Studies look at risks, benefits of using marginal donors

With the scarcity of organs available for transplant worldwide, centers have looked at the risks and rewards of transplanting older or compromised deceased donor kidneys into older-age recipients. Two studies presented during ASN’s Kidney Week examined results from two transplant centers to determine if the outcomes were positive.

In the first study, Seong Sik Kang, MD, and colleagues from the University School of Medicine in Daegu, The Republic of Korea observed the accelerated efforts at decreased donor kidney transplantation in that country. The demand for organs, however, has meant that “the organ shortage for transplantation is getting worse and deceased donor kidney transplant using acute kidney injury (AKI), expanded criteria donor (ECD) or high kidney donor profile index (KDPI) kidney is increasing,” they wrote.

The physician group evaluated the outcome of kidney transplant recipients (KTRs) between January 2010 and December 2014. Ninety-four deceased donors, along with their 95 KTRs, were part of the study.

“We analyzed the clinical outcomes of [decreased donor kidney transplantation] DDKT according to AKI, ECD, and high KDPI (> 85%),” the authors wrote.

Results showed the KTRs were highest in the AKI group (44.2%), followed by the ECD group (24.2%) and the high KDPI group (16.8%). The mean follow-up period was 42.6 months.

“The incidence of delayed graft function (DGF) was significantly higher in the AKI group than in the non-AKI group (P = 0.011), but not in the ECD group and the high KDPI group,” the authors wrote. “The estimated glomerular filtration rate (eGFR) of the AKI group was significantly lower at 1 week, 2 weeks and 1 month after KT compared to the non-AKI group. After 3 months of KT, there was no significant difference in eGFR between the AKI group and non-AKI group, the ECD group and standard criteria donor group, and the high KDPI group and low KDPI group,” they reported.

When looking at patient and graft survival, the rate showed no significant difference among the AKI, ECD or high KDPI groups compared with the control groups. However, the authors noted, “allograft survival rate was significantly lower only in the group with acute rejection (AR) than in the group without AR (P < 0.001). In a multivariate analysis, AR was an independent risk factor for graft failure (hazard ratio 85.75, 95% confidence interval, 7.02-1047.77, P < 0.001), but AKI, ECD or high KDPI were not.”

Thus, the study showed deceased donor kidneys that had experienced AKI had a significant association with increased incidence of DGF.

“However, KT using AKI, ECD or high KDPI donor kidney performed similarly to the control group in terms of graft function, graft survival and patient survival,” the researchers wrote.

In a second study, Hernando Trujillo Cuellar and colleagues from the Hospital 12 de Octubre in Madrid looked at the outcomes of kidney transplants performed in recipients older than age 70 years.

“The major limitation in this group of patients is shortage of donors since kidneys from young donors are assigned to younger recipients,” they wrote.

They performed a retrospective analysis of pre-transplant clinical factors associated with graft and recipient survival in patients older than 70 years and who had received a kidney transplant from a donor of 70 years of age or older. Transplants and outcomes were reviewed from October 2004 to December 2013, with follow-up through April 25, 2017. There were 112 donors and 155 recipients.

Despite the older age of the donors and recipients (median ages of 77 and 75 years, respectively), the 3-year patient survival was 73.1% and the 5-year patient survival was 67.1%. In the first year, mortality was 15.9%.

“Death-censored graft survival was 83.4% at year 3 and 80.8% at year 5,” the authors wrote. “History of cerebrovascular disease in the recipient was the only factor associated with patient survival (HR 5.12, P = 0.027), while history of diabetes mellitus in the recipient was the only factor associated with the risk of graft loss (HR 4.40, P = 0.0001).”

Despite the ages of both the donor kidney and the recipient, kidney transplantation from old donors in patients older than 70 years “offers a survival advantage over staying on dialysis,” the authors wrote. “History of cerebrovascular disease in the recipient was associated with an increased risk of recipient mortality, while history of diabetes in the recipient was associated with increased risk of graft loss.

“Further studies are needed to identify pre-transplant clinical factors associated with increased risk of graft failure and recipient mortality in this population to improve allocation of these old allografts in the elderly patients,” the researchers wrote. – by Mark E. Neumann

References:

Seong Sik K, et al. Abstract FR-PO1027. Presented at: Kidney Week 2017; Oct. 31-Nov. 5, 2017; New Orleans.

Trujillo Cuellar H, et al. Abstract FR-PO1033. Presented at: Kidney Week 2017; Oct. 31-Nov. 5, 2017; New Orleans.

Disclosures: The authors reported no relevant financial disclosures.