Impact of donor kidney function and donor age on poor outcome of living‐unrelated kidney transplantation (KT) in comparison with living‐related KT

Living‐unrelated donors (LURD) have been widely used for kidney transplantation (KT). We retrospectively reviewed 779 patients who underwent living‐donor KT from 2000 to 2012, to compare outcomes of 264 KT from LURD and 515 from living‐related donors (LRD), and to identify risk factors for living KT. Median follow‐up was 67 months. Mean donor age, total human leukocyte antigen (HLA) mismatches, and HLA–DR mismatches were higher, and mean estimated glomerular filtration rate (eGFR) was lower in LURD. Acute rejection (AR)‐free survival (p = 0.018) and graft survival (p = 0.025) were lower for LURD than LRD, whereas patient survival rate was comparable. Cox regression analysis showed HLA–DR mismatches (OR 1.75 for one mismatch; OR 2.19 for two mismatches), recipient age ≤ 42 yr, and donor age > 50 yr were significant risk factors for acute rejection. For graft survival, AR and donor eGFR (OR 1.90, p = 0.035) were significant. We also identified significant impact of recipient age > 50 yr and diabetes for patient survival. However, KT from LURD was not a significant risk factor for AR (p = 0.368), graft survival (p = 0.205), and patient survival (p = 0.836). Our data suggest that donor eGFR and donor age are independent risk factors for clinical outcomes of living KT, which can be related with poor outcome of KT from LURD.