Treatment of antibody-mediated rejection including immunoadsorption during first year after renal transplantation – Clinical results and regulation of endothelial progenitor cells

ObjectiveAntibody-mediated rejection (AMR) is associated with poor allograft survival. Therefore, effective treatment strategies are required. Extracorporeal strategies are increasingly included in treatment of antibody-mediated rejection to eliminate the detrimental alloantibodies. Yet, other mechanisms contributing to the beneficial effect of apheresis besides the removal of antibodies are under consideration.MethodsWe retrospectively analyzed data of 427 transplant patients from 2006 to 2013 with special focus on occurrence, treatment – always including immunoadsorption – and 12-months outcome of antibody-mediated rejection.Besides, we prospectively monitored how the number and phenotype of endothelial progenitor cells in four patients experiencing antibody-mediated rejection changed during the treatment course of 6–20 sessions of immunoadsorption in comparison to seven patients subjected to immunoadsorption because of preparation for ABO-incompatible transplantation.Results24 patients were diagnosed with acute AMR and treated with immunoadsorption resulting in patient and allograft survival of 100% and 87.5%, respectively. In patients with antibody-mediated rejection, the endothelial progenitor cell number after successful immunoadsorption therapy was always transiently decreased and the adhesive and migratory ability improved. This regulation of circulating endothelial precursor cells was not seen in patients undergoing repetitive immunoadsorptions before ABO-incompatible transplantation.ConclusionCombined therapy with immunoadsorption allows a successful treatment of AMR. Treatment seems to be associated with a transient regulation of circulating endothelial precursor cells.