The Kidney Allocation System Does Not Appropriately Stratify Risk of Pediatric Donor Kidneys: Implications for Pediatric Recipients

Kidney Allocation System (KAS) was enacted in 2014 to improve graft utility, while facilitating transplantation of highly-sensitized patients and preserving pediatric access to high-quality kidneys. Central to this system is the Kidney Donor Profile Index (KDPI), a metric intended to predict transplant outcomes based on donor characteristics but derived using only adult donors. We posited that KAS had inadvertently altered the profile and quantity of kidneys made available to pediatric recipients. This question arose from our observation that most pediatric donors carry a KDPI over 35 and have therefore been rendered relatively inaccessible to pediatric recipients under KAS. Here we explore early trends in pediatric transplantation following KAS, including: (i) use of pediatric donors, (ii) use of Public Health System (PHS) high infectious risk donors, (iii) wait time, and (iv) living donor transplantation. We note some concerning preliminary changes following KAS implementation, including the allocation of fewer deceased donor pediatric kidneys to children and stagnation in pediatric wait times. Moreover, the poor predictive power of the KDPI for adult donors appears to be even worse when applied to pediatric donors. These early trends warrant further observation and consideration of changes in pediatric kidney allocation if they persist.