Delayed graft function of more than six days strongly decreases long-term survival of transplanted kidneys

Impact of Deceased-donor Acute Kidney Injury on Kidney Transplantation

Even as record numbers of deceased donors are undergoing organ recovery, the global transplant community continues to struggle with a shortage of donor organs and a high organ discard rate. Acute kidney injury (AKI) occurs in many hospitalized patients, including up to 25% of patients in critical condition. Registry studies have shown a significant increase in nonrecovery or organ discard rates in AKI donors, despite most studies reporting similar clinical outcomes compared with non-AKI donors. This review aims to capture the salient information learned from these studies and to summarize the efforts that have been made to gain a more granular understanding of how kidneys from donors with AKI behave posttransplant. In particular, we reviewed the studies that analyzed the clinical outcomes in different stages of AKI and AKI in marginal donors, such as kidney donor profile index of >85%, older donors, and donation after circulatory death donors. We summarized studies investigating molecular biomarkers, transcriptomics, and possible future therapeutic targets for postdonation AKI.

Delayed Graft Function and the Renin-angiotensin System

Delayed graft function (DGF) is a form of acute kidney injury (AKI) and a common complication following kidney transplantation. It adversely influences patient outcomes increases the financial burden of transplantation, and currently, no specific treatments are available. In developing this form of AKI, activation of the renin-angiotensin system (RAS) has been proposed to play an important role. In this review, we discuss the role of RAS activation and its contribution to the pathophysiology of DGF following the different stages of the transplantation process, from procurement and ischemia to transplantation into the recipient and including data from experimental animal models. Deceased kidney donors, whether during cardiac or brain death, may experience activation of the RAS. That may be continued or further potentiated during procurement and organ preservation. Additional evidence suggests that during implantation of the kidney graft and reperfusion in the recipient, the RAS is activated and may likely remain activated, extrapolating from other forms of AKI where RAS overactivity is well documented. Of particular interest in this setting is the status of angiotensin-converting enzyme 2, a key RAS enzyme essential for the metabolism of angiotensin II and abundantly present in the apical border of the proximal tubules, which is the site of predominant injury in AKI and DGF. Interventions aimed at safely downregulating the RAS using suitable shorter forms of angiotensin-converting enzyme 2 could be a way to offer protection against DGF.

Histopathological Features and Role of Allograft Kidney Biopsy Among Recipients With Prolonged Delayed Graft Function: A Review

Delayed graft function (DGF) is an early posttransplant complication predictive of adverse outcomes. This "acute kidney injury of transplantation" is often defined as allograft dysfunction requiring renal replacement within 7 d posttransplantation. DGF is an important area of study because it is emerging with efforts to expand the donor pool and address the supply-demand gap in kidney transplantation. DGF is often caused by severe kidney injury mechanisms because of multiple donors, recipients, and immunologic factors. The role of kidney biopsy, particularly in prolonged DGF, is an ongoing area of research and inquiry for clinicians and researchers alike to better define, manage, and predict outcomes of this early posttransplant event. This review aims to provide an in-depth, comprehensive summary of the literature to date on the histopathology of DGF and the role of kidney transplant biopsies in prolonged DGF.

MR Perfusion Imaging for Kidney Disease

Renal perfusion reflects overall function of a kidney. As an important indicator of kidney diseases, renal perfusion can be noninvasively measured by multiple methods of MR imaging, such as dynamic contrast-enhanced MR imaging, intravoxel incoherent motion analysis, and arterial spin labeling method. In this article we introduce the principle of the methods, review their recent technical improvements, and then focus on summarizing recent applications of the methods in assessing various renal diseases. By this review, we demonstrate the capability and clinical potential of the imaging methods, with the hope of accelerating their adoption to clinical practice.

