Outcomes of kidneys utilized from deceased donors with severe acute kidney injury

Short-Term, Mid-Term, and Long-Term Outcomes after Deceased Donor Kidney Transplantation in Patients with AKI: A Systematic Review and Meta-Analysis

Key Points

Background

AKI is a common complication in hospitalized patients and may occur in potential kidney donors. Observational studies have suggested that kidney transplantation in patients with AKI is feasible and safe, but no systematic evaluation has been performed.

Methods

We performed a systematic review and meta-analysis to evaluate the outcomes of kidney transplantation in patients with AKI. We searched MEDLINE, Embase, Cochrane, Google Scholar, and other databases for studies reporting outcomes of donor kidneys with AKI. We included single-center, multicenter, and registry-based studies and analyzed them according to the definition and severity of AKI. End points were primary and delayed graft function (DGF), primary nonfunction (PNF), length of hospital stay, rejection, graft function, and patient and graft survival at 1, 3, 5, and 8–10 years after transplantation. This study was registered in PROSPERO, number CRD42021260088.

Results

We identified 33 single-center, four multicenter, and seven registry studies with more than 100,000 patients published between 2005 and 2022. Recipients from donors with AKI had a higher risk of DGF (relative risk, 1.51; 95% confidence interval [CI], 1.35 to 1.68). Graft function at discharge was worse in the AKI group (MDCrea [95% CI]: 0.96 mg/dl [0.36 to 1.56, I2=96%], MDGFR [95% CI]: −8.88 ml/min per 1.73 m2 [−15.32 to −2.44, I2=93%]), but improved thereafter and was similar in both groups at 3 months after transplantation (MDCrea [95% CI]: −0.05 mg/dl [−0.18 to 0.07, I2=0%], MDGFR [95% CI]: −1.83 ml/min per 1.73 m2 [−5.29 to 1.63, I2=91%]). Primary nonfunction and patient and graft survival were similar at 1, 3, 5, and 8–10 years after transplantation. There were no differences in rejections regardless of AKI definition and severity.

Conclusions

Transplantation of kidneys with AKI is associated with satisfactory short-term and long-term outcomes and should be pursued to increase the donor pool.

Impact of acute kidney injury and renal recovery status in deceased donor to kidney transplant outcome: results from the Thai national transplant registry

The influence of acute kidney injury (AKI) and renal recovery in deceased donor (DD) on long-term kidney transplant (KT) outcome has not previously been elucidated in large registry study. Our retrospective cohort study included all DDKT performed in Thailand between 2001 and 2018. Donor data was reviewed case by case. AKI was diagnosed according to the KDIGO criteria. Renal recovery was defined if DD had an improvement in AKI to the normal or lower stage. All outcomes were determined until the end of 2020. This study enrolled 4234 KT recipients from 2198 DD. The KDIGO staging of AKI was as follows: stage 1 for 710 donors (32.3%), stage 2 for 490 donors (22.3%) and stage 3 for 342 donors (15.6%). AKI was partial and complete recovery in 265 (17.2%) and 287 (18.6%) before procurement, respectively. Persistent AKI was revealed in 1906 KT of 990 (45%) DD. The ongoing AKI in DD significantly increases the risk of DGF development in the adjusted model (HR 1.69; 95% CI 1.44-1.99; p < 0.001). KT from DD with AKI and partial/complete recovery was associated with a lower risk of transplant loss (log-rank P = 0.04) and recipient mortality (log-rank P = 0.042) than ongoing AKI. KT from a donor with ongoing stage 3 AKI was associated with a higher risk of all-cause graft loss (HR 1.8; 95% CI 1.12-2.88; p = 0.02) and mortality (HR 2.19; 95% CI 1.09-4.41; p = 0.03) than stage 3 AKI with renal recovery. Persistent AKI, but not recovered AKI, significantly increases the risk of DGF. Utilizing kidneys from donors with improving AKI is generally safe. KT from donors with persistent AKI stage 3 results in a higher risk of transplant failure and recipient mortality. Therefore, meticulous pretransplant evaluation of such kidneys and intensive surveillance after KT is recommended.

