Association of Intracellular T(H)1-T(H)2 Balance in CD4+ T-cells and MIP-1α in CD8+ T-cells with Disease Severity in Adults with Dengue

Dengue fever in hyperglycemic patients: an emerging public health concern demanding eyes on the effective management strategies

Background and aims

Hyperglycemia, also known as diabetes, is a metabolic disorder characterized by elevated levels of glucose in the bloodstream. It can lead to the prolonged dysfunction, injury, and deterioration of several organs. In addition, dengue is a viral illness transmitted by mosquitoes that has reached epidemic proportions worldwide. In this article, we focused on the severity of comorbidities, difficulties in managing them, and preventive measures meant to lessen the risks associated with comorbidities in diabetic patients with dengue infection.

Methods

We explored a number of databases, including PubMed, Scopus, Embase, Web of Science, Google Scholar, and the Cochrane Library, for this review article using various related keywords.

Results

The findings of this review article indicate that elderly dengue patients with diabetes should be admitted to the hospital for close observation and early management using fluid therapy. An observed association exists between dengue hemorrhagic fever (DHF) and diabetes, indicating a possible consequence in this specific group. Additionally, patients with diabetes who contract dengue show elevated levels of inflammatory markers. Diabetes mellitus deteriorates the immune system, which exacerbates the progression of dengue fever. Cutting-edge technology and scientific research may assist in addressing the challenges that diabetes and dengue viruses pose in low- and middle-income countries. Implementing innovative diabetic care management is essential to ensuring consistency of care, improving a healthy lifestyle, and lowering patient risk factors and comorbidities.

Conclusion

Dengue fever has spread to epidemic levels throughout the world. Inflammatory markers increase and the prevalence of DHF is greater in diabetes individuals with dengue infection. Given the continued growth of dengue in Asian nations, it is imperative that we concentrate our efforts and resources on providing more precise and effective treatment for this emerging issue.

Viral infection and host immune response in diabetes

Diabetes, a chronic metabolic disorder disrupting blood sugar regulation, has emerged as a prominent silent pandemic. Uncontrolled diabetes predisposes an individual to develop fatal complications like cardiovascular disorders, kidney damage, and neuropathies and aggravates the severity of treatable infections. Escalating cases of Type 1 and Type 2 diabetes correlate with a global upswing in diabetes-linked mortality. As a growing global concern with limited preventive interventions, diabetes necessitates extensive research to mitigate its healthcare burden and assist ailing patients. An altered immune system exacerbated by chronic hyperinflammation heightens the susceptibility of diabetic individuals to microbial infections, including notable viruses like SARS-CoV-2, dengue, and influenza. Given such a scenario, we scrutinized the literature and compiled molecular pathways and signaling cascades related to immune compartments in diabetics that escalate the severity associated with the above-mentioned viral infections in them as compared to healthy individuals. The pathogenesis of these viral infections that trigger diabetes compromises both innate and adaptive immune functions and pre-existing diabetes also leads to heightened disease severity. Lastly, this review succinctly outlines available treatments for diabetics, which may hold promise as preventive or supportive measures to effectively combat these viral infections in the former.

An open-label, randomized prospective study to evaluate the efficacy and safety of Carica papaya leaf extract for thrombocytopenia associated with dengue fever in pediatric subjects

Objective

Thrombocytopenia in dengue fever (DF) is a well-known complication in both adults and pediatric subjects. Management of DF primarily includes symptomatic and intensive supportive care. There are studies available on the efficacy and safety of Carica papaya leaf extract (CPLE) in adult patients with DF. However, there are no published studies available on the efficacy and safety of CPLE in the pediatric age group. Hence, this study was conducted.

Methodology

A prospective, open-label, randomized controlled study was conducted in subjects aged between 1 and 12 years having thrombocytopenia associated with DF (NS-1 antigen positive) or dengue hemorrhagic fever (DHF) grades I and II. All participants were randomized into the intervention group (n =147, CPLE syrup + standard therapy) and the control group (n=147, received only standard therapy). All subjects were followed up daily for 5 days with monitoring of blood counts.

