Evaluation of Methods to Obtain Peripheral Blood Mononuclear Cells From Deceased Donors for Tolerance-Induction Protocols.

Regulatory cell therapies have shown promise in tolerance-induction protocols in living donor organ transplantation. These protocols should be pursued in deceased donor transplantation. Donor peripheral mononuclear cells (PBMCs) are an optimal source of donor antigens for the induction of donor-specific regulatory cells. During the development of a regulatory cell tolerance-induction protocol with organs from deceased donors, we compared 3 methods of obtaining PBMCs from deceased donors focusing on cell yield, viability, and contamination of unwanted cell types. PBMC procurement methods: 1. During organ procurement at the time of cold perfusion, blood was collected from the vena cava and placed into a 10-liter blood collection bag, and thereafter transported to Karolinska University Hospital, where leukapheresis was performed (BCL). 2. Blood was collected via the vena cava into blood donation bags before cold perfusion. The bags underwent buffy coat separation and thereafter automated leukocyte isolation system (BCS). 3. To collect PBMCs, leukapheresis was performed via a central dialysis catheter on deceased donors in the intensive care unit (ICU) prior to the organ procurement procedure (LEU).All 3 methods to obtain PBMC from deceased donors were safe and did not affect the procurement of organs. BCL contained around 50% of NK cells in lymphocytes population. LEU had a highest yield of donor PBMC among 3 groups. LEU had the lower amount of granulocyte contamination, compared to BCS and BCL. Based on these results, we choose LEU as the preferred method to obtain donor PBMC in the development of our tolerance-induction protocol.