Efficacy of immunoadsorption to reduce donor-specific alloantibodies in kidney-transplant candidates

We implemented a desensitization program at our center to enable transplant in kidney-transplant candidates who have a living human-leukocyte antigen-incompatible (HLAi) donor. We report on the efficacy of semispecific immunoadsorption to allow HLAi kidney transplant in 6 highly sensitized patients.

We chose immunoadsorption as the apheresis technique coupled to hemodialysis as a means to decrease donor-specific alloantibodies in kidney transplant candidates submitted to a pretransplant desensitization program to remove detrimental antibodies.

Six highly sensitized kidney-transplant patients (5 females), awaiting their first (n = 1) or second (n = 5) kidney transplant from a living donor, were enrolled in this desensitization program. They had 1 (n = 2), 2 (n = 1), 3 (n = 2), or 4 (n = 1) donor-specific alloantibodies; their mean fluorescent intensities at predesensitization ranged from 1200 to 19 000. Each patient underwent between 10 and 16 immunoadsorption sessions. At the time of transplant, donor-specific alloantibodies were undetectable in 2 patients (A24, DR3); donorspecific alloantibodies decreased by > 50% in 8 patients (A11, B44, DR3, DR11, DQ3 thrice, DQ5); donor-specific alloantibodies remained unchanged in 2 patients (B50, DR13); and mean fluorescent intensities were slightly increased in 2 patients (Cw6, DQ8). In the analysis of final outcomes, 2 patients experienced no rejection (1 experienced donor-specific alloantibody elimination, and 1 experienced a > 50% decrease in donor-specific alloantibodies). One patient presented with acute antibody-mediated rejection, which required immunoadsorption sessions and eculizumab therapy (donor-specific alloantibodies between 5000 and 19 000). Two patients presented with subacute antibody-mediated rejection; 1 was treated by plasmapheresis/rituximab therapy, and the other was treated with plasmapheresis/ methylprednisolone pulses. Another patient presented with chronic antibody-mediated rejection, which was treated unsuccessfully with plasmapheresis/rituximab; a tentative of rescue therapy with eculizumab was attempted without success.

Desensitization of the humanleukocyte antigen using this immunoadsorption procedure effectively reduced or eliminated donorspecific alloantibodies in 71% of patients undergoing kidney transplant, at the time of transplant.