Outcome of kidney transplantation from high-risk donors is determined by both structure and function.

METHOD: Despite the need to expand the donor pool, it is unclear what parameters should be used. The value of donor renal pathology and calculated creatinine clearance (CrCl) in determining recipient outcome was assessed in 57 kidney transplants from 34 donors in whom pretransplant renal biopsies were performed because of age > or =60, hypertension, and/or vascular disease. We retrospectively compared clinical outcomes in these recipients and 57 control recipients selected to have the same baseline demographics but receiving transplants from low risk donors who were significantly younger (32+/-13.9 vs. 61+/-7.3 years) and lighter weight (71+/-18.1 vs. 84+/-20.2 kg) than the high-risk donors (P<.001 for both).
RESULTS: Recipients of high-risk kidneys had a higher incidence of delayed graft function, defined by a <10% fall in serum creatinine (Cr) in the first 24 hr, (56% vs. 30%, P<.01), a higher incidence of rejection (60% vs. 37%, P = .02) and a higher Cr level (197+/-64 vs. 144+/-54 micromol/L at 18 months, P<.005). Graft and patient survival were similar; 12% and 5% vs. 91% and 9% in high-risk vs. control groups, respectively (P = NS). Donor renal pathology was scored 0-3 (none to severe disease) in four areas: glomerulosclerosis, interstitial fibrosis, tubular atrophy, and vascular disease. A donor vessel score of 3/3 was associated with a 100% incidence of delayed graft function and a mean 1-year Cr level of 275+106 micromol/L (compared with 43% and 192+54 micromol/L in those with lower vessel scores, P<.05). Calculated donor CrCl <100 ml/min was associated with higher recipient Cr levels at 1 year, 240+/-95 micromol/L vs. 180+/-54 micromol/L in recipients of kidneys from donors with CrCl levels >100 ml/min (P<.05). The mean 1-year Cr level was 320+/-102 micromol/L in recipients with both a vascular score of 3/3 and a donor CrCl <100 ml/min and 184+/-63 micromol/L in those with neither factor (P = .001).
CONCLUSION: Calculated donor CrCl and donor vascular pathology predict recipient graft function and may be helpful in selecting high-risk donors for single kidney transplantation.