LAUSR

Andalusian Group for Highly Sensitized Patients. Background Organ-exchange strategies based on virtual crossmatch (V-XM) can improve kidney transplantation in very highly-sensitized (HS) patients. Methods Andalusia started a V-XM protocol for very-HS patients in june, 2012 (calculated panel reactive antibodies 95%). After organ allocation a cytotoxic-XM performed immediately before transplantation had to be negative for surgery to proceed. The results of 5 years since the beginning of this protocol are analyzed. Whenever possible we also compared the course of the recipient (non-HS) of the other kidney from the same donor. Results Of the 87 grafts, 77 kidney transplantations were performed (the pretransplantation cytotoxic-XM was positive in 10; predictive value 88.8%). 10 patients (12.9%) experienced acute rejection (6 antibody-mediated rejections (AMRs);7.7%). Donor specific antibodies developed in 14 patients. One patient died but he had received a combined liver-kidney transplantation and died by liver failure. One-year graft survival was 98%. One-year graft survival was 97% among HS patients. We compared the course of the non-HS recipient of the other kidney, excluding cases with no pair (n:10), pairs who were children recipients(n:3),pancreas-kidney recipients(n:5), Liver-Kidney recipients(n:6) or pairs already included in the V-XM protocol (n:20). Finally, 46 pairs were studied. More HS-patients developed donor-specific antibodies (p=0.042). No significant differences were seen in acute rejection, but AMR was more common(p:0.054). One patient died in each group but dead was not related with kidney transplant, and there were no differences in graft survival or renal function. Conclusion Although a few patients still developed AMR, our V-XM based protocol with a final pretransplantation cytotoxic-XM achieved very satisfactory results. Immunological monitoring is very important in the follow- up of HS patients. Although the number of patients was limited, the initial survival of these high-risk recipients was comparable to the controls. We observe a decrease in 5-years graft survival among HS patients but with not statistical significance.