American Society of Hirudotherapy

Activated protein C and sepsis.

Review published in Frontiers in bioscience : a journal and virtual library (2006)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Narrative reviewDrug DevelopmentO'Brien et al. · Frontiers in bioscience : a journal and virtual library, 2006

Abstract

Protein C is a plasma protease that when activated plays a central role in modulating the function of the vascular endothelium and its interface with the innate immune system. A recombinant form of human activated protein C (APC), drotrecogin alfa (activated), has shown efficacy in a number of preclinical models of thrombosis and ischemia and reduces mortality in patients that have a high risk of dying from severe sepsis. Studies have begun to elucidate the mechanism for the multifunctional role of APC in modulating not only coagulation, but also inflammation and apoptotic processes. From gene profiling to pharmacology studies, drotrecogin alfa (activated) appears to directly modulate endothelial dysfunction by blocking cytokine signaling, functional cell adhesion expression, vascular permeability and preventing the induction of apoptosis. Moreover, APC, via endothelial protein C receptor/protease activated receptor-1 mediated mechanisms, also appears to directly modulate leukocyte migration and adhesion. The ability of APC to suppress pro-inflammatory pathways and enhance cellular survival suggests that APC has a role in the adaptive response at the vessel wall, in which it protects the wall from vascular insult and prolongs endothelial, cellular, and organ survival. The emerging data further suggest that APC effectively modulates the complex changes that occur during multi-system activation and dysfunction in sepsis.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal ArticleReview
Indexed MeSH termsAnti-Inflammatory AgentsBlood CoagulationBlood Coagulation FactorsCell AdhesionCell MovementCytokinesEndothelium, VascularFibrinolysisFibrinolytic AgentsHumansInflammationIschemia

Summary

Protein C is a plasma protease that when activated plays a central role in modulating the function of the vascular endothelium and its interface with the innate immune system. A recombinant form of human activated protein C (APC), drotrecogin alfa (activated), has shown efficacy in a number of...

Why This Matters for Hirudotherapy

This review details the multifunctional role of activated protein C (APC) and its recombinant form, drotrecogin alfa, in modulating endothelial function, coagulation, inflammation, and apoptosis during severe sepsis. It explains how APC protects the vascular wall and prolongs cellular survival by blocking cytokine signaling, functional cell adhesion, and apoptotic processes. Although APC is a potent natural anticoagulant and anti-inflammatory agent, its connection to the leech secretome or hirudotherapy is only conceptual, representing parallel mechanisms of physiological anticoagulation and cytoprotection. The abstract contains absolutely no mention of leeches, hirudin, or leech-derived therapies.

Citation

Activated protein C and sepsis.

O'Brien et al. · Frontiers in bioscience : a journal and virtual library, 2006

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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