Results

A total of 285 subjects were finally evaluated for efficacy, and nine dropped out (seven in the control group and two in the intervention group). However, all 294 subjects were evaluated for safety. CPLE (Caripill) syrup increased the platelet count significantly compared to the control group (P<0.05). In the intervention group, the platelet count increased from day 3 onward: platelet count on day 3 (mean platelet count =89,739.31, P=0.030), day 4 (mean platelet count =120,788.96, P=0.019), and day 5 (mean platelet count =168,922.75 P=0.023). Two children complained of nausea in the intervention group. Overall, Caripill syrup was well tolerated.

Conclusion

CPLE syrup significantly increases the platelet count in pediatric DF patients and is well tolerated.

Associations of DC-SIGN (CD209) promoter -336G/A polymorphism (rs4804803) with dengue infection: A systematic review and meta-analysis

BACKGROUND AND AIM

Dengue virus entry into a host is associated with a cell surface protein, DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3 grabbing non-integrin). A common CD209-336G/A (rs4804803) polymorphism in DC-SIGN may affect severity of dengue virus infection (DEN) and incidence of dengue fever (DF) or the more severe dengue hemorrhagic fever (DHF). However, the reported associations of these two outcomes and CD-209 have been inconsistent, which prompted a meta-analysis to obtain more precise estimates.

METHODS

A literature search yielded seven case-control studies. We calculated pooled odds ratios (OR) and 95% confidence intervals using standard genetic models. Outlier treatment examined sources of potential heterogeneity. Subgroup analysis was performed for ethnicity and age.

RESULTS

All significant outcomes for association indicating reduced risk were pegged at P=0.007-0.05. In the homozygous and recessive models, these were observed in the overall analysis (OR 0.52-0.55), and subgroups of South/Central Americans (OR 0.30-0.32) and school-age children (OR 0.44) in the DHF analysis as well as the codominant model among Asians in DF (OR 0.59). These significant outcomes are strengthened by their non-heterogeneity (P>0.10) and robustness of the effects. Most pooled effects in DF and DEN were variable.

CONCLUSIONS

The DC-SIGN -336G/A polymorphism significantly affects DHF and DF incidence with the effect more pronounced in certain analyzed patient subgroups.

Polymorphism of DC-SIGN (CD209) promoter in association with clinical symptoms of dengue fever

C-type lectin DC-SIGN receptor, encoded by CD209, plays a key role in the infection of dendritic cells by dengue virus (DENV). Because the -336A/G SNP (rs4804803) polymorphism in the promoter of CD209 modulates DC-SIGN expression, we investigated the putative association of this polymorphism with DENV infection and its pathogenesis. A control sample of 72 individuals, rigorously selected through a clinical investigation for absence of past dengue fever (DF) was compared to a sample of 168 patients (156 classical DF; 12 dengue hemorrhagic fever), all residents from Pará, Brazil. However, the prevalence of symptoms showed a trend higher in the AA genotype (Wilcoxon test; Z=2.02; p=0.04). Hence, our findings indicate that the G allele downregulates the spectrum of symptoms during the early acute phase of DENV infection, putatively decreasing the viremia, as suggested in the literature.

Apoptotic mediators in patients with severe and non-severe dengue from Brazil

Despite being the most significant arboviral disease worldwide, dengue has no antiviral treatment or reliable severity predictors. It has been shown that apoptotic cells from blood and tissues may be involved in the complex pathogenesis of dengue. However, very little is known about the interplay between proapoptotic and antiapoptotic mediators in this disease. Therefore, plasma levels of the three proapoptotic mediators Fas ligand (FasL), tumor necrosis factor‐α (TNF‐α), and TNF‐related apoptosis‐inducing ligand (TRAIL) were measured in dengue patients. Patients were classified according to the World Health Organization classification of dengue revised in 2009. Additionally, inhibitors of apoptosis protein (IAPs) were determined in plasma (Survivin) and peripheral blood mononuclear cells (PBMCs) lysates (cIAP‐1, cIAP‐2, XIAP). Levels of apoptotic proteins in plasma were correlated with counts of blood cells. FasL and TRAIL levels were elevated in dengue patients without warning signs when compared to patients with severe dengue and controls. Dengue patients with warning signs showed decreased levels of Survivin compared to patients with severe dengue and controls. TRAIL was inversely correlated with counts of lymphocyte subsets. In contrast, Survivin was positively correlated with leukocyte counts. There was a trend of elevated IAPs levels in PBMCs of patients with severe dengue. The results suggest a likely antiviral effect of TRAIL in dengue. It appears that TRAIL might be involved with apoptosis induction of lymphocytes, whereas IAPs might participate in protecting leukocytes from apoptosis. Further research is needed to explore the interactions between pro and antiapoptotic molecules and their implications in dengue pathogenesis. J. Med. Virol. 86:1437–1447, 2014. © 2013 Wiley Periodicals, Inc.

