GENOMIC HLA-DR COMPATIBILITY IN LONG-TERM SURVIVING RECIPIENTS OF CADAVER KIDNEY-TRANSPLANTS

The finding that HLA-DR compatibility assessed by DNA typing correlate s with short-term graft outcome better than serology prompted us to st udy the degree of genomic HLA-DR compatibility on 55 patients with a g raft functioning for more than 10 years (group A), compared with 82 pa tients with more recent transplants regardless of survival (group B). Because adequate blood donor samples were not available for group A lo ng-term survivors, we used donor renal cells obtained by fine needle a spiration biopsy as a source of DNA. We found that in long-term surviv ors, the distribution of HLA-DR mismatches was significantly different from that observed in group B patients. In particular, whereas a simi lar proportion of patients with 1 mismatch was seen in both groups, 27 .3% of group A patients vs. 6.1% of group B patients had no mismatch, and 23.6% of group A vs. 41.5% of group B patients received transplant s with no HLA-DR compatibility (P=0.001). We also investigated a possi ble correlation between number of incompatibilities and graft function . Well-matched patients received less steroid pulses than less well-ma tched recipients, and steroid-resistant rejection episodes were more c ommon among less well-matched recipients. These results suggest a prog nostic role of genomic HLA-DR compatibility on long-term success of ca daver kidney transplantation.