Comparison of live donor predonation and post-transplant kidney volumes and glomerular size in pediatric patients weighing less than 15 kg - a retrospective study.

Abstract

Renal transplantation of adult-size kidneys presents a size mismatch in small children. This study presents a comparison of live donor predonation and recipient post-transplant kidney volumes (k-vol) and glomerular size at 1year after transplantation. We analyzed 47 pediatric renal transplant recipients weighing <15kg between 2009 and 2017. The k-vol before and 1year after transplantation and glomerular size at implant and 1year post-transplant were evaluated. We estimated the relationships between these changes and graft function, and the factors associated with k-vol. Pretransplant k-vol was 158.1±25.1ml, and the k-vol at 1year post-transplant was significantly reduced by -17.2% to 132.3±27.3ml (P<0.001). Implant glomerular size showed the diameter was 165.3±15.1µm and the area 20737.1±3230.6µm2 . One-year post-transplant, the glomerular diameter was 150.6±11.4µm and the area 17428.3±2577.9µm2 , significantly reduced compared with implantation values (both P<0.001). The change in k-vol was affected by pretransplant abdominal cavity (ml/200ml cavity volume, partial regression coefficient=0.029, SE=0.009, P=0.004) and recipient's weight gain (ml/5% of weight gain, partial regression coefficient=0.020, SE=0.006, P=0.002). In small pediatric transplants, an adult-size kidney is acceptable with reduction in k-vol. Moreover, the post-transplant k-vol might be regulated by pretransplant physique and post-transplant somatic growth.