Kidney donor age of 50 years or above is a risk factor for calcineurin inhibitor-induced nephrotoxicity.

INTRODUCTION: Calcineurin inhibitor (CNI)-induced nephrotoxicity (CNI-T) is a post-transplantation complication that leads to graft dysfunction. Older-donor kidney grafts may be susceptible to chronic CNI exposure because of long-term arteriolar damage. The primary aim of this study was to examine the CNI-T incidence and time-course changes in the graft function according to donor age.

METHODS: We included 334 kidney transplant recipients. CNI-T was defined by Banff arteriolar hyaline thickening scores of ≥2 based on allograft protocol biopsy. Depending on donor age, participants were divided into the D > 70 (≥70 years), D60 (60-69 years), D50 (50-59 years), and D < 49: (≤49 years) groups. We investigated the extent to which CNI-T affected the transplanted kidney function. Patients who did not develop CNI-T during the study period were included in the non-CNI-T group; the remaining were grouped into the CNI-T group.

RESULTS: The CNI-T incidence was higher in donors aged >50 years. Compared to D < 49, the CNI-T risk was 1.86 times higher in D50 and 2.9 times higher in D > 70. Furthermore, the CNI-T group exhibited a significantly lower graft function 10 years after transplantation.

CONCLUSION: CNI-T incidence increases in donors aged ≥50 years and affects renal function after 10 years.