Thrombocytopenia in Dengue: Interrelationship between Virus and the Imbalance between Coagulation and Fibrinolysis and Inflammatory Mediators

Reduced protein-coding transcript diversity in severe dengue emphasises the role of alternative splicing

Dengue fever, a neglected tropical arboviral disease, has emerged as a global health concern in the past decade. Necessitating a nuanced comprehension of the intricate dynamics of host-virus interactions influencing disease severity, we analysed transcriptomic patterns using bulk RNA-seq from 112 age- and gender-matched NS1 antigen-confirmed hospital-admitted dengue patients with varying severity. Severe cases exhibited reduced platelet count, increased lymphocytosis, and neutropenia, indicating a dysregulated immune response. Using bulk RNA-seq, our analysis revealed a minimal overlap between the differentially expressed gene and transcript isoform, with a distinct expression pattern across the disease severity. Severe patients showed enrichment in retained intron and nonsense-mediated decay transcript biotypes, suggesting altered splicing efficiency. Furthermore, an up-regulated programmed cell death, a haemolytic response, and an impaired interferon and antiviral response at the transcript level were observed. We also identified the potential involvement of the RBM39 gene among others in the innate immune response during dengue viral pathogenesis, warranting further investigation. These findings provide valuable insights into potential therapeutic targets, underscoring the importance of exploring transcriptomic landscapes between different disease sub-phenotypes in infectious diseases.

Severe COVID-19 multisystem inflammatory syndrome versus severe dengue in children from Indonesia: a cross-sectional study

INTRODUCTION

Severe multisystem inflammatory syndrome in children (MIS-C) and severe dengue are challenging to identify during the COVID-19 pandemic in dengue-endemic areas. Fever, multiorgan involvement, and shock characterize both severe MIS-C and severe dengue. Distinguishing between the two diseases is beneficial in initiating proper management.

METHODS

Medical records of children < 18 years old who were hospitalized at Hasan Sadikin General Hospital's PICU between December 2020 and July 2022 with severe MIS-C or severe dengue were recorded. Differences were assessed using comparative and descriptive analyses.

RESULTS

Seventeen severe dengue patients and 4 severe MIS-C were included. The average age of severe MIS-C was 11.5 years (SD ± 2.9, 95% CI), and that of severe dengue patients was 6.2 years (SD ± 4.4, 95% CI) (p value = 0.034, 95%). Fever and abdominal pain were the most common symptoms in both groups (p = 0.471, 95% CI). Rash (p = 0.049) and nonpurulent conjunctivitis (p = 0.035) were two symptoms with significant differences. The highest platelet count (p-value = 0.006, 95% CI), AST (p-value = 0.026, 95% CI), and D-dimer level (p-value = 0.025, 95% CI) were significantly different between the two cohorts. Cardiac abnormalities were found in all (100%) severe MIS-C patients, but only one (5.9%) in severe dengue patients.

CONCLUSION

Age, rash, nonpurulent conjunctivitis, platelet count, AST and D-dimer level may distinguish severe MIS-C from severe dengue fever.

In-silico screening and identification of potential drug-like compounds for dengue-associated thrombocytopenia from Carica papaya leaf extracts

Dengue virus is a mosquito-borne pathogen that causes a variety of illnesses ranging from mild fever to severe and fatal dengue haemorrhagic fever or dengue shock syndrome. One of the major clinical manifestations of severe dengue infection is thrombocytopenia. The dengue non-structural protein 1 (NS1) is the primary protein that stimulates immune cells via toll-like receptor 4 (TLR4), induces platelets, and promotes aggregation, which could result in thrombocytopenia. The leaf extracts of Carica papaya seem to have therapeutic benefits in managing thrombocytopenia associated with dengue. The present study focuses on understanding the underlying mechanism of the use of papaya leaf extracts in treating thrombocytopenia. We have identified 124 phytocompounds that are present in the papaya leaf extract. The pharmacokinetics, molecular docking, binding free energy calculations, and molecular dynamic simulations were performed to investigate the drug-like properties, binding affinities, and interaction of phytocompounds with NS1 protein as well as the interactions of NS1 with TLR4. Three phytocompounds were found to bind with the ASN130, a crucial amino acid residue in the active site of the NS1 protein. Thus, we conclude that Rutin, Myricetin 3-rhamnoside, or Kaempferol 3-(2''-rhamnosylrutinoside) may serve as promising molecules by ameliorating thrombocytopenia in dengue-infected patients by interfering the interaction of NS1 with TLR4. These molecules can serve as drugs in the management of dengue-associated thrombocytopenia after verifying their effectiveness and assessing the drug potency, through additional in-vitro assays.Communicated by Ramaswamy H. Sarma.

Atypical Hemorrhages Secondary to Dengue Infection and Cardiopulmonary Resuscitation: Subcutaneous Thrombin Injection as a Salvage Technique for Refractory Femoral Artery Hemorrhage

Dengue fever is a viral infection transmitted by the bites of female Aedes mosquitoes. Repeat infections with different viral serotypes are possible, with an increased risk of severe dengue. Dengue hemorrhagic fever is one of the most severe presentations of dengue, with thrombocytopenia, increased capillary permeability with resultant rash, and an increased risk of spontaneous bleeding. The management of severe dengue is done through supportive care and symptomatic management only, as there are no specific treatments available. We describe a case of severe dengue hemorrhagic fever presenting with atypical hemorrhage from both the psoas muscle and the femoral arterial puncture sites. These were successfully treated with large calibrated Gelfoam particle embolization for the psoas hemorrhage and regional thrombin injection for the femoral arterial puncture sites.

Role of auto-antibodies in the mechanisms of dengue pathogenesis and its progression: a comprehensive review

A complex interaction among virulence factors, host-genes and host immune system is considered to be responsible for dengue virus (DENV) infection and disease progression. Generation of auto-antibodies during DENV infection is a major phenomenon that plays a role in the pathophysiology of dengue hemorrhagic fever and dengue shock syndrome. Hemostasis, thrombocytopenia, hepatic endothelial dysfunction, and autoimmune blistering skin disease (pemphigus) are different clinical manifestations of dengue pathogenesis; produced due to the molecular mimicry of DENV proteins with self-antigens like coagulation factors, platelets and endothelial cell proteins. This review elaborately describes the current advancements in auto-antibody-mediated immunopathogenesis which inhibits coagulation cascade and promotes hyperfibrinolysis. Auto-antibodies like anti-endothelial cell antibodies-mediated hepatic inflammation during severe DENV infection have also been discussed. Overall, this comprehensive review provides insight to target auto-antibodies that may act as potential biomarkers for disease severity, and a ground for the development of therapeutic strategy against DENV.

Potential Pathways and Pathophysiological Implications of Viral Infection-Driven Activation of Kallikrein-Kinin System (KKS)

Microcirculatory and coagulation disturbances commonly occur as pathological manifestations of systemic viral infections. Research exploring the role of the kallikrein-kinin system (KKS) in flavivirus infections has recently linked microvascular dysfunctions to bradykinin (BK)-induced signaling of B2R, a G protein-coupled receptor (GPCR) constitutively expressed by endothelial cells. The relevance of KKS activation as an innate response to viral infections has gained increasing attention, particularly after the reports regarding thrombogenic events during COVID-19. BK receptor (B2R and B1R) signal transduction results in vascular permeability, edema formation, angiogenesis, and pain. Recent findings unveiling the role of KKS in viral pathogenesis include evidence of increased activation of KKS with elevated levels of BK and its metabolites in both intravascular and tissue milieu, as well as reports demonstrating that virus replication stimulates BKR expression. In this review, we will discuss the mechanisms triggered by virus replication and by virus-induced inflammatory responses that may stimulate KKS. We also explore how KKS activation and BK signaling may impact virus pathogenesis and further discuss the potential therapeutic application of BKR antagonists in the treatment of hemorrhagic and respiratory diseases.

APRI as a predictor of severe dengue fever

Introduction

The AST/platelet ratio index (APRI) is a well-researched indicator of liver fibrosis. Some studies have shown that APRI can be used as a predictor of severe dengue, but the data is limited. As dengue epidemics are common in our country with limited healthcare resources, we believe APRI can help emergency physicians/primary physicians in predicting the severity of dengue and plan for the appropriate use of limited healthcare resources.

Objective

1) To determine the utility of APRI as a predictor of severe dengue. 2) To determine the association of APRI with length of hospital stay and platelet requirement.

Materials and Methods

A retrospective cross-sectional study was done on patients presented to the Emergency Medicine department at Travancore Medicity Medical College with a positive Dengue NS1 antigen or IgM antibody.

Results

We found from the univariate analysis results that ALT > 74.5 IU/L has a sensitivity of 59.6 and a specificity of 76.3 (AUC: 0.696; 95% CI: 0.606-0.786), AST > 160.5 IU/L has a sensitivity of 42.3 and a specificity of 93.7 (AUC: 0.747; 95% CI: 0.665-0.829), and APRI > 3.2 has a sensitivity of 69.2 and a specificity of 84.2 (AUC: 0.806; 95% CI: 0.72-0.884) to predict severe dengue. Patients with an APRI of >3.2 required a mean hospital stay of 5.47 days (P = 0.005); 27 (81.8%) requiring platelet transfusion had an APRI of > 3.2 (P = 0.00).

