6.1
TITLE: THE IMPACT OF HLA AND CREG MISMATCHES ON THE FIVE–YEAR RESULTS WITH LIVING UNRELATED DONOR RENAL TRANSPLANTATION
Angelo N. Arnold,1 Lorita M. Rebellato.2
1Transplant Immunology Laboratory, Sentara Norfolk General Hospital, Norfolk, Virginia; 2Pathology, PCMC/East Carolina University School of Medicine, Greenville, North Carolina
In recent years, the greatest growth in renal transplants (TX) has been from the use of living–unrelated donors (LURD). Reports have shown that LURD TX are equivalent to haplotype–matched living–related donor (LRD) TX and are superior to cadaver (CAD) TX. This retrospective analysis was done see if our LURD (N = 57) results are equivalent to LRD (N = 268) TX and are better than CAD (N = 321) TX. We also examined if HLA and CREG mismatches (MM) impact the LURD TX results. The 646 TX were 54% male, 55% African American, 11% reTX, 8% pediatric, with an average age of 43 years (range 2–77 years). Immunosuppression was primarily triple–drug and 64% of patients were given an anti–lymphocyte cytolytic antibody or anti–IL2 receptor antibody. Peak T cell PRA was over 10% in 28% of patients. The 5yr. patient (P), 5 yr. graft (G), and 1 yr. rejection–free (RF) survivals (S) were 87%, 62%, and 80% for LURD; 92%, 75%, and 79% for LRD; and 89%, 58%, and 78% for CAD TX. Contrary to other reports, our LURD results were worse than our LRD TX results (p < 0.02) and were not statistically different from CAD TX, even when zero HLA mm TX were excluded from the LRD and CAD groups. Similar results were found when the data were examined by TX center and recipient race. Excluding zero MM TX, the serum creatinine at 3 years was higher in the LURD group (1.8 ± 0.2 mg/dL) versus the LRD group (1.5 ± 0.5 mg/dL, p < 0.05) and not different from the CAD group (1.9 ± 0.1 mg/dL) p = NS). Overall, HLA MM at the B locus and DR locus had the best correlation with RFS and GS. There were more HLA MM in the LURD group compared to the LRD and CAD groups (p < 0.001). The HLA and CREG MM influence on RFS and GS was minimal in the LURD group. There was more hypertension (HTN) and older donor age in the LURD group compared to the LRD group (HTN 51% versus 38% p = NS; mean age 41 versus 35 yr. p < 0.03). We conclude that the long–term benefit of HLA matching seen in our LRD and CAD groups is masked in LURD TX by factors such as HTN and increased donor age.