Immunologic and patient selection strategies for successful utilization of less than 15 kg pediatric donor kidneys--long term experiences with 40 transplants.

Renal transplantation using infant donors is associated with significantly less graft survival (GS) and increased morbidity, especially from very young and small donors. We report our results using specific strategies to determine which age and size donor require en bloc renal transplant reconstruction and associated immunologic protocols for optimization of subsequent GS. Forty cadaveric pediatric en bloc renal transplants were performed. Mean donor age was 23.6+/-18.4 months with subgroups: 2-12 months, n=14; 13-24 months, n=19; and 25-60 months, n=7. Mean donor weight was 14.4+/-4.5 kg. All kidneys were placed in primary, nonsensitized (peak PRA = 7.9+/-5.6%) adult (41.6+/-16 years) recipients. Low weight was preferred (62.4+/-12.8 kg). Mean cold ischemia time was 26.9+/-8.6 hr. Immunosuppression consisted of quadruple immunosuppression (QI) with OKT3 induction. All patients had ureteral stents placed intraoperatively. Mean follow-up was 16.9 months. Actuarial GS at 12, 24, and 33 months were 100% (n=13), 85% (n=20), and 71% (n=7), respectively. Total GS was 35/40=88%. All grafts functioned immediately and there were no technical losses. Biopsy proven rejections occurred in 12 (30%) patients, developing at 16-167 days postoperatively (mean = 50.3 days). Mean serum creatinine at one week and 1, 6, 12, and 18 months were 2.1+/-2.0, 1.5+/-0.8, 1.3+/-0.5, 1.1+/-0.4, and 0.9+/-0.4 mg/dl, respectively. Functional isotopic renography, as well as sonographic monitoring reflected rapid initial and continued growth in these kidneys. Mean BP at 12 and 24 months postoperatively were 145/83+/-18/13 and 122/76+/-20/10 mmHg, respectively, with no significant proteinuria noted. Excellent results with minimal complications utilizing very small and young infant donors can be achieved with QI immunosuppression, and selection of low immune reactive and noncomplicated adult recipients. Additionally, maximal renal dosing by minimizing recipient weight may prevent future hyperfiltration damage.