Conclusion

APRI is a straightforward index that can be easily derived from AST and platelet values. APRI values of >3.2 can predict severe dengue with a sensitivity of 69.2 and a specificity of 84.2. APRI values of >3.2 are also associated with the length of hospital stay and requirement of platelet transfusion.

Prothymosin α accelerates dengue virus-induced thrombocytopenia

Thrombocytopenia is the hallmark finding in dengue virus (DENV) infection. Prothymosin α (ProT) has both intracellular and extracellular functions involved in cell cycle progression, cell differentiation, gene regulation, oxidative stress response, and immunomodulation. In this study, we found that ProT levels were elevated in dengue patient sera as well as DENV-infected megakaryoblasts and their culture supernatants. ProT transgenic mice had reduced platelet counts with prolonged bleeding times. Upon treatment with DENV plus anti-CD41 antibody, they exhibited severe skin hemorrhage. Furthermore, overexpression of ProT suppressed megakaryocyte differentiation. Infection with DENV inhibited miR-126 expression, upregulated DNA (cytosine-5)-methyltransferase 1 (DNMT1), downregulated GATA-1, and increased ProT expression. Upregulation of ProT led to Nrf2 activation and reduced reactive oxygen species production, thereby suppressing megakaryopoiesis. We report the pathophysiological role of ProT in DENV infection and propose an involvement of the miR-126-DNMT1-GATA-1-ProT-Nrf2 signaling axis in DENV-induced thrombocytopenia.

Platelet derived exosomes disrupt endothelial cell monolayer integrity and enhance vascular inflammation in dengue patients

Background

Thrombocytopenia is the most notable phenomenon in dengue. Activation status of platelets and interaction of platelets with endothelium contribute towards dengue disease pathogenesis. Platelets are the major cell types known to release extracellular vesicles, especially exosomes in circulation. However, the role of platelet derived exosomes (PLT-EXOs) in endothelial dysfunction during dengue infection remains unknown.

Methods

In this study, we recruited 28 healthy subjects and 69 dengue patients categorized as WS- (n=31), WS+ (n=29) and SD (n=9). Platelets were isolated from platelet rich plasma of dengue patients and their activation was assessed by flow cytometry. PLT-EXOs were isolated by ultracentrifugation method. Western blot analyses were performed to characterize the exosomes. Exosome uptake experiment was carried out to see the internalization of exosomes inside endothelial cells (HUVECs). To observe the effect of exosomes on endothelial cells, exosomes were added on HUVECs and expression of adherens and tight junctional proteins were examined by immunofluorescence assay and western blot. Expression levels of vascular injury markers were measured in the culture supernatants of Exosome-HUVEC coculture and sera of dengue patients by MSD-multiplex assay.

Results

As compared to healthy subjects, CD41/CD61 expression was significantly reduced (p<0.0001) and CD62p expression was significantly increased (p<0.0001) on platelets in dengue patients. PLT-EXOs isolated from the dengue patients showed higher expression of CD63 and CD9 proteins than the healthy subjects. With in-vitro immunofluorescence assays, we illustrated the internalization of PLT-EXOs by the HUVECs and observed disruption of endothelial cell monolayer integrity in the presence of PLT-EXOs from WS+ and SD patients. Furthermore, the significant reduction in the expressions of ZO-2, VE-Cadherin and CD31 in endothelial cells following exposure to PLT-EXOs from the dengue patients provide direct evidence of PLT-EXOs mediated vascular permeability. PLT-EXOs stimulated the release of inflammatory markers CRP, SAA, sVCAM-1 and sICAM-1 in the supernatants of HUVEC cells. Importantly, significantly higher levels of CRP, sVCAM-1 and sICAM-1 in the sera of severe than mild dengue patients (p<0.0001) suggest their role in disease severity.

Conclusions

In summary, our data suggest that PLT-EXOs promote vascular leakage via release of proinflammatory mediators and compromise vascular barrier integrity in dengue patients.

Seroprevalence study of dengue-malaria coinfection in an East-Cameroonian public hospital: A comparison between malarial and non-malarial groups

BACKGROUNDS OBJECTIVES

Recent research in Cameroon reported several occurrences of dengue in urban settings, but concurrent dengue-malaria infection has received less attention, particularly in the East region.

METHODS

A two-month cross-sectional and comparative research was performed at Bertoua Regional Hospital which included 50 malaria-positive participants and 90 non-malaria subjects. Participants were selected and provided with a questionnaire to collect sociodemographic data. Blood samples were collected and tested for dengue infection and hematological parameters were assessed.

RESULTS

Dengue fever was found in 14% of malarial patients vs 66.66% of controls. Secondary dengue infection was more prevalent in malarial patients than in non-malarial patients. Gender, age, and place of residence were positively correlated to dengue seropositivity. Platelets were substantially lower (P<0.001) in the malarial group than in the non-malarial group.

INTERPRETATION CONCLUSION

In the study, coinfected patients were found to be more vulnerable to dengue, emphasizing the importance of epidemiological surveillance.

Descriptive and comparative analysis of mucocutaneous manifestations in patients with dengue fever: A prospective study

BACKGROUND

Dengue is an arbovirosis affecting nearly 4 billion people worldwide. Since 2018, dengue has been re-emerging in Reunion Island. The incidence of mucocutaneous manifestations varies according to the studies and is generally called 'rash'.

OBJECTIVES

To assess the prevalence of different mucocutaneous symptoms and describe the characteristics of patients developing these symptoms and the clinical signs associated with severe dengue.

METHODS

A prospective study was conducted in 2019 at the University Hospital of La Réunion, in patients presenting a positive PCR for dengue. Descriptive analyses were performed. All cases in the prospective study were examined by a dermatologist.

RESULTS

A total of 163 cases were included. The prevalence of mucocutaneous signs was 80.4%. A pruritus was reported in 33.7% cases, an erythematous rash in 29.4% and a mouth involvement including lip, tongue, cheek, angular cheilitis, pharyngitis, mouth ulcer and gingivitis in 31.3%. Most of symptoms appeared in the first days, but some of them could disappear only after the 3rd week. Mucocutaneous signs were not associated with a severe dengue fever (p = 0.54), but ecchymotic purpura was (p = 0.037). In multivariate analysis, skin involvement was associated with flu-like syndrome (headache, pharyngitis, rachis pain) and patient required rehydration but not invasive reanimation.

CONCLUSION

This work confirms the high prevalence of skin symptoms in dengue disease, but also their wide diversity. The mucocutaneous involvement of dengue fever appears to be accompanied by a pronounced flu-like syndrome in people without severity, but careful examination to identify ecchymotic purpura or sign of dehydration in the mucous membranes would better identify cases that may worsen.

Updates in the Management of Dengue Shock Syndrome: A Comprehensive Review

Dengue is a very serious public health problem that can manifest a wide range of symptoms from asymptomatic to fatal conditions, such as dengue shock syndrome (DSS). It is a life-threatening mosquito-borne viral infection widely spread in tropical areas. Dengue virus transmission occurs from an infected Aedes mosquito to humans. Various factors are responsible for the occurrence of the disease, such as viral load, age of the host, immune status of the host, and genetic variability. Dengue infection occurs in three phases: febrile, critical, and recovery. The febrile phase lasts for seven days and manifests symptoms such as high-grade fever, headache, arthralgia, and backache, and in some cases, the upper respiratory tract and gastrointestinal tract are also involved. Severe dengue is characterized by endothelial dysfunction that causes vascular permeability and plasma leakage. The fundamental mechanisms of these immune pathologies are not yet known. Dengue manifests various complications such as dengue encephalopathy, encephalitis, stroke, ocular involvement, acute transverse myelitis, myalgia, and cerebellar syndrome, but the most commonly seen is liver involvement. Dengue is managed supportively because there are no proven curative treatments. The cornerstone of care during the critical period of dengue is prudent fluid resuscitation. The first fluid of preference is a crystalloid. Prophylactic transfusion of platelets is not advised. The occurrence of four antigenically different dengue virus serotypes, each able to elicit a cross-reactive and disease-enhancing antibody response against the other three serotypes, has made the creation of the dengue vaccine a difficult undertaking. The development of a dengue vaccine has faced significant challenges due to a lack of the best animal models and a variety of immunological conditions in people, particularly in endemic locations. Dengvaxia is a live attenuated vaccine, which was developed by Sanofi. It is made up of four chimeric vaccine viruses produced by Vero cells.

Reinvestigation of the risk of stroke after dengue virus infection: A population-based cohort study

BACKGROUND

Dengue virus (DENV) infection is the most prevalent mosquito-borne viral disease. Stroke is a severe manifestation of dengue. However, few large-scale studies have investigated post-dengue risk of stroke.

METHODS

This population-based cohort study included 57,934 newly diagnosed, laboratory-confirmed dengue patients in Taiwan from 2002 to 2015; patients were matched to nondengue individuals by age, sex, and area of residence at a ratio of 1:4 (n = 231,736). We used subdistribution hazard regression to evaluate short-term (≤ 30 days), medium-term (31-365 days), and long-term (1-3 years) risk of stroke after DENV infection. The robustness of the results to unmeasured confounding was assessed with E-values.

