Serum neutrophil gelatinase-associated lipocalin as a predictor of organ recovery from delayed graft function after kidney transplantation from donors after cardiac death

Because of a worldwide shortage of renal grafts, kidneys procured from donors after cardiac death (DCD) have recently become an important source of renal transplants. However, DCD kidneys often have complications with delayed graft function (DGF) and recipients require hemodialysis (HD) in the early period after kidney transplantation (KTx). This study evaluated serum NGAL as a potential specific parameter to predict early functional recovery of transplanted DCD kidneys. The average serum neutrophil gelatinase-associated lipocalin (NGAL) level in normal samples was 53 +/- 30 ng/ml, while that in patients with chronic renal failure requiring HD was markedly raised at 963 +/- 33 ng/ml. In patients undergoing a living-related KTx from a living donor (n=11), serum NGAL level decreased rapidly after KTx, and only in two cases, with serum NGAL levels over 400 ng/ml on postoperative day 1 (POD1), was HD required due to DGF. In contrast, all patients undergoing a KTx from a DCD (n=5) required HD due to DGF. Even in these cases, serum NGAL levels decreased rapidly several days after a KTx prior to the recovery of urine output and preceding the decrease in serum creatinine level. The pattern of decline in serum NGAL was biphasic, the decrease after the second peak indicating a functional recovery within the next several days. These data suggest that monitoring of serum NGAL levels may allow us to predict graft recovery and the need for HD after a KTx from a DCD.     

Total Cell-Free DNA as a Noninvasive Biomarker of a Delayed Graft Function After Kidney Transplantation From Donors After Cardiac Death

BackgroundBecause of the organ shortage, donation after cardiac death (DCD) kidney transplantation (KTx) is an alternative way of achieving KTx using brain-dead donors (BDs). Although the prognosis of DCD-KTx is improving, the graft suffers from delayed graft function (DGF), the management of which is essential. With progress in understanding the characteristics of cell-free DNA (CF-DNA), we consider plasma total CF-DNA (tCF-DNA) to be a useful biomarker for predicting DGF in DCD-KTx.Study Design and MethodConsecutive patients from living donors (LDs; n = 9), BDs (n = 8), or DCD donors (n = 13) were enrolled. Plasma samples were collected after KTx and on postoperative days 3 and 5. CF-DNA was isolated, and tCF-DNA was quantified using the TapeStation 2200 software program.ResultsThe tCF-DNA levels after BD-KTx and DCD-KTx were higher than those after LD-KTx (LD, 78 ± 27 (ng/mL); BD, 99 ± 20; DCD, 150 ± 23); the difference between DCD-KTx and LD-KTx was statistically significant (P < .05). The tCF-DNA levels declined at postoperative day 5 (LD, 45 ± 10; BD, 51 ± 11; DCD, 66 ± 13). tCF-DNA levels were significantly increased in patients with DGF after KTx (DGF, 139 ± 22; immediate function, 91 ± 18; P < .05). The tCF-DNA level was correlated with the duration of DGF (r = 0.5825, P < .05).ConclusionAlthough the mechanism underlying DNA release from transplanted grafts into the recipient circulation remains unclear, cell death by apoptosis or necrosis and the active secretion of the immune system may play important roles in DGF. These data suggest that monitoring tCF-DNA may help predict graft recovery after DCD-KTx.     

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.     

Impact of donor age on long‐term outcomes after delayed graft function: 10‐year follow‐up

Delayed graft function (DGF) has a negative impact on graft survival in donation after brain death (DBD) but not for donation after cardiac death (DCD) kidneys. However, older donor age is associated with graft loss in DCD transplants. We sought to examine the interaction between donor age and DGF in DBD kidneys. This is a single‐center, retrospective review of 657 consecutive DBD recipients transplanted between 1990 and 2005. We stratified the cohort by decades of donor age and studied the association between DGF and graft failure using Cox models. The risk of graft loss associated with DGF was not significantly increased for donor age below 60 years (adjusted hazard ratio [aHR] 1.12, 1.51, and 0.90, respectively, for age <40, 41–50 and 51–60 years) but significantly increased after 60 years (aHR 2.67; P = 0.019). Analysis of death‐censored graft failure yielded similar results for donor age below 60 years and showed a substantially increased risk with donors above 60 years (aHR 6.98, P = 0.002). This analysis reveals an unexpectedly high impact of older donor age on the association between DGF and renal transplant outcomes. Further research is needed to determine the best use of kidneys from donors above 60 years old, where DGF is expected.     

