The utility of thromboelastography and thrombin generation in assessing the prothrombotic state of adults with sickle cell disease

Introduction: Previous studies have suggested a chronic hypercoagulable state in SCD, and that thrombosis also plays a role in the pathophysiology of sickle cell vaso-occlusive pain crises (VOC). Studies looking at thrombin generation have produced conflicting results. In this study we aimed to assess and compare whole blood thromboelastography (TEG) and plasma Calibrated Automated Thrombogram (CAT) in SCD versus healthy controls and in four different SCD subgroups. Materials and methods: In this prospective observational study, TEG and 1 pM TF activated CAT assays were performed in citrated blood samples from 77 adult (18-66 years old) SCD patients (HbSS and HbSB) and 22 healthy (HbAA) ethnically-matched controls. Results and conclusions: SCD was associated with a prothrombotic state in all TEG parameters. CAT results showed that the upslope of the CAT in SCD displayed a hypercoagulable state with shorter time to peak and higher velocity index, but the downslope was also faster leading to an overall lower endogenous thrombin potential (ETP) compared to healthy controls. TEG subgroup analyses showed that during VOC the prothrombotic state is greater compared to patients on disease ameliorating therapy. CAT did not display statistically significant differences between the SCD subgroups. This study shows that the prothrombotic state in SCD is best displayed with TEG, and suggests the hypercoagulable changes of SCD rely at least in part in the cellular components of blood, which can only be detected in whole blood assays.