Kidney Donor Profile Index and allograft outcomes: interactive effects of estimated post-transplant survival score and ischaemic time

Lay Summary The ongoing disparity between donor organ availability and the increasing demand for donor kidneys for patients with kidney failure has resulted in an increased utilization of lower-quality donor kidneys for transplantation worldwide. The Kidney Donor Profile Index (KDPI) is a metric derived to improve the assessment of donor quality and prediction of kidney transplant outcome. In this article we show that non-donor factors such as lower patient survival score and longer ischaemic time adversely influence the relationship between the KDPI and transplant outcome such that clinicians have to be cognizant when interpreting the clinical applicability and significance of the KDPI.

Background The Kidney Donor Profile Index (KDPI) is routinely reported by the donation agencies in Australia. We determined the association between KDPI and short-term allograft loss and assessed if this association was modified by the estimated post-transplant survival (EPTS) score and total ischaemic time. Methods Using data from the Australia and New Zealand Dialysis and Transplant Registry, the association between KDPI (in quartiles) and 3-year overall allograft loss was examined using adjusted Cox regression analysis. The interactive effects between KDPI, EPTS score and total ischaemic time on allograft loss were assessed. Results Of 4006 deceased donor kidney transplant recipients transplanted between 2010 and 2015, 451 (11%) recipients experienced allograft loss within 3 years post-transplant. Compared with recipients of kidneys with a KDPI of 0-25%, recipients who received donor kidneys with a KDPI >75% experienced a 2-fold increased risk of 3-year allograft loss {adjusted hazard ratio [HR] 2.04 [95% confidence interval (CI) 1.53-2.71]}. The adjusted HRs for kidneys with a KDPI of 26-50% and 51-75% were 1.27 (95% CI 0.94-1.71) and 1.31 (95% CI 0.96-1.77), respectively. There were significant interactions between KDPI and EPTS scores (P-value for interaction