PhD defence M.W.J. (Maurice) Swinkels

Brief summary of the doctoral thesis:

Platelets play an important role in hemostasis, or blood clotting, in case of injury. In hemostatic disorders this clotting process is not working correctly, which can sometimes be attributed to malfunctioning platelets. In immune thrombocytopenia (ITP), platelets are targeted by the own immune system which leads to lower platelet numbers. We have monitored platelet counts at different timepoints in ITP patients undergoing vaccination, as vaccination may worsen ITP. Vaccination appeared safe but a subgroup requires close monitoring.

Von Willebrand Disease (VWD) is hallmarked by defects in von Willebrand Factor (VWF), which is an important partner of platelets in the clotting process. A platelet marker was studied in a large cohort of VWD patients in relation to VWF levels and clinical properties of patients. We found that platelets may play a role in various subgroups of VWD patients, which opens avenues for further research.

VWF resides in platelets and can be released to assist in blood clotting. To adequately look at VWF in the minuscule platelet, a method based on super-resolution microscopy was developed. With this method it was possible to distinguish healthy controls and various VWD patients.

Finally,  the biological process of VWF and VWF-propeptide (VWFpp) release was studied in platelets. This process has been previously studied in another celltype, but it was found that this process is different in platelets. This potentially has consequences for the clotting process and how VWF and VWFpp act therein.