We report a case of dengue hemorrhagic fever (DHF) complicated by acute myocarditis and review the literature. A 65-year-old woman experienced DHF due to dengue virus serotype 3, complicated with acute myocarditis and acute pulmonary edema. Clinically this masqueraded as acute myocardial infarction, with an electrocardiographically depressed ST segment in precordial leads and elevated serum cardiac-specific troponin I level. Under supportive management, the patient recovered 3 days later. A total of 18 pertinent articles involving 339 dengue-affected patients with cardiac complications were found by PubMed search. Clinical manifestations of cardiac complications varied considerably, from self-limiting tachy-brady arrhythmia to severe myocardial damage, leading to hypotension and pulmonary edema. Although rare, a fatal outcome was reported in some cases of dengue with cardiac complications. To avoid otherwise preventable morbidity and mortality, physicians should have a high index of suspicion for cardiac complications in patients with dengue illness and should manage this accordingly.
BackgroundThe C-type lectin DC-SIGN (CD209) is known to be the major dengue receptor on human dendritic cells, and a single nucleotide polymorphism (SNP) in the promoter region of CD209 (−336 A/G; rs4804803) is susceptible to many infectious diseases. We reason that variations in the DC-SIGN gene might have a broad influence on viral replication and host immune responses.Methods and FindingsWe studied whether the rs4804803 SNP was associated with a susceptibility to dengue fever (DF) and/or dengue hemorrhagic fever (DHF) through genotyping analysis in a Taiwanese cohort. We generated monocyte-derived dendritic cells (MDDCs) from individuals with AA or AG genotype of rs4804803 to study the viral replication and immune responses for functional validation. A total of 574 DNA samples were genotyped, including 176 DF, 135 DHF, 143 other non-dengue febrile illnesses (OFI) and 120 population controls. A strong association between GG/AG genotypes of rs4804803 and risk of DHF was found when compared among DF, OFI and controls (p = 0.004, 3×10−5 and 0.001, respectively). The AA genotype was associated with protection against dengue infection compared with OFI and controls (p = 0.002 and 0.020, respectively). Moreover, MDDCs from individuals with AG genotype with a higher cell surface DC-SIGN expression had a significantly higher TNFα, IL-12p40, and IP-10 production than those with AA genotype in response to dengue infection. However, the viral replication in MDDCs with AG genotype was significantly lower than those with AA genotype. With both genotypes, MDDCs revealed an increase in viral replication following the addition of anti-IP-10 neutralizing antibody.Conclusions/SignificanceThe rs4804803 SNP in the CD209 promoter contributed to susceptibility to dengue infection and complication of DHF. This SNP with AG genotype affects the cell surface DC-SIGN expression related to immune augmentation and less viral replication.
Septic shock is a determinant of fatality in patients with V vulnificus septicemia without HBNCLs; our data suggest that the combination of a third-generation cephalosporin and tetracycline or its analogue may be a better choice in antimicrobial treatment of V vulnificus septicemic patients with HBNCLs.
IntroductionThe adverse effects of delayed admission to the intensive care unit (ICU) have been recognized in previous studies. However, the definitions of delayed admission vary across studies. This study proposed a model to define ‘delayed admission’, and explored the effect of ICU waiting time on patients’ outcome.MethodsThis retrospective cohort study included nontraumatic adult patients on mechanical ventilation in the emergency department (ED), from July 2009 to June 2010. The primary outcomes measures were 21-ventilator-day mortality and prolonged hospital stays (over 30 days). Models of Cox regression and logistic regression were used for multivariate analysis. The non-delayed ICU waiting was defined as a period in which the time effect on mortality was not statistically significant in a Cox regression model. To identify a suitable cutoff point between ‘delayed’ and ‘non-delayed’ subsets from the overall data were made based on ICU waiting time and the hazard ratio of ICU waiting hour in each subset was iteratively calculated. The cutoff time was then used to evaluate the impact of delayed ICU admission on mortality and prolonged length of hospital stay.ResultsThe final analysis included 1,242 patients. The time effect on mortality emerged after 4 hours, thus we deduced ICU waiting time in the ED of >4 hours as delayed. By logistic regression analysis, delayed ICU admission affected the outcomes of 21-ventilator-day mortality and prolonged hospital stay, with an odds ratio of 1.41 (95% confidence interval, 1.05 to 1.89) and 1.56 (95% confidence interval, 1.07 to 2.27) respectively.ConclusionsFor patients on mechanical ventilation in the ED, delayed ICU admission is associated with higher probability of mortality and additional resource expenditure. A benchmark waiting time of no more than 4 hours for ICU admission is recommended.
Severe acute respiratory syndrome (SARS) has spread to a global pandemic, especially in Asia. The transmission route of SARS has been clarified, but the immunopathogenesis of SARS is unclear. In an age-matched case-control design, we studied immune parameters in 15 SARS patients who were previously healthy. Plasma was harvested for detection of virus load, cytokines, and nitrite/nitrate levels, and blood leukocytes were subjected to flow cytometric analysis of intracellular mitogen-activated protein kinases (MAPKs) in different leukocytes. Patients with SARS had significantly higher IL-8 levels (p = 0.016) in early stage, and higher IL-2 levels (p = 0.039) in late stage than normal controls. Blood TNF-α, IL-6, and IL-10, and nitrite/nitrate levels were not significantly elevated. In contrast, TGF-β and PGE2 levels were significantly elevated in SARS patients. Five of the 15 SARS patients had detectable coronaviruses in blood, but patients with detectable and undetectable viremia had no different profiles of immune mediators. Flow cytometric analysis of MAPKs activation by phospho-p38 and phospho-p44/42 (extracellular signal-regulated kinase) expression showed that augmented p38 activation (p = 0.044) of CD14 monocytes associated with suppressed p38 activation (p = 0.033) of CD8 lymphocytes was found in SARS patients. These results suggest that regulation of TGF-β and PGE2 production and MAPKs activation in different leukocytes may be considered while developing therapeutics for the SARS treatment.
The immunopathogenesis of leukopenia and thrombocytopenia in patients with severe acute respiratory syndrome (SARS) is unclear. In order to explore the leukopenia mechanism, we studied 15 SARS patients who were previously healthy, and 15 age-matched normal controls in a paired design. Soluble vascular cell adhesion molecule-1 (sVCAM-1) and soluble Fas ligand (sFasL) in plasma were measured by ELISA, and intracellular activated caspase-3 fragment in different leukocytes was determined by flow cytometry. Patients with SARS had significantly lower lymphocyte and platelet counts and significantly higher sVCAM-1 and sFasL levels compared to healthy controls. sVCAM-1 levels correlated negatively with total leukocytes and platelet counts, but positively with plasma sFasL levels. Intracellular cleaved caspase-3 expression was also significantly higher in lymphocytes from SARS patients in acute phase than in convalescent stage. Lymphopenia and thrombocytopenia in SARS patients may be caused, in part, by enhanced vascular sequestration associated with increased sVCAM-1 levels. However, lymphopenia may be due to enhanced cell death. Inhibition of cell adhesion and caspase-3 activation could, therefore, have prevented SARS patients from developing thrombocytopenia and lymphopenia.
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