Subclinical structural features in the kidney at the time of donation modestly contribute to graft failure, independent of living donor and recipient clinical characteristics, investigators reported online in the Journal of the American Society of Nephrology.
In an analysis of 2293 kidney donor-recipient pairs, interstitial fibrosis/tubular atrophy (IF/TA), arteriolar hyalinosis, and nephron enlargement in the intraoperative biopsy specimens independently predicted graft failure, Andrew D. Rule, MD, of Mayo Clinic in Rochester, Minnesota, and colleagues reported. IF/TA exceeding 5% (vs 0%), arteriolar hyalinosis, and larger tubular area were associated with 4.5-, 1.6-, and 1.2-fold increased risks for death-censored graft failure, respectively. The final model adjusted for both donor and recipient characteristics, such as measured glomerular filtration rate and 24-hour urine albumin excretion.
IF/TA exceeding 5% and arteriolar hyalinosis may indicate injury to the kidney unrelated to aging, the researchers stated.
“These findings provide insights into a graft’s ‘intrinsic quality’ at the time of donation, and further support the use of intraoperative biopsies to identify kidney grafts that are at higher risk for failure,” Dr Rule’s team wrote. They suggested increased monitoring of the graft and follow-up biopsies if intraoperative biopsy specimens reveal arteriolar hyalinosis, IF/TA greater than 5%, or enlarged nephrons. These patients may benefit from non-calcineurin-inhibitor-based immunosuppression or more aggressive management of blood pressure, they stated. Future studies are still needed to determine best practices.
Among the current study’s limitations, the researchers did not take into account major changes in immunosuppression during 1999 to 2017 or noncompliance with immunosuppressive regimens.
Issa N, Lopez C, Denic A, et al. Kidney structural features from living donors predict graft failure in the recipient. J Am Soc Nephrol.