Venous Thrombosis Biomarkers in Sickle Cell Disease and Sickle Cell Trait

National Heart, Lung, And Blood Institute

Investigators

Abstract

Since recruitment began in August 2020, protocol 20H0068 has recruited subjects with Sickle Cell Disease (SCD) with and without a recent history of venous thromboembolism. In addition, the protocol recruits individuals with Sickle Cell Trait (SCT) and those individuals identifying themselves as healthy and of African ancestry. The two cohorts of subjects (SCD and SCT) will be followed prospectively for a period of two years. Subjects in the SCD cohort receive phone follow up every 3 months. Subjects in the SCT cohort receive annual telephone follow up. At the end of 2 years, all subjects in the SCD cohort return for study close out. In collaboration with the department of laboratory medicine, thromboelastography is performed on all subjects recruited to the protocol. Assays to study plasma hyper coagulability are under development and samples that are being collected are stored for batch analysis under standard conditions. Assays to assess cell derived extracellular vesicles and tissue factor bearing vesicles are being performed. In collaboration with extramural investigators, the possibility that plasma contains cell derived vesicles from subendothelial compartments is under exploration. As of the date of this report, a total of 98 research subjects in all four of the study cohorts out of a possible 200 have been enrolled. A total of 52 research subjects has completed the two year follow up period of the study and are off study. An additional 8 subjects have been brought into the NIH CC for study of biomarker variability during acute vast-occlusive crisis.