More donors or more delayed graft function? A cost‐effectiveness analysis of DCD kidney transplantation

Expansion of the donor pool with expanded criteria donors and donation after cardiac death (DCD) donors is essential. DCD grafts result in increased rates of primary non‐function (PNF) and delayed graft function (DGF). However, long‐term patient and graft survival is similar between donation after brain death (DBD) donors and DCD donors. The aim of this study was to evaluate the cost‐effectiveness of the use of DCD donors. A Markov‐based decision analytic model was created to simulate outcomes for two wait list strategies: (i) wait list composed of only DBD organs and (ii) wait list combining DBD and DCD organs. Baseline values and ranges were determined from the Scientific Registry of Transplant Recipients (SRTR) database and literature review. Sensitivity analyses were conducted to test model strength and parameter variability. The wait list strategy consisting of DBD donors only provided recipients 5.4 Quality‐adjusted life years (QALYs) at $65 000/QALY, whereas a wait list strategy combining DBD + DCD donors provided recipients 6.0 QALYs at a cost of $56 000/QALY. Wait lists with DCD donors provide adequate long‐term survival despite more DGF. This equates to an improvement in quality of life and decreased cost when compared to remaining on dialysis for any period of time.     

Kidney transplantation from donation after cardiac death donors: lack of impact of delayed graft function on post‐transplant outcomes

Singh RP, Farney AC, Rogers J, Zuckerman J, Reeves‐Daniel A, Hartmann E, Iskandar S, Adams P, Stratta RJ. Kidney transplantation from donation after cardiac death donors: lack of impact of delayed graft function on post‐transplant outcomes.
Clin Transplant 2011: 25: 255–264. © 2010 John Wiley & Sons A/S. Abstract: Introduction: Delayed graft function (DGF) is more common in recipients of kidney transplants from donation after cardiac death (DCD) donors compared to donation after brain death (DBD) donors. Methods: Single‐center retrospective study to evaluate the impact of DGF on controlled (Maastricht category III) DCD donor kidney transplant outcomes. Results: From 10/01 to 6/08, 578 adult deceased donor kidney transplants were performed including 70 (12%) from DCD and 508 (88%) from DBD donors. Mean follow‐up was 36 months. DCD donor kidney transplants had significantly greater rates of DGF (57% DCD vs. 21% DBD, p < 0.0001)) and acute rejection (29% DCD vs. 16% DBD, p = 0.018) compared to DBD donor kidney transplants, but patient and graft survival rates were similar. DBD donor kidney transplants with DGF (n = 109) had significantly greater rates of death‐censored graft loss (12.5% DCD vs. 31% DBD), primary non‐function (0 DCD vs. 10% DBD) and higher 2 year mean serum creatinine levels (1.4 DCD vs. 2.7 mg/dL DBD) compared to DCD donor kidney transplants with DGF (n = 40, all p < 0.04). On univariate analysis, the presence of acute rejection and older donor age were the only significant risk factors for death‐censored graft loss in DCD donor kidney transplants, whereas DGF was not a risk factor. Conclusion: Despite higher rates of DGF and acute rejection in DCD donor kidney transplants, subsequent outcomes in DCD donor kidney transplants with DGF are better than in DBD donor kidney transplants experiencing DGF, and similar to outcomes in DCD donor kidney transplants without DGF.     

Delayed kidney graft function in simultaneous pancreas‐kidney transplant recipients is associated with early pancreas allograft failure

Delayed graft function (DGF) is a common complication associated with significant untoward effects in kidney‐alone transplantation. The incidence and outcomes following kidney delayed graft function (K‐DGF) among patients undergoing simultaneous pancreas‐kidney (SPK) transplantation are less certain. We analyzed SPK recipients transplanted at our center between January 1994 and December 2017. A total of 632 recipients fulfilled the selection criteria, including 69 (11%) with K‐DGF and 563 without. The incidence of K‐DGF was significantly higher in recipients of organs from older donors and donation after circulatory death (DCD). The presence of K‐DGF was significantly associated with an increased risk of pancreas graft failure during the first 90 days (n = 9, incidence rate [IR] 2.45/100 person‐months), but not with late pancreas failure (n = 32, IR 0.84/100 person‐months), kidney graft failure, or patient death. Although DCD was associated with K‐DGF, it was not associated with either pancreas (hazard ratio [HR] 0.91, 95% CI 0.58‐1.44, P = .69) or kidney (HR 1.09, 95% CI 0.66‐1.82, P = .74) graft failure after adjustment for potential confounders. We found K‐DGF to be a significant risk factor for pancreas graft failure but not kidney graft failure, with the major risk period being early (<90 days) posttransplant, and the major donor risk factor being older donor age.     

