COVID-19: A Disease Driven by Protease/Antiprotease Imbalance? A Specific Review Five Years into the Pandemic.

COVID-19, caused by SARS-CoV-2, has profoundly impacted global health since late 2019. Beyond respiratory complications, the disease involves systemic manifestations driven by immune dysregulation, inflammation, and coagulopathy. Among the many mechanisms implicated in severe disease, a growing body of evidence suggests a central role for the imbalance between proteases and antiproteases. This review examines how dysregulated protease activity contributes to viral entry, cytokine activation, vascular injury, and thrombosis. We focus on the integration of proteolytic systems such as the renin-angiotensin system, coagulation cascade, and neutrophil extracellular traps with established pathways like endothelial dysfunction and immune hyperactivation. Furthermore, we highlight therapeutic strategies aimed at restoring proteolytic balance and discuss the potential relevance of this paradigm in the management of long COVID.