Update on persistent acute kidney injury in critical illnesses

Acute kidney injury (AKI) affects about half of patients admitted to the intensive care unit (ICU), and worsens their short- and long-term outcomes. Apparently self-limiting AKI episodes initiate a progression toward chronic kidney disease (CKD) through cellular and molecular mechanisms that are yet to be explained. In particular, persistent AKI, defined in 2016 by the Acute Dialysis Quality Initiative as an AKI which lasts more than 48 h from its onset, has been correlated with higher morbidity and mortality, and with a higher progression to acute kidney disease (AKD) and CKD than transient AKI (i.e. AKI with a reversal within 48 h). This classification has been also used in the setting of solid organ transplantation, demonstrating similar outcomes. Due to its incidence and poor prognosis and because prompt interventions seem to change its course, persistent AKI should be recognized early and followed-up also after its recovery. However, while AKI and CKD are well-described syndromes, persistent AKI and AKD are relatively new entities. The purpose of this review is to highlight the key phases of persistent AKI in ICU patients in terms of both clinical and mechanistic features in order to offer to clinicians and researchers an updated basis from which to start improving patients' care and direct future research.

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

BACKGROUND

Because 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 METHOD

Consecutive 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.

RESULTS

The 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).

CONCLUSION

Although 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.

Delayed Graft Function Duration in Deceased Donor Kidney Transplants

BACKGROUND

Delayed graft function (DGF) is an important prognostic indicator after kidney transplantation. Depending on the severity of the ischemia-reperfusion injury, DGF can have several clinical presentations, with different renal function recovery times. Both the presence and duration of DGF can have an impact on kidney transplantation outcomes. However, the definition of the cutoff point, above which the outcomes are worse, varies widely in the literature.

METHODS

To investigate the impact of DGF and its duration on patient and graft survivals, a single-center retrospective study including all deceased donor kidney transplants was performed between November 2008 and December 2015 (n = 188). Through the analysis on the receiver operating characteristic curve, the cutoff point that determined the worst outcome was reached. DGF patients were then divided according to the duration of DGF (<8 days or ≥8 days).

RESULTS

The overall incidence of DGF was 62.2%. Higher HLA mismatches was an independent risk factor for prolonged DGF. DGF ≥8 days was associated with acute rejection and this one was associated with patient death in 3 years.

CONCLUSION

DGF with a duration of more than 8 days associated with higher HLA mismatches increases the risk of acute rejection, but graft loss and patient survival are not affected by DGF, regardless of its duration.

Kidney Transplant Outcomes after Prolonged Delayed Graft Function

Background: The protracted recovery of renal function may be an actionable marker of post-transplant adverse events, but a paucity of data are available to determine if the duration of graft recovery serves to stratify risk. Materials and Methods: Single-center data of adult-isolated deceased-donor kidney transplant (KTX) recipients between 1 July 2015 and 31 December 2018 were stratified by delayed graft function (DGF) duration, defined as time to serum creatinine < 3.0 mg/dL. Results: Of 355 kidney transplants, the time to creatinine < 3.0 mg/dL was 0−3 days among 96 cases (DGF ≤ 3), 4−10 days among 85 cases (DGF4-10), 11−20 days among 93 cases (DGF11-20), and ≥21 days for 81 cases (DGF ≥ 21). DGF ≥ 21 recipients were significantly more likely to be male, non-sensitized, and receive kidneys from donors that were older, with donation after circulatory death, non-mandatory share, hypertensive, higher KDPI, higher terminal creatinine, and longer cold and warm ischemia time. On multivariate analysis, DGF ≥ 21 was associated with a 5.73-fold increased odds of 12-month eGFR < 40 mL/min compared to DGF ≤ 3. Lesser degrees of DGF had similar outcomes. Conclusions: Prolonged DGF lasting over 20 days signifies a substantially higher risk for reduced eGFR at 1 year compared to lesser degrees of DGF, thus serving as a threshold indicator of increased risk.

Evaluation of severity of delayed graft function in kidney transplant recipients

BACKGROUND

The most common definition of delayed graft function (DGF) relies on dialysis during the first week post-transplant and does not consider DGF severity. The impact of DGF severity on long-term graft outcome remains controversial.