RESULTS

DENV infection was associated with a significantly increased risk of overall stroke (aSHR 4.51; 95% CI: 3.23-6.32; P < 0.0001; E-value = 8.49), hemorrhagic stroke (aSHR 4.13; 95% CI: 2.20-7.76; P < 0.0001; E-value =7.73), and ischemic stroke (aSHR 3.80; 95% CI: 2.37-6.11; P < 0.0001; E-value = 7.06) within 30 days. Stratified analysis by age showed that the aSHRs for overall stroke, hemorrhagic stroke, and ischemic stroke were larger among dengue patients aged ≥ 65 during the first 30 days. The 30-day risks of overall stroke, hemorrhagic stroke, and ischemic stroke among elderly dengue patients were 6.71, 1.29, and 3.49 per 1000, respectively. No increased risk was observed after 30 days.

CONCLUSION

DENV infection was associated with a significant short-term increased risk of stroke. Clinical practitioners should remain alert to patients with stroke-associated symptoms during epidemic seasons, especially elderly patients.

Dengue, Chikungunya, and Zika: The Causes and Threats of Emerging and Re-emerging Arboviral Diseases

The recent emergence and re-emergence of viral infections transmitted by vectors, Zika, chikungunya, dengue, and others, is a cause for international concern. Here, we provide a summary of the current understanding of the transmission, clinical features, diagnosis, global burden, and the likelihood of future epidemics by these viruses. Arboviruses transmitted by mosquitoes are challenging to diagnose and can have surprising clinical complications. Dengue, chikungunya, and Zika are the most important diseases caused by arboviruses worldwide, especially in tropical and subtropical regions. These are transmitted to humans by day-biting Aedes aegypti and Aedes albopictus mosquitoes. In India, the increase in the incidence of dengue and chikungunya cases is primarily linked to the dissemination of Aedes aegypti. A rapid and accurate diagnosis is paramount for effectively controlling dengue outbreaks. As there is no vaccination or specific treatment available for these viruses, vector control is the only comprehensive solution available.

A Comparative Analysis of Effectiveness of Recombinant Interleukin-11 Versus Papaya Leaf Extract for Treatment of Thrombocytopenia: A Review

Platelets or thrombocytes play an important role in thrombosis and maintaining hemostasis. Thrombocytes help in forming blood clots at the site of the wound. When the level of platelets decreases, uncontrolled bleeding occurs which can result in mortality. A decrease in the blood platelet level is known as thrombocytopenia which can be caused due to various reasons. A variety of treatment options are available for thrombocytopenia like platelet transfusion, splenectomy, platelet management with various types of corticosteroids, and recombinant interleukin-11 (rhIL-11). The use of rhIL-11 is approved by FDA for the treatment of thrombocytopenia. rhIL-11 is a recombinant cytokine that is administered to patients suffering from chemotherapy-induced thrombocytopenia as it enhances megakaryocytic proliferation which aids in platelet production. But this treatment has various side effects and is costly. Hence, there is a crucial need to identify cost-effective alternative strategies that present no side effects. The majority of the population in low-income countries requires a functional and cost-effective treatment for low thrombocyte count. Carica papaya is a tropical herbaceous plant that has been reported in recovering low platelet count during dengue virus infection. Even though multiple benefits of the Carica papaya leaf extract (CPLE) are popular, the active compound present in it, which mediates these benefits, remains to be identified. This review aims to highlight the different aspects of rhIL-11 and CPLE-induced platelet counts and their limitations and benefits in the treatment of thrombocytopenia. The literature related to the treatment of thrombocytopenia using rhIL-11 and CPLE from 1970 to 2022 was searched using PubMed and Google Scholar databases with the keywords Recombinant Interleukin-11, Papaya Leaf Extract, Thrombocytopenia, and Platelets.

Dengue hemorrhagic fever with bleeding and fluid overload in a patient with active lupus nephritis: a case report of diagnostic and therapeutic challenges

BACKGROUND

Diagnosis and management of dengue hemorrhagic fever (DHF) can be challenging in the presence of confounding comorbidities. Important confounders are conditions that alter hematological parameters and intra/extra vascular fluid distribution. We report the case of a patient with active lupus nephritis, who developed DHF with subsequent bleeding and fluid overload. This is the first case report to highlight a unique set of diagnostic and therapeutic challenges in DHF in this context.

CASE PRESENTATION

A seventeen-year-old girl with lupus nephritis class IV developed a renal flare of lupus and subsequently developed DHF with bleeding per vaginum. Due to acute kidney injury, she was managed with a restrictive fluid approach during the ascending limb with blood transfusion when required, and close monitoring for hemodynamic instability. During the descending limb, hourly input was transiently increased due to a rise in hematocrit. This precipitated nephrogenic pulmonary edema, which was managed with mechanical ventilation and continuous renal replacement therapy.

CONCLUSIONS

This patient posed two diagnostic challenges: diagnosis of dengue in a patient with lupus-related bicytopenia, and diagnosis of dengue leakage in a patient with nephrotic syndrome-related ascites. There were three therapeutic difficulties: deciding the fluid quota for DHF in the presence of renal impairment, and balancing the risks and benefits of steroids and anticoagulation in lupus nephritis with dengue. As decisions in such instances are patient-specific, sharing of individual experiences will help guide management decisions.

Dengue in Early Pregnancy: A Neglected Problem?

Introduction Dengue is caused by a virus from the Flaviviridae family. Although the literature on this disease is sparse, some studies have shown the effects of dengue in the first trimester of pregnancy. However, the sample size in these studies is limited. Aims and objective The current study aimed to compare foetomaternal outcomes in pregnant patients with dengue in early (< 24 weeks) and late (> 24 weeks) pregnancy and find the prevalence and predictive factors for abortion in pregnant patients with dengue. Material and methods This retrospective study included all pregnant patients (n = 62) admitted to the labour room over a period of six years from April 2016 to February 2022 and who were diagnosed with dengue anytime during pregnancy. Data were collected from their medical records and analysed. Differences between the two groups were assessed by the Chi-square test, Fisher's exact test, and Mann-Whitney U test. A p value of less than 0.05 was considered significant. Results Out of a total of 62 patients, those with dengue at a gestational age of less than 24 weeks (n = 15) had more incidence of intrauterine growth restriction (55.6 vs 12.9%) (p value = 0.012) and oligohydramnios (66.7 vs 17.9%) (p value = 0.007). The incidence of abortion was 33.3%; among the patients at a gestational age of less than 12 weeks, 71.4% had an abortion. When the patients who had abortions were compared with those who did not, the factors predicting abortion were found to be a history of previous abortion (p value = 0.004), gestational age of less than 12 weeks (p value = 0.003), and decreased platelet count (p value = 0.03). Conclusion  The effect of dengue infection in early pregnancy includes abortion, intrauterine growth restriction, and oligohydramnios, and these patients should be managed in a tertiary care hospital.

Chimeric flavivirus causes vascular leakage and bone marrow suppression in a mouse model

Previously, we demonstrated the utility of a recombinant chimeric flavivirus (DV2ChimV), which carries the premembrane (prM) and envelope (E) genes of a type 2 DENV clinical (Thai) isolate on a backbone of Japanese encephalitis virus, for evaluating the protective efficacy of antidengue envelope antibodies both in vitro and in vivo. Here, to assess the potential use of this model for pathological studies, we aimed to characterize interferon-α/β-γ-receptor double-knockout mice (IFN-α/β/γR dKO mice) infected with DV2ChimV. Vascular leakage and bone marrow suppression are unique features of severe dengue. In the current model, DV2ChimV caused vascular leakage in the liver and intestine at the moribund stage. High levels of virus were detected in the bone marrow, and strong bone marrow suppression (i.e., disappearance of megakaryocytes and erythroblastic islets) was observed. These observations suggest that the DV2ChimV-infected mouse model mimics the vascular leakage and bone marrow suppression observed in human cases.

The association of obesity and dengue severity in hospitalized adult patients

BACKGROUND

Obesity is associated with unfavorable outcomes for infectious diseases. Most researches exploring the association between nutritional status and dengue severity have focused on pediatric populations, with only few studies assessing adult patients.

METHODS

Adult patients with laboratory-confirmed dengue admitted to a tertiary hospital in southern Taiwan between 2014 and 2015 were enrolled retrospectively. Demographics, comorbidities, clinical presentation, laboratory findings, and outcomes were obtained from case-record forms. Patients were categorized into obese group and nonobese group. The obese group comprised patients with a body mass index of ≥27.5 kg/m².

