Plasma Levels of Inter-α Inhibitor Proteins in Children with Acute Dengue Virus Infection

Background: Inter-α inhibitor proteins (IaIp) belong to a family of protease inhibitors that are involved in the haemostatic and the vascular system. Dengue viruses (DENV) infections are characterized by coagulopathy and increased vascular permeability. In this study we measured the concentration of IaIp during DENV infections and evaluated its potential as a biomarker. Methods and Findings: Concentrations of IaIp were measured in patients with acute DENV infections using a quantitative, competitive enzyme linked immunoassay. Concentrations of IaIp measured in pediatric patients suffering from severe DENV infections were significantly lower than in healthy controls. Conclusions: This is the first report to demonstrate changes in concentration of IaIp during viral infections. The data also highlight the potential of IaIp as a biological marker for severity of DENV infections

Differential Gene Expression Changes in Children with Severe Dengue Virus Infections

Dengue virus infection is an impressively emerging disease that can be fatal in severe cases. It is not precisely clear why some patients progress to severe disease whereas most patients only suffer from a mild infection. In severe disease, a “cytokine storm” is induced, which indicates the release of a great number of inflammatory mediators (“cytokines”). Evidence suggested that a balance could be involved between protective and pathologic cytokine release patterns. We studied this concept in a cohort of Indonesian children with severe dengue disease using a gene expression profiling method

Risk Factors for Mortality in Dengue Shock Syndrome (DSS)

Background: Dengue shock syndrome (DSS) is the most severe form of dengue hemorrhagic fever (DHF) and has a high mortality. There are two major pathological changes in DHF determining the severity of disease, plasma leakage and bleeding. Cytokines released during the immune response to dengue virus have been thought to be mediators of the process. Methods: The study involved 50 children with DSS, of whom 13 (26%) died. We investigated which clinical signs and laboratory findings are related to mortality. Results: We found that gastrointestinal bleeding and bilateral pleural effusion were significantly more frequent in non-survivors than in survivors (p<0.02 and p=0.0006, respectively). Also, mean admission levels of thrombin-antithrombin complexes (TATc) and plasminogen activator inhibitor type 1 (PAI-1), activation markers of coagulation and fibrinolysis, respectively, were significantly higher in non-survivors (p=0.004 and p=0.0006, respectively). In regression analysis, bilateral pleural effusion and admission levels of TATc were significantly associated with mortality (p=0.007 and p=0.048, respectively). Conclusions: Our data provide evidence for a relationship of mortality with pleural effusion, a marker of plasma leakage, and coagulation activation, both characteristic pathological changes in dengue shock syndrome

Cytokine patterns during dengue shock syndrome

Objective. To investigate the patterns of tumor necrosis factor-a (TNF-a), interleukin-1b (IL-1b), IL-6, interferon-c (IFN-c) and interleukin-1 receptor antagonist (IL-1Ra) during the course of dengue shock syndrome. Design. Prospective clinical study. Setting. Pediatric Intensive Care Unit, Dr. Kariadi Hospital, the university hospital of Diponegoro University, Semarang, Indonesia. Patients. Fifty children with dengue shock syndrome. Measurements. The plasma concentration and the ex vivo production, with and without lipopolysaccharide (LPS), of TNF-a, IL-1b and IL-1Ra were measured in duplicate by nonequilibrium radioimmunoassay (RIA); IFN-c and IL-6 were measured by ELISA. Results. During the acute phase, the plasma concentrations and the ex vivo production without LPS of IL-1Ra were considerably elevated and returned to normal on recovery. However, the ex vivo LPS-stimulated production of the proinflammatory cytokines TNF-a and IL-1b were considerably depressed. Also, these concentrations returned towards normal on recovery. In non-survivors, the plasma concentrations of IL-6 and IL-1Ra were significantly higher than in survivors (p < 0.00001 and p = 0.0005, respectively). In addition, the ex vivo production of IL-1Ra in non-survivors was significantly higher than in survivors, both without LPS stimulation (p = 0.0008) and with LPS (p < 0.004). IL-1Ra was significantly associated with mortality (p = 0.007). Conclusion. Since IL-1Ra was significantly associated with mortality, this measurement may be used as an index of disease severity in dengue shock syndrome

The Role of Cytokines in Activation of Coagulation and Fibrinolysis in Dengue Shock Syndrome