Long‐term outcomes of donation after cardiac death liver allografts from a single center

Abstract: Organ shortage continues to be a major challenge in transplantation. Recent experience with controlled non‐heart‐beating or donation after cardiac death (DCD) are encouraging. However, long‐term outcomes of DCD liver allografts are limited. In this study, we present outcomes of 19 DCD liver allografts with follow‐up >4.5 years. During 1998–2001, 19 (4.1%) liver transplants (LT) with DCD allografts were performed at our center. Conventional heart‐beating donors included 234 standard criteria donors (SCD) and 214 extended criteria donors (ECD). We found that DCD allografts had equivalent rates of primary non‐function and biliary complications as compared with SCD and ECD. The overall one‐, two‐, and five‐yr DCD graft and patient survival was 73.7%, 68.4%, and 63.2%, and 89.5%, 89.5%, and 89.5%, respectively. DCD graft survival was similar to graft survival of SCD and ECD in non hepatitis C virus (HCV) recipients (p > 0.370). In contrast, DCD graft survival was significantly reduced in HCV recipients (p = 0.007). In conclusion, DCD liver allografts are durable and have acceptable long‐term outcomes. Further research is required to assess the impact of HCV on DCD allograft survival.     

Dynamics of early post‐operative plasma ddcfDNA levels in kidney transplantation: a single‐center pilot study

Donor‐derived cell‐free DNA (ddcfDNA) is reported to be a promising noninvasive biomarker for acute rejection in organ transplant. However, studies on monitoring ddcfDNA dynamics during the early periods after organ transplantation are scarce. Our study assessed the dynamic variation in ddcfDNA in early period with various types and status of kidney transplantation. Target region capture sequencing used identifies ddcfDNA level in 21 kidney transplant recipients. Median ddcfDNA level was 20.69% at the initial time post‐transplant, and decreased to 5.22% on the first day and stayed at the stable level after the second day. The ddcfDNA level in DCD (deceased donors) group (44.99%) was significantly higher than that in LDRT (living donor) group (10.24%) at initial time, P < 0.01. DdcfDNA level in DGF (delayed graft function) recipients was lower (23.96%) than that in non‐DGF (47.74%) at the initial time, P = 0.89 (19.34% in DGF and 4.46% in non‐DGF on the first day, P = 0.17). DdcfDNA level at initial time significantly correlated with serum creatinine (r² = 0.219, P = 0.032) and warm ischemia time (r² = 0.204, P = 0.040). Plasma ddcfDNA level decreased rapidly follow an L‐shaped curve post‐transplant, and level in DGF declined slower than non‐DGF. The rebound of ddcfDNA level may indicate the occurrence of acute rejection.     

An mTOR‐inhibitor‐based protocol and calcineurin inhibitor (CNI)‐free treatment in kidney transplant recipients from donors after cardiac death: good renal function,but high incidence of conversion to CNI

Donor after cardiac death (DCD) grafts have excellent survival despite the high incidence of delayed graft function (DGF). We assessed the feasibility of a mammalian target of rapamycin inhibitor (mTOR‐I) protocol in uncontrolled DCD kidney transplantation and compared it with brain‐dead donor (DBD) transplantation under calcineurin inhibitor (CNI) treatment. This retrospective study (2002–2011) included 109 Maastricht category II DCD patients and 218 standard‐criteria DBD as controls. Immunosuppression consisted of polyclonal antibody induction, mycophenolate mofetil, prednisone, and mTOR‐I (starting on day 6) in the DCD group and tacrolimus in the DBD group. DGF occurred in 72.5% of the DCD group vs. 26.1% of the DBD group (P = 0.001). Patient survival at 1 year was 99.1% vs. 95.9% (P = 0.112), and graft survival was 89% vs. 92.2% (P = 0.253). Patient survival at 5 years was 85.3% vs. 90.1% (P = 0.340) and graft survival was 85.5% vs. 78.8% (P = 0.166). During the first year, 46.8% (n = 51) of DCD patients were converted to CNI therapy. Serum creatinine at 1 year was 1.5(1.26–2) mg/dl vs. 1.4(1.16–1.8) mg/dl (P = 0.078). At 1 year, the acute rejection rate was 7.3% vs. 12.5% (P = 0.766). mTOR‐I‐based therapy was not associated with inferior graft function or higher rejection rates than standard CNI therapy. DCD kidney transplantation with an mTOR‐I‐based protocol is feasible but is associated with a high conversion rate to CNI‐based therapy.     

