The University of Georgia College of Veterinary Medicine

eorgia Veterinary Scholars Program

GVSP Summer 2007 Scholars

Georgia Veterinary Scholar	Faculty Mentor

Staci Hutsell University of Georgia Class of 2010	Drs. Michelle Barton & Jim Moore

Thrombelastography to Identify Lipopolysaccharide-induced Hypercoagulability in Horses

Staci Hutsell*, James Moore, Michelle Barton, Benjamin Brainard
University of Georgia College of Veterinary Medicine
Athens, Georgia, 30602, USA

Abstract

Justification: Thrombosis is a complicating factor in many equine inflammatory diseases, especially those characterized by endotoxemia. Because early detection of coagulation defects can improve the response to treatment in affected horses, new laboratory tests are needed to identify horses in a hypercoagulable state.

Hypothesis: Thrombelastography (TEG), a technique that dynamically assesses the rapidity and elasticity of blood coagulation, will detect early stages of hypercoagulability in horses with intestinal diseases.

Objectives: The main objective of this project is to establish TEG assay parameters for the horse. This will be accomplished by investigating the effects of pre-incubation time and temperature and the in vitro effects of thromboplastin and lipopolysaccharide (endotoxin) on coagulation of equine whole blood as determined by the TEG assay.

Procedures: Citrated whole blood was collected from four healthy adult horses, and evaluated using TEG. Reaction time (R), clotting time (K), angle (α), and maximum amplitude (MA) were recorded during analysis. Parameters assessed included pre-incubation time, temperature, and five concentrations of recombinant human thromboplastin diluted in PBS/albumin 4%. The effects of four concentrations of lipopolysaccharide on TEG indices will be determined.

Results: Optimal incubation parameters were determined to be pre-incubation for 30 minutes at room temperature, and addition of recombinant human thromboplastin diluted 1:3600 in the reaction cup. Mean values in the absence of recombinant thromboplastin were R = 11.9, K = 2.65, α = 55.95, and MA = 58, and R = 4.9, K = 1.95, α = 63.3, and MA = 60.85 in the presence of thromboplastin.

Conclusions: Addition of recombinant thromboplastin (1:3600) significantly shortens the recalcification (reaction) time of equine blood, while not interfering with other measured parameters during TEG. The effects of incubation with lipopolysaccharide have yet to be determined.