Survival after Kidney Transplantation during Childhood and Adolescence

Abstract

Background and objectives: Survival in pediatric kidney transplant recipients has improved over the past five decades, but changes in cause-specific mortality remain uncertain. The aim of this retrospective cohort study was to estimate the associations between transplant era and overall and cause-specific mortality for child and adolescent recipients of kidney transplants.

Design, setting, participants, & measurements: Data were obtained on all children and adolescents (aged <20 years) who received their first kidney transplant from 1970 to 2015 from the Australian and New Zealand Dialysis and Transplant Registry. Mortality rates were compared across eras using Cox regression, adjusted for confounders.

Results: A total of 1810 recipients (median age at transplantation 14 years, 58% male, 52% living donor) were followed for a median of 13.4 years. Of these, 431 (24%) died, 174 (40%) from cardiovascular causes, 74 (17%) from infection, 50 (12%) from cancer, and 133 (31%) from other causes. Survival rates improved over time, with 5-year survival rising from 85% for those first transplanted in 1970-1985 (95% confidence interval [95% CI], 81% to 88%) to 99% in 2005-2015 (95% CI, 98% to 100%). This was primarily because of reductions in deaths from cardiovascular causes (adjusted hazard ratio [aHR], 0.25; 95% CI, 0.08 to 0.68) and infections (aHR, 0.16; 95% CI, 0.04 to 0.70; both for 2005-2015 compared with 1970-1985). Compared with patients transplanted 1970-1985, mortality risk was 72% lower among those transplanted 2005-2015 (aHR, 0.28; 95% CI, 0.18 to 0.69), after adjusting for potential confounders.

Conclusions: Survival after pediatric kidney transplantation has improved considerably over the past four decades, predominantly because of marked reductions in cardiovascular- and infection-related deaths.

Keywords: New Zealand; adolescent; child; children; humans; kidney transplantation; living donors; male; neoplasms; proportional hazards models; registries; renal dialysis; retrospective studies; risk; survival; survival rate; transplant outcomes; transplantation.

Graphical abstract

Figure 1.

Improvement with more recent transplant eras for all-cause mortality after kidney transplantation during childhood and adolescence, stratified by donor source. 95% CI, 95% confidence interval; CIF Est, cumulative incidence function; HR, hazard ratio.

Figure 2.

Mortality rates are highest in the first year post first transplant, but are improved in the more recent transplant era.

Figure 3.

Cause-specific mortality after kidney transplantation has improved in more recent transplant eras, especially for cardiovascular- and infection-related mortality.

Figure 4.

Cardiovascular- and infection-related deaths are more common during dialysis after a failed transplant than during transplant function for childhood and adolescent recipients of a kidney transplant.