Effect of Hypothermic Machine Perfusion on the Preservation of Kidneys Donated After Cardiac Death: A Single‐Center,Randomized, Controlled Trial

To assess the application of a hypothermic machine perfusion device (LifePort) in kidney transplantation from donation after cardiac death (DCD) donors, 24 pairs of DCD kidneys were randomly divided into two groups: one of the paired kidneys from the same donor was perfused with the LifePort machine (hypothermic machine perfusion [HMP]), and the contralateral kidney was prepared using common static cold preservation (CCP). The two groups were compared with respect to the incidence of delayed graft function (DGF), level of graft function, and pathological changes in time‐zero biopsy specimens. The incidence of DGF was 16.7 and 37.5% in the HMP and CCP groups, respectively; the difference between the two groups was statistically significant (P < 0.05). The incidence of acute rejection was 4.1 (1/24) and 8.3% (2/24) in the HMP and CCP groups, respectively; this difference was not statistically significant (P > 0.05). Forty‐eight kidney patients were followed up for 6 months, and the two groups of recipients all survived, yielding a survival rate of 100%. The mean 6‐month serum creatinine levels were 98.7 ± 23.6 µmol/L in the HMP group and 105.3 ± 35.1 µmol/L in the CCP group; there was no significant difference between the two groups. HMP can reduce the incidence of DGF in DCD kidneys, and this effect is greater for expanded criteria donors kidneys. HMP can also improve early renal function.     

Kidney transplant from uncontrolled donation after circulatory death donors maintained by nECMO has long‐term outcomes comparable to standard criteria donation after brain death

Uncontrolled donation after circulatory death (uDCD) increases organ availability for kidney transplant (KT) with short‐term outcomes similar to those obtained from donation after brain death (DBD) donors. However, heterogeneous results in the long term have been reported. We compared 10‐year outcomes between 237 KT recipients from uDCD donors maintained by normothermic extracorporeal membrane oxygenation (nECMO) and 237 patients undergoing KT from standard criteria DBD donors during the same period at our institution. We further analyzed risk factors for death‐censored graft survival in the uDCD group. Delayed graft function (DGF) was more common in the uDCD group (73.4% vs 46.4%; P < .01), although glomerular filtration rates at the end of follow‐up were similar in the 2 groups. uDCD and DBD groups had similar rates for 10‐year death‐censored graft (82.1% vs 80.4%; P = .623) and recipient survival (86.2% vs 87.6%; P = .454). Donor age >50 years was associated with graft loss in the uDCD group (hazard ratio: 1.91; P = .058), whereas the occurrence of DGF showed no significant effect. uDCD KT under nECMO support resulted in similar graft function and long‐term outcomes compared with KT from standard criteria DBD donors. Increased donor age could negatively affect graft survival after uDCD donation.     

DCD donor hemodynamics as predictor of outcome after kidney transplantation

Insufficient hemodynamics during agonal phase—ie, the period between withdrawal of life‐sustaining treatment and circulatory arrest—in Maastricht category III circulatory‐death donors (DCD) potentially exacerbate ischemia/reperfusion injury. We included 409 Dutch adult recipients of DCD donor kidneys transplanted between 2006 and 2014. Peripheral oxygen saturation (SpO2‐with pulse oximetry at the fingertip) and systolic blood pressure (SBP‐with arterial catheter) were measured during agonal phase, and were dichotomized into minutes of SpO2 > 60% or SpO2 < 60%, and minutes of SBP > 80 mmHg or SBP < 80 mmHg. Outcome measures were and primary non‐function (PNF), delayed graft function (DGF), and three‐year graft survival. Primary non‐function (PNF) rate was 6.6%, delayed graft function (DGF) rate was 67%, and graft survival at three years was 76%. Longer periods of agonal phase (median 16 min [IQR 11‐23]) contributed significantly to an increased risk of DGF (P = .012), but not to PNF (P = .071) and graft failure (P = .528). Multiple logistic regression analysis showed that an increase from 7 to 20 minutes in period of SBP < 80 mmHg was associated with 2.19 times the odds (95% CI 1.08‐4.46, P = .030) for DGF. In conclusion, duration of agonal phase is associated with early transplant outcome. SBP < 80 mmHg during agonal phase shows a better discrimination for transplant outcome than SpO2 < 60% does.     

