Clinical Outcomes in Recipients of Living-Donor Kidney Transplantation by Donor Age Group
Takayoshi Yokoyama1,2, Yu Kihara2, Osamu Konno2, Yuki Nakamura2, Hitoshi Iwamoto2, Takashi Oda3, Shigeyuki Kawachi1.
1Digestive and Transplantation Surgery, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan; 2Kidney Disease Center, Surgery, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan; 3 Kidney Disease Center, Nephrology, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan
Introduction: Living-donor kidney transplantation (LDKT) accounts for more than 90% of all kidney transplants in Japan. In accordance with LDKT guidelines, donors are healthy individuals aged 20–70 years. However, LDKT from elderly donors is controversial because of uncertainty in graft function. We evaluated the clinical outcomes of LDKT recipients by donor age group.
Materials and Methods: Between January 2008 and December 2015, 119 patients underwent LDKT at our center. Patients were grouped into younger -age (Y group; LDKT from donors ≦50 years; n = 45), middle-age (M group; LDKT from donors 51–64 years; n = 52), and older-age groups (O group; LDKT from donors ≧65 years; n = 22). We compared these three groups with respect to baseline data, graft function, immunosuppressant, graft survival rate, and recipient mortality.
Results and Discussion: Donor age in the Y, M, and O groups was 39.9 ± 7.8, 57.8 ± 3.8, and 68.9 ± 2.7 years, respectively. The donors in the Y group showed significantly good preoperative HbA1c status (Y vs. M vs. O: 5.5 ± 0.3% vs. 5.8 ± 0.4% vs. 5.9 ± 0.4%; P < 0.001), estimated glomerular function rates (95.2 ± 19.5 vs. 81.3 ± 13.7 vs. 76.0 ± 12.7 mL/min; P < 0.001), and creatinine clearance rate (115.0 ± 24.1 vs. 100.1 ± 15.1 vs. 91.7 ± 19.1 mL/min; P < 0.001). The incidence of rejection (13.3% vs. 28.8% vs. 5.8%; P = 0.026) and cytomegalovirus infections (4.4% vs. 25.0% vs. 18.2%; P = 0.021) within 1 year after the LDKT was significantly different among the groups. The serum creatinine level was significantly lower in the Y group compared with the other groups at any point within 5 years after the LDKT (Figure 1). The graft survival (89.4% vs. 90.5% vs. 100.0%; P = 0.555) and patient mortality rates (92.0% vs. 96.2% vs. 90.2%; P = 0.738) 5 years after LDKT were not significantly different among the groups.
Conclusion: In this study, LDKT from elderly donors was found to be relatively safe. As expected, lower initial renal function and lower apparent serum creatinine level after LDKT were found in the elderly group; however, the graft survival and recipient mortality rates were sufficiently comparable. Careful selection of elderly donors and delicate follow-up may result in successful transplant outcomes.