RESULTS

A total of 1417 hospitalized patients with dengue were evaluated. The mean age was 57.9 years (range: 18-92 years). The obese and nonobese groups comprised 333 (23.5%) and 1084 (76.5%) patients, respectively. The obese group included more patients with hypertension (85%, p < 0.001), diabetes mellitus (33%, p < 0.001), and congestive heart failure (6.3%, p = 0.049). Multivariate analysis revealed that the obese group had more petechiae (AOR: 1.353, 95% CI: 1.025-1.786, p = 0.033), more dyspnea (AOR: 1.380, 95% CI: 1.015-1.876, p = 0.040), and more severe hepatitis (AOR: 2.061, 95% CI: 1.050-4.048, p = 0.036). The obese group also had higher peak hematocrit values (44.1%, p < 0.001) and lower nadir platelet count (45.3 × 10³/μL, p = 0.049) than the nonobese group.

CONCLUSION

In adult patients with dengue, obese group had more petechiae, dyspnea, severe hepatitis, lower nadir of platelet count, and higher peak hematocrit level. We observed no difference in severe dengue or mortality between obese and nonobese group.

Hantaan virus-induced elevation of plasma osteoprotegerin and its clinical implications in hemorrhagic fever with renal syndrome

OBJECTIVES

The bleeding tendency is a hallmark of hemorrhagic fever with renal syndrome (HFRS) after Hantaan virus (HTNV) infection. Growing reports indicate the importance of osteoprotegerin (OPG) in vascular homeostasis, implying OPG might be involved in the pathogenesis of coagulopathy in patients with HFRS.

METHODS

Acute and convalescence plasmas of 32 patients with HFRS were collected. Enzyme-linked immunosorbent assays (ELISA) were used to detect plasma OPG levels and other parameters. The human umbilical vein endothelial cells were stimulated with HTNV and/or tumor necrosis factor-α (TNF-α) to explore the source of OPG.

RESULTS

Plasma OPG levels of patients with HFRS were elevated and correlated positively with the severity of HFRS and negatively with platelet counts. Abundant OPG was released from endothelial cells in response to TNF-α stimuli, along with HTNV infection, which was in accordance with the findings of positive correlations between plasma OPG and TNF-α or c-reactive protein. Importantly, plasma OPG levels correlated positively with activated partial thromboplastin time and the content of d-dimer.

CONCLUSION

These findings suggested that increased plasma OPG levels induced by HTNV might be an important factor for the severity of HFRS, and was likely involved in endothelium dysfunction and hemorrhagic disorder of HFRS, which might contribute to the pathogenesis of hemorrhage in HFRS.

Differential expression of interferon inducible protein: Guanylate binding protein (GBP1 & GBP2) in severe dengue

Dengue virus is reported to activate endothelial cells (EC), but the precise cause for severe dengue (SD) is not known. Guanylate binding proteins (GBPs) are IFN-inducible proteins secreted by ECs and are involved in the anti-oxidant and anti-viral response. The involvement of GBPs in the pathogenesis of dengue remains under explored. In the present study, we quantified the mRNA and protein levels of GBP1 and 2 during acute, defervescence and convalescent phase in SD-10, dengue without warning sign-15 and dengue with warning sign-25 compared to other febrile illnesses-10 and healthy controls-8 using RT-PCR and ELISA respectively. Lipid peroxidation in plasma samples were measured using the Kei Satoh method. Protein and DNA oxidation were determined by ELISA. The efficacy of the proteins in predicting disease severity was done by Support Vector Machine (SVM) model. A significant (P ≤ 0.01) decrease in the levels of mRNA and protein of both GBP1 and GBP2 was observed during defervescence in both SD and DWW cases. The levels were significantly (P ≤ 0.05) tapered off in SD cases from acute till critical phases compared to other study groups. DNA, protein and lipid oxidation markers showed an increasing trend in SD (P ≤ 0.01). Both GBP1 & 2 were found to be negatively associated plasma leakage and oxidative stress markers. EC's activated with SD serum showed a reduced expression of GBP 1 and 2. Nevertheless, the SVM model revealed that plasma levels of proteins along with clinical symptoms could predict the disease outcomes with higher precision. This is the first study reporting a downregulated expression of GBP1 & 2 and their association with oxidative stress and plasma leakage in dengue cases. This suggests the importance of GBPs in regulating disease manifestation. However, further investigations are required to ascertain its role as a biomarker or therapeutic target in dengue infection.

Aetiology and Outcomes of Thrombocytopenia in Pregnancy: A Cross-Sectional Study in a University Hospital, India

Background: Thrombocytopenia (TCP) is the second most common haematological finding in pregnancy next to anaemia. It carries a risk for both the mother and the fetus, associated with substantial maternal or neonatal morbidity and mortality. However, a specific therapy, if instituted promptly, improves the outcome for affected patients and their offspring. In patients in India, TCP during pregnancy is an underexplored condition. Objectives: To assess the aetiology of TCP in pregnancy and to assess the maternal outcomes of TCP in pregnancy. Methodology: The authors included a total of 133 patients in their third trimester (>32 weeks), with a platelet count <149,000 /mm3, admitted to the authors’ institution from 1st January 2021 to 31st December 2021. Patient-related data such as menstrual and obstetric history, presenting complaints, obstetric examination, and basic investigations were collected in a pre-designed, pre-tested proforma. All cases were followed until delivery to record any maternal complications, or any other morbidities. The data were analysed using SPSS (International Business Machines Corporation, Armonk, New York, USA) software. χ2 test was used to compare the proportions between the groups. p<0.05 was considered significant. Results: Overall, 64.7% of patients were in the 18–25 years age group and 49.6% of patients were primigravida. Furthermore, 60.9% of patients were diagnosed to have mild TCP, 32.3% had moderate TCP, and only 6.8% patients had severe TCP. The majority (75.2%) of cases were of gestational TCP. In total, 15.8% of cases had pregnancy-induced hypertension (PIH); 3.0% had dengue; 2.3% were COVID-19 positive; 1.5% were diagnosed with haemolysis, elevated liver enzymes, and low platelets syndrome; 1.5% had immune TCP; and only one patient had leptospirosis. Four percent of cases had gestational TCP, 9.5% had PIH, one patient (25.0%) had dengue, and both cases of immune TCP had severe TCP. Twenty-eight percent of gestational TCP cases; 47.6% of PIH cases, both cases of haemolysis, elevated liver enzymes, and low platelets syndrome; 50.0% of dengue cases; and one COVID-19 positive case (33.0%) had moderate TCP. Finally, 6.25% of patients who underwent lower segment caesarean section had severe TCP, 6.00% of patients who underwent vaginal delivery had severe TCP, and out of two patients who had a spontaneous abortion, one (50.00%) had severe TCP at the time of admission. The association was significant (p<0.05). Conclusion: TCP is a crucial condition among pregnant patients. Mild TCP is a common type. Correct aetiological diagnosis, and promptly administered adequate and specific therapy are, therefore, essential to significantly improve the outcomes of pregnant patients and their offspring.

Discovery and validation of circulating miRNAs for the clinical prognosis of severe dengue

Background

Early prognostic markers of severe dengue may improve case management and reduce dengue-related mortalities. This study aimed to identify circulating microRNAs (miRNAs) as biomarkers for predicting severe dengue.

Methodology

Serum samples from dengue-infected patients were collected on the first day of admission. Patients were followed up for 14 days after admission to determine the final diagnosis. Participants were divided into non-severe and severe dengue, as defined by WHO 2009 criteria. Circulating microtranscriptome analysis was performed using NanoString miRNA Expression Assay. The expression level of candidate miRNAs were then validated by quantitative reverse transcription-PCR method.

Principal findings

The discovery cohort (N = 19) lead to the identification of 37 differentially expressed miRNAs between the two groups. Six up-regulated candidate miRNAs were selected and further validated in the larger cohort (N = 135). MiR574-5p and miR1246 displayed the highest diagnostic performance in discriminating between severe from non-severe dengue (ROC-AUC = 0.83). Additionally, miR574-5p and miR1246 had high sensitivity and high negative predictive value for detecting severe dengue. Multivariate analysis suggested that serum miR574-5p was an independent predictor of severe dengue (odds ratio 3.30, 95% CI 1.81–6.04; p<0.001).

Conclusion

Our study indicated that circulating miRNAs, especially miR-574-5p and miR-1246, might be a promising diagnostic and prognostic biomarker for severe dengue upon hospital admission, especially when using these biomarkers on days 1 to 2 before the onset of severe dengue complications.

Dengue infection, a mosquito-borne disease, is an expanding global problem. It has a broad clinical spectrum that includes severe and non-severe clinical manifestations with a high risk of death. Identifying early prognostic markers of severe complications may improve case management and reduce dengue-related mortalities. The circulating microRNA (miRNA) profile has been widely used to identify potential biomarkers against viral infections. Our data revealed that the circulating miRNA expression pattern of severe dengue patients was significantly different from the non-severe group. In addition, circulating miRNAs, especially miR-574-5p and miR-1246, could be promising diagnostic and prognostic biomarkers for severe dengue. These data have implications for developing biomarkers for clinical use and could improve risk prediction in dengue patients.