Kidney Transplantation From Donors With Acute Kidney Injury: Are the Concerns Justified? A Systematic Review and Meta-Analysis

Renal transplantation improves quality of life and prolongs survival in patients with end-stage kidney disease, although challenges exist due to the paucity of suitable donor organs. This has been addressed by expanding the donor pool to include AKI kidneys. We aimed to establish whether transplanting such kidneys had a detrimental effect on graft outcome. The primary aim was to define early outcomes: delayed graft function (DGF) and primary non-function (PNF). The secondary aims were to define the relationship to acute rejection, allograft survival, eGFR and length of hospital stay (LOS). A systematic literature review and meta-analysis was conducted on the studies reporting the above outcomes from PubMed, Embase, and Cochrane Library databases. This analysis included 30 studies. There is a higher risk of DGF in the AKI group (OR = 2.20, p < 0.00001). There is no difference in the risk for PNF (OR 0.99, p = 0.98), acute rejection (OR 1.29, p = 0.08), eGFR decline (p = 0.05) and prolonged LOS (p = 0.11). The odds of allograft survival are similar (OR 0.95, p = 0.54). Transplanting kidneys from donors with AKI can lead to satisfactory outcomes. This is an underutilised resource which can address organ demand.

Disparities in Deceased Donor Kidney Offer Acceptance: A Survey of Canadian Transplant Nephrologists, General Surgeons and Urologists

Background

Significant variability in organ acceptance thresholds have been demonstrated across the United States, but data regarding the rate and rationale for kidney donor organ decline in Canada are lacking.

Objective

To examine decision making regarding deceased kidney donor acceptance and non-acceptance in a population of Canadian transplant professionals.

Design

A survey study of theoretical deceased donor kidney cases of increasing complexity.

Setting

Canadian transplant nephrologists, urologists, and surgeons making donor call decisions responding to an electronic survey between July 22 and October 4, 2022.

Participants

Invitations to participate were distributed to 179 Canadian transplant nephrologists, surgeons, and urologists through e-mail. Participants were identified by contacting each transplant program and requesting a list of physicians who take donor call.

Measurements

Survey respondents were asked whether they would accept or decline a given donor, assuming there was a suitable recipient. They were also asked to cite reasons for donor non-acceptance.

Methods

Donor scenario-specific acceptance rates (total acceptance divided by total number of respondents for a given scenario and overall) and reasons for decline were determined and presented as a percentage of the total cases declined.

Results

In all, 72 respondents from 7 provinces completed at least one question of the survey, with considerable variability between acceptance rates for centers; the most conservative center declined 60.9% of donor cases, whereas the most aggressive center declined only 28.1%, P-value < .001. There was an increased risk of non-acceptance with advancing age, donation after cardiac death, acute kidney injury, chronic kidney disease, and comorbidities.

Limitations

As with any survey, there is the potential for participation bias. In addition, this study examines donor characteristics in isolation, however, asks respondent to assume there is a suitable candidate available. In reality, whenever donor quality is considered, it should be considered in the context of the intended recipient.

Conclusion

In a survey of increasingly medically complex deceased kidney donor cases, there was significant variability in donor decline among Canadian transplant specialists. Given relatively high rates of donor decline and apparent heterogeneity in acceptance decisions, Canadian transplant specialists may benefit from additional education regarding the benefits achieved from even medically complex kidney donors for appropriate candidates relative to remaining on dialysis on the transplant waitlist.

Deceased Donor Kidney Transplantation From Donors With Acute Kidney Injury: Realities and Costs

OBJECTIVES

Transplant of kidneys from donors with acute kidney injury has shown favorable outcomes. We investigated the outcomes of kidney transplant recipients with deceased donors who developed acute kidney injury before organ procurement.

MATERIALS AND METHODS

We retrospectively reviewed the medical records of recipients from January 2016 to December 2021 in a single center. Outcomes in recipients of kidney grafts from donors with and without acute kidney injury were compared.

RESULTS

The mean follow-up time was 40 months. Our study included 129 (34%) kidneys transplanted from donors with acute kidney injury and 251 (66%) kidneys from donors without acute kidney injury. Delayed graft function rate in recipients was 33% in the acute kidney injury group and 25.5% in the group without acute kidney injury (P = .099). Readmission rate at 30 days was significantly higher among recipients of kidneys with acute kidney injury compared with recipients of kidneys without acute kidney injury (45% vs 33.5%; P = .02). The mean overall costs of transplant in the acute kidney injury group were comparable to the group without acute kidney injury ($253 865 vs $253 611; P = .97). The acute rejection rate was comparable between the 2 groups (4% in both groups; P = .96). Delayed graft function rate was increased with increased stage of acute kidney injury (18% stage 1, 45% stage 2, 36% stage 3; P = .03). However, the overall length of hospital stay and costs were comparable among recipients of different stages of acute kidney injury.

CONCLUSIONS

Our study showed that kidney transplants from donors with acute kidney injury have early and late outcomes comparable to kidney transplants from donors without acute kidney injury. Allografts from donors with acute kidney injury can be used safely and can expand the donor pool in kidney transplant without increasing perioperative resource utilization.

