Ex Vivo Removal of CD41 positive platelet microparticles from Plasma by a Medical Device containing a <i>Galanthus nivalis agglutinin</i> (GNA) affinity resin

ABSTRACT Background Platelet microparticles (PMP) are elevated in and associated with disease activity in a number of diseases including cancer, neurological conditions, autoimmune diseases, and infectious diseases. This finding raises the possibility of a removal of these microparticles as a therapeutic strategy. The Hemopurifier is an experimental device consisting of a plasma separator and an affinity resin containing Galanthus nivalis agglutinin (GNA) affinity resin that has previously been shown to remove extracellular vesicles in vitro and in vivo. In this proof on concept study, we sought to determine ex vivo removal of platelet-derived microparticles from healthy human plasma by the Hemopurifier. Methods Two hundred milliliters of thawed healthy human plasma were circulated over the Hemopurifier device at a rate of 100 mL/minute. Plasma samples were taken at time points equivalent to a 4-, 6- and 8-hour clinical Hemopurifier session in a healthy adult. Microparticles were isolated from these timepoints and analyzed for treatment concentration changes. Platelet microparticle counts were determined by binding to antiCD41. Results The Hemopurifier removed 98.5% of platelet microparticles during the equivalent of a 4-hour clinical session. Conclusions We demonstrated that an extracorporeal device with a GNA affinity resin removes platelet microparticles from normal healthy plasma. Next steps would be demonstration of the removal of PMPs from plasma by the Hemopurifier in different disease states and characterization of the cargo within removed PMPs.