The risk of graft loss 5 years after kidney transplantation is increased if cold ischemia time exceeds 14 hours.

The state of the evidence is unclear regarding the impact of cold ischemia time (CIT) on the outcome of kidney transplantation. The aim of this study was to investigate the effect of CIT on the short- and long-term function of kidneys transplanted at the Sahlgrenska University Hospital in 2007-2009 from donors after brain death (DBDs). This study was designed as a retrospective analysis of data from local and national transplantation registers. The study endpoints were as follows: delayed graft function (DGF), primary nonfunction (PNF), biopsy-proven acute rejection (BPAR), serum creatinine (S-creatinine) level at discharge, days of hospitalization after transplantation, and graft survival at 5 years post-transplantation. Adjusted regression analyses were used to determine causal relationships with CIT. A further aim was to estimate a threshold for CIT by analyzing event rates and coordinates of the receiver-operated characteristic (ROC) curve. There was a causal relationship between CIT as a continuous variable and the following endpoints: graft survival at 5 years post-transplantation, though this was not significant (hazard ratio (HR) 1.07, P = 0.057), DGF (odds ratio (OR) 1.09, P = 0.03) and S-creatinine (P = 0.003). In our material, the risk for impaired outcome was higher with longer CIT. We were therefore able to estimate a threshold value for CIT, set to 14 hours for both graft survival at 5 years post-transplantation and DGF. This was proved with significance by analyzing both event rates and the coordinates of the ROC curve. The risk of graft loss increased, with HR 2.3 (P = 0.023), when comparing a CIT cutoff of ≥14 hours with CIT < 14 hours. Delayed graft function increased, with an OR of 2.6 (P = 0.001). Our study confirms that, in this patient material, longer CIT was associated with increased risk for both impaired graft survival and incidence of DGF. We estimated a threshold for CIT of 14 hours.

Hansson J ，Mjörnstedt L ，Lindnér P 《-》

Impact of machine perfusion after long static cold storage on delayed graft function incidence and duration and time to hospital discharge.

Delayed graft function (DGF) is very high in our center (70%-80%), and we usually receive a kidney for transplant after more than 22 hours of static cold ischemia time (CIT). Also, there is an inadequate care of the donors, contributing to a high rate of DGF. We decided to test whether machine perfusion (MP) after a CIT improved the outcome of our transplant patients. We analyzed the incidence of DGF, its duration, and the length of hospital stay (LOS) in patients who received a kidney preserved with MP after a CIT (hybrid perfusion-HP). We included 54 deceased donors kidneys preserved with HP transplanted from Feb/13 to Jul/14, and compared them to 101 kidney transplants preserved by static cold storage (CS) from Nov/08 to May/12. The median pumping time was 11 hours. DGF incidence was 61.1% vs 79.2% (P = .02), median DGF duration was 5 vs 11 days (P < .001), and median LOS was 13 vs 18 days (P < .011), for the HP compared to CS group. The observed reduction of DGF with machine perfusion did not occur in donors over 50 years old. In the multivariate analysis, risk factors for DGF, adjusted for CIT, were donor age (OR, 1.04; P = .005) and the absence of use of MP (OR, 1.54; P = .051). In conclusion, the use of HP contributed to faster recovery of renal function and to a shorter length of hospital stay.

Matos ACC ，Requiao Moura LR ，Borrelli M ，Nogueira M ，Clarizia G ，Ongaro P ，Durão MS ，Pacheco-Silva A ... -  《-》

Is prolonged cold ischemia a contraindication to using kidneys from acute kidney injury donors?

To determine the impact of prolonged cold ischemia time (CIT) on the outcome of acute kidney injury (AKI) renal grafts, we therefore performed a single-center retrospective analysis in adult patients receiving kidney transplantation (KT) from AKI donors. Outcomes were stratified according to duration of CIT. A total of 118 patients receiving AKI grafts were enrolled. Based on CIT, patients were stratified as follows: (i) <20 hours, 27 patients; (ii) 20-30 hours, 52 patients; (iii) 30-40 hours, 30 patients; (iv) ≥40 hours, nine patients. The overall incidence of delayed graft function DGF was 41.5%. According to increasing CIT category, DGF rates were 30%, 42%, 40%, and 78%, respectively (P = .03). With a mean follow-up of 48 months, overall patient and graft survival rates were 91% and 81%. Death-censored graft survival (DCGS) rates were 84% and 88% for patients with and without DGF (P = NS). DCGS rates were 92% in patients with CIT <20 hours compared to 85% with CIT >20 hours (P = NS). In the nine patients with CIT >40 hours, the 4-year DCGS rate was 100%. We conclude that prolonged CIT in AKI grafts may not adversely influence outcomes and so discard of AKI kidneys because of projected long CIT is not warranted when donors are wisely triaged.

