cases.

Results

Out of 17 cases, the majority (16 cases, 94.1%) were male and butchers (eight cases, 47.1%) by profession. All cases had significant contact with animals. Four patients (23.5%) died. Three out of the four non-survivors (75%) had ALT < 5 times the upper limit of normal with a static pattern of liver enzymes without much decline in ALT till death. One non-survivor (25%) had marked elevation of ALT at presentation, which had a declining trend till death. Seven out of 13 survivors (53.8%) had moderate to marked elevation in the level of ALT at presentation. The ALT showed a downward trend during the course of illness in all these patients. The remaining survivors (six out of 13, 46.2%) had a mild elevation of ALT and 50% of them showed improvement in the ALT level during hospitalization. All patients had thrombocytopenia at presentation. None of the non-survivors showed a persistent increase in the platelet count, and three cases remained severely thrombocytopenic at the time of death. However, the trend in platelet count among all the survivors was increasing. The CRP level in the majority (three out of four cases, 75%) of the non-survivors remained elevated till death, while all survivors showed a progressive decline in CRP level. A majority (11 out of 17 cases) had blood group B. Half of the non-survivors (two out of four cases) and the majority of the survivors (nine out of 13 cases) had blood group B. AKI was found in all non-survivors, while all the survivors had normal renal function throughout the course.

Conclusion

A persistently raised ALT and CRP level, a persistently low or decreasing platelet count, and AKI were associated with mortality. Blood group B was the commonest blood group among patients of CCHF, which is not reflective of the blood group distribution of the general population from which this case series has been reported.

Crimean-Congo haemorrhagic fever-induced liver injury: A systematic review and meta-analysis

BACKGROUND

Crimean-Congo haemorrhagic fever (CCHF) is a fatal acute tick-borne viral infection and substantial emerging global public health threat. This illness has a high case fatality rate of up to 40%. The liver is one of the important target organs of the CCHF virus.

OBJECTIVE

The aim of this meta-analysis to evaluate the correlation between CCHF and liver injury and draw more generalised inferences about the abnormal serum markers of liver injury such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) in CCHF patients.

METHODS

A literature search was accomplished for published eligible articles with MEDLINE/PubMed and Embase databases. All eligible observational studies and case series were included from around the world. The inclusion criteria were articles describing liver injury biomarkers amongst patients diagnosed with CCHF.

RESULTS

Data from 18 studies, consisting of 1238 patients with CCHF were included in this meta-analysis. Overall pooled incidence of at least one raised liver injury biomarker was 77.95% (95% CI, I²  =  88.50%, P < .0001). Similarly, pooled incidence of elevated AST and ALT was 85.92% (95% CI, I²  = 85.27%, P < .0001) and 64.30% (95% CI, I²  =  88.32%, P < .0001), respectively. Both Egger and Begg-Mazumdar's tests detected no apparent publication bias in all three meta-analyses (P > .05).

CONCLUSION

Our study shows that CCHF has a very detrimental effect on liver function. Abnormal liver function may lead to poor prognosis and increased morbidity and mortality in CCHF patients. Hence, Physicians must recognise and continuously monitor these biomarkers, since these markers may aid in early stratification of prognosis and the prevention of severe outcomes in infection with such a high case fatality rate.

Dengue Virus Induces the Expression and Release of Endocan from Endothelial Cells by an NS1-TLR4-Dependent Mechanism

A common hallmark of dengue infections is the dysfunction of the vascular endothelium induced by different biological mechanisms. In this paper, we studied the role of recombinant NS1 proteins representing the four dengue serotypes, and their role in promoting the expression and release of endocan, which is a highly specific biomarker of endothelial cell activation. We evaluated mRNA expression and the levels of endocan protein in vitro following the stimulation of HUVEC and HMEC-1 cell lines with recombinant NS1 proteins. NS1 proteins increase endocan mRNA expression 48 h post-activation in both endothelial cell lines. Endocan mRNA expression levels were higher in HUVEC and HMEC-1 cells stimulated with NS1 proteins than in non-stimulated cells (p < 0.05). A two-fold to three-fold increase in endocan protein release was observed after the stimulation of HUVECs or HMEC-1 cells with NS1 proteins compared with that in non-stimulated cells (p < 0.05). The blockade of Toll-like receptor 4 (TLR-4) signaling on HMEC-1 cells with an antagonistic antibody prevented NS1-dependent endocan production. Dengue-infected patients showed elevated serum endocan levels (≥30 ng/mL) during early dengue infection. High endocan serum levels were associated with laboratory abnormalities, such as lymphopenia and thrombocytopenia, and are associated with the presence of NS1 in the serum.

Thrombocytopenia in Virus Infections

Thrombocytopenia, which signifies a low platelet count usually below 150 × 10⁹/L, is a common finding following or during many viral infections. In clinical medicine, mild thrombocytopenia, combined with lymphopenia in a patient with signs and symptoms of an infectious disease, raises the suspicion of a viral infection. This phenomenon is classically attributed to platelet consumption due to inflammation-induced coagulation, sequestration from the circulation by phagocytosis and hypersplenism, and impaired platelet production due to defective megakaryopoiesis or cytokine-induced myelosuppression. All these mechanisms, while plausible and supported by substantial evidence, regard platelets as passive bystanders during viral infection. However, platelets are increasingly recognized as active players in the (antiviral) immune response and have been shown to interact with cells of the innate and adaptive immune system as well as directly with viruses. These findings can be of interest both for understanding the pathogenesis of viral infectious diseases and predicting outcome. In this review, we will summarize and discuss the literature currently available on various mechanisms within the relationship between thrombocytopenia and virus infections.

