Renal transplantation of highly sensitised patients via prioritised renal allocation programs. Shorter waiting time and above-average graft survival.
BACKGROUND
Highly sensitised renal transplant candidates (HSP) have a reduced chance of receiving a transplant. In Eurotransplant (ET), two special allocation programs have been made available for such patients: the Highly Immunised Tray (HIT) program and the Acceptable Mismatch program (AM), albeit with different inclusion and exclusion criteria (HIT, current PRA% >or=85%; AM, current and/or historical PRA% >or=85%). When a suitable kidney is available for a patient, included in these special programs, the kidney is mandatory offered. In contrast, in the point score system of the standard ET kidney allocation procedure (ETKAS), HSP (PRA >or=85%) only get a marginal bonus according to their current sensitisation. It was tested whether the allocation priority of the two special allocation programs is justified from the perspective of transplant outcome.


METHODS
The post- transplant outcomes of recent consecutive cohorts of AM, HIT and HSP-ETKAS transplants were compared. The end points were initial graft function, rejection episodes during the first three months post-transplant, and 1-year kidney graft outcome.


RESULTS
Between January 1, 1997 and June 30, 1998, 101 HSP received a kidney-only transplant: 29 via AM, 39 via HIT and 33 via ETKAS. HLA-A,B,DR matching was more favourable in the AM and HIT allocation groups and their waiting times till transplantation were much shorter than those of the HSP-ETKAS allocation group. The incidence of initial graft non-function was similar among the three HSP allocation groups, averaging 50%. Recovery of the initial non-function was more likely for AM and HIT transplants. No difference was present with regard to the percentage of patients who experienced at least one rejection episode during the first three months post-transplant, averaging 43%. However, the AM group had less severe and/or less recurrent rejection episodes. The 1-year kidney graft survival, censored for death with functional graft, was 96% for AM, 82% for HIT and 75% for HSP-ETKAS transplants (p = 0.04).


CONCLUSIONS
The two special allocation programs for HSP do yield adequate results and offer a shorter waiting time, compared to the standard kidney allocation procedure. The AM approach might be preferred because of the smoother post-transplant management and the better graft survival, keeping the HIT approach as a back up. Since the allocation priority is justified in view of efficiency, the renal transplant community should support the incorporation of a special allocation program for HSP in their respective organ exchange program.
De Meester
Johan
J
Eurotransplant International Foundation, Department of Immunohematology and Blood Transfusion, Leiden University Medical Center, Leiden, The Netherlands. johan.de.meester@olvz-aalst.be
Doxiadis
Ilias I N
II
Persijn
Guido G
GG
Claas
Frans H J
FH
D006084:Graft Rejection / Q000453:epidemiology*; D006085:Graft Survival / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D015994:Incidence; D016030:Kidney Transplantation / Q000276:immunology* / Q000706:statistics & numerical data*; D013997:Time Factors; D014019:Tissue Donors; D009927:Tissue and Organ Procurement; D016896:Treatment Outcome; D014850:Waiting Lists