METHODS

We analyzed 627 deceased-donor kidney transplant recipients (KTR) transplanted 2005-2015 at our center for DGF-severity, associated risk factors and long-term consequences of DGF.

RESULTS

We found 349 (55.7%) KTR with DGF, which were classified into 4 groups according to DGF duration (0-1, 2-7, 8-14, >14 days) and were compared to KTR with no DGF. Increasing duration of DGF was associated with progressive worsening of 10-year death-censored graft survival (no DGF: 88.3% (95%CI: 82.4-94.2), 0-1 day: 81.3% (95%CI: 68.2-94.4), 2-7 days: 61.5% (95%CI: 43.1.1-79.9), 8-14 days: 66.6% (95%CI: 47.4-85.8), >14 days: 51.2% (95%CI: 33-69.4); p < 0.001). In kidneys with a Kidney Donor Profile Index (KDPI) ≥85% all DGF severity groups demonstrated reduced graft survival. However, in < 85%KDPI kidneys, only > 14 days DGF duration showed worse outcomes.

CONCLUSIONS

DGF had a duration-dependent effect on graft survival, which varied depending on KDPI. Of note, 0-1-day DGF showed comparable results to no DGF in the whole cohort.

Elevated plasma free thiols are associated with early and one-year graft function in renal transplant recipients

Background

Reduced free thiols in plasma are indicative of oxidative stress, which is an important contributor to ischaemia-reperfusion injury (IRI) in kidney transplantation leading to kidney damage and possibly delayed graft function (DGF). In a post-hoc, exploratory analysis of the randomised controlled CONTEXT trial, we investigated whether higher (i.e. less oxidised) plasma levels of free thiols as a biomarker of reduced oxidative stress are associated with a better initial graft function or a higher GFR.

Methods

Free thiol levels were measured in plasma at baseline, 30 and 90 minutes after reperfusion of the kidney as well as at Day 1, Day 5 and twelve months after kidney transplantation in 217 patients from the CONTEXT study. Free thiol levels were compared to the kidney graft function measured as the estimated time to a 50% reduction in plasma creatinine (tCr50), the risk of DGF and measured GFR (mGFR) at Day 5 and twelve months after transplantation.

Results

Higher levels of free thiols at Day 1 and Day 5 are associated with higher mGFR at Day 5 (p<0.001, r²_adj. = 0.16; p<0.001, r²_adj. = 0.25), as well as with mGFR at twelve months (p<0.001, r²_adj. = 0.20; p<0.001, r²_adj. = 0.16). However, plasma levels of free thiols at 30 minutes and 90 minutes, but not Day 1, were significantly higher among patients experiencing DGF.

Conclusion

Higher levels of plasma free thiols at Day 1 and Day 5, which are reflective of lower levels of oxidative stress, are associated with better early and late graft function in recipients of a kidney graft from deceased donors.

Trial registration

ClinicalTrials.gov Identifier:NCT01395719.

Risk factors and outcomes of prolonged recovery from delayed graft function after deceased kidney transplantation

Objective

We aimed to evaluate the effect of prolonged recovery from DGF on outcomes, using a new definition of DGF recovery time, among deceased donor kidney transplant recipients with DGF, and to examine the risk factors for prolonged recovery.

Methods

From 2007 to 2016, 91 deceased donor kidney transplant recipients with DGF were retrospectively analyzed. DGF recovery time was defined as the time from transplantation to achieve a stable estimated glomerular filtration rate (eGFR). Recipients with a DGF recovery time greater than or equal to the median were assigned to the prolonged recovery group, while the others were assigned to the rapid recovery group.

Result

The median DGF recovery time was 27 days. Donor terminal eGFR was significantly lower in the prolonged recovery group (n = 46) compared with the rapid recovery group (n = 45) (median 24.9 vs. 65.4 ml/min/1.73m², p = 0.004). The eGFR at 1 year post-transplant in the prolonged recovery group was significantly lower than that in the rapid recovery group (50.6 ± 20.0 vs. 63.5 ± 21.4 ml/min/1.73m², p = 0.005). The risk of adverse outcomes (acute rejection, pneumonia, graft failure, and death) was significantly greater in the prolonged recovery group (hazard ratio 2.604, 95% confidence interval 1.102–6.150, p = 0.029) compared with the rapid recovery group.

