The impact of HLA matching on graft survival and on sensitization after a failed transplant : evidence that failure of poorly matched renal transplants does not result in increased sensitization

There are costs (both financial and ethical) to distributing kidneys by HLA-match (time, transportation, repeat crossmatch; possibly bypassing a more deserving recipient). Arguments favoring matching include better short- and long-term survival, and decreased panel-reactive antibody (PRA) if a well-matched vs. poorly matched transplant fails. We studied these phenomena in a single institution. Since 1970, 1329 patients received cadaver (CAD) transplants; for those with defined antigens (n = 1316) there was no difference in 10-year graft survival in those with a less than or equal to 1 AB match vs. those with greater than 1 AB match or those with less than or equal to 1 AB mismatch (mm) vs. greater than 1 AB mm. Similarly there was no difference in those with less than or equal to 2 BDR mm vs. greater than 2 BDR mm. In fact, those with less than ABDR mm had worse 10-year graft survival (55%) than those with greater than or equal to 3 ABDR mm (61%) (P = .001). For patients with function greater than 6 months there was no difference in long-term outcome based on HLA match or mm. These findings were similar for patients both with and without CsA immunosuppression, and for primary and retransplants. A total of 382 patients transplanted since 1980 have lost their grafts (146 died with function). All had received pretransplant transfusions. Of 236 alive after graft loss, 64 had no postgraft failure PRAs (22 out of state, 23 chose to remain on dialysis, 19 died less than 3 months after graft loss); 172 had PRAs after failure; 106 (62%) have been retransplanted. Mean peak PRA in those retransplanted was 23 +/- 31 (range 0-100) vs. 46 +/- 39 (range 0-100) in those not retransplanted (P less than .05). Patients were stratified by PRA prior to first transplant (0%, 1-20%, greater than 20%). For recipients with 0% PRA, failure of a CAD transplant (n = 58) was no more likely to result in an increase of PRA than failure of a living-related donor (LRD) transplant (n = 49) (NS). For those with an increase, mean increase was 45% +/- 34 after LRD transplant and 41% +/- 28 after CAD transplant (NS). The proportion developing PRA greater than or equal to 60% was not different after a failed LRD (7/49) or CAD (11/58) transplant (NS). Other subgroups had similar results. AZA or CsA immunosuppression did not affect development of increased PRA after a failed graft.