High serum levels of neopterin in patients with Crimean-Congo hemorrhagic fever and its relation with mortality

The Effect of Fetuin-A and Other Laboratory Paremeters on Prognosis and Mortality in Crimean-Congo Hemorrhagic Fever

Background

Crimean-Congo Hemorrhagic Fever (CCHF) is a disease with high morbidity and mortality, which is an important health problem in the world. Therefore, we aimed to evaluate the effects of plasma fetuin-A (FA) level, which is a new parameter in terms of prognosis and mortality of CCHF.

Methods

A total of 87 patients were included who presented to the Emergency Department, Bağcılar Training and Research Hospital, İstanbul, Turkey with the diagnosis of CCHF from Feb 1, 2019 to Feb 1, 2020. The patients were divided into three groups as tick bite, contact history, and endemic area travel according to the transmission type, and two groups according to the presence of mortality or not. The laboratory data of the patients were compared within these groups. Relationship of hemogram, C-reactive protein (CRP), D-Dimer, sedimentation, lactate, and FA levels between groups were evaluated.

Results

The average age of the patients was 62.52±14.94 years and 27(31%) of them were women. Mortality rates were in 6(6.9%) patients from endemic areas (P=0.015). While the FA level of the mortality group was 171.6±30.0 mg/L, it was 230.3±25.0 mg/L in the survivors (P=0.001). There was a moderate and strong negative correlation of FA level with mortality, tick history, and hospitalization. In ROC curve analysis of mortality and FA levels, parameters were determined as sensitivity 97.4% and specificity 96.2%.

Conclusion

In addition to FA levels, as anticipated by our hypothesis, lactate, CRP, and sedimentation values can be used to predict prognosis and mortality in cases of CCHF.

Immunobiology of Crimean-Congo hemorrhagic fever

Human infection with Crimean-Congo hemorrhagic fever virus (CCHFV), a tick-borne pathogen in the family Nairoviridae, can result in a spectrum of outcomes, ranging from asymptomatic infection through mild clinical signs to severe or fatal disease. Studies of CCHFV immunobiology have investigated the relationship between innate and adaptive immune responses with disease severity, attempting to elucidate factors associated with differential outcomes. In this article, we begin by highlighting unanswered questions, then review current efforts to answer them. We discuss in detail current clinical studies and research in laboratory animals on CCHF, including immune targets of infection and adaptive and innate immune responses. We summarize data about the role of the immune response in natural infections of animals and humans and experimental studies in vitro and in vivo and from evaluating immune-based therapies and vaccines, and present recommendations for future research.

Neopterin: A Promising Candidate Biomarker for Severe COVID-19

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has rapidly spread across the world since its first emergence in China in late 2019. It is a major public health concern with no effective treatct 3ments. The immunopathology of SARS-CoV-2 is associated with an excessive inflammatory response. Macrophage activation syndrome (MAS) is also associated with the severity of the disease in SARS-CoV-2-infected patients. Neopterin is a macrophage activation marker produced by monocytes and macrophages upon activation by interferon-gamma (IFN-γ). Neopterin is a well-established marker in a variety of diseases, and recent evidence indicates that it could be helpful in early prediction of the severity of COVID-19 disease and serve as a prognostic marker. Here, we outline the role of macrophage activation syndrome in the pathogenesis of SARS-CoV-2 and suggest that neopterin could be used as a biomarker for progression of COVID-19.

Animal Models for Crimean-Congo Hemorrhagic Fever Human Disease

Crimean-Congo hemorrhagic fever virus (CCHFV) is an important tick-borne human pathogen endemic throughout Asia, Africa and Europe. CCHFV is also an emerging virus, with recent outbreaks in Western Europe. CCHFV can infect a large number of wild and domesticated mammalian species and some avian species, however the virus does not cause severe disease in these animals, but can produce viremia. In humans, CCHFV infection can lead to a severe, life-threating disease characterized by hemodynamic instability, hepatic injury and neurological disorders, with a worldwide lethality rate of ~20-30%. The pathogenic mechanisms of CCHF are poorly understood, largely due to the dearth of animal models. However, several important animal models have been recently described, including novel murine models and a non-human primate model. In this review, we examine the current knowledge of CCHF-mediated pathogenesis and describe how animal models are helping elucidate the molecular and cellular determinants of disease. This information should serve as a reference for those interested in CCHFV animal models and their utility for evaluation of medical countermeasures (MCMs) and in the study of pathogenesis.

