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Related Experiment Video

Updated: Jun 18, 2026

Polyelectrolyte Complex for Heparin Binding Domain Osteogenic Growth Factor Delivery

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Published on: August 22, 2016

"Heparinization" and hyperfibrinogenolysis by wasp sting.

Cristina Lombardini¹, Robert-Ebadi Helia, Françoise Boehlen

¹Service of Intensive Care, Department of Anesthesiology, Pharmacology and Intensive Care, University Hospitals of Geneva, 1211 Geneva, Switzerland. cristina.lombardini@hcuge.ch

The American Journal of Emergency Medicine

|November 26, 2009

Summary

Wasp sting anaphylaxis can cause unusual bleeding disorders by activating mast cells. These cells release heparin and tryptase, leading to anticoagulation and fibrinogen degradation, mimicking heparin therapy.

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Basophil Activation Test for Allergy Diagnosis

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Published on: May 31, 2021

Area of Science:

Hematology
Immunology
Toxicology

Background:

Anaphylaxis, a severe allergic reaction, can trigger complex physiological responses.
Coagulation abnormalities are not typically considered a primary manifestation of anaphylaxis.

Observation:

A patient presented with an unclottable activated partial thromboplastin time and significant anti-Xa activity post-wasp sting, despite no heparin administration.
The patient also exhibited an extremely low fibrinogen level with a normal platelet count and only a slight increase in D-dimers.

Findings:

Mast cell activation during anaphylaxis released endogenous heparin, causing "heparinization" and anticoagulant effects.
Serum tryptase cleaved fibrinogen and activated fibrinolysis, leading to hyperfibrinogenolysis and low fibrinogen levels.
These combined mechanisms explained the observed coagulation abnormalities, distinct from disseminated intravascular coagulation.

Implications:

This case highlights a novel mechanism of coagulation derangement in human anaphylaxis.
Understanding these mechanisms is crucial for managing anaphylaxis patients, especially in settings with potential bleeding risks like trauma or surgery.
Further research into in vivo anaphylaxis-induced coagulopathy is warranted.