Hypoperfusion warm ischaemia time in renal transplants from donors after circulatory death

KLF10 Induced by Hypothermic Machine Perfusion Alleviates Renal Inflammation Through BIRC2 /Noncanonical NF-κB Pathway

BACKGROUND

Hypothermic machine perfusion (HMP) is becoming the main preservation method for donation after circulatory death (DCD) kidneys. It can provide continuous flow and form shear stress (SS) upon endothelial cells (ECs), thereby regulating EC injury. Krüppel-like factor 10 (KLF10) has been shown to lessen vascular damage. However, how SS and KLF10 impact HMP-regulated injury is unclear.

METHODS

In this study, we investigated the influences of KLF10 on HMP in animal models and human renal biopsy and explored how SS affected KLF10 expression in a parallel-plate flow chamber system. Chromatin Immunoprecipitation sequencing and luciferase assay were performed to seek the target genes of KLF10. The influences of KLF10 on HMP-regulated injury were investigated by transfecting si-KLF10 adeno-associated virus serotype 9 into rat kidneys. The molecular expression was examined using immunofluorescence staining, Western blotting, and quantitative polymerase chain reaction.

RESULTS

Our results show KLF10 expression was augmented in human, rabbit, and rat DCD kidneys after HMP. HMP improved ECs and tubule injury and attenuated inflammation; however, the knockdown of KLF10 reversed this effect. SS regulated KLF10 expression in ECs by affecting F-actin, and KLF10 could maintain ECs homeostasis. Chromatin Immunoprecipitation sequencing and luciferase assay revealed that baculoviral inhibitor of apoptosis protein repeat-containing 2 (BIRC2) is a target gene of KLF10. Furthermore, BIRC2 linked to nuclear factor kappa B (NF-κB)-inducing kinase, induced NF-κB)-inducing kinase ubiquitination, and resulted in inhibiting the noncanonical NF-κB pathway.

CONCLUSIONS

SS can mediate KLF10 expression, whereas HMP can protect against warm ischemic injury by reducing inflammation via KLF10/BIRC2/noncanonical NF-κB pathway. Therefore, KLF10 might be a novel target for improving DCD kidney quality.

Impact of Donor Warm Ischemia Time on Graft Survival for Donation After Circulatory Death Kidney Transplantation

BACKGROUND

The utilization of kidneys donated after circulatory death (DCD) is an important strategy to address the ongoing shortage of organs suitable for transplantation in the United States. However, the nonuse rate of DCD kidneys remains high compared with kidneys donated after brain death (DBD) because of concerns regarding the injury incurred during donor warm ischemia time (DWIT). Therefore, we investigated the impact of DWIT on the risk of death-censored graft failure after DCD kidney transplantation (KT).

METHODS

Retrospective analysis was conducted on DCD KTs using the Standard Transplant Analysis and Research data set. The association of DWIT with death-censored graft failure was evaluated using multivariable Cox proportional hazard regression, with reference to DCD KTs with Kidney Donor Risk Index (KDRI) of ≤0.78 and the median DWIT of 26 min.

RESULTS

A total of 28 032 DCD kidney-alone transplants between January 2010 and December 2021 were studied. When stratified by KDRI, increasing DWIT was associated with a clinically significant increased risk for death-censored graft failure only in the subset of kidneys with KDRI >1.14 but not in those with KDRI >0.78-≤0.94 and >0.94-≤1.14, compared with the reference group.

CONCLUSIONS

We suggest that clinicians should not decline kidneys on the basis of DWIT in favor of potential offers of DBD or other DCD kidneys with shorter DWIT, provided that their KDRI scores are within an acceptable limit. Our study highlights opportunities for more efficient usage of DCD kidneys and improving the shortage of transplantable organs.