Prognostic factors, pathophysiology and novel biomarkers in Crimean-Congo hemorrhagic fever

Crimean-Congo hemorrhagic fever (CCHF) is a geographically widespread tick-borne zoonosis. The clinical spectrum of the illness varies from mild infection to severe disease and death. In severe cases, hemorrhagic manifestations develop, with fatality rates of 4-20%, depending on the geographic region and quality of the health care. Although vast majority of the CCHF cases were reported from Turkey, mortality rate is lower than the other regions, which is 5% on average. Prediction of the clinical course of the disease enables appropriate management planning by the physician and prompt transportation, if needed, of the patient to a tertiary care hospital for an intensive therapy. Thus, predicting the outcome of the disease may avert potential mortality. There are numerous studies investigating the prognostic factors of CCHF in the literature. Majority of them were reported from Turkey and included investigations on clinical and biochemical parameters, severity scoring systems and some novel biomarkers. Somnolence, bleeding, thrombocytopenia, elevated liver enzymes and prolonged bleeding times are the most frequently reported prognostic factors to predict the clinical course of the disease earlier. High viral load seems to be the strongest predictor to make a clinical decision about the patient outcome. The severity scoring systems based on clinically important mortality-related parameters are especially useful for clinicians working in the field to predict the course of the disease and to decide which patient should be referred to a tertiary care hospital for intensive care. In the light of the pathophysiological characteristics of CCHF, some new biomarkers of prognosis including cytokines, soluble adhesion molecules, genetic polymorphisms and coagulopathy parameters were also investigated. However most of these tests are not available to clinicians and they were obtained mostly for research purposes. In spite of the various studies about prognostic factors, they have several inherent limitations, including large variability in the results and confusing data that are not useful for clinicians in routine practice. In this paper, the results of diverse studies of the prediction of the prognosis in CCHF based on epidemiological, clinical and laboratory findings of the disease were summarized and suggestions for future studies are provided.

Crimean-Congo hemorrhagic fever (CCHF) in Southern Kordofan

Crimean-Congo hemorrhagic fever (CCHF) is a disease that poses a great threat to public health owing to its high mortality rate (30-70%), mode of transmission and geographic distribution. Here, we report on a nine years-old Sudanese boy from Southern Kordofan State who presented with Jaundice, high-grade fever, severe headache, abdominal pain and a history of hematemesis. The diagnosis of CCHF was confirmed based on clinical and serological findings.

Crimean-Congo hemorrhagic fever: history, epidemiology, pathogenesis, clinical syndrome and genetic diversity

Crimean-Congo hemorrhagic fever (CCHF) is the most important tick-borne viral disease of humans, causing sporadic cases or outbreaks of severe illness across a huge geographic area, from western China to the Middle East and southeastern Europe and throughout most of Africa. CCHFV is maintained in vertical and horizontal transmission cycles involving ixodid ticks and a variety of wild and domestic vertebrates, which do not show signs of illness. The virus circulates in a number of tick genera, but Hyalomma ticks are the principal source of human infection, probably because both immature and adult forms actively seek hosts for the blood meals required at each stage of maturation. CCHF occurs most frequently among agricultural workers following the bite of an infected tick, and to a lesser extent among slaughterhouse workers exposed to the blood and tissues of infected livestock and medical personnel through contact with the body fluids of infected patients. CCHFV is the most genetically diverse of the arboviruses, with nucleotide sequence differences among isolates ranging from 20% for the viral S segment to 31% for the M segment. Viruses with diverse sequences can be found within the same geographic area, while closely related viruses have been isolated in far distant regions, suggesting that widespread dispersion of CCHFV has occurred at times in the past, possibly by ticks carried on migratory birds or through the international livestock trade. Reassortment among genome segments during co-infection of ticks or vertebrates appears to have played an important role in generating diversity, and represents a potential future source of novel viruses. In this article, we first review current knowledge of CCHFV, summarizing its molecular biology, maintenance and transmission, epidemiology and geographic range. We also include an extensive discussion of CCHFV genetic diversity, including maps of the range of the virus with superimposed phylogenetic trees. We then review the features of CCHF, including the clinical syndrome, diagnosis, treatment, pathogenesis, vaccine development and laboratory animal models of CCHF. The paper ends with a discussion of the possible future geographic range of the virus. For the benefit of researchers, we include a Supplementary Table listing all published reports of CCHF cases and outbreaks in the English-language literature, plus some principal articles in other languages, with total case numbers, case fatality rates and all CCHFV strains on GenBank.

Coagulopathy parameters in patients with Crimean-Congo hemorrhagic fever and its relation with mortality

BACKGROUND

Crimean-Congo hemorrhagic fever (CCHF) is an acute illness affecting multiple organ systems and characterized by ecchymosis, visceral bleeding, and hepatic dysfunction. In this study, we aimed to investigate the profile of coagulopathy markers (platelet count, activated partial tromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), fibrinogen, protein C, protein S, antithrombin III, activated protein C resistance (APCR), and D-dimer) and their clinical significance in 83 CCHF-infected patients.