Conclusion

Decreased donor terminal eGFR is a risk factor for prolonged recovery from DGF after deceased kidney transplantation. Prolonged DGF recovery time is associated with reduced graft function at 1-year post-transplant, and poor transplant outcome.

Acute Kidney Injury (AKI) before and after Kidney Transplantation: Causes, Medical Approach, and Implications for the Long-Term Outcomes

Acute kidney injury (AKI) is a common finding in kidney donors and recipients. AKI in kidney donor, which increases the risk of delayed graft function (DGF), may not by itself jeopardize the short- and long-term outcome of transplantation. However, some forms of AKI may induce graft rejection, fibrosis, and eventually graft dysfunction. Therefore, various strategies have been proposed to identify conditions at highest risk of AKI-induced DGF, that can be treated by targeting the donor, the recipient, or even the graft itself with the use of perfusion machines. AKI that occurs early post-transplant after a period of initial recovery of graft function may reflect serious and often occult systemic complications that may require prompt intervention to prevent graft loss. AKI that develops long after transplantation is often related to nephrotoxic drug reactions. In symptomatic patients, AKI is usually associated with various systemic medical complications and could represent a risk of mortality. Electronic systems have been developed to alert transplant physicians that AKI has occurred in a transplant recipient during long-term outpatient follow-up. Herein, we will review most recent understandings of pathophysiology, diagnosis, therapeutic approach, and short- and long-term consequences of AKI occurring in both the donor and in the kidney transplant recipient.

Rate, Factors, and Outcome of Delayed Graft Function After Kidney Transplantation of Deceased Donors

BACKGROUND

Delayed graft function (DGF) is a frequent complication after kidney transplantation affecting long-term outcome.

PATIENTS AND METHODS

A total of 525 consecutive recipients (age 54.2 ± 13.4 years, 33% female) of kidneys from deceased donors transplanted between 2005 and 2012 were retrospectively examined. DGF was defined as the need of dialysis within the first week after transplantation.

RESULTS

DGF developed in 21.1% (n = 111). Factors associated with DGF (P ≤ .035, respectively) were recipient body mass index, C-reactive protein of the recipient, residual diuresis, cold ischemia time, donor age, and diuresis in the first hour after transplantation. Median duration of DGF was 16 (2-66) days. Patients after DGF had a significantly lower GFR compared with recipients without DGF either after 3 (32.9 ± 16.5 vs 46.3 ± 18.4 mL/min/1.73 m²) or after 12 months (38.9 ± 19.3 vs 48.6 ± 20.4 mL/min/1.73 m², P < .001, resp.). During DGF, 12.4% developed BANFF II and 18.0% BANFF I rejection, 20.2% had signs of transplant glomerulitis (first biopsy), and 16.2% (n = 18) remained on dialysis.

CONCLUSION

DGF affects 1 out of 5 kidney transplants from deceased donors. Minimizing modifiable risk factors, in particular immunologic risk, may ameliorate the incidence and outcome of DGF. The outcome of DGF depends mainly on the diagnosis of any rejection and worsens upon detection of transplant glomerulitis and pronounced interstitial fibrosis and tubular atrophy (IFTA).

Renal Function Improvement Following ANG-3777 Treatment in Patients at High Risk for Delayed Graft Function After Kidney Transplantation

BACKGROUND

Patients (20%-50%) undergoing renal transplantation experience acute kidney injury resulting in delayed graft function. ANG-3777 is an hepatocyte growth factor mimetic that binds to the c-MET receptor. In animal models, ANG-3777 decreases apoptosis, increases proliferation, and promotes organ repair and function.