Orlando G ，Khan MA ，El-Hennawy H ，Farney AC ，Rogers J ，Reeves-Daniel A ，Gautreaux MD ，Doares W ，Kaczmorski S ，Stratta RJ ... -  《-》

Shipping living donor kidneys and transplant recipient outcomes.

Kidney paired donation (KPD) is an important tool to facilitate living donor kidney transplantation (LDKT). Concerns remain over prolonged cold ischemia times (CIT) associated with shipping kidneys long distances through KPD. We examined the association between CIT and delayed graft function (DGF), allograft survival, and patient survival for 1267 shipped and 205 nonshipped/internal KPD LDKTs facilitated by the National Kidney Registry in the United States from 2008 to 2015, compared to 4800 unrelated, nonshipped, non-KPD LDKTs. Shipped KPD recipients had a median CIT of 9.3 hours (range = 0.25-23.9 hours), compared to 1.0 hour for internal KPD transplants and 0.93 hours for non-KPD LDKTs. Each hour of CIT was associated with a 5% increased odds of DGF (adjusted odds ratio: 1.05, 95% confidence interval [CI], 1.02-1.09, P < .01). However, there was not a significant association between CIT and all-cause graft failure (adjusted hazard ratio [aHR]: 1.01, 95% CI: 0.98-1.04, P = .4), death-censored graft failure ( [aHR]: 1.02, 95% CI, 0.98-1.06, P = .4), or mortality (aHR 1.00, 95% CI, 0.96-1.04, P > .9). This study of KPD-facilitated LDKTs found no evidence that long CIT is a concern for reduced graft or patient survival. Studies with longer follow-up are needed to refine our understanding of the safety of shipping donor kidneys through KPD.

Treat E ，Chow EKH ，Peipert JD ，Waterman A ，Kwan L ，Massie AB ，Thomas AG ，Bowring MG ，Leeser D ，Flechner S ，Melcher ML ，Kapur S ，Segev DL ，Veale J ... -  《-》

Interaction between cold ischemia time and Kidney Donor Profile Index on postrenal transplant outcomes.

We analyzed whether there is an interaction between the Kidney Donor Profile Index (KDPI) and cold ischemia time (CIT) in recipients of deceased donor kidney transplant (KTs). Adults who underwent KTs in the United States between 2014 and 2020 were included and divided into 3 KDPI groups (≤20%, 21%-85%, >85%) and 4 CIT strata (<12, 12-17.9, 18-23.9, ≥24 hours). Multivariate analyses were used to test the interaction between KDPI and CIT for the following outcomes: primary graft nonfunction (PGNF), delayed graft function (DGF), estimated glomerular filtration rate (eGFR) at 6 and 12 months, patient survival, graft survival, and death-censored graft survival (DCGS). A total of 69,490 recipients were analyzed: 18,241 (26.3%) received a graft with KDPI ≤20%, 46,953 (67.6%) with KDPI 21%-85%, and 4,296 (6.2%) with KDPI >85%. Increasing KDPI and CIT were associated with worse post-KT outcomes. Contrary to our hypothesis, howerver, the interaction between KDPI and CIT was statistically significant only for PGNF and DGF and eGFR at 6 months. Paradoxically, the negative coefficient of the interaction suggested that increasing duration of CIT was more detrimental for low and intermediate-KDPI organs relative to high-KDPI grafts. Conversely, for mortality, graft survival, and DCGS, we found that the interaction between CIT and KDPI was not statistically significant. We conclude that, high KDPI and prolonged CIT are independent risk factors for inferior outcomes after KT. Their interaction, however, is statistically significant only for the short-term outcomes and more pronounced on low and intermediate-KDPI grafts than high-KDPI kidneys.

Cashion WT ，Zhang X ，Puttarajappa C ，Sharma A ，Mehta R ，Ganoza A ，Gunabushanam V ，Sood P ，Wu C ，Cherukuri A ，Shah N ，Kaltenmeier C ，Liu H ，Dharmayan S ，Hariharan S ，Molinari M ... -  《-》