The Role of Growth Factors in the Pathogenesis of Dengue: A Scoping Review

Growth factors (GFs) have a role in tissue repair and in the modulation of the expression of inflammatory cells in damage caused by pathogens. This study aims to systematize the evidence on the role of GFs in the pathogenesis of dengue. This scoping review considered all published peer-reviewed studies in the MEDLINE and Embase databases. Ultimately, 58 studies that analyzed GFs in dengue patients, published between 1998 and 2021, were included. DENV-2 infection and secondary infection were more frequent in the patients studied. ELISA and multiplex immunoassay (Luminex) were the most used measurement techniques. Increased levels of vascular endothelial growth factor, granulocyte–macrophage colony-stimulating factor, granulocyte colony-stimulating factor, transforming growth factor beta, and hepatocyte growth factor as well as reduced levels of platelet-derived growth factor and epidermal growth factor were observed in severe dengue in most studies. Vascular endothelial growth factor and hepatocyte growth factor were identified as biomarkers of severity. In addition, there is evidence that the dengue virus can use the growth factor pathway to facilitate its entry into the cell and promote its viral replication. The use of tyrosine kinase inhibitors is an alternative treatment for dengue that is being studied.

Clinical Profile, Severity Spectrum, and Hospital Outcome of Dengue Patients in a Tertiary Care Hospital in Dhaka City

Background

Bangladesh saw its most severe dengue outbreak in 2019, with the highest number of deaths reported. This study investigated the clinical characteristics, severity spectrum, and potential outcomes of dengue in patients admitted to a tertiary care institution in Dhaka.

Methods

This prospective observational study was done between May 2019 to April 2020. A total of 478 nonstructural protein 1 (NS1) antigen positive confirmed dengue cases were finally enrolled. The dengue patient's stratification and severity grading were performed according to the World Health Organization (WHO) dengue guidelines, for diagnosis, treatment, prevention, and control (2009). In addition, in-hospital outcomes were assessed in terms of mortality.

Results

The patient’s mean age was 33.90±15.82 (SD) years. The male-to-female ratio was 1.23:1. In addition to fever, the most common symptoms were myalgia (67.78%) and rashes (58.58%). According to WHO classification 33.90% of patients (n=162) were in group A, 49.40% (n=236) were in group B, and 16.70% (n=80) were in group C. The overall mortality was 1.23% in groups A, 2.97% in group B, and 11.25% in group C. The mortality was higher in the more severe group with statistical significance (p<0.001). The mean hospital stay time was significantly less in the surviving group (survival vs. death: 3.07±1.78 vs. 5.61±3.13 SD {days}, p<0.001). Leukopenia and thrombocytopenia were commonly seen in all of the severity groups.

Conclusion

Dengue epidemics are increasing in Bangladesh. Many group B and C cases are fatal. To reduce mortality and morbidity, health care providers must remain alert. This challenge requires public health interventions and hospital readiness.

Coagulopathy of Dengue and COVID-19: Clinical Considerations

Thrombocytopenia and platelet dysfunction commonly occur in both dengue and COVID-19 and are related to clinical outcomes. Coagulation and fibrinolytic pathways are activated during an acute dengue infection, and endothelial dysfunction is observed in severe dengue. On the other hand, COVID-19 is characterised by a high prevalence of thrombotic complications, where bleeding is rare and occurs only in advanced stages of critical illness; here thrombin is the central mediator that activates endothelial cells, and elicits a pro-inflammatory reaction followed by platelet aggregation. Serological cross-reactivity may occur between COVID-19 and dengue infection. An important management aspect of COVID-19-induced immunothrombosis associated with thrombocytopenia is anticoagulation with or without aspirin. In contrast, the use of aspirin, nonsteroidal anti-inflammatory drugs and anticoagulants is contraindicated in dengue. Mild to moderate dengue infections are treated with supportive therapy and paracetamol for fever. Severe infection such as dengue haemorrhagic fever and dengue shock syndrome often require escalation to higher levels of support in a critical care facility. The role of therapeutic platelet transfusion is equivocal and should not be routinely used in patients with dengue with thrombocytopaenia and mild bleeding. The use of prophylactic platelet transfusion in dengue fever has strained financial and healthcare systems in endemic areas, together with risks of transfusion-transmitted infections in low- and middle-income countries. There is a clear research gap in the management of dengue with significant bleeding.

Styrylpyrone Derivative (SPD) Extracted from Goniothalamus umbrosus Binds to Dengue Virus Serotype-2 Envelope Protein and Inhibits Early Stage of Virus Replication

A study was conducted to investigate the anti-viral effect of a styrylpyrone derivative (SPD) called goniothalamin and the effects on the dengue virus serotype 2 (DENV-2) replication cycle. The SPD was prepared from the root of Goniothalamus umbrosus after purification with petroleum ether. The isolated SPD was then subjected to gas chromatography–mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) analyses for structure validation. The cytotoxicity of the SPD was evaluated using a cell viability assay, while the anti-viral activity of the SPD towards DENV-2 was confirmed by conducting a foci reduction assay which involved virus yield reduction, time-of-addition, and time removal assays. Transcriptomic analysis via quantitative real-time polymerase chain reaction (qRT-PCR) using the DENV-2 E gene was conducted to investigate the level of gene transcript. Immunocytochemistry analysis was used to investigate the effects of SPD treatment on protein E expression. Finally, software molecular docking of the SPD and E protein was also performed. The cytotoxicity assay confirmed that the SPD was not toxic to Vero cells, even at the highest concentration tested. In the time-of-addition assay, more than 80% foci reduction was observed when SPDs were administered at 2 h post-infection (hpi), and the reduction percentage then dropped with the delay of the treatment time, suggesting the inhibition of the early replication cycle. However, the time removal assay showed that more than 80% reduction could only be observed after 96 h post-treatment with the SPD. Treatment with the SPD reduced the progeny infectivity when treated for 24 h and was dose-dependent. The result showed that transcript level of the E gene in infected cells treated with the SPD was reduced compared to infected cells without treatment. In immunocytochemistry analysis, the DENV-2 E protein exhibited similar expression trends, shown by the gene transcription level. Molecular docking showed that the SPD can interact with E protein through hydrogen bonds and other interactions. Overall, this study showed that SPDs have the potential to be anti-DENV-2 via a reduction in viral progeny infectivity and a reduction in the expression of the DENV-2 E gene and protein at different phases of viral replication. SPDs should be further researched to be developed into an effective anti-viral treatment, particularly for early-phase dengue viral infection.

Epidemiological and hematological investigation of Dengue Virus infection

Dengue is a mosquito-borne viral illness that infects humans. For the last few decades, it has been declared a global public health problem. The current study was conducted at the district headquarter hospital (DHQ) Bannu between June to September 2018 based on the seroprevalence of antibodies against dengue virus serotypes and their hematological parameters among the patients. A total of 1738 suspected individuals were diagnosed through NS1, IgG, and IgM antibodies and RT-PCR techniques. Out of all the samples, 716 (41.19%) were found to be positive for dengue. A higher infection rate was found in males (65.92%) as compared to females (34.07%). The most affected age group was 16-40 years, whereas the most affected tehsil was Bannu, where the DENV-3 serotype was prevalent. The rare serotype (DENV-4) was found in 1% of cases. Symptoms including fever (100%), myalgia (100%), headache (61.31%), vomiting (34.63%), and rashes were common among the dengue patients. However, the mild cases showed fewer clinical signs compared to the severe infected cases. The study also revealed a significant association (P<0.05) between hematological parameters and dengue infection, showing a significant decrease in TC, eosinophils, neutrophils, and platelets and a significant increase in monocytes and lymphocytes. Based on the current report, it is concluded that patients with the above symptoms and hematological changes may have increased probability of Dengue and should be kept under observation to separate dengue positive patients and enhance treatment process. This article is protected by copyright. All rights reserved.

Clinicopathological alteration of symptoms with serotype among dengue infected pediatric patients

Dengue fever is a self-limiting, acute febrile illness caused by an arbovirus. This infection may be asymptomatic or symptomatic with its potential life-threatening form as DHF/DSS. Severe dengue cases occur typically in children due to overproduction of pro-inflammatory and anti-inflammatory cytokines (called cytokines storm) as well as increased microvascular permeability in them. This study aimed to find prevalent circulating dengue serotype and their clinicopathological association among pediatric patients admitted to tertiary care hospitals in Kolkata, India. Overall, 210 patients were approached and among them, 170 dengue suspected children admitted to three tertiary care hospitals were included in this study. Dengue samples were screened for the presence of NS1 antigen and dengue IgM antibodies by ELISA. Viral RNA was extracted from NS1 seropositive serum samples and subjected to molecular serotyping by semi-nested RT-PCR. All patients were followed up for clinical manifestations and biochemical parameters associated with dengue. Co-circulation of all four serotypes was observed and DENV2 was the major circulating strain. Physiological classification of associated clinical symptoms was done and represented as a percentage variable. A multivariate logistic regression approach was used for making a regression model including dengue-associated clinical symptoms with dengue positivity and negativity as dependent variables. Thrombocytopenia was observed in 69% of patients and the commonest bleeding manifestation was petechia. Liver function profiles of infected patients were observed during follow-up and represented using a box plot. A significant change in trends of dengue-associated clinical manifestations and differential expression of liver functional profile with different phase transitions of dengue fever was obtained in the study population. This article is protected by copyright. All rights reserved.

