Donor‐Directed MHC Class I Antibody Is Preferentially Cleared from Sensitized Recipients of Combined Liver/Kidney Transplants

For patients with chronic renal and liver diseases, simultaneous liver and kidney transplantation (SLKT) is the best therapeutic option. The role of a pretransplant donor‐specific antibody (DSA) in SLKT is unclear. We report the results of a retrospective review from 7/08 to 10/09 of SLKT at our institution. Monitoring of DSA was performed using single antigen bead assay. Between 7/08 and 10/09, there were six SLKT who had preformed DSA and positive XM (four class I and II DSA, one class I DSA only, one class II only). One‐year patient and renal graft survival was 83%. Death‐censored liver allograft survival was 100%. Acute humoral rejection (AHR) of the kidney occurred in 66% (three with both class I and II DSA and one with only class II DSA) of patients. In those with AHR, class I antibodies were rapidly cleared (p < 0.01) while class II antibodies persisted (p = 0.25). All patients who had humoral rejection of their kidney had preformed anticlass II antibodies. Liver allografts may not be fully protective of the renal allograft, especially with pre‐existing MHC class II DSA. Long‐term and careful follow‐up will be critical to determine the impact of DSA on both allografts. Donor‐directed MHC class I antibody is preferentially cleared, relative to class II antibody, in sensitized recipients of combined liver/kidney transplants.