Long term outcomes following kidney transplantation in children who weighed less than 15 kg - report from the UK Transplant Registry

BACKGROUND

Kidney transplantation is the treatment of choice in chronic kidney disease (CKD) stage 5. It is often delayed in younger children until a target weight is achieved due to technical feasibility and historic concerns about poorer outcomes.

METHODS

Data on all first paediatric (aged < 18 years) kidney only transplants performed in the United Kingdom between 1 January 2006 and 31 December 2016 were extracted from the UK Transplant Registry (n = 1,340). Children were categorised by weight at the time of transplant into those < 15 kg and those ≥ 15 kg. Donor, recipient and transplant characteristics were compared between groups using chi-squared or Fisher's exact test for categorical variables and Kruskal-Wallis test for continuous variables. Thirty day, one-year, five-year and ten-year patient and kidney allograft survival were compared using the Kaplan-Meier method.

RESULTS

There was no difference in patient survival following kidney transplantation when comparing children < 15 kg with those ≥ 15 kg. Ten-year kidney allograft survival was significantly better for children < 15 kg than children ≥ 15 kg (85.4% vs. 73.5% respectively, p = 0.002). For children < 15 kg, a greater proportion of kidney transplants were from living donors compared with children ≥ 15 kg (68.3% vs. 49.6% respectively, p < 0.001). There was no difference in immediate graft function between the groups (p = 0.54) and delayed graft function was seen in 4.8% and 6.8% of children < 15 kg and ≥ 15 kg respectively.

CONCLUSIONS

Our study reports significantly better ten-year kidney allograft survival in children < 15 kg and supports consideration of earlier transplantation for children with CKD stage 5. A higher resolution version of the Graphical abstract is available as Supplementary information.