Short-term outcomes after transplantation of deceased donor kidneys with acute kidney injury: a retrospective analysis of a multicenter cohort of marginal donor kidneys with post-explantation biopsies

BACKGROUND

Deceased donor kidneys with acute kidney injury (AKI) are often discarded because of concerns about inferior transplant outcomes. A means of grading the quality of such kidneys is the performance of procurement biopsies.

METHODS

This is a retrospective study of 221 brain death donors with marginal kidneys transplanted in 223 recipients in Germany. Marginal kidneys were defined as kidneys with procurement biopsies done exceptionally to assess suitability for transplantation in otherwise potentially discarded organs. The impact of deceased donor AKI on patient survival and death-censored graft survival at 1, 3 and 5 years and graft function at 1 and 3 years after transplantation was investigated.

RESULTS

Recipients of kidneys with stage 3 AKI had a greater incidence of delayed graft function [DGF; OR_{Stage 1}: 1.435 (95% CI 0.438-0.702), OR_{Stage 2}: 2.463 (95% CI 0.656-9.245), OR_{Stage 3}: 4.784 (95% CI 1.421-16.101)] but a similar graft and patient survival compared to recipients of donors without AKI and with AKI stage 1 and 2 as well. The coexistence of recipient DGF and donor AKI was associated with the lowest graft survival and function rates.

CONCLUSION

The transplantation of deceased donor marginal kidneys with AKI confers a higher risk for DGF but is associated with acceptable graft and patient outcomes, which do not differ in comparison with marginal donor kidneys without AKI. Graft prognosis is especially poor if donor AKI and recipient DGF concur. Donor AKI was a risk factor independent of the histological lesions of procurement biopsies.

Donor Predictors of Donor Pancreas Retrieval and Subsequent Solid Pancreas Transplantation in Australia and New Zealand from 2007 to 2016

BACKGROUND

Donor characteristics help guide donor pancreas acceptance for solid pancreas-kidney transplantation; however, these criteria vary worldwide. Such variation could result in nonuse of potentially transplantable organs. Using a registry cohort, we identified donor characteristics associated with donor pancreas retrieval and subsequent solid pancreas transplantation in Australia and New Zealand.

METHODS

Australia and New Zealand Organ Donor registry donor data from 2007 to 2016 were used to define cohort 1 (all donors authorized for pancreas retrieval) and cohort 2 (all retrieved donor pancreata considered for solid pancreas transplantation). Donor factors significantly associated with donor pancreas retrieval (cohort 1) and solid pancreas transplantation of retrieved donor pancreata (cohort 2) were determined via multivariable logistic regression.

RESULTS

Nonretrieval and nonuse of solid organ donor pancreas increased throughout the study period, and nonauthorization for pancreas donation remained stable. Donor body mass index, sex, and viral serology were associated with donor pancreas retrieval but not transplantation. Donor age, cause of death, donation after brain death status, terminal serum creatinine, and donor region were associated with both donor pancreas retrieval and acceptance for solid pancreas transplantation with donation after brain death status being the strongest predictor for both outcomes.

CONCLUSIONS

Donor age, cause of death, donation after brain death status, terminal serum creatinine, and donor region were associated with both donor pancreas retrieval and subsequent transplantation in Australia and New Zealand. Subsequent correlation of these factors with post-pancreas transplant outcomes would help guide pancreas transplant decisions and minimize nonuse of potentially usable donor pancreata.

Impact of deceased donor with acute kidney injury on subsequent kidney transplant outcomes-an ANZDATA registry analysis

BACKGROUND

The need for kidney transplantation drives efforts to expand organ donation. The decision to accept organs from donors with acute kidney injury (AKI) can result in a clinical dilemma in the context of conflicting reports from published literature.

MATERIAL AND METHODS

This observational study included all deceased donor kidney transplants performed in Australia and New Zealand between 1997 and 2017. The association of donor-AKI, defined according to KDIGO criteria, with all-cause graft failure was evaluated by multivariable Cox regression. Secondary outcomes included death-censored graft failure, death, delayed graft function (DGF) and acute rejection.

RESULTS

The study included 10,101 recipients of kidneys from 5,774 deceased donors, of whom 1182 (12%) recipients received kidneys from 662 (11%) donors with AKI. There were 3,259 (32%) all-cause graft failures, which included 1,509 deaths with functioning graft. After adjustment for donor, recipient and transplant characteristics, donor AKI was not associated with all-cause graft failure (adjusted hazard ratio [HR] 1.11, 95% CI 0.99-1.26), death-censored graft failure (HR 1.09, 95% CI 0.92-1.28), death (HR 1.15, 95% CI 0.98-1.35) or graft failure when death was evaluated as a competing event (sub-distribution hazard ratio [sHR] 1.07, 95% CI 0.91-1.26). Donor AKI was not associated with acute rejection but was associated with DGF (adjusted odds ratio [OR] 2.27, 95% CI 1.92-2.68).

