Use Of Thromboelastography (TEG) In Preclinical Studies

By N Lalayeva and K Thrall

Preclinical drug development focusing on coagulation typically involves frequent analyses of hematology and coagulation, with thromboelastography (TEG) serving as a valuable tool for monitoring clot strength, fibrinolysis, and diagnosing platelet dysfunction and hypercoagulability. Since TEG must be initiated shortly after blood collection, it is considered a point-of-care technique. In practice, whole blood is collected in sodium citrate, and an aliquot is mixed with Kaolin before being pipetted into a disposable TEG cup for analysis on a calibrated machine. The resulting TEG tracing provides critical data, including the rate of clot formation (alpha-angle), time to achieve a certain clot strength (K), time to initial fibrin formation (R), overall clot stability (MA), and the decrease in clot stability at 30 or 60 minutes (LY30 or LY60). TEG analysis has been applied in preclinical studies investigating bleeding disorders and platelet dysfunction in large animal models, correlating well with conventional hematology data.

For instance, a TEG tracing with prolonged R and K times, along with low alpha-angle and MA, suggestive of thrombocytopenia, directly correlated with decreased platelet counts. Additionally, prolonged R times, indicative of clotting factor deficiencies, were compared with measured levels of individual coagulation factors. The data showed significant alterations in coagulation factors VIII, XI, XII, and XIII during critical stages of thrombocytopenia, supporting the continued use of multiple methods to evaluate the coagulation cascade for the most accurate interpretation.