METHODS

This was a randomized, double-blind, placebo-controlled, phase 2 trial of patients undergoing renal transplantation with <50 cc/h urine output for 8 consecutive hours over the first 24 hours posttransplantation, or creatinine reduction ratio <30% from pretransplantation to 24 hours posttransplantation. Subjects were randomized as 2:1 to 3, once-daily IV infusions of ANG-3777, 2 mg/kg (n = 19), or placebo (n = 9). Primary endpoint: time in days to achieve ≥1200 cc urine for 24 hours.

RESULTS

Patients treated with ANG-3777 were more likely to achieve the primary endpoint of 1200 cc urine for 24 hours by 28 days posttransplantation (83.3% versus 50% placebo; log-rank test: χ2 = 2.799, P = 0.09). Compared with placebo, patients in the ANG-3777 arm had larger increases in urine output; lower serum creatinine; greater reduction in C-reactive protein and neutrophil gelatinase-associated lipocalin; fewer dialysis sessions and shorter duration of dialysis; fewer hospital days; significantly less graft failure; and higher estimated glomerular filtration rate. Adverse events occurred in a similar percentage of subjects in both arms. Events per subject were twice as high in the placebo arm.

CONCLUSIONS

There was an efficacy signal for improved renal function in subjects treated with ANG-3777 relative to placebo, with a good safety profile.

Does the Microbiome Affect the Outcome of Renal Transplantation?

The role of the human microbiome in health and disease is becoming increasingly apparent. Emerging evidence suggests that the microbiome is affected by solid organ transplantation. Kidney transplantation is the gold standard treatment for End-Stage Renal Disease (ESRD), the advanced stage of Chronic Kidney Disease (CKD). The question of how ESRD and transplantation affect the microbiome and vice versa includes how the microbiome is affected by increased concentrations of toxins such as urea and creatinine (which are elevated in ESRD), whether restoration of renal function following transplantation alters the composition of the microbiome, and the impact of lifelong administration of immunosuppressive drugs on the microbiome. Changes in microbiome composition and activity have been reported in ESRD and in therapeutic immunosuppression, but the effect on the outcome of transplantation is not well-understood. Here, we consider the current evidence that changes in kidney function and immunosuppression following transplantation influence the oral, gut, and urinary microbiomes in kidney transplant patients. The potential for changes in these microbiomes to lead to disease, systemic inflammation, or rejection of the organ itself is discussed, along with the possibility that restoration of kidney function might re-establish orthobiosis.

Phase 3 trial Design of the Hepatocyte Growth Factor Mimetic ANG-3777 in Renal Transplant Recipients With Delayed Graft Function

Introduction

One-third of kidney transplantation patients experience acute kidney injury (AKI) resulting in delayed graft function (DGF), associated with increased risk of graft failure and mortality. Preclinical and phase 2 data indicate that treatment with ANG-3777 (formerly BB3), a hepatocyte growth factor (HGF) mimetic, may improve long-term kidney function and reduce health care resource use and cost, but these data require validation in a phase 3 randomized controlled trial.

Methods

The Graft Improvement Following Transplant (GIFT) trial is a multicenter, double-blind randomized controlled trial, designed to determine the efficacy and safety of ANG-3777 in renal transplantation patients showing signs of DGF. Subjects are randomized 1:1 to ANG-3777 (2 mg/kg) administered intravenously once daily for 3 consecutive days starting within 30 hours after transplantation, or to placebo.

Results

The primary endpoint is estimated glomerular filtration rate (eGFR) at 12 months. Secondary endpoints include proportion of subjects with eGFR >30 at days 30, 90, 180, and 360; proportion of subjects whose graft function is slow, delayed, or primary nonfunction; length of hospitalization; and duration of dialysis through day 30. Adverse events are assessed throughout the study.

Conclusion

GIFT will generate data that are important to advancing treatment of DGF in this medically complex population.

Pericardectomy after pericarditis constrictiva led to onset of transplant kidney function after 98 days of anuric kidney graft: a case report

BACKGROUND

Constrictive pericarditis is easily overlooked and can lead to severe problems in hemodynamics and end-organ perfusion, in our patient leading to 98 days of anuria after living kidney transplantation. This was completely reversible after pericardectomy.