CONCLUSION

Donor AKI stage was not associated with any kidney transplant outcome, except DGF. Use of kidneys with AKI for transplantation appears to be justified.

Urine Injury Biomarkers Are Not Associated With Kidney Transplant Failure

BACKGROUND

Kidneys transplanted from deceased donors with serum creatinine-defined acute kidney injury (AKI) have similar allograft survival as non-AKI kidneys but are discarded at a higher rate. Urine injury biomarkers are sensitive markers of structural kidney damage and may more accurately predict graft outcomes.

METHODS

In the 2010-2013 multicenter Deceased Donor Study of 2430 kidney transplant recipients from 1298 donors, we assessed the association of donor urine injury biomarkers microalbumin, neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, IL-18, and liver-type fatty acid binding protein with graft failure (GF) and death-censored GF (dcGF) using Cox proportional hazard models (median follow-up 4 y). We examined if serum creatinine-defined donor AKI modified this association to assess the relationship between subclinical donor AKI (elevated biomarkers without creatinine-defined AKI) and GF. Through chart review of a subcohort (1137 recipients), we determined associations between donor injury biomarkers and a 3-year composite outcome of GF, mortality, or estimated glomerular filtration rate ≤ 20mL/min/1.73m.

RESULTS

Risk of GF, dcGF, and 3-year composite outcome did not vary with donor injury biomarker concentrations after adjusting for donor, transplant, and recipient characteristics (adjusted hazard ratio ranged from 0.96 to 1.01 per log-2 increase in biomarker). Subclinical injury in transplanted kidneys without AKI was not associated with GF.

CONCLUSIONS

AKI measured using injury biomarkers was not associated with posttransplant graft outcomes (at median 4 y posttransplant). When assessing posttransplant graft viability, clinicians can prioritize other donor and recipient factors over donor kidney injury, measured by either serum creatinine or urine injury biomarkers.

Sex-dependent mechanisms involved in renal tolerance to ischemia-reperfusion: Role of inflammation and histone H3 citrullination

Ischemia-reperfusion (I/R) injury, an inevitable result of kidney transplantation, triggers early inflammatory events that affect graft viability. Evidence from human transplantation and preclinical models of I/R suggests that a female hormonal environment positively influences the ability to recover from ischemic injury. However, the mechanisms behind these effects remain mostly unexplored. Here, we studied the influence of sex on pro-inflammatory mediators involved in the pathophysiology of acute I/R injury in male, female, and female ovariectomized (OVX) Wistar rats that underwent unilateral renal ischemia for 45 min, followed by 24 h of reperfusion. We found improved renal function, reduced cytokine expression, and decreased infiltration of myeloperoxidase-positive cells in females after I/R, when compared to their male and female OVX counterparts. Remarkably, citrullination of histone H3 was exacerbated in serum and renal tubules of females after I/R. In contrast, we observed lower levels of citrullinated histone H3 in male and female OVX rats in response to I/R, mostly in neutrophil extracellular traps. Our results demonstrate that female sex promotes renal I/R tolerance by attenuating pro-inflammatory mediators involved in I/R-induced damage.

A Review of Donor Acute Kidney Injury and Posttransplant Outcomes

Although over 90 000 people are on the kidney transplant waitlist in the United States, some kidneys that are viable for transplantation are discarded. Transplant surgeons are more likely to discard deceased donors with acute kidney injury (AKI) versus without AKI (30% versus 18%). AKI is defined using changes in creatinine from baseline. Transplant surgeons can use DonorNet data, including admission, peak, and terminal serum creatinine, and biopsy data when available to differentiate kidneys with AKI from those with chronic injury. Although chronic kidney disease is associated with reduced graft survival, an abundance of literature has demonstrated similar graft survival for deceased donors with AKI versus donors without AKI. Donors with AKI are more likely to undergo delayed graft function but have similar long-term outcomes as donors without AKI. The mechanism for similar graft survival is unclear. Some hypothesized mechanisms include (1) ischemic preconditioning; (2) posttransplant and host factors playing a greater role in long-term survival than donor factors; and (3) selection bias of transplanting only relatively healthy donor kidneys with AKI. Existing literature suggests transplanting more donor kidneys with stage 1 and 2 AKI, and cautious utilization of stage 3 AKI donors, may increase the pool of viable kidneys. Doing so can reduce the number of people who die on the waitlist by over 500 every year.