SUBJECTS AND METHODS

We studied 83 CCHF patients who were admitted to Ankara Numune Education and Research Hospital during the spring and summer of2007. We compared the coagulopathy markers of fatal CCHF patients (n=9) with nonfatal cases (n=74).

RESULTS

Platelet count, PT, aPTT, INR, and fibrinogen were prognostic factors associated with mortality for CCHF. Especially, platelet count<20 x 10(9) cells/l and aPTT>60 sec were important. Protein C, protein S, APCR, and antithrombin III levels were not associated with mortality.

CONCLUSION

Laboratory tests including classical parameters (platelet count, PT, aPTT, INR, and fibrinogen) of coagulopathy seem to be enough for the followup of CCHF. Protein S, protein C, APCR, and D-dimer levels were not associated with mortality.

Evidence of vascular endothelial damage in Crimean-Congo hemorrhagic fever

BACKGROUND

Endothelial infection has an important role in the pathogenesis of Crimean-Congo hemorrhagic fever (CCHF). In this study, we investigated the causes of vascular endothelial damage in patients with CCHF.

METHODS

This prospective case-controlled study was carried out at Ankara Numune Education and Research Hospital between April and September 2007. Seventy-five patients with a laboratory-confirmed diagnosis of CCHF and 88 healthy controls were enrolled in the study. Serum levels of soluble cell adhesion molecules (sICAM-1, sVCAM-1, sE-selectin, sP-selectin, sL-selectin), vascular endothelial growth factor (VEGF), and macrophage migration inhibitory factor (MIF) were investigated in these patients by quantitative sandwich ELISA technique.

RESULTS

In the patient group, serum levels of sVCAM-1, sL-selectin and MIF were significantly higher than in the control group; serum levels of sICAM-1, sP-selectin, sE-selectin, and VEGF were significantly lower than in the control group. Serum levels of sVCAM-1 and sICAM-1 were significantly higher in severe cases than in non-severe cases, whereas the serum level of VEGF was significantly lower. sVCAM-1 was significantly higher in non-survivors than in survivors, while serum VEGF was significantly lower in non-survivors. The optimum cut-offs of sVCAM-1 and VEGF for the prediction of mortality were 205 ng/ml and 125 ng/ml, respectively. At these cut-offs, sVCAM-1 and VEGF had a sensitivity of 100% and specificity of 42.5% and 54.5%, respectively, in identifying CCHF patients who would die from the disease. The positive predictive values were 19% and 23%, respectively; negative predictive values were 100% for both.

CONCLUSION

Endothelial activation can affect the course of CCHF, and vascular endothelial damage is probably indirect. Further studies are needed for general conclusions to be drawn.

Molecular biology and pathogenesis of Crimean–Congo hemorrhagic fever virus

Over the last several years, we have experienced an increase of large outbreaks of Crimean–Congo hemorrhagic fever virus in European countries and neighboring areas. This disease poses a great threat to public health owing to its high mortality rate, modes of transmission and geographical distribution. Clinical symptoms of infection commonly include hemorrhage, myalgia and fever. The complexity of the technical and facility requirements, in combination with the sporadic outbreaks and consequent lack of clinical specimens has resulted in very limited research of Crimean–Congo hemorrhagic fever virus. To date, there is no vaccine available and a selective antiviral drug for the treatment of the disease is not expected in the near future. Here, we review the most recent findings on the Crimean–Congo hemorrhagic fever virus molecular biology and pathogenesis, including aspects of virus–host cell interactions.

Interacting roles of immune mechanisms and viral load in the pathogenesis of crimean-congo hemorrhagic fever

Until now, the pathogenesis of Crimean-Congo hemorrhagic fever (CCHF) has not been well described. However, it has been hypothesized that it could be a result of the direct injury of virus-infected tissues in combination with the indirect effects of host immune responses, including cytokines. To shed more light on the role of viral load and cytokines, differential influences of CCHF virus (CCHFV) RNA load, antibody response, and cytokine production on severity and outcome of the disease were studied in sera of 46 patients with confirmed acute CCHF from Kosovo. In this study, viral load proved to be strongly related to the severity and outcome of the disease, with higher viral loads detected in patients with fatal outcomes than in surviving patients. Also, patients with fatal outcome had on average a weaker antibody response, if one was present at all. High levels of interleukin-10 (IL-10), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) were associated with poor outcome, since detected concentrations were highest in patients with fatal outcome and lowest in patients with moderate disease course. Additionally, a positive linear dependence between viral load and these cytokines was observed. Interestingly, reduced levels of IL-12 were detected in all CCHF patients. Our study favors the hypothesis that CCHF could be a result of a delayed and downregulated immune response caused by IL-10, which leads to an increased replication and spread of CCHFV throughout the body. This consequently triggers increased production of IFN-gamma and TNF-alpha, cytokines mediating vascular dysfunction, disseminated intravascular coagulation, organ failure, and shock.