In a prospective clinical study of 50 patients with Dengue Shock Syndrome (DSS), we investigated the association of tumor necrosis factor- (TNF-), interleukin-1 (IL-1), IL-1 receptor antagonist (IL-1Ra), and IL-6 with activation markers of coagulation (F1+2 and TATc) and fibrinolysis (t-PA, PAPc, and D-dimer). We found that TNF-, IL-1 and Il-1Ra, but not IL-6, concentrations were elevated in the circulation during the early stage of infection and at discharge from hospital. TNF- was significantly associated with D-dimer, an activation marker of fibrinolysis (p < 0.003), but not with activation markers of coagulation. IL-1 was significantly associated with t-PA (p < 0.03). IL-1Ra was significantly associated with F1+2, TATc (p < 0.04 and p < 0.02, respectively), whereas IL-6 was significantly associated with both, activation markers of coagulation (F1+2; p < 0.03) and fibrinolysis (PAPc; p = 0.002). Our data are in line with studies in bacterial sepsis. In severe dengue virus infection the same cytokines are involved in the onset and regulation of hemostasis

Detection of Immune-Complex-Dissociated Nonstructural-1 Antigen in Patients with Acute Dengue Virus Infections

Accurate and timely diagnosis of dengue virus (DEN) infections is essential for the differential diagnosis of patients with febrile illness and hemorrhagic fever. In the present study, the diagnostic value of a newly developed immune-complex dissociated nonstructural-1 (NS-1) antigen dot blot immunoassay (DBI) was compared to a commercially available DEN antigen detection kit (denKEY Blue kit; Globio Co., Beverly, Mass.) and a reverse transcription-PCR (RT-PCR) kit. Serial serum or plasma samples (n = 181) obtained from 55 acute DEN-infected patients were used. In samples obtained from 32 of these 55 DEN-infected patients, viral RNA could be detected by RT-PCR. DEN antigen was detected in only 10 of these 55 patient samples by using the denKEY kit. When these samples were treated with acid to release the immune-complex-associated NS-1 antigen for detection by DBI, 43 of these 55 patients were found to be positive for DEN NS-1 antigen. In nondissociated samples, 22 of these patients were found to be positive by the DBI. In the presence of DEN-specific immunoglobulin M antibodies, both viral RNA and DEN (NS-1) antigen could be detected. The number of positive samples identified by RT-PCR and DBI from these patients with primary DEN infections varied between 28 and 78%. In secondary DEN infections, the number of samples that tested positive by the DBI after immune-complex dissociation (DIS-DBI) was 25% higher than the number of samples that tested positive by RT-PCR and was 35% higher than that determined by nondissociated antigen (NDIS-DBI) detection. We conclude that the denKEY kit has limited diagnostic value for acute DEN infections compared to the RT-PCR and the NDIS-DBI and DIS-DBI methods. We clearly demonstrate that in secondary DEN infections the dissociation of NS-1 immune complexes is essential for early diagnosis of DEN infections

Elevated levels of total and dengue virus-specific immunoglobulin E in patients with varying disease severity

The kinetics of total and dengue virus-specific immunoglobulin E (IgE) were studied in serial serum samples obtained from 168 patients, 41 of whom suffered from primary dengue virus infection and 127 suffered from secondary dengue virus infection. Seventy-one patients were classified as dengue fever, 30 as dengue hemorrhagic fever, and 67 as dengue shock syndrome. A control group included single serum samples from patients with a herpes virus infection (n = 14), non-dengue febrile patients (n = 10), and healthy blood donors (n = 10). Patients with dengue virus infection had higher levels of total and dengue virus-specific IgE than non-dengue patients (P < 0.05). Patients with secondary dengue virus infections had not significantly increased levels of both total and dengue virus-specific IgE in the acute phase of disease compared to patients with primary dengue virus infections. Dengue virus-specific IgE was significantly higher in dengue hemorrhagic fever and/or dengue shock syndrome patients compared to dengue fever and non-dengue patients (P < 0.05). In conclusion, this study showed elevated total and dengue virus-specific IgE serum antibody levels in the acute stage of disease. Therefore, measurement of both total and dengue virus-specific IgE serum antibodies can be used as an additional prognostic marker in the development of severe complications in dengue virus infections. In addition, the presence and increase of dengue virus-specific IgE serum antibodies in patients with dengue virus infections is suggestive of the pathogenetic role that IgE may play in the hemostatic disorders observed in dengue hemorrhagic fever and dengue shock syndrom

Characteristics of patients included in the study.

<p>*on time of admission.</p><p>n.a.: not applicable.</p

Concentration of IaIp in DENV infected patients with varying disease severity on different time points after infection.

<p>Data are depicted as mean ± standard deviation.</p