Acute-phase Serum Cytokine Levels and Correlation with Clinical Outcomes in Children and Adults with Primary and Secondary Dengue Virus Infection in Myanmar between 2017 and 2019

The dengue virus (DENV) has been endemic in Myanmar since 1970, causing outbreaks every 2–3 years. DENV infection symptoms range from mild fever to lethal hemorrhage. Clinical biomarkers must be identified to facilitate patient risk stratification in the early stages of infection. We analyzed 45 cytokines and other factors in serum samples from the acute phase of DENV infection (within 3–5 days of symptom onset) from 167 patients in Yangon, Myanmar, between 2017 and 2019. All of the patients tested positive for serum DENV nonstructural protein 1 antigen (NS1 Ag); 78.4% and 62.9% were positive for immunoglobulin M (IgM) and G (IgG), respectively; and 18.0%, 19.8%, and 11.9% tested positive for serotypes 1, 3, and 4, respectively. Although the DENV-4 viral load was significantly higher than those of DENV-1 or DENV-3, disease severity was not associated with viral load or serotype. Significant correlations were identified between disease severity and CCL5, SCF, PDGF-BB, IL-10, and TNF-α levels; between NS1 Ag and SCF, CCL5, IFN-α, IL-1α, and IL-22 levels; between thrombocytopenia and IL-2, TNF-α, VEGF-D, and IL-6 levels; and between primary or secondary infection and IL-2, IL-6, IL-31, IL-12p70, and MIP-1β levels. These circulating factors may represent leading signatures in acute DENV infections, reflecting the clinical outcomes in the dengue endemic region, Myanmar.

Innate Immune Response to Dengue Virus: Toll-like Receptors and Antiviral Response

Dengue is a mosquito-borne viral disease caused by the dengue virus (DENV1-4). The clinical manifestations range from asymptomatic to life-threatening dengue hemorrhagic fever (DHF) and/or Dengue Shock Syndrome (DSS). Viral and host factors are related to the clinical outcome of dengue, although the disease pathogenesis remains uncertain. The innate antiviral response to DENV is implemented by a variety of immune cells and inflammatory mediators. Blood monocytes, dendritic cells (DCs) and tissue macrophages are the main target cells of DENV infection. These cells recognize pathogen-associated molecular patterns (PAMPs) through pattern recognition receptors (PRRs). Pathogen recognition is a critical step in eliciting the innate immune response. Toll-like receptors (TLRs) are responsible for the innate recognition of pathogens and represent an essential component of the innate and adaptive immune response. Ten different TLRs are described in humans, which are expressed in many different immune cells. The engagement of TLRs with viral PAMPs triggers downstream signaling pathways leading to the production of inflammatory cytokines, interferons (IFNs) and other molecules essential for the prevention of viral replication. Here, we summarize the crucial TLRs’ roles in the antiviral innate immune response to DENV and their association with viral pathogenesis.

Dengue Virus and Platelets: From the Biology to the Clinic

Dengue is one of the most important vector-borne viral illnesses found in tropical and subtropical regions. Colombia has one of the highest rates of dengue cases in the Americas. Severe dengue virus (DENV) infection presents with capillary leakage, hemorrhage, and organ compromise, eventually leading to death. Over the years, there have been many efforts to develop a vaccine that guarantees protective immunity, but they have been partially successful, as such immunity would need to guarantee protection against four distinct viral serotypes. Absolute platelet count is a laboratory parameter used to monitor the clinical progression of DENV, as infection is often accompanied by thrombocytopenia. Although this finding is well described with respect to the natural history of the disease, there are various hypotheses as to the cause of this rapid decrease, and several in vivo and ex vivo models have been used to explain the effect of DENV infection on platelets and their precursors. DENV infects and activates platelets, facilitating their elimination through recognition by phagocytic cells and peripheral margination. However, infection also affects the precursors in the bone marrow by modulating megakaryopoiesis. The objective of this article is to explore various proposed mechanisms of DENV-induced thrombocytopenia to better understand the pathophysiology and clinical presentations of this highly relevant viral infection.

Rotational thromboelastometry in critical phase of dengue infection: Association with bleeding

Background

The critical phase of dengue carries a high risk of bleeding. Associations of coagulation test parameters and the risk of bleeding in the critical phase is unclear. This study examines the association of rotational thromboelastometry (ROTEM delta and ROTEM platelet) with bleeding risk of patients with dengue in the critical phase.

Methods

A total of 105 patients with confirmed dengue in the critical phase were recruited, with two subsequent prospective time point analyses of ROTEM parameters and platelet count within 24 and 48 hours from the onset of the critical phase. Conventional coagulation tests were performed only at the initial time point.

Results

Twenty of 105 patients developed bleeding after onset of the critical phase. Within the first 24 hours of critical‐phase onset, platelet count, coagulation tests, and ROTEM delta were unable to differentiate patients with bleeding manifestations from those without (P < .05). Area under the curve of thrombin receptor activating peptide‐6 assay of ROTEM platelet (TRAPTEM) discriminated patients with bleeding manifestations from those without, at a cutoff value of <12.5 Ω*min at a sensitivity and specificity of 73.7%, and 60.2%. In patients who developed bleeding, the maximum lysis of extrinsic pathway of ROTEM was significantly lower in patients with severe bleeding compared to those with mild to moderate bleeding. (4.3 ± 3.4% vs 9.4 ± 7.5%; P = .01).

Conclusion

An association with bleeding manifestations and TRAPTEM suggest a potential role for defective platelet aggregation in the pathogenesis of bleeding in the critical phase of dengue.

Elevated TNF-α Induces Thrombophagocytosis by Mononuclear Cells in ex vivo Whole-Blood Co-Culture with Dengue Virus

Background

Infection with dengue virus (DENV) causes hematological complications in dengue diseases characterized by thrombocytopenia accompanied by macrophage activation syndrome and hemophagocytosis in fatal patients.

Methods

In this study, we investigate the undefined mechanisms underlying the progression of thrombocytopenia caused by thrombophagocytosis based on an ex vivo whole-blood co-culture model of DENV infection for mimicking the acute febrile phase of infection.

Results

In this model, complete blood count test showed a decrease in monocytes (p < 0.01), but not neutrophils nor other white blood cells, accompanied by a low thrombocyte count (p < 0.01) in DENV infection with a positive correlation (r = 0.636, p < 0.05). Furthermore, DENV exposure caused significant thrombophagocytosis in mononuclear cells (p < 0.05). Abnormal production of tumor necrosis factor (TNF)-α was highly associated with induction of thrombophagocytosis (r = 0.758, p < 0.01), decreased monocytes (r = −0.758, p < 0.01), and decreased thrombocyte (r = −0.728, p < 0.01). Neutralizing TNF-α considerably (p < 0.05) reversed such DENV-induced effects and was further validated by immunostaining-based flow cytometry analysis on mononuclear CD14 positive monocytes. Exogenous administration of TNF-α effectively caused thrombophagocytosis accompanied by decreased monocytes and thrombocytes, probably causing monocyte activation.

Conclusion

These results demonstrate the potential pathogenesis of thrombocytopenia caused by TNF-α-induced thrombophagocytosis in monocytes during DENV infection.

Prognostic indicators associated with progresses of severe dengue

Background

Dengue usually progress abnormally, especially in the critical phase. The main causes of death were shock, severe bleeding and organ failure. The aim of our study was to evaluate prognostic indicators of severe dengue according to the phases of the disease progression.

Methods

A cross-sectional study was conducted from July to December 2017 at the National Hospital for Tropical Diseases and the Hospital for Tropical Diseases of Ho Chi Minh City. 326 patients, aged 6 years and over, including 99/326 patients with severe dengue and 227/326 patients with non-severe dengue, hospitalized in the first 3 days of illness, confirmed Dengue virus by the RT-PCR assay have been registered for the study. Clinical manifestations were monitored daily. The hematocrit, white blood cells, platelet, serum albumin, ALT, AST, bilirubin, prothrombin time (PT%, PTs), fibrinogen, aPTT, INR and creatinine were evaluated at two times: febrile phase and critical phase.

Results

Independent factors associated with severe dengue were identified on multivariate logistic regression models. During the first 3 days of the disease, the prognostic indicators were platelet count ≤ 100 G/L (OR = 2.2; 95%CI: 1.2–3.9), or serum albumin < 35 g/L (OR = 3.3; 95%CI: 1.8–6.1). From day 4–6, the indicator were AST > 400 U/L (OR = 3.0; 95%CI: 1.1–7.9), ALT > 400 U/L (OR = 6.6; 95%CI: 1.7–24.6), albumin < 35 g/L (OR = 3.0; 95%CI: 1.5–5.9), and bilirubin total >17 μmol/L (OR = 4.6; 95%CI: 2.0–10.4).

Conclusion

To predict the risk of patients with severe dengue, prognostic laboratory indicators should be indicated consistent with the progression of the disease. During the first 3 days of illness, prognostic indicators should be platelet count, or serum albumin. From the 4th - 6th day of illness, prognostic indicators should be AST, ALT, albumin, or bilirubin total.