High-dose methylprednisolone in children with Crimean-Congo haemorrhagic fever

Treatment options for Crimean-Congo haemorrhagic fever (CCHF) are limited and based on general supportive managements. Thrombocytopenia is the major risk factor of CCHF. We report our experience with high-dose methylprednisolone (HDMP). This study included five patients with CCHF. Patients were given HDMP if there were findings compatible with virus-associated haemophagocytic syndrome and the effects of HDMP were evaluated. Following this, HDMP fever subsided and platelet counts increased within 24 hours. Leukocyte counts began to increase and visceral bleedings were improved. HDMP treatment was discontinued within approximately five days. After HDMP, only one patient required blood products. HDMP is effective in CCHF, especially on fever and platelet counts. Dependency on blood products was decreased. Further controlled randomized studies with large series are needed in order to analyse the timing and duration of HDMP treatment and its effect on outcome.

Differential activation profiles of Crimean-Congo hemorrhagic fever virus- and Dugbe virus-infected antigen-presenting cells

Crimean-Congo hemorrhagic fever virus (CCHFV) is a highly pathogenic, tick-borne member of the family Bunyaviridae and the genus Nairovirus. To better elucidate the pathogenesis of CCHFV, we analysed the host innate immune response induced in antigen-presenting cells (APCs) infected in vitro by CCHFV. Monocyte-derived dendritic cells (DCs) and macrophages (MPs) were both shown to be permissive for CCHFV and to replicate the virus, as monitored by genomic and antigenomic strand quantification. Virus replication was, however, controlled, corroborating an efficient alpha interferon-induced response. The upregulation of CD-83 and CD-86 indicated that CCHFV induced a partial maturation of DCs, which were also shown to activate the secretion of interleukin (IL)-6 and IL-8, but no tumour necrosis factor alpha (TNF-alpha). On the other hand, in MPs, CCHFV infection elicited a high IL-6 and TNF-alpha response and a moderate chemokine response. Nevertheless, when we compared these APC responses with those seen after infection with Dugbe virus (DUGV), a mildly pathogenic virus genetically close to CCHFV, we found that, in spite of some similarities, DUGV induced a higher cytokine/chemokine response in MPs. These results suggest that CCHFV is able to inhibit the activation of inflammatory mediators selectively in infection in vitro and that these differences could be relevant in pathogenesis.

Analysis of lymphocyte subgroups in Crimean-Congo hemorrhagic fever

OBJECTIVES

This study examined the association between lymphocyte subgroups and mortality in patients with Crimean-Congo hemorrhagic fever (CCHF) in Turkey.

METHODS

During the spring and summer of 2007, peripheral blood was collected from hospitalized patients with suspected CCHF. Lymphocyte subgroups were characterized by fluorescence-activated cell sorting. CCHF cases were confirmed by detecting viral RNA by PCR and/or IgM antibodies by ELISA. Lymphocyte subgroups were compared between fatal and non-fatal cases. The correlation between lymphocyte subgroups and viral loads was also investigated.

RESULTS

Seventy-seven confirmed cases of CCHF were included in this study (five cases were fatal (6.5 %)). No differences in lymphocyte subgroups were found between fatal and non-fatal cases, except for significantly higher CD3+CD8+ T cells in the fatal cases (p=0.017). A positive correlation between viral load and CD3+CD8+ T cells was also detected (p=0.044). There was no correlation between other lymphocyte subgroups and viral load.

CONCLUSIONS

Higher levels of CD3+CD8+ T lymphocytes were detected in fatal compared to non-fatal CCHF cases. Despite this cytotoxic immune activation, a fatal outcome could not be prevented. We hypothesize that high viral load and other factors may influence this outcome, although more studies are required to explain the pathogenesis of CCHF.

Interferon and cytokine responses to Crimean Congo hemorrhagic fever virus; an emerging and neglected viral zonoosis

Crimean Congo hemorrhagic fever virus (CCHFV) causes an acute disease with the potential of a fatal outcome. The virus is prevalent in about 30 countries. Clinical symptoms of infection commonly include fever, myalgia, and hemorrhages. Levels of liver enzymes are raised, and bleeding markers are often increased. A role of inflammatory cytokines in the pathogenesis has been suggested, and CCHFV employs a range of passive and active mechanisms to avoid induction of the antiviral type I interferons. Here, we review the most recent findings on the molecular pathogenesis and the interaction of CCHFV with the type I interferon and cytokine responses and discuss implications for pathogenesis.