Successful emergency renal auto-transplantation in a child with renovascular disease

Renal artery occlusion is a rare but potentially catastrophic complication of paediatric endovascular renal artery intervention. Emergency auto-transplantation may be required to salvage the kidney; to date this has only been described in adults. We report our experience of performing emergency kidney auto-transplantation following acute renal artery thrombosis in a child undergoing redo renal artery angioplasty A 20-month-old boy presented with refractory hypertension and hypertensive cardiomyopathy secondary to multifocal fibromuscular dysplasia (FMD) with a single functioning kidney. Acute thrombosis of the renal artery during redo-endovascular balloon angioplasty necessitated emergency renal auto-transplantation. Subsequent acute kidney injury was reversible with benefit to renal function in the medium-term despite prolonged warm ischaemic time of two hours. We recommend that high-risk patients undergoing renal artery intervention do so at centres with on-site renal and vascular surgical backup.

Donor Time to Death and Kidney Transplant Outcomes in the Setting of a 3-Hour Minimum Wait Policy

Importance

Lengthening waiting lists for organ transplant mandates the development of strategies to expand the deceased donor pool. Due to concerns regarding organ viability, most organ donation organizations internationally wait no longer than 1 to 2 hours for potential donation after circulatory death (DCD), possibly underutilizing an important organ source; UK policy mandates a minimum 3-hour wait time.

Objective

To assess whether time to death (TTD) from withdrawal of life-sustaining treatment (WLST) is associated with kidney transplant outcomes.

Design, Setting, and Participants

This population-based cohort study used data from the prospectively maintained UK Transplant Registry from all 23 UK kidney transplant centers from January 1, 2013, to December 31, 2021; follow-up was until the date of data extraction (October 2023). Participants comprised 7183 adult recipients of DCD kidney-alone transplants.

Exposure

Duration of TTD, defined as time from WLST to donor mechanical asystole.

Main Outcomes and Measures

Primary outcome was 12-month estimated glomerular filtration rate (eGFR; for the main eGFR model, variables with significant right skew [histogram visual assessment] were analyzed on the log2 scale), with secondary outcomes of delayed graft function and graft survival (censored at death or 5 years).

Results

This study included 7183 kidney transplant recipients (median age, 56 years [IQR, 47-64 years]; 4666 men [65.0%]). Median donor age was 55 years (IQR, 44-63 years). Median TTD was 15 minutes (range, 0-407 minutes), with 885 kidneys transplanted from donors with TTD over 1 hour and 303 kidneys transplanted from donors with TTD over 2 hours. Donor TTD was not associated with recipient 12-month eGFR on adjusted linear regression (change per doubling of TTD, -0.25; 95% CI, -0.68 to 0.19; P = .27), nor with delayed graft function (adjusted odds ratio, 1.01; 95% CI, 0.97-1.06; P = .65) or graft survival (adjusted hazard ratio, 1.00; 95% CI, 0.95-1.07; P = .92). These findings were confirmed with restricted cubic spline models (assessing nonlinear associations) and tests of interaction (including normothermic regional perfusion). In contrast, donor asystolic time, cold ischemic time, and reperfusion time were independently associated with outcomes. Compared with a theoretical 1-hour maximum wait time, the UK policy (minimum 3-hour wait time) has been associated with 885 extra DCD transplants compared with 6298 transplants (14.1% increase).

Conclusions and Relevance

In this cohort study of DCD kidney recipients, donor TTD was not associated with posttransplant outcomes, in contrast to subsequent ischemic times. Altering international transplant practice to mandate minimum 3-hour donor wait times could substantially increase numbers of kidney transplants performed without prejudicing outcomes.

Effect of Cardiac Arrest in Brain-dead Donors on Kidney Graft Function

BACKGROUND

Cardiac arrest (CA) causes renal ischemia in one-third of brain-dead kidney donors before procurement. We hypothesized that the graft function depends on the time interval between CA and organ procurement.

