Graft-versus-Host-disease, alias: GvHD. For most people an unknown disease. For patients in need of a bone marrow transplant however a potential lethal complication of their treatment, in which the new donor-immune system fails to consider its receiver as a friend and starts treating it as an enemy that needs to be fully destroyed. If any leukemic cell remained after treatment this destruction is beneficial to prevent death from the original disease, but when healthy tissue comes under attack the result is disastrous.
The army of white blood cells in our body contains many different soldiers, like T cells and B cells. Many of them are involved in this GvHD-battle. Having a high amount of regulatory T cells (which try to function as a mediator to calm this battle down) and depletion of B cells with Rituximab, is however beneficial for patients with GvHD. Unfortunately, we fail to understand why Rituximab doesn’t appear work for all patients and whether the mediators and B cells interact with each other is a mystery as well.
This thesis therefore focusses on the potential relation between these two cells: where do they go and do they influence each other in quantity or function after being introduced as a donor cell? Also, the mysterious difference in severity between clinical symptoms and histology is (partially) unraveled. The results from this thesis will provide clinicians and researchers with new insights, that might help us better understand and treat GvHD in the future.