Impact of warm ischemia time on outcomes for kidneys donated after cardiac death Post-KAS

Prolonged warm (WIT) and cold (CIT) ischemia times are often important considerations in the discard of DCD kidneys, but their impact on post-transplant outcomes in the post-KAS era is unclear. We examined the association of ischemia time on delayed graft function (DGF) and death-censored graft failure for DCD kidneys. The 2018 SRTR SAF was utilized to identify post-KAS DCD kidney transplants occurring from 2015 to 2018. Relative risk and Cox regression were used to calculate risk of delayed graft function and hazard of death-censored graft failure, respectively. We identified 4,680 kidneys from DCD donors transplanted from 2015 to 2018 with recorded WIT and CIT times. Median WIT was 21.0 minutes (IQR 14.0-28.0), and CIT was 18.5 hours (IQR 13.9-23.5). The overall incidence of DGF was 42.7%. In a univariable relative risk regression model, extended CIT (24-30 hours:RR 1.37, 95% CI 1.15-1.77; >30 hours:RR 1.47, 95% CI 1.22-1.77) and WIT (20-40 minutes:RR 1.10, 95% CI 1.03-1.17) were associated with increased risk of DGF. When included in a multivariable model, neither prolonged CIT nor WIT were significantly associated with death-censored graft failure. Prolonged WIT and CIT are associated with increased DGF but not death-censored graft failure in recipients of DCD kidney transplants in the post-KAS era. Extended ischemia alone should not be used as a basis for discard or non-utilization of these organs.     

Duration of delayed graft function and outcomes after kidney transplantation from controlled donation after circulatory death donors: a retrospective study

The impact of the duration of delayed graft function (DGF) on graft survival is poorly characterized in controlled donation after circulatory death (DCD) donor kidney transplantation. A retrospective analysis was performed on 225 DCD donor kidney transplants between 2011 and 2016. When patients with primary nonfunction were excluded (n = 9), 141 recipients (65%) had DGF, with median (IQR) duration of dialysis dependency of 6 (2–11.75) days. Longer duration of dialysis dependency was associated with lower estimated glomerular filtration rate at 1 year, and a higher rate of acute rejection. On Kaplan–Meier analysis, the presence of DGF was associated with lower graft survival (log‐rank test P = 0.034), though duration of DGF was not (P = 0.723). However, multivariable Cox regression analysis found that only acute rejection was independently associated with lower graft survival [HR (95% CI) 4.302 (1.617–11.450); P = 0.003], whereas the presence of DGF and DGF duration were not. In controlled DCD kidney transplantation, DGF duration itself may not be independently associated with graft survival; rather, it may be that acute rejection associated with prolonged DGF is the poor prognostic factor.     

Elevated Preoperative Recipient Neutrophil-Lymphocyte Ratio Is Associated With Delayed Graft Function Following Kidney Transplantation

Introduction

The neutrophil-lymphocyte ratio (NLR) is an indicator of inflammatory status. We studied the effect of preoperative elevated NLR in the recipient in relation to the risk of developing delayed graft function (DGF) after kidney transplantation.

Methods

We retrospectively analysed the preoperative white blood cell count of renal transplant recipients between 2003 and 2005. An NLR >3.5 was considered elevated. There were 398 kidney transplant recipients of whom 249 received organs from donors after brain death (DBD), 61 from donors after circulatory death (DCD), and 88 from living donors.