Effectiveness of serum beta-2 microglobulin as a tool for evaluating donor kidney status for transplantation

Kidney transplantations using expanded criteria donors (ECD) are being increasingly adopted, but no consensus tools are available to evaluate donor kidney status. Beta-2 microglobulin (B2MG) is a marker of kidney function, and herein, we evaluate the usefulness of assessing B2MG to evaluate donor kidney status. Fifty-seven kidney transplantations were performed from March 2017 to April 2019. Medical records were retrospectively reviewed, and relationships between clinical and laboratory variables and transplant outcomes were investigated. Thirty-eight patients received a standard criteria donor kidney and 19 patients an ECD kidney. Ten patients experienced delayed graft function (DGF), but no patient experienced primary nonfunction. Of the parameters studied, only donor renal replacement therapy (RRT) [odds ratio (OR) 24.162; p = 0.018] and donor serum B2MG (OR 22.685; p = 0.022) significantly predicted DGF. The presence of either of these two risk factors can better reflect the condition of the donor than previous classification. However, on their last follow-up creatinine and estimated glomerular filtration rate values in those with or without these risk factors were not significantly different. For an ECD with a B2MG level of <7.18 and no history of RRT, kidney transplantation can be undertaken without considering the possibility of kidney discard.

Deceased donor organ transplantation potential: A peep into an untapped gold mine

Organ transplantation is the gold standard for treating end-stage organ diseases, many of whom are on waiting lists. The reasons for this include the nonavailability of suitable organs to be transplanted. In many nations, most of these challenges have been surmounted by the adoption of deceased donor program, which is not so in sub-Saharan countries such as Nigeria. This study is to audit the potentially transplantable organs available from potential deceased donors from a Nigerian tertiary hospital. This is a study of deaths in the intensive care unit (ICU) and the accident and emergency units of the University of Ilorin Teaching Hospital, Nigeria. Data included the biodata, social history, diagnosis or indications for admission, time of arrival and death, causes of death, associated comorbidities, potential organs available, social history, and availability of relations at the time of death. There were 104 deaths in the ICU and 10 patients in the accident and emergency unit. There were 66 males (57.9%) and 48 females (42.1%). Eighty patients were Muslims (70.2%) and 34 were Christians (19.8%). A total of 33 participants were unmarried (28.9%),whereas 81 (71.1%) were married. The tribes of the patients were Yoruba (105, 92.1%), Igbo (7, 6.1%), Hausa (1, 0.9%), and Nupe (1, 0.9%). The age range was 0.08-85 years. Twenty-two (19.3%) had primary and the remaining had at least secondary education. The causes of death were myriad, and there were relatives available at the times of all deaths. The Maastricht classification of the deaths were Class I - 1 (0.9%), Class II - 37 (32.2%), Class III - 9 (7.8%), Class IV - 20 (17.4%), and Class V - 47(40.9%). There were no transplantable organs in 42 (36.5%), one organ in eight (7%), two organs in two (7%), three organs in one (0.9%), four organs in 13 (11.3%), five organs in six (5.2%), six organs in 11 (9.6%), seven organs in 11 (9.6%), eight organs in five (13%), and nine organs in five (4.3%). Deceased donor sources of organs are worthy of being exploited to improve organ transplantation in Nigeria.

Should we use kidneys from donors with acute kidney injury for renal transplantation?

The scarcity of donor organs for transplant results in long waiting times for kidney transplantation and low transplant rate worldwide. Utilization of kidneys from donors with acute kidney injury (AKI) is one of the strategies that has attracted attention recently. This article reviewed the outcomes of transplanted renal allografts from donors with acute kidney injury. Key findings about the transplant outcomes included a higher incidence of delayed graft function and primary non function, but respectable outcomes in the context of similar acute rejection rates, and graft function and graft survival. Against this background and with evidence of high mortality for patients remaining on waiting list of transplant, we advocate consideration of AKI donors for kidney transplantation.

Factors of Acute Kidney Injury Donors Affecting Outcomes of Kidney Transplantation From Deceased Donors

BACKGROUND

This study aimed to investigate the outcomes of kidney transplantation (KT) from deceased acute kidney injury (AKI) donors and analyzed the factors affecting these outcomes.

METHODS

All patients who underwent KT from deceased donors at our institution from 1998 to 2016 were retrospectively reviewed. Recipients were divided into the AKI and non-AKI donor groups. We analyzed delayed graft function (DGF), serum creatinine levels at 1 month and 1 year after KT, cold ischemia time, donors' initial and terminal serum creatinine levels, Kidney Donor Profile Index, and patient and graft survival in each group.

