UQ Study Reveals Fat-Tailed Scorpion Venom Causes Blood Clots

A University of Queensland (UQ) study has identified that the neurotoxic venom of fat-tailed scorpions also causes blood clots.

The research, conducted by Professor Bryan Fry and PhD candidate Sam Campbell from UQ’s School of the Environment, focused on the venoms of scorpions in the Androctonus genus, which are found in the Middle East and North Africa.

Clinicians had previously observed abnormal clotting in some scorpion sting patients, but the underlying mechanism was unclear until this study.

Understanding the Clotting Mechanism

The UQ team demonstrated that these venoms rapidly accelerate clotting in human blood plasma. The study revealed that Androctonus venoms activate major clotting factors, specifically Factor VII and Factor X, and that this process is dependent on Factor V being in its activated form.

Antivenom Limitations and New Solutions

Testing showed that a routinely used antivenom for fat-tailed scorpion stings, while effective against neurotoxic effects, did not prevent this procoagulant activity. However, two small-molecule metalloprotease inhibitors, marimastat and prinomastat, successfully neutralized the procoagulant effects during testing.

Implications for Patient Care and Beyond

These findings suggest that medical staff should monitor and test for clotting in scorpion envenomation cases. The research also indicates that adjunct treatments targeting specific venom enzymes could be valuable, especially when antivenom does not fully neutralize all effects.

Professor Fry noted that the novel mechanisms identified could lead to new diagnostic tools for blood disorders or treatments for controlling blood loss during surgery or after injury.