The battle between infection and host immune responses of dengue virus and its implication in dengue disease pathogenesis

Dengue virus (DENV) is a mosquito-transmitted single stranded RNA virus belonging to genus Flavivirus. The virus is endemic in the tropical and subtropical countries of the world, causing diseases classified according to symptoms and severity (from mild to severe) as dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Among a variety of human cell types targeted by DENV, monocytes, macrophages, and dendritic cells are members of innate immunity, capable of mounting rapid inflammatory responses. These cells are also major antigen presenting cells, responsible for activating the adaptive immunity for long-term memory. This paper is an overview of the current understanding of the following mutually affected aspects: DENV structure, viral infectivity, cellular receptors, innate immune response, and adaptive immunity.

Dengue in India

Dengue virus belongs to family Flaviviridae, having four serotypes that spread by the bite of infected Aedes mosquitoes. It causes a wide spectrum of illness from mild asymptomatic illness to severe fatal dengue haemorrhagic fever/dengue shock syndrome (DHF/DSS). Approximately 2.5 billion people live in dengue-risk regions with about 100 million new cases each year worldwide. The cumulative dengue diseases burden has attained an unprecedented proportion in recent times with sharp increase in the size of human population at risk. Dengue disease presents highly complex pathophysiological, economic and ecologic problems. In India, the first epidemic of clinical dengue-like illness was recorded in Madras (now Chennai) in 1780 and the first virologically proved epidemic of dengue fever (DF) occurred in Calcutta (now Kolkata) and Eastern Coast of India in 1963-1964. During the last 50 years a large number of physicians have treated and described dengue disease in India, but the scientific studies addressing various problems of dengue disease have been carried out at limited number of centres. Achievements of Indian scientists are considerable; however, a lot remain to be achieved for creating an impact. This paper briefly reviews the extent of work done by various groups of scientists in this country.

Regulation of inflammatory chemokine receptors on blood T cells associated to the circulating versus liver chemokines in dengue fever

Little is known about the role of chemokines/chemokines receptors on T cells in natural DENV infection. Patients from DENV-2 and -3- outbreaks were studied prospectively during the acute or convalescent phases. Expression of chemokine receptor and activation markers on lymphocyte subpopulations were determined by flow cytometry analysis, plasma chemokine ligands concentrations were measured by ELISA and quantification of CCL5/RANTES⁺ cells in liver tissues from fatal dengue cases was performed by immunochemistry. In the acute DENV-infection, T-helper/T-cytotoxic type-1 cell (Th1/Tc1)-related CCR5 is significantly higher expressed on both CD4 and CD8 T cells. The Th1-related CXCR3 is up-regulated among CD4 T cells and Tc2-related CCR4 is up-regulated among CD8 T cells. In the convalescent phase, all chemokine receptor or chemokine ligand expression tends to reestablish control healthy levels. Increased CCL2/MCP-1 and CCL4/MIP-1β but decreased CCL5/RANTES levels were observed in DENV-patients during acute infection. Moreover, we showed an increased CD107a expression on CCR5 or CXCR3-expressing T cells and higher expression of CD29, CD44^HIGH and CD127^LOW markers on CCR4-expressing CD8 T cells in DENV-patients when compared to controls. Finally, liver from dengue fatal patients showed increased number of cells expressing CCL5/RANTES in three out of four cases compared to three death from a non-dengue patient. In conclusion, both Th1-related CCR5 and CXCR3 among CD4 T cells have a potential ability to exert cytotoxicity function. Moreover, Tc1-related CCR5 and Tc2-related CCR4 among CD8 T cells have a potential ability to exert effector function and migration based on cell markers evaluated. The CCR5 expression would be promoting an enhanced T cell recruitment into liver, a hypothesis that is corroborated by the CCL5/RANTES increase detected in hepatic tissue from dengue fatal cases. The balance between protective and pathogenic immune response mediated by chemokines during dengue fever will be discussed.