RESULTS

Of 181 recipients, 30 received kidneys from 21 AKI donors, whereas the remaining 151 received kidneys from donors without AKI. DGF more frequently developed in the AKI donor group than in the non-AKI donor group (40% vs 7.28%; P = .001). Allograft functions at 1 month and 1 year after KT did not differ between the AKI and non-AKI donor groups (1 month: P = .469; 1 year: P = .691). Factors affecting DGF were recipient weight and donor AKI. Recipient factors affecting graft function at 1 year were recipient height, length of hospital stay, serum creatinine levels at 1 month and 6 months, and biopsy-proven acute rejection. Older donor age was the only donor factor that affected graft function at 1 year.

CONCLUSION

KT from deceased AKI donors showed a higher DGF rate but favorable patient and graft survival and graft functions. Donor AKI and recipient weight affected DGF, and only older donor age affected graft function at 1 year.

Successful transplantation of kidneys from deceased donors with terminal acute kidney injury

BACKGROUND

There are many doubts with regards to accepting deceased kidneys with acute kidney injury (AKI) for transplantation.

PURPOSE

The aim of this study was to present the 5-years outcome of kidney transplantation cases where deceased donors developed AKI before organ procurement.

METHODS

Two hundred twenty-six deceased renal transplants were analyzed. Data regarding donors and recipients were collected. Terminal AKI was defined as terminal serum creatinine concentration higher than 1.99 mg/dL and 66 such cases were diagnosed. All kidney transplant recipients were followed for 60 months.

RESULTS

AKI group presented more episodes of delayed graft function (DGF) compared to the non-AKI group (56% vs 35%, p < .05). No differences were observed between the groups in the rate of acute rejection episodes, kidney function as well as patient and graft survival.

CONCLUSIONS

Transplants with AKI present more often DGF and comparable graft survival to transplants without AKI. Kidneys with AKI can be a valuable source of organs provided attentive selection and appropriate care of deceased donors.

Expanding the donor pool in kidney transplantation: Should organs with acute kidney injury be accepted?-A retrospective study

BACKGROUND

Given the gap between patients in need of a renal transplantation (RTx) and organs available, transplantation centers increasingly accept organs of suboptimal quality, e.g. from donors with acute kidney injury (AKI).

METHODS

To determine the outcome of kidney transplants from deceased donors with AKI (defined as ≥ AKIN stage 1), all 107 patients who received a RTx from donors with AKI between August 2004 and July 2014 at our center were compared to their respective consecutively transplanted patients receiving kidneys from donors without AKI. 5-year patient and graft survival, frequencies of delayed graft function (DGF), acute rejections and glomerular filtration rate (eGFR, CKD-EPI) were assessed.

RESULTS

Patient survival was similar in both groups, whereas death-censored and overall graft survival were decreased in AKI kidney recipients. AKI kidney recipients showed higher frequencies of DGF and had a reduced eGFR at 7 days, three months and one and three years after RTx. However, mortality was noticeably lower compared to waiting list candidates. Rejection-free survival was similar between groups.

CONCLUSIONS

In our cohort, both short-term and long-term renal function was inferior in recipients of AKI kidneys, while patient survival was similar. Our data indicates that recipients of donor AKI kidneys should be carefully selected and additional factors impairing short- and long-term outcome should be minimized to prevent further deterioration of graft function.

Impact of acute kidney injury in donors on renal graft survival: a systematic review and Meta-Analysis

The acute kidney injury (AKI) of deceased donors was an important strategy to address donor shortage. This meta-analysis was conducted to explore the clinical effect of kidney transplantation from donors with AKI. PubMed, Embase, and Cochrane Library were searched through July 2017. Fourteen cohort studies, involving a total of 15,345 donors, were included. Studies were pooled, and the hazard ratio (HR), relative risk (RR), weighted mean difference (WMD), and their corresponding 95% confidence interval (CI) were calculated. The present meta-analysis showed no significant difference in allograft survival between the AKI and non-AKI groups (HR = 1.16, 95% CI = 0.99–1.37, P_{heterogeneity} = 0.238, I² = 21.6%) from 12 months to 120 months after kidney transplantation. However, the time of hospital stay was significantly longer (WMD = 2.49, 95% CI = 1.06–3.92, P_{heterogeneity} = 0.458, I² = 0%) and the incidence of delayed graft function (DGF) was significantly higher (RR = 1.76, 95% CI = 1.52–2.04, P_{heterogeneity} < 0.001, I² = 71.2%) in the AKI group than in the non-AKI group. We concluded that even though hospital stay time was longer and the incidence of DGF was significantly higher in the AKI group, there is no significant difference in allograft survival between the two groups.

Success of kidney transplantations from deceased donors with acute kidney injury

Background

The acceptance of organs from deceased donors with acute kidney injury (AKI) varies considerably, with uncertain outcomes. The current organ shortage has led to increased use of marginal donor organs.

