Differential Profile of Hemostasis in Dengue Fever Before and After COVID-19.

Dengue and COVID-19 are viral diseases characterized by coagulopathies, with Dengue associated with fibrinolysis and COVID-19 with prothrombotic events. Furthermore, cross-reactivity between anti-SARS-CoV-2 and anti-DENV antibodies may confer protective immunity or exacerbate disease severity. Our investigation explored the impact of prior COVID-19 exposure on the immunopathogenesis of Dengue, focusing on hemostatic parameters. We quantified nitrites, procoagulant, anticoagulant, and fibrinolytic mediators in the plasma of Dengue patients before and after the COVID-19 pandemic. We also evaluated the influence of plasma from dengue patients on platelet activation in vitro using platelets from healthy donors exposed to DENV-2. Hemorrhagic manifestations were more frequent in pre-COVID-19 Dengue, while nitrite levels were elevated in post-COVID-19 Dengue patients, particularly among those without hemorrhagic signs. Among procoagulant factors, tissue factor (TF) levels were increased in post-COVID-19 Dengue, whereas Factor XIII was higher in pre-COVID-19 Dengue. In contrast, antithrombin (an anticoagulant) and plasminogen (a profibrinolytic factor) were more elevated in pre-COVID-19 Dengue than in post-COVID-19 cases. In vitro, DENV-2-infected platelets exposed to plasma of Dengue patients before and after COVID-19 showed decreased nitrite production in relation to DENV-2 alone. These findings suggest that prior COVID-19 exposure may influence hemostatic responses in Dengue, potentially modulating disease pathophysiology and opening new avenues for research and therapeutic strategies.