Identification of a new orthonairovirus associated with human febrile illness in China

The genus Orthonairovirus, which is part of the family Nairoviridae, includes the important tick-transmitted pathogens Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, as well as many other poorly characterized viruses found in ticks, birds and mammals^1,2. In this study, we identified a new orthonairovirus, Songling virus (SGLV), from patients who reported being bitten by ticks in Heilongjiang Province in northeastern China. SGLV shared similar genomic and morphological features with orthonairoviruses and phylogenetically formed a unique clade in Tamdy orthonairovirus of the Nairoviridae family. The isolated SGLV induced cytopathic effects in human hepatoma cells in vitro. SGLV infection was confirmed in 42 hospitalized patients analyzed between 2017 and 2018, with the main clinical manifestations being headache, fever, depression, fatigue and dizziness. More than two-thirds (69%) of patients generated virus-specific antibody responses in the acute phase. Taken together, these results suggest that this newly discovered orthonairovirus is associated with human febrile illness in China.

Dual RNA-Seq characterization of host and pathogen gene expression in liver cells infected with Crimean-Congo Hemorrhagic Fever Virus

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne virus that can cause a hemorrhagic fever in humans, with a case fatality rate of up to 40%. Cases of CCHFV have been reported in Africa, Asia, and southern Europe; and recently, due to the expanding range of its vector, autochthonous cases have been reported in Spain. Although it was discovered over 70 years ago, our understanding of the pathogenesis of this virus remains limited. We used RNA-Seq in two human liver cell lines (HepG2 and Huh7) infected with CCHFV (strain IbAr10200), to examine kinetic changes in host expression and viral replication simultaneously at 1 and 3 days post infection. Through this, numerous host pathways were identified that were modulated by the virus including: antiviral response and endothelial cell leakage. Notably, the genes encoding DDX60, a cytosolic component of the RIG-I signalling pathway and OAS2 were both shown to be dysregulated. Interestingly, PTPRR was induced in Huh7 cells but not HepG2 cells. This has been associated with the TLR9 signalling cascade, and polymorphisms in TLR9 have been associated with poor outcomes in patients. Additionally, we performed whole-genome sequencing on CCHFV to assess viral diversity over time, and its relationship to the host response. As a result, we have demonstrated that through next-generation mRNA deep-sequencing it is possible to not only examine mRNA gene expression, but also to examine viral quasispecies and typing of the infecting strain. This demonstrates a proof-of-principle that CCHFV specimens can be analyzed to identify both the virus and host biomarkers that may have implications for prognosis.

Chronic stress: a critical risk factor for atherosclerosis

Chronic stress refers to the non-specific systemic reaction that occurs when the body is stimulated by various internal and external negative factors over a long time. The physiological response to chronic stress exposure has long been recognized as a potent modulator in the occurrence of atherosclerosis. Furthermore, research has confirmed the correlation between atherosclerosis and cardiovascular events. Chronic stress is pervasive during negative life events and may lead to the formation of plaque. Several epidemiological studies have shown that chronic stress is an independent risk factor for the development of vascular disease and for increased morbidity and mortality in patients with pre-existing coronary artery disease. One possible mechanism for this process is that chronic stress causes endothelial injury, directly activating macrophages, promoting foam cell formation and generating the formation of atherosclerotic plaque. This mechanism involves numerous variables, including inflammation, signal pathways, lipid metabolism and endothelial function. The mechanism of chronic stress in atherosclerosis should be further investigated to provide a theoretical basis for efforts to eliminate the effect of chronic stress on the cardiocerebral vascular system.

Common Injuries and Repair Mechanisms in the Endothelial Lining

Objective:

Endothelial cells (ECs) are important metabolic and endocrinal organs which play a significant role in regulating vascular function. Vascular ECs, located between the blood and vascular tissues, can not only complete the metabolism of blood and interstitial fluid but also synthesize and secrete a variety of biologically active substances to maintain vascular tension and keep a normal flow of blood and long-term patency. Therefore, this article presents a systematic review of common injuries and healing mechanisms for the vascular endothelium.

Data Sources:

An extensive search in the PubMed database was undertaken, focusing on research published after 2003 with keywords including endothelium, vascular, wounds and injuries, and wound healing.

Study Selection:

Several types of articles, including original studies and literature reviews, were identified and reviewed to summarize common injury and repair processes of the endothelial lining.

Results:

Endothelial injury is closely related to the development of multiple cardiovascular and cerebrovascular diseases. However, the mechanism of vascular endothelial injury is not fully understood. Numerous studies have shown that the mechanisms of EC injury mainly involve inflammatory reactions, physical stimulation, chemical poisons, concurrency of related diseases, and molecular changes. Endothelial progenitor cells play an important role during the process of endothelial repair after such injuries. What's more, a variety of restorative cells, changes in cytokines and molecules, chemical drugs, certain RNAs, regulation of blood pressure, and physical fitness training protect the endothelial lining by reducing the inducing factors, inhibiting inflammation and oxidative stress reactions, and delaying endothelial caducity.

Conclusions:

ECs are always in the process of being damaged. Several therapeutic targets and drugs were seeked to protect the endothelium and promote repair.