METHODS

We conducted a retrospective population-based study on a prospectively curated database. We included 1469 kidney transplantations from donors with a history of resuscitated CA in 2015-2017 in France. CA was the cause of death (primary CA) or an intercurrent event (secondary CA). The main outcome was the percentage of delayed graft function, defined by the use of renal replacement therapy within the first week posttransplantation.

RESULTS

Delayed graft function occurred in 31.7% of kidney transplantations and was associated with donor function, vasopressors, cardiovascular history, donor and recipient age, body mass index, cold ischemia time, and time to procurement after primary cardiac arrest. Short cold ischemia time, perfusion device use, and the absence of cardiovascular comorbidities were protected by multivariate analysis, whereas time <3 d from primary CA to procurement was associated with delayed graft function (odds ratio 1.38).

CONCLUSIONS

This is the first description of time to procurement after a primary CA as a risk factor for delayed graft function. Delaying procurement after CA should be evaluated in interventional studies.

British Transplantation Society guidelines on abdominal organ transplantation from deceased donors after circulatory death

The British Transplantation Society (BTS) 'Guideline on transplantation from deceased donors after circulatory death' has recently been updated and this manuscript summarises the relevant recommendations in abdominal organ transplantation from Donation after Circulatory Death (DCD) donors, encompassing the chapters on liver, kidney, pancreas and islet cell transplantation.

Intraoperative Verapamil Fails to Reduce Delayed Graft Function in Donation After Circulatory Death Renal Allografts

Background.

The shortage of transplantable organs has led to increased utilization of kidneys that may be particularly vulnerable to ischemia-reperfusion injury (IRI) and delayed graft function (DGF). Kidneys from donation after circulatory death (DCD) donors have additional IRI from donor procurement that results in increased risk of DGF. Verapamil may reduce IRI in kidney allografts when given at the time of organ reperfusion. This study sought to determine if intraoperative administration of verapamil (Ver) could reduce the risk of DGF in DCD kidney transplants.

Methods.

A single-center retrospective matched cohort study was performed of 93 Ver (–) kidney transplant recipients compared with 93 Ver (+) kidney transplant recipients, matched by donor age, Kidney Donor Profile Index, and DCD status. Covariates that could impact DGF risk were evaluated by univariate and multivariate logistic regression analyses.

Results.

The Ver (–) and Ver (+) matched cohorts did not have any significant differences in the demographic covariates. There was no difference in DGF rate between the Ver cohorts in either the overall study population or within the DCD subgroup. There was a trend toward reduced DGF in the Ver (+) cohort for cold ischemia time (CIT) ≤24 h, but this failed to achieve statistical significance. On multivariate analysis, only CIT was found to be independently associated with DGF.

Conclusions.

Intraoperative verapamil failed to reduce DGF risk in DCD kidney allografts. Limitations to this study include nonrandomization for the intraoperative administration of verapamil and the mean CIT >24 h in the study population. Only CIT was an independent prognosticator for DGF on multivariate analysis in a cohort matched for DCD status, consistent with prior studies.

Effect of delayed graft function on longer-term outcomes after kidney transplantation from donation after circulatory death donors in the United Kingdom: A national cohort study

Kidneys from donation after circulatory death (DCD) donors are utilized variably worldwide, in part due to high rates of delayed graft function (DGF) and putative associations with adverse longer-term outcomes. We aimed to determine whether the presence of DGF and its duration were associated with poor longer-term outcomes after kidney transplantation from DCD donors. Using the UK transplant registry, we identified 4714 kidney-only transplants from controlled DCD donors to adult recipients between 2006 and 2016; 2832 recipients (60·1%) had immediate graft function and 1882 (39·9%) had DGF. Of the 1847 recipients with DGF duration recorded, 926 (50·1%) had DGF < 7 days, 576 (31·2%) had DGF 7-14 days, and 345 (18·7%) had DGF >14 days. After risk adjustment, the presence of DGF was not associated with inferior long-term graft or patient survivals. However, DGF duration of >14 days was associated with an increased risk of death-censored graft failure (hazard ratio 1·7, p = ·001) and recipient death (hazard ratio 1·8, p < ·001) compared to grafts with immediate function. This study suggests that shorter periods of DGF have no adverse influence on graft or patient survival after DCD donor kidney transplantation and that DGF >14 days is a novel early biomarker for significantly worse longer-term outcomes.