Results

One hundred three patients (26%) developed DGF, of which 67 (65%) had NLRs >3.5. Of 295 recipients with primary graft function, only 44 (15%) had elevated NLR. Univariate analysis revealed three factors that significantly influenced graft function: NLR >3.5, cold ischemic time (CIT) >15 hours, and donor type. On multivariate analysis, both donor type (DCD: hazard ratio [HR] = 2.421, confidence interval [CI] = 1.195–4.905, P = .014; LD: HR = 0.289, CI = 0.099–0.846, P = .024) and NLR (HR = 10.673, CI = 6.151–18.518, P < .0001) remained significant.

Conclusions

Elevated recipient preoperative NLR could contribute to increase the risk of developing DGF, which appears to be more pronounced in patients receiving grafts from living donors.     

Transplanting kidneys from donation after cardiac death donors with acute kidney injury

Donation after cardiac death (DCD) and acute kidney injury (AKI) donors have historically been considered independent risk factors for delayed graft function (DGF), allograft failure, and inferior outcomes. With growing experience, updated analyses have shown good outcomes. There continues to be limited data, however, on outcomes specific to DCD donors who have AKI. Primary outcomes for this study were post–kidney transplant patient and allograft survival comparing two donor groups: DCD AKIN stage 2‐3 and DBD AKIN stage 2‐3. In comparing these groups, there were no short‐ or long‐term differences in patient (hazard ratio [HR] 1.07, 95% confidence interval [CI] 0.54‐1.93, P = .83) or allograft survival (HR 1.47, 95% CI 0.64‐2.97, P = .32). In multivariate models, the DCD/DBD status had no significant impact on the estimated GFR (eGFR) at 1 (P = .38), 2 (P = .60), and 3 years (P = .52). DGF (57.9% vs 67.9%, P = .09), rejection (12.1% vs 13.9%, P = .12), and progression of interstitial fibrosis/tubular atrophy (IFTA) on protocol biopsy (P = .16) were similar between the two groups. With careful selection, good outcomes can be achieved utilizing severe AKI DCD kidneys. Historic concerns regarding primary nonfunction, DGF resulting in interstitial fibrosis and rejection, and inferior outcomes were not observed. Given the ongoing organ shortage, increased effort should be undertaken to further utilize these donors.     

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.     

Presence of CD163+ macrophages in DCD kidneys with high DGF reduces the risk for acute cellular rejection in 6 months after kidney transplantation

Acute cellular rejection (ACR) occurs in 10% of renal allograft recipients and is characterized by leukocyte infiltration as observed in needle biopsies. ACR onset is subject to several risk factors, including delayed graft function (DGF). As the impact of DGF on the etiology of ACR remains unclear, this study analyzed the association between presence of leukocyte subsets and ACR onset, in DCD kidney biopsies with extensive DGF following transplantation. Immunohistochemical analysis of protocol biopsies taken 10 days after kidney transplantation revealed that patients with high levels of renal CD163⁺ macrophages have a decreased risk (OR = 0.021, P = 0.008) for ACR in the first 6 months after transplantation. In pre-transplant biopsies of a comparable DCD cohort, with >80% DGF, presence of donor CD163+ macrophages showed no effect on ACR risk. Therefore, leukocyte infiltrate present during the inflammatory response at the time of DGF may contain anti-inflammatory macrophages that exert a protective effect against ACR development.     

Early renal function recovery and long‐term graft survival in kidney transplantation

Following kidney transplantation (KTx), renal function improves gradually until a baseline eGFR is achieved. Whether or not a recipient achieves the best‐predicted eGFR after KTx may have important implications for immediate patient management, as well as for long‐term graft survival. The aim of this cohort study was to calculate the renal function recovery (RFR) based on recipient and donor eGFR and to evaluate the association between RFR and long‐term death‐censored graft failure (DCGF). We studied 790 KTx recipients between January 1990 and August 2014. The last donor SCr prior to organ procurement was used to estimate donor GFR. Recipient eGFR was calculated using the average of the best three SCr values observed during the first 3 months post‐KTx. RFR was defined as the ratio of recipient eGFR to half the donor eGFR. 53% of recipients had an RFR ≥1. There were 127 death‐censored graft failures (16%). Recipients with an RFR ≥1 had less DCGF compared with those with an RFR <1 (HR 0.56; 95% CI 0.37–0.85; P = 0.006). Transplant era, acute rejection, ECD and DGF were also significant determinants of graft failure. Early recovery of predicted eGFR based on donor eGFR is associated with less DCGF after KTx.