Improved diagnostics for heparin induced thrombocytopenia

Emory University, Atlanta GA

Investigators

Abstract

Project abstract Heparin has long been used as an anti-coagulant in the management of coronary artery disease, deep vein thrombosis, pulmonary embolism, and in the prevention of thrombosis during cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO). A small fraction of patients on heparin (0.1% - 5.0%), will progress to having heparin-induced thrombocytopenia (HIT) which can lead to significant morbidity, particularly thrombosis, bleeding, and amputation, and in some cases death. The current gold standard assay to detect HIT is complex, requires C14-serotonin, and can only be performed in several reference laboratories in the US. Therefore, patients awaiting definitive diagnosis of HIT are on inferior anticoagulants with increased cost and bleeding risk. Hence there is a need for rapid and accurate detection of HIT. The central hypothesis of this project is that the mechanical forces generated by platelets provide a physical biomarker of platelet activity and may serve as a diagnostic marker of HIT. This hypothesis is supported by strong rigor of prior research as well as strong preliminary data. Platelets mechanically contract with significant force after their initial activation, contributing to the strength and stability of platelet aggregates as part of normal blood coagulation. Therefore, our approach is to develop and test a new molecular sensor that can detect the mechanical forces generated by platelets. To address this need, we have assembled an interdisciplinary team including Dr. Salaita who is a biophysical chemist, Dr. Roman Sniecinski a recognized expert in perioperative coagulation, and Dr. Cheryl Maier an expert on immune coagulation disorders including HIT. The team developed a new technology named MCATS (Mechano-assisted Cas12a Tension Sensor) that can detect the forces generated by human platelets using a conventional fluorescence plate-reader. Preliminary data shows that MCATS can detect platelet dysfunction including HIT using 5 uL volume samples of platelets in a 1 hr time window. The MCATS technology is the center-piece of this proposal and represents the focus of the approach. One goal of this application is to investigate the signaling link between HIT activation and platelet forces. Another goal is focused on optimizing the MCATS technology to enhance the signal obtained from human platelets. Finally, we will validate and benchmark MCATS against that of standard laboratory tests for HIT such as ELISA and SRA, which are the current standard of care for diagnosing HIT. If successful, then our planned work will lead to the development of mechanical assays to detect HIT in a rapid and broadly accessible manner.