Immunologic Long-term Outcomes of Living-Related Kidney Transplantations Depending on the Donor-Recipient Relationship

The aim of this study is to analyze the long-term immunologic outcomes of living-related kidney transplantations depending on the donor-recipient relationship. This retrospective single-center study included adult kidney transplant recipients (KTR) transplanted between 2000 and 2014. Among 1117 KTRs, 178 patients (15.9%) received living-related donations. Those patients were further categorized according to the donor-recipient relationship: 65 transplantations between siblings, 39 father-to-child (F-t-C) and 74 mother-to-child (M-t-C) donations. Allograft biopsies were performed for clinically suspected rejections. Data analysis included patient and graft survival, biopsy proven rejections (T-cell mediated [TCMR] or antibody mediated) and development of de novo donor-specific antibody. Outcome data were assessed over a period of a maximum 14 years. There was no significant difference between the groups (F-t-C, M-t-C, and siblings) with regard to HLA-mismatches, prior kidney transplantations, time on dialysis, and cold ischemia time. Among KTRs with related donors, the type of relationship had no significant influence on graft survival. F-t-C and M-t-C pairs showed comparable incidences of TCMR at 7 years post-transplantation, both significantly exceeding the rate in sibling-to-sibling pairs (26.2% and 26.8% vs 10%, respectively; P = .043). A multivariate Cox regression analysis adjusted for recipient age, donor age, and HLA (A, B, DR)–mismatches identified both M-t-C- and F-t-C-donations as important independent risk factors for TCMR (hazard ratio: 8.13; P < .001 and hazard ratio: 8.09; P = .001, respectively). There was no significant difference between the groups concerning the incidence of antibody-mediated rejection and de novo donor-specific antibody. Our results indicate that parent-to-child kidney donation is an independent risk factor for TCMR.