Replication of Dengue Virus in K562-Megakaryocytes Induces Suppression in the Accumulation of Reactive Oxygen Species

Dengue virus can infect human megakaryocytes leading to decreased platelet biogenesis. In this article, we report a study of Dengue replication in human K562 cells undergoing PMA-induced differentiation into megakaryocytes. PMA-induced differentiation in these cells recapitulates steps of megakaryopoiesis including gene activation, expression of CD41/61 and CD61 platelet surface markers and accumulation of intracellular reactive oxygen species (ROS). Our results show differentiating megakaryocyte cells to support higher viral replication without any apparent increase in virus entry. Further, Dengue replication suppresses the accumulation of ROS in differentiating cells, probably by only augmenting the activity of the transcription factor NFE2L2 without influencing the expression of the coding gene. Interestingly pharmacological modulation of NFE2L2 activity showed a simultaneous but opposite effect on intracellular ROS and virus replication suggesting the former to have an inhibitory effect on the later. Also cells that differentiated while supporting intracellular virus replication showed reduced level of surface markers compared to uninfected differentiated cells.

A review of severe thrombocytopenia in Zika patients - Pathophysiology, treatment and outcome

BACKGROUND

During the 2015 Zika virus infection (ZVI) epidemic swiping through the Americas, few cases of ZVI with severe, potentially life-threatening thrombocytopenia were reported. Platelet transfusion, corticosteroids and intravenous immunoglobulins (IVIG) were in most cases applied as therapeutic options, predominantly with success. We present a comprehensive overview concerning the pathophysiology, treatment strategies and outcomes of patients with ZVI and severe thrombocytopenia (platelet count <50 × 10⁹/L).

METHOD

A literature search was performed.

RESULTS

Eleven case reports and case series with a total of 28 patients met the inclusion criteria; including five cases with lethal outcome. Therapeutic strategies, including platelet transfusion, administration of steroids and/or IVIG were described in 24 cases.

CONCLUSIONS

Severe thrombocytopenia is a rare, but potentially life-threatening complication of ZVI. The principal pathophysiological mechanism appears to immune-induced thrombocytopenia. Due to a paucity of cases, the optimal treatment strategy remains to be elucidated.

Unique characteristics of new complete blood count parameters, the Immature Platelet Fraction and the Immature Platelet Fraction Count, in dengue patients

The advanced platelet parameters Immature Platelet Fraction and Immature Platelet Fraction Count have been implemented in clinical practice as measures of thrombopoietic activity, mainly in hematologic disorders that cause thrombocytopenia. The purpose of this observational study was to examine thrombopoiesis as reflected by these 2 new CBC parameters in patients infected with dengue. The study was conducted in infectious disease referral hospital in Metro Manila, the Philippines. We enrolled hospitalized patients at admission who were diagnosed with acute dengue or community acquired bacterial infection (CABI). Immature Platelet Fraction (IPF) and Immature Platelet Fraction Count were evaluated at admission and during hospitalization. A total of 606 patients were enrolled from May 1, 2017 to June 1, 2018. The participants consisted of 152 patients with dengue infection, 180 confirmed CABI, and 274 suspected CABI patients. At admission, the percent IPF (IPF%) of the patients with dengue was significantly higher than that of the confirmed CABI patients (median 3.7% versus 1.9%; p <0.001). In a time course evaluation, there was no significant difference of IPF% between the patients with dengue infection and the confirmed CABI patients in the febrile phase (median 1.9% versus 2.4%; p = 0.488), however, the IPF% of the patients with dengue infection increased to be significantly higher than that of the confirmed CABI patients in the critical phase (median 5.2% versus 2.2%; p <0.001). Our study elucidated the unique characteristics and time-course trends of IPF percent and number (IPF#) in the patients with dengue infection. IPF% and IPF# are potentially valuable parameters in dengue and further investigation is required for the optimal use in clinical practice.

Proteomic profiles of Zika virus-infected placentas bearing fetuses with microcephaly

PURPOSE

Zika virus (ZIKV) transmission to the fetus during pregnancy could enable a collection of severe fetal malformations like microcephaly (MC), termed Congenital Zika Syndrome (CZS). The mechanisms involved in ZIKV transplacental transmission are not fully understood.

EXPERIMENTAL DESIGN

Here we aim to identify in placental tissues the deregulated proteins associated with ZIKV-induced MC using label-free proteomics.

RESULTS

We found proteins associated with DNA damage and gene expression inhibition up-regulated in infected placentas with no MC fetuses (Z+) compared to the control group (Ctr). Actin filament organization and the immune response were also found deregulated in the Z+ group. In ZIKV-positive placentas bearing fetuses with MC (MC+) was detected an increase in T cell activation, indicating an elevated immune response. A comparison between MC+ and Z+ groups showed a higher abundance of proteins related to endocytosis and autophagy in MC+, suggesting a higher transcytosis of vesicles with ZIKV particles across the maternal-fetal interface.

CONCLUSIONS AND CLINICAL RELEVANCE

Our results suggest that higher expression of integrins in MC+ might be associated with high internalization of the virus since these proteins are known as virus receptors. Similarly, an increased immune response in the placenta and higher infiltration of the virus to the fetus could contribute to the neurological malformation of the CZS.

Predictive markers for the early prognosis of dengue severity: A systematic review and meta-analysis

BACKGROUND

Predictive markers represent a solution for the proactive management of severe dengue. Despite the low mortality rate resulting from severe cases, dengue requires constant examination and round-the-clock nursing care due to the unpredictable progression of complications, posing a burden on clinical triage and material resources. Accordingly, identifying markers that allow for predicting disease prognosis from the initial diagnosis is needed. Given the improved pathogenesis understanding, myriad candidates have been proposed to be associated with severe dengue progression. Thus, we aim to review the relationship between the available biomarkers and severe dengue.

METHODOLOGY

We performed a systematic review and meta-analysis to compare the differences in host data collected within 72 hours of fever onset amongst the different disease severity levels. We searched nine bibliographic databases without restrictive criteria of language and publication date. We assessed risk of bias and graded robustness of evidence using NHLBI quality assessments and GRADE, respectively. This study protocol is registered in PROSPERO (CRD42018104495).

PRINCIPAL FINDINGS

Of 4000 records found, 40 studies for qualitative synthesis, 19 for meta-analysis. We identified 108 host and viral markers collected within 72 hours of fever onset from 6160 laboratory-confirmed dengue cases, including hematopoietic parameters, biochemical substances, clinical symptoms, immune mediators, viral particles, and host genes. Overall, inconsistent case classifications explained substantial heterogeneity, and meta-analyses lacked statistical power. Still, moderate-certainty evidence indicated significantly lower platelet counts (SMD -0.65, 95% CI -0.97 to -0.32) and higher AST levels (SMD 0.87, 95% CI 0.36 to 1.38) in severe cases when compared to non-severe dengue during this time window.

CONCLUSION

The findings suggest that alterations of platelet count and AST level-in the first 72 hours of fever onset-are independent markers predicting the development of severe dengue.

Predictive analysis on gall bladder wall thickness as a marker for bleeding risk and need of transfusion in dengue patients

Increased gallbladder wall thickening (GBWT) is one manifestation of increased capillary permeability caused by severe dengue. This study was carried out to link the severity of GBWT with the bleeding risk and the need for transfusion. It was conducted retrospectively including all the patients with a diagnosis of dengue infection either via Dengue nonstructural protein-1 (NS-1) antigen or IgM antibody. Pearson's correlation, linear regression and receiver operating characteristic (ROC) curves were used for predictive analysis of GBWT with event of bleeding and need for transfusion of platelets during the hospital stay. A total of 177 participants met the inclusion criteria with a mean age of 33.17 ± 13.63 years. Mean GBWT was found to be 0.37 ± 0.15 cm, with 46.3% of patients had a thickness greater than 0.30 cm. A total of 16 patients were documented with bleeding events out of which 7.3% had minor bleeding and 1.7% had a major bleeding event. Linear regression analysis showed increased GBWT was found associated with decreased platelet count on admission (p=0.002) and lowest platelet counts (p=0.004). GBWT was found predictive of bleeding event and transfusion of platelets at higher sensitivity and specificity than platelet count on admission and lowest platelet counts.

Differential Expression of Human MicroRNAs During Dengue Virus Infection in THP-1 Monocytes

Dengue virus (DENV) is the most widespread arbovirus, responsible for a wide range of clinical manifestations, varying from self-limited illness to severe hemorrhagic fever. Dengue severity is associated with host intense proinflammatory response and monocytes have been considered one of the key cell types involved in the early steps of DENV infection and immunopathogenesis. To better understand cellular mechanisms involved in monocyte infection by DENV, we analyzed the expression levels of 754 human microRNAs in DENV-infected THP-1 cells, a human monocytic cell line. Eleven human microRNAs showed differential expression after DENV infection and gene ontology and enrichment analysis revealed biological processes potentially affected by these molecules. Five downregulated microRNAs were significantly linked to cellular response to stress, four to cell death/apoptosis, two to innate immune responses and one upregulated to vesicle mediated, TGF-β signaling, phosphatidylinositol mediated signaling, lipid metabolism process and blood coagulation.

