Impact of Donor-Recipient Relationship on Long-Term Outcomes in Living-Related Donor Kidney Transplantation

Background: This study aimed to evaluate the impact of the donor-recipient relationship on the long-term outcomes of living-related kidney transplantation (LRKT), a topic that has been previously underreported. Material/Methods: A total of 598 LRKTs performed between 2001 and 2021were analyzed and classified into 5 groups based on the donor-recipient relationship: 228 from mothers (M-to-C), 160 from fathers (F-to-C), 115 from siblings, 55 from spouses, and 40 from offspring. Graft survival, postoperative complications within the first year, serum creatinine (Scr), and hazard ratio (HR) for all-cause graft loss were assessed. Results: The overall 1-, 3-, 5-, 7-, and 10-year graft survival rates were 96.0%, 92.4%, 86.4%, 79.9%, and 69.9%, respectively. The graft survival rate in the sibling group was slightly higher than those in the M-to-C and F-to-C groups, and the differences between the groups were insignificant. The survival rates of grafts donated by spouses and offspring were lower than in other groups, and the incidence of graft loss within the first postoperative year was higher in the offspring group. In comparison to the sibling group, spouse and offspring donations increased the graft loss risk (HR, 3.3; 95% CI, 1.6-6.9) and 3.8 (1.7-8.4), respectively, followed by M-to-C and F-to-C donations (HR, 1.9; 95% CI: 1.2-3.4) and 1.8 (1.1-3.1), respectively, which were associated with elevated postoperative Scr levels. Conclusions: Spouse and offspring donations significantly increased the risk of graft loss compared to donations from siblings, followed by M-to-C and F-to-C pairings, which were associated with higher postoperative Scr levels.