Imbalance of angiopoietin-1 and angiopoetin-2 in severe dengue and relationship with thrombocytopenia, endothelial activation, and vascular stability.

The pathogenesis of plasma leakage during dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) is largely unknown. Angiopoietins are key regulators of vascular integrity: Angiopoietin-1 is stored in platelets and maintains vascular integrity, and endothelium-derived angiopoietin-2 promotes vascular leakage. We determined angiopoietin-1 and angiopoietin-2 levels in a cohort of children in Indonesia with DHF/DSS and related them to plasma leakage markers. Patients with DHF/DSS had reduced angiopoietin-1 and increased angiopoietin-2 plasma levels on the day of admission when compared with levels at discharge and in healthy controls. There was an inverse correlation between angiopoietin-1 and markers of plasma leakage and a positive correlation between angiopoietin-2 and markers of plasma leakage. Angiopoietin-1 levels followed the same trend as the soluble platelet activation marker P-selectin and correlated with platelet counts. Dengue-associated thrombocytopenia and endothelial activation are associated with an imbalance in angiopoietin-2: angiopoietin-1 plasma levels. This imbalance may contribute to the transient plasma leakage in DHF/DSS.