Subclinical structural features of donated kidneys — identified through biopsy — appeared to contribute to graft failure in the recipient, according recently published study results.
“The quality of a kidney obtained from a living donor is often inferred from the donor’s age, risk factors and kidney function,” Naim Issa, MD, of the Mayo Clinic, and colleagues wrote. “Little is known about the influence of a donated kidney’s structural features on the risk of death-censored graft failure in the recipient.”
They added, “Transplantation is a unique setting to study how kidney structural features contribute to the development of kidney failure since the donated kidney, once placed in the recipient, becomes independent of the non-kidney characteristics of the donor.”
Using CT and implantation biopsy to examine structural features of the donated kidneys, researchers identified 2,293 donor-recipient pairs. Considered features included nephrosclerosis, nephron size and nephron number. Using each of these structural features, death-censored risk of graft failure was determined and recipients were followed for a mean of 6.3 years.
During this time, there were 287 death-censored graft failures and 424 deaths. Researchers found donor clinical characteristics that independently predicted death-censored graft failure included older age, black race and higher 24-hour urine albumin. Recipient clinical characteristics that predicted graft failure were younger age, black race, diabetes, etiology of chronic kidney disease, any HLA-antigen mismatch, HLA-donor recipient mismatch, previous kidney transplant, pre-transplant dialysis and delayed graft function.
Subclinical structural features of donated kidneys appeared to contribute to graft failure in the recipient.
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After adjusting for these predictive clinical characteristics, researchers determined subclinical nephrosclerosis (the presence of interstitial fibrosis/tubular atrophy), larger cortical nephron size and smaller medullary volume were predictive of graft failure. No association between nephron number and graft failure was observed.
“We think that these subtle features in the living donor kidney make the recipient more susceptible to lose the kidney transplant over time,” Issa said in a related press release. “These important findings may provide insights into previously unrecognized predictors of kidney transplant failure in recipients.” – by Melissa J. Webb
Disclosures: The authors report no relevant financial disclosures.