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. One cohort consisting of SCD patients will be followed up on site whereas the other cohort of SCT and healthy individuals will be followed up via Telehealth. Standard operating protocols for processing of blood samples have been tested in the laboratory and assays for platelet function have been developed. 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 60 research subjects in all four of the study cohorts out of a possible 200 have been enrolled. An additional 8 subjects have been brought into the NIH CC for study of biomarker variability during acute vast-occlusive crisis. Subjects in the SCD cohort receive 3 monthly phone follow up. Subjects in the SCT cohort receive annual telephone follow up.