Unassisted Return of Spontaneous Circulation Following Withdrawal of Life-Sustaining Therapy During Donation After Circulatory Determination of Death in a Child

OBJECTIVES

To describe the unassisted return of spontaneous circulation following withdrawal of life-sustaining treatment in a child.

DESIGN

Case report based on clinical observation and medical record review.

SETTING

Community Children's Hospital.

PATIENT

Two-year old child.

INTERVENTIONS

Following hypoxic-ischemic brain injury, the child was taken to the operating room for withdrawal of life-sustaining treatment during controlled donation after circulatory determination of death.

MEASUREMENTS AND MAIN RESULTS

In addition to direct observation by experienced pediatric critical care providers, the child was monitored with electrocardiography, pulse oximetry, and invasive blood pressure via femoral arterial catheter in addition to direct observation by experienced pediatric critical care providers. Unassisted return of spontaneous circulation occurred greater than 2 minutes following circulatory arrest and was accompanied by return of respiration.

CONCLUSIONS

We provide the first report of unassisted return of spontaneous circulation following withdrawal of life-sustaining treatment in a child. In our case, return of spontaneous circulation occurred in the setting of controlled donation after circulatory determination of death and was accompanied by return of respiration. Return of spontaneous circulation greater than 2 minutes following circulatory arrest in our patient indicates that 2 minutes of observation is insufficient to ensure that cessation of circulation is permanent after withdrawal of life-sustaining treatment in a child.

Implementation of donation after circulatory death kidney transplantation can safely enlarge the donor pool: A systematic review and meta-analysis

BACKGROUND

Donation after circulatory death (DCD) kidney transplantation has been introduced to address organ shortage. However, DCD kidneys are not accepted worldwide due to concerns about inferior quality. To investigate whether these concerns are justified, we performed a systematic review and meta-analysis to investigate DCD graft outcomes compared to donation after brain death (DBD).

MATERIALS AND METHODS

EMBASE, Medline, Cochrane, Web of Science and Google Scholar were searched from database inception until September 2020. Exclusion criteria were studies reporting on pediatric/dual kidney transplants, multi-organ transplants or studies including normothermic perfusion techniques. The primary outcome was graft survival. Secondary outcomes were primary non-function (PNF), delayed graft function (DGF), 3-months biopsy-proven acute rejection (BPAR), 1-year estimated Glomerular Filtration Rate (eGFR), patient survival, and urologic complications. A random-effects model was used for meta-analysis. Meta-regression analysis was performed in case of high between-study heterogeneity.

RESULTS

Fifty-one studies were included, comprising 73,454 DCD and 518,229 DBD recipients. One-year graft loss was increased in DCD recipients (death-censored: risk ratio (RR) 1.10 (95%-confidence interval (CI) 1.04-1.16), all-cause: RR 1.13 (95%-CI 1.08-1.19)). Ten-year graft loss was similar to DBD (death-censored: RR 1.02 (95%-CI 0.92-1.13), all-cause: RR 1.03 (95%-CI 0.94-1.13)). DCD recipients had an increased risk of PNF (RR 1.43 (95%-CI 1.26-1.62)), DGF (RR 2.02 (95%-CI 1.88-2.16)), and 1-year mortality (RR 1.10 (95%-CI 1.01-1.21)). No differences were observed for 3-months BPAR, ureter stenosis/leakage, 1-year eGFR and 10-year mortality.

CONCLUSION

Long-term DCD kidney transplant outcomes are similar to DBD despite a higher risk of PNF, DGF, and a 13% increased risk of graft loss in the first year after transplantation. These results should encourage implementation of DCD programs.