Different Profiles of Cytokines, Chemokines and Coagulation Mediators Associated with Severity in Brazilian Patients Infected with Dengue Virus

The incidence of dengue in Latin America has increased dramatically during the last decade. Understanding the pathogenic mechanisms in dengue is crucial for the identification of biomarkers for the triage of patients. We aimed to characterize the profile of cytokines (IFN-γ, TNF-α, IL-1β, IL-6, IL-18 and IL-10), chemokines (CXCL8/IL-8, CCL2/MCP-1 and CXCL10/IP-10) and coagulation mediators (Fibrinogen, D-dimer, Tissue factor-TF, Tissue factor pathway inhibitor-TFPI and Thrombomodulin) during the dengue-4 epidemic in Brazil. Laboratory-confirmed dengue cases had higher levels of TNF-α (p < 0.001), IL-6 (p = 0.005), IL-10 (p < 0.001), IL-18 (p = 0.001), CXCL8/IL-8 (p < 0.001), CCL2/MCP-1 (p < 0.001), CXCL10/IP-10 (p = 0.001), fibrinogen (p = 0.037), D-dimer (p = 0.01) and TFPI (p = 0.042) and lower levels of TF (p = 0.042) compared to healthy controls. A principal component analysis (PCA) distinguished between two profiles of mediators of inflammation and coagulation: protective (TNF-α, IL-1β and CXCL8/IL-8) and pathological (IL-6, TF and TFPI). Lastly, multivariate logistic regression analysis identified high aspartate aminotransferase-to-platelet ratio index (APRI) as independent risk factors associated with severity (adjusted OR: 1.33; 95% CI 1.03–1.71; p = 0.027), the area under the receiver operating characteristics curve (AUC) was 0.775 (95% CI 0.681–0.869) and an optimal cutoff value was 1.4 (sensitivity: 76%; specificity: 79%), so it could be a useful marker for the triage of patients attending primary care centers.

Pseudobasophilia as a Screening Tool in Dengue: A Single Center Study

Objectives  Proper serological testing for the definite diagnosis of dengue is costly and may not be easily available in a resource-limited setting. Hematological parameters can help in the early identification of dengue cases. This study aims to evaluate the occurrence and utility of pseudobasophilia in identifying dengue-affected patients.

Materials and Methods  This retrospective cross-sectional study included 1,304 dengue cases confirmed by serology and 1,044 dengue serology negative acute febrile illness cases as controls. Complete blood count (CBC) values of the first EDTA (ethylenediamine tetraacetic acid) blood sample from automated hematology analyzers were reviewed. The hematological parameters in the dengue and control groups were compared and the variation of these parameters with the day of fever was also analyzed.

Statistical Analysis  Mann-Whitney’s test, Kruskal-Wallis test, and Fisher’s exact test were used for statistical analysis. A p -value < 0.05 was considered statistically significant for all tests.

Results  There was a statistically significant variation between dengue cases and controls for hematocrit, platelet count, mean platelet volume, total white blood cell count, and absolute basophil count. The dengue group had a higher hematocrit from day 2 to day 10, platelet count ≤ 100,000/µL from day 4 to day 9, higher mean platelet volume from day 2 to day 7, leucopenia from day 3 to day 5, and higher absolute basophil count from day 2 to day 10. Interestingly, pseudobasophilia was seen in 533 (40.87%) of dengue cases and only 3 (0.28%) of the controls. Pseudobasophilia was also observed to have an increasing trend to the day of fever.

Conclusion  Pseudobasophilia along with other CBC parameters is useful and cost effective for the early identification of dengue. This can prompt early investigations and supportive treatment leading to improved clinical outcomes.

Dengue virus 3 genotype I shows natural changes in heparan sulphate binding sites, cell interactions, and neurovirulence in a mouse model

Dengue virus (DENV) is the most prevalent pathogen of the Flaviviridae family. Due to the considerable increase in DENV incidence and spread, symptoms such as CNS involvement have increased. Heparan sulphate (HS) was the first molecule identified as an adhesion factor for DENV in mammalian cells. Viral phenotypes with different HS interactions are associated with various clinical symptoms, including neurological alterations. Here, using in silico analyses, in vitro studies, and the in vivo mouse model, we characterized two natural circulating DENV3 genotype I (GI) lineage 1 (L1) in Brazil-DENV3 MG-20 (from Minas Gerais) and DENV3 PV_BR (from Rondônia) that present divergent neurovirulent profiles and sensitivity to sulphated molecules. We identified substitutions at the viral envelope (E) in positions 62 and 123 as likely responsible for the differences in neurovirulence. The E62K and E123Q substitutions in DENV3 MG-20 and DENV3 PV_BR, respectively, greatly influenced in silico electrostatic density and heparin docking results. In vivo, mice inoculated with DENV3 MG-20 died, but not those infected with DENV3 PV_BR. The clinical symptoms, such as paralysis of the lower limbs and meningoencephalitis, and histopathology, also differed between the inoculated groups. In vitro heparin and heparinases assays further demonstrated the biological impact of these substitutions. Other characteristics that have been previously associated with alterations in cell tropism and neurovirulence, such as changes in the size of lysis plaques and differences in cytopathic effects in glioblastoma cells, were also observed.

Platelet enhancement by Carica papaya L. leaf fractions in cyclophosphamide induced thrombocytopenic rats is due to elevated expression of CD110 receptor on megakaryocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Carica papaya leaf juice/decoction has been in use in folk medicine in Srilanka, Malaysia and in few parts of India for enhancing the platelet counts in dengue. In Siddha medicine, a traditional form of medicine in India, papaya leaf juice has been used for increasing the platelet counts. Papaya leaf has been reported to enhance blood volume in ancient Ayurveda books in India. Carica papaya leaf is well known for its platelet enhancement activity. Although many preclinical and clinical studies have demonstrated the ability of papaya leaf juice for platelet enhancement, but the underlying mechanisms are still unclear.

AIM OF THE STUDY

The study is aimed at identifying the key ingredients of papaya leaf extract and elucidate the mechanism (s) of action of the identified potent component in mitigating thrombocytopenia (Thp).

MATERIALS AND METHODS

C. papaya leaf juice was subjected for sequential fractionation to identify the anti-thrombocytopenic phytochemicals. In vivo, stable thrombocytopenia was induced by subcutaneous injection of 70 mg/kg cyclophosphamide (Cyp). After induction, rats were treated with 200 and 400 mg/kg body weight papaya leaf juice and with identified fractions for 14 days. Serum thrombopoietin level was estimated using ELISA. CD110/cMpl, a receptor for thrombopoietin on platelets was measured by western blotting.

RESULTS

Administration of cyclophosphamide for 6 days induced thrombocytopenia (210.4 ± 14.2 × 103 cells/μL) in rats. Treating thrombocytopenic rats with papaya leaf juice and butanol fraction for 14 days significantly increased the platelet count to 1073.50 ± 29.6 and 1189.80 ± 36.5 × 103 cells/μL, respectively. C.papaya extracts normalized the elevated bleeding and clotting time and decreased oxidative markers by increasing endogenous antioxidants. A marginal increase in the serum thrombopoietin (TPO) level was observed in Cyp treated group compared to normal and treatment groups. Low expression of CD110/cMpl receptor found in Cyp treated group was enhanced by C. papaya extracts (CPJ) and CPJ-BT. Furthermore, examination of the morphology of bone marrow megakaryocytes, histopathology of liver and kidneys revealed the ability of CPJ and fractions in mitigating Cyp-induced thrombocytopenia in rats.

CONCLUSION

C. papaya leaf juice enhances the platelet count in chemotherapy-induced thrombocytopenia by increasing the expression of CD110 receptor on the megakaryocytes. Hence, activating CD110 receptor might be a viable strategy to increase the platelet production in individuals suffering from thrombocytopenia.

The atypical lymphocyte count: a novel predictive factor for severe thrombocytopenia related to dengue

BACKGROUND

Early identification of patients at risk of severe dengue disease (DD) is critical to guide its management. We evaluated whether the atypical lymphocyte count (ALC), generated from the Sysmex automated full blood count analyzer, is predictive of severe thrombocytopenia secondary to Dengue infection.

METHODS

We prospectively collected data on patients admitted with DD between December 2017 and October 2018. ALC data were extracted from the Sysmex XS500i analyzer from day 1 to day 7 of admission. Clinical data were obtained from patients' medical records.

RESULTS

We enrolled 256 patients with DD. A negative correlation between ALC on admission and platelet count on day 5 to day 7 (Spearmen's correlation; day 5:-0.485, day 6:-0.428 and day 7:-0.344) (p=0.001) was observed. Based on receiver operator characteristic curve analysis, we found that an ALC of >0.5x103/L had 90% sensitivity and 70% specificity for severe thrombocytopenia (platelet count <50x109/L) on day 5. The positive and negative predictive values were 74.4 and 91.2%, respectively (power 84.7).

CONCLUSIONS

We propose that ALC on admission may be a novel negative predictive factor for severe thrombocytopenia on day 5 to day 7 of DD. Further studies are required to validate our findings and evaluate whether ALC is predictive of other complications of DD.