Exploring the ex vivo effects of Bitis arietans snake venom on the coagulation, ultrastructure, and viscoelastic properties of human blood

Abstract

Background

Snakebite envenoming represents a significant and frequently overlooked public health challenge affecting tropical and subtropical regions. Bitis arietans venom toxins have cytotoxic effects and result in coagulopathy. However, there is limited literature on coagulopathies associated with B arietans envenomation or comparing traditional diagnostic tests with point-of-care (POC) methods.

Objectives

This study investigated the effects of B arietans venom on the coagulation of human blood, with a focus on comparing the 20-minute whole blood clotting test (20-WBCT) to other POC coagulation tests.

Methods

This study exposed human blood to 2 ng/μL B arietans venom ex vivo. Clot formation was studied using the 20-WBCT. Prothrombin time, activated partial thromboplastin time, thrombin time, and fibrinogen levels were measured to obtain hematological clotting profiles of each participant. Viscoelastic properties of whole blood clot kinetics were quantified using thromboelastography (TEG). Red blood cell morphology and clot architecture were analyzed using scanning electron microscopy.

Results

Bitis arietans venom had significant effects on red blood cell morphology and clot structure. Both the 20-WBCT and clinical coagulation assays revealed notable differences in the results of venom-exposed samples; however, they were still in the normal range. TEG indicated hypocoagulation and decreased clot stability. Morphological studies of venom-exposed samples revealed echinocytes with varying degrees of morphological abnormalities and membrane blebbing. In addition, venom-exposed blood clots had sparse, disorganized fibrin networks and limited crosslinking.

Conclusion

Bitis arietans venom contains various hemotoxins that disrupt normal clot formation and affect TEG parameters. These insights provide a necessary link between clinical and laboratory analysis of B arietans venom. The study demonstrates the value of TEG as a POC test in snakebite management as it could provide a better indication of coagulopathy associated with envenomation.