Neurological manifestations in dengue

Clinical and Laboratory Characteristics of Hemophagocytic Lymphohistiocytosis in Children With Severe Dengue During the 2019-2020 Outbreak in Southern Colombia

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is characterized by uncontrolled activation of inflammatory cells and an exaggerated release of cytokines. It can be triggered by different factors, including viruses, such as dengue. The objective of this study was to characterize the clinical and laboratory profiles of children with severe dengue and HLH, and to identify the risk factors for this clinical complication.

METHODS

An analytical study was conducted in children with severe dengue who were treated in an intensive care unit between January 2019 and March 2020. Clinical and laboratory factors were compared between patients with and without HLH.

RESULTS

HLH represented 13.4% (15/112) of children with severe dengue. Patients with HLH had a long-lasting fever (10.1 vs. 5.8 days; P = 0.012), low hemoglobin levels (7.6 vs. 10.8 g/dL; P = 0.000) and high aspartate aminotransferase values (4443 vs. 1061 U/L; P = 0.002), alanine transaminase (1433 vs. 487 U/L; P = 0.004), partial thromboplastin time (80.6 vs. 51.8 seconds; P = 0.010), prothrombin time (23.5 vs. 19.6 seconds; P = 0.024), triglycerides (333.7 vs. 223.2 mg/dL; P = 0.005), lactate dehydrogenase (4209 vs. 1947 U/L; P = 0.006), soluble CD25 (3488 vs. 1026 pg/mL; P = 0.014), and presented with higher frequency of myocarditis (66.7% vs. 38.3%; P = 0.048), hepatitis (5.3% vs. 1.3%; P = 0.014), bacterial coinfection (73.3% vs. 26.7%; P = 0.010) and fatal outcome (26% vs. 5%; P = 0.037).

CONCLUSIONS

HLH is a serious life-threatening clinical complication of dengue virus infection that must be considered, particularly during outbreaks.

Vimentin Inhibits Dengue Virus Type 2 Invasion of the Blood-Brain Barrier

Dengue virus (DENV) causes dengue fever, which is prevalent in the tropical and subtropical regions, and in recent years, has resulted in several major epidemics. Vimentin, a cytoskeletal component involved in DENV infection, is significantly reorganized during infection. However, the mechanism underlying the association between DENV infection and vimentin is still poorly understood. We generated vimentin-knockout (Vim-KO) human brain microvascular endothelial cells (HBMECs) and a Vim-KO SV129 suckling mouse model, combining the dynamic vimentin changes observed in vitro and differences in disease course in vivo, to clarify the role of vimentin in DENV-2 infection. We found that the phosphorylation and solubility of vimentin changed dynamically during DENV-2 infection of HBMECs, suggesting the regulation of vimentin by DENV-2 infection. The similar trends observed in the phosphorylation and solubility of vimentin showed that these characteristics are related. Compared with that in control cells, the DENV-2 viral load was significantly increased in Vim-KO HBMECs, and after DENV-2 infection, Vim-KO SV129 mice displayed more severe disease signs than wild-type SV129 mice, as well as higher viral loads in their serum and brain tissue, demonstrating that vimentin can inhibit DENV-2 infection. Moreover, Vim-KO SV129 mice had more disordered cerebral cortical nerve cells, confirming that Vim-KO mice were more susceptible to DENV-2 infection, which causes severe brain damage. The findings of our study help clarify the mechanism by which vimentin inhibits DENV-2 infection and provides guidance for antiviral treatment strategies for DENV infections.