We used 4 antibody methods: (1) Luminex single antigen (LSA), (2) LSA with a 1:8 serum dilution, (3) C1q LSA, and (4) CDC panel. The UAs were prioritized in the following order: (1) all C1q+/CDC+, (2) LSA 1:8 >7,500 median fluorescence intensity, and (3) LSA >10,000 median fluorescence intensity.
Of 295 heart transplants that were performed at our center, 69 (23%) recipients had detectable human leukocyte antigen specific antibody at the time of transplant. All donor specific antibodies (DSAs) were avoided for 44 of 69 (64%) (DSA−). There were 25 recipients who had DSA at the time of transplant: 12 (48%) had negative FXM (DSA+/FXM−), and 13 (52%) had positive T-cell and/or B-cell FXM (DSA+/FXM+). Lower freedom from antibody-mediated rejection was observed for the DSA+/FXM+ group compared with the DSA− group (p < 0.0001). DSA remained detectable after transplant in the sera of 14 recipients, and de novo DSA was detected in 32 recipients. Freedom from antibody-mediated rejection was comparable for both groups (p = 0.53) but was lower than the DSA− group (p < 0.0001). Survival was comparable for all groups at 1,200 days post-transplant.
Strategic prioritization of UA assignment has allowed transplantation of highly sensitized patients across the DSA barrier with survival rates comparable to DSA− heart transplant recipients.