Material/Methods

This retrospective, single-center study included 642 patients who underwent kidney allograft transplantation between 2005 and 2016. The recipients were categorized into 3 groups: AKI-1 (n=214), comprising donors with a peak serum creatinine (SCr) level of 1.1–2.0 mg/dl; AKI-2 (n=89), comprising donors with a peak SCr level >2 mg/dl; and non-AKI (n=339), comprising donors with normal kidney function (SCr <1.1 mg/dl).

Results

The cumulative survival rates for patients and grafts did not significantly differ among the AKI-1, AKI-2, and non-AKI groups at the 1-year (91.6%/79.4%, 92.1%/83.1%, 95.3%/88.5%, respectively) and 5-year assessments (79.4%/67.8%, 86.8%/71.7%, 80.5%/71.1%, respectively). These findings were corroborated by mean SCr values and estimated glomerular filtration rates at the 1-year (2.08±1.7/51.16±23.45, 2.01±1.52/56.46±23.63, 1.81±1.13/ 55.44±23.26 mg/dl, respectively) and 5-year assessments (1.91±1.28/51.06±24.65, 1.74±0.66/57.44±31.21, 1.7±0.88/ 58.56±26.04 mg/dl, respectively). The incidence of delayed graft function in each group was 29.9%, 44.9%, and 28.6%, respectively.

Conclusions

Kidney transplantation from donors with AKI, although associated with a higher rate of delayed graft function, results in good long-term transplant survival and reliable kidney functionality after 5 years. The inclusion of donors with AKI may widely extend the pool of available organs; however, careful donor selection is necessary.

Deceased-donor acute kidney injury is not associated with kidney allograft failure

Deceased-donor acute kidney injury (AKI) is associated with organ discard and delayed graft function, but data on longer-term allograft survival are limited. We performed a multicenter study to determine associations between donor AKI (from none to severe based on AKI Network stages) and all-cause graft failure, adjusting for donor, transplant, and recipient factors. We examined whether any of the following factors modified the relationship between donor AKI and graft survival: kidney donor profile index, cold ischemia time, donation after cardiac death, expanded-criteria donation, kidney machine perfusion, donor-recipient gender combinations, or delayed graft function. We also evaluated the association between donor AKI and a 3-year composite outcome of all-cause graft failure or estimated glomerular filtration rate ≤ 20 mL/min/1.73 m² in a subcohort of 30% of recipients. Among 2,430 kidneys transplanted from 1,298 deceased donors, 585 (24%) were from donors with AKI. Over a median follow-up of 4.0 years, there were no significant differences in graft survival by donor AKI stage. We found no evidence that pre-specified variables modified the effect of donor AKI on graft survival. In the subcohort, donor AKI was not associated with the 3-year composite outcome. Donor AKI was not associated with graft failure in this well-phenotyped cohort. Given the organ shortage, the transplant community should consider measures to increase utilization of kidneys from deceased donors with AKI.

Limitation of Terminal Serum Creatinine as a Kidney Donor Profile Index Variable in Predicting Long-Term Kidney Transplant Outcomes

BACKGROUND

Donor final serum creatinine (SCr) is a dynamic variable and is 1 of 10 factors used in calculating kidney donor profile index (KDPI). We hypothesize that deceased-donor kidneys (DDKs) with higher SCr were likely accepted for transplantation if procurement biopsy findings were favorable and with long-term outcomes no worse than kidneys with lower final SCr within a KDPI group.

METHODS

Using the Organ Procurement and Transplant Network/United Network for Organ Sharing database, we identified DDK transplant recipients from 2000 to 2015 who received induction and calcineurin inhibitor/mycophenolate mofetil maintenance. Patients were divided into 4 KDPI groups: 0-20%, 21%-50%, 51%-85%, and >85%. In each KDPI category, long-term outcomes were compared, with the use of Cox models, between patients who received kidneys with final SCr >2 versus ≤2 mg/dL.

RESULTS

A total of 59,644 patients were divided into KDPI groups 0-20% (SCr >2 mg/dL, n = 478; SCr ≤2 mg/dL, n = 14,769), 21%-50% (SCr >2 mg/dL, n = 1,592; SCr ≤2 mg/dL, n = 17,762), 51%-85% (SCr >2 mg/dL; n = 1,388, SCr ≤2 mg/dL, n = 18,024), and >85% (SCr >2 mg/dL, n = 349; SCr ≤2 mg/dL, n = 5,282). Adjusted overall graft failure risks (hazard ratio [HR] 0.88, P = .04; HR, 0.86, P = .007) and patient death risks (HR, 0.86, P = .04; HR, 0.84, P = .01) for final SCr >2 versus ≤2 mg/dL groups were lower in KDPI categories 21%-50% and 51%-85%, respectively, with similar death-censored graft failure risks.

