Survival after kidney transplantation during childhood and adolescence has improved substantially in the past four decades, according to findings from the Australian and New Zealand dialysis and Transplantation (ANZDATA) Registry. Transplantation is favored over dialysis for the treatment of end-stage kidney disease, but it remains associated with significant morbidity and mortality. Mortality among pediatric kidney-transplant recipients has improved in recent years, but it remains unclear how cause-specific mortality has changed. Dr. Anna Francis of Queensland Children's Hospital, in South Brisbane, and the University of Sydney and colleagues used ANZDATA data to characterize changes in all-cause and cause-specific mortality among 1,810 children and adolescents who underwent a first kidney transplant between 1970 and 2015. They divided the era according to the predominant baseline immunosuppression: from 1970 to 1985 (azathioprine and prednisone); from 1986 to 1997 (cyclosporine/azathioprine/prednisone); from 1998 to 2004 (cyclosporine/mycophenolate/prednisone); and from 2005 to 2015 (tacrolimus/mycophenolate/prednisone). Overall, the median time to death was 10 years, and the median age at death was 24 years. For living-donor recipients, five-year survival increased from 93% among those first transplanted 1970-1985 to 99% among those first transplanted 2005-2015, a significant increase. Deceased-donor recipients had poorer survival, but also saw significant improvements in 5-year survival, from 81% in the 1970-1985 era to 99% in the 2005-2015 era. The risk of mortality was highest in the first year after transplant, and mortality rates were substantially lower in years 2 to 10, the researchers report in the Clinical Journal of the American Society of Nephrology. In multivariable analysis, transplantation in 2005-2015 was associated with a significant lower risk of dying compared with transplantation in 1970-1985 (adjusted hazard ratio, 0.28). Being on dialysis after a failed transplant increased the risk of death 2.9 times. Most deaths were due to cardiovascular causes (40%), while 17% were attributed to infection, 12% to cancer and 31% to other causes. The 5-year mortality from cardiovascular causes fell from 7.5% to 0.4% during this period (P<0.001), while infection-related mortality fell from 2.7% to 0.2% (P=0.007). Cancer deaths remained unchanged. Despite these substantial improvements in mortality, the authors conclude that "losing a kidney transplant, very young age at the time of transplant, and deceased donor source remain important risk factors for mortality. Future research directions include collaborative registry studies to examine changes in cause-specific mortality from a global perspective." Dr. Francis was not available for comment. —Reuters Staff Source