Frequency of T cell expressing Th1 and Th2 associated chemokine receptor in patients with renal allograft dysfunction

Acute rejection of human renal allografts is a frequent, serious posttransplantation complication, occurring in up to 50% of recipients. Leukocyte recruitment is a central feature of acute allograft rejection. Chemokine receptors are expressed on leukocytes in a cell type-specific manner. Recently CCR5+ and CXCR3+ cells have been observed in allograft biopsy specimens of patients undergoing acute cellular rejection (ACR). Herein we investigated the expression of Th1 (CCR5, CXCR3, and CCR2) and Th2 (CCR4, CCR3, and CCR8)-associated chemokine receptors on CD4 and CD8 T-cell populations. We sought to correlate chemokine receptor expression in peripheral blood T-cell subsets with the types of graft dysfunction (biopsy-proven rejections). In the peripheral blood CD4+ and CD8+ T-cell populations of patients with graft dysfunction, we observed a high frequency of Th1-associated chemokine receptors CCR5+ and CCR2+ but not CXCR3.

Nitric oxide activity in platelets of dengue haemorrhagic fever patients: the apparent paradoxical role of ADMA and l-NMMA

Dengue haemorrhagic fever (DHF) is a prevalent acute disease that occurs in patients infected by an arbovirus in tropical and subtropical regions. We have previously shown increased intraplatelet nitric oxide (NO) production in patients with dengue fever associated with reduced platelet aggregation. In this study, l-arginine transport as well as expression and activity of nitric oxide synthase (NOS) isoforms in the presence or absence of l-arginine analogues were examined in 23 DHF patients. l-arginine transport and NOS activity in platelets were increased in patients with DHF compared with controls. However, platelet endothelial NOS (eNOS) and inducible (iNOS) protein levels did not differ between healthy controls and DHF patients. Endogenous or exogenous analogues did not inhibit platelet NOS activity from DHF patients. In contrast, endogenous l-arginine analogues [N(G)-monomethyl-l-arginine (l-NMMA) and asymmetric dimethylarginine (ADMA)] inhibited NOS activity in platelets from healthy subjects. These results show the first evidence that the intraplatelet l-arginine-NO pathway is activated in DHF patients. The lack of inhibition of NO formation in vitro by all l-arginine analogues tested in DHF platelets may suggest another mechanism by which NOS activity can be regulated.

Dengue and soluble mediators of the innate immune system

Huge emphasis has been placed on the role of the adaptive immune system in dengue pathogenesis. Yet there is increasing evidence for the importance of the innate immune system in regulating dengue infection and possibly influencing the disease. This review focuses on the interplay between the innate immune system and dengue and highlights the role of soluble immunological mediators. Type I and type II interferons of the innate immune system demonstrate non-overlapping roles in dengue infection. Furthermore, while some IFN responses to dengue are protective, others may exert disease-related effects on the host. But aside from interferons, a number of cytokines have also been implicated in dengue pathogenesis. Our expanding knowledge of cytokines indicates that these soluble mediators act upon a complicated network of events to provoke the disease. This cytokine storm is generally attributed to massive T cell activation as an outcome of secondary infection. However, there is reason to believe that innate immune response-derived cytokines also have contributory effects, especially in the context of severe cases of primary dengue infection. Another less popular but interesting perspective on dengue pathogenesis is the effect of mosquito feeding on host immune responses and viral infection. Various studies have shown that soluble factors from vector saliva have the capacity to alter immune reactions and thereby influence pathogen transmission and establishment. Hence, modulation of the innate immune system at various levels of infection is a critical component of dengue disease. In the absence of an approved drug or vaccine for dengue, soluble mediators of the innate immune system could be a strategic foothold for developing anti-viral therapeutics and improving clinical management.