DISCUSSION

Outcomes of transplanting DDKs with elevated final SCr are no worse than transplanting kidneys with lower final SCr, highlighting the limitation of the single value of final SCr as a variable for calculating KDPI.

Perspective on Clinical Application of Biomarkers in AKI

Several biomarkers of renal injury have been identified but the utility of these biomarkers is largely confined to research studies, whereas widespread clinical applicability is limited. This is partly because the use of serum creatinine as the comparator has several limitations and restricts the full interpretation of biomarker performance. To highlight the potential for clinical application of biomarkers, the most pertinent biomarker data are summarized here, using clinically relevant scenarios in which biomarkers could assist with diagnostic and management dilemmas. The paradigms proposed in this review aim to enhance the clinical diagnosis, management, and prognosis of AKI through the combined use of available clinical markers and novel inflammatory, injury, and repair biomarkers.

Prediction of clinical outcomes after kidney transplantation from deceased donors with acute kidney injury: a comparison of the KDIGO and AKIN criteria

Background

Acute kidney injury (AKI) is frequently detected in deceased donors (DDs), and it could be associated with adverse clinical outcomes in corresponding kidney transplant recipients (KTRs). In this regard, we sought to identify which criteria is better between the KDIGO and AKIN criteria for the diagnosis of AKI in DDs in the prediction of clinical outcomes after kidney transplantation (KT).

Methods

Two hundred eighty-five cases of deceased donor kidney transplantation (DDKT) were included. We divided them into three groups; the non-AKI by both KDIGO and AKIN criteria group (n = 120), the AKI by KDIGO only group (n = 61), and the AKI by both criteria group (n = 104) according to the diagnosis of AKI using the KDIGO and AKIN criteria in the corresponding 205 DDs. We compared the development of delayed graft function (DGF), the change in allograft function, the allograft survival among the three groups.

Results

The incidence of DGF was significantly higher in the AKI by KDIGO only and the AKI by both criteria groups than in the non-AKI by both criteria group (P < 0.05 each). But no difference was detected between the AKI by KDIGO only group and the AKI by both criteria group (P > 0.05). Therefore, the KDIGO criteria had a better predictive value for DGF occurrence than the AKIN criteria (Area under the curve = 0.72 versus 0.63, P < 0.05) in Receiver Operation Characteristic analysis. On comparison of allograft function, the AKI by KDIGO only and the AKI by both criteria groups showed a significantly deteriorating pattern by 6 months after KT in comparison with the non-AKI by both criteria group (P < 0.05). However, the differences disappeared at 1 year from KT and long-term allograft survival did not differ among the three groups. AKI stage either by KDIGO or AKIN in DDs did not affect long-term allograft survival in corresponding KTRs as well.

Conclusions

The KDIGO criteria may be more useful for predicting DGF than the AKIN criteria. However, AKI or AKI stage by either criteria in DDs failed to affect long-term allograft outcomes in KTRs.

YKL-40 Associates with Renal Recovery in Deceased Donor Kidney Transplantation

Deceased donor kidneys with AKI are often discarded for fear of poor transplant outcomes. Donor biomarkers that predict post-transplant renal recovery could improve organ selection and reduce discard. We tested whether higher levels of donor urinary YKL-40, a repair phase protein, associate with improved recipient outcomes in a prospective cohort study involving deceased kidney donors from five organ procurement organizations. We measured urinary YKL-40 concentration in 1301 donors (111 had AKI, defined as doubling of serum creatinine) and ascertained outcomes in the corresponding 2435 recipients, 756 of whom experienced delayed graft function (DGF). Donors with AKI had higher urinary YKL-40 concentration (P<0.001) and acute tubular necrosis on procurement biopsies (P=0.05). In fully adjusted analyses, elevated donor urinary YKL-40 concentration associated with reduced risk of DGF in both recipients of AKI donor kidneys (adjusted relative risk, 0.51 [95% confidence interval (95% CI), 0.32 to 0.80] for highest versus lowest YKL-40 tertile) and recipients of non-AKI donor kidneys (adjusted relative risk, 0.79 [95% CI, 0.65 to 0.97]). Furthermore, in the event of DGF, elevated donor urinary YKL-40 concentration associated with higher 6-month eGFR (6.75 [95% CI, 1.49 to 12.02] ml/min per 1.73 m²) and lower risk of graft failure (adjusted hazard ratio, 0.50 [95% CI, 0.27 to 0.94]). These findings suggest that YKL-40 is produced in response to tubular injury and is independently associated with recovery from AKI and DGF. If ultimately validated as a prognostic biomarker, urinary YKL-40 should be considered in determining the suitability of donor kidneys for transplant.