CASE PRESENTATION

A 43-year-old female caucasian patient received a living kidney donation from her mother. She had developed end-stage renal disease 2 years prior due to nephrotic syndrome linked to graft-versus-host disease after allogenic stem-cell transplantation for aplastic anemia. The graft showed insufficient function already in the early postoperative phase. Dialysis was paused after surgery, but the patient developed hypervolemia with ascites and edema in the lower extremities. Doppler ultrasonography showed scarce perfusion, with intrarenal arterial waveforms without end-diastolic flow. The venous perfusion profiles showed pulsatile retrograde flow. There was no identifiable reason for a primary vascular perfusion problem on ultrasonography or transplant kidney angiography. Kidney transplant biopsy revealed no rejection but extensive acute tubular necrosis. Three weeks after transplantation, the patient developed an acute anuric graft failure caused by severe cardiac decompensation. Echocardiography revealed a previously unnoticed constrictive pericarditis, which could be confirmed in a cardio computed tomography scan. The constrictive pericarditis had not been apparent on previous x-rays, computed tomography scans, or echocardiographies, including those for transplantation evaluation. Conservative management of the constrictive pericarditis was not successful and the graft remained anuric. Eventually, the patient underwent pericardectomy 16 weeks after kidney transplantation. Shortly after surgery, the graft started urine production again, which significantly increased within a few days. The clearance improved and 2 weeks later, the patient was free from dialysis.

CONCLUSIONS

This case illustrates that special attention should be given to the pericardium during transplant evaluation, especially for patients who previously underwent stem-cell transplantations, chemotherapy or radiation.

The Role of Peritoneal Dialysis as the First-Line Renal Replacement Modality

Twenty years after its introduction, peritoneal dialysis (PD) is a well-established alternative to hemodialysis (HD) as a modality of renal replacement therapy. Much debate and research is apparent in the literature, comparing hemodialysis and PD as “opposite” modalities and trying to ascertain which modality should be more optimal.

In our opinion, HD and PD are two distinct modalities, each with its own advantages and disadvantages. In addition, it is clear that for both HD and PD, rates of technique failure are high, causing patients to transfer between modalities. The question is thus not which modality is best, but rather, which flow-chart of modalities makes best use of the advantages of each modality, while avoiding its disadvantages. In this respect, HD and PD appear to be complementary modalities.

The better preservation of residual renal function, lower risk of infection with hepatitis B and C, better outcome after transplantation, preservation of vascular access, and lower costs are arguments to promote PD as a good initial treatment. When PD-related problems arise (adequacy, ultrafiltration, peritonitis, patient burnout), a timely transfer to HD has to be planned.

This editorial tries to review arguments supporting the complementary nature of both modalities, and especially the role of PD as the first-line renal replacement therapy.

Prediction of kidney transplant outcome based on different DGF definitions in Chinese deceased donation

Background

Delayed graft function (DGF) is an important complication of kidney transplantation and can be diagnosed according to different definitions. DGF has been suggested to be associated with the long-term outcome of kidney transplantation surgery. However, the best DGF definition for predicting renal transplant outcomes in Chinese donations after cardiac death (DCDs) remains to be determined.

Method

A total of 372 DCD kidney transplant recipients from June 2013 to July 2017 in the First Affiliated Hospital of Xi’an Jiaotong University were included in this retrospective study to compare 6 different DGF definitions. The relationships of the DGF definitions with transplant outcome were analyzed, including graft loss (GL) and death-censored graft loss (death-censored GL). Renal function indicators, including one-year estimated glomerular filtration rate (eGFR) and three-year eGFR, and were compared between different DGF groups.

Results

The incidence of DGF varied from 4.19 to 35.22% according to the different DGF diagnoses. All DGF definitions were significantly associated with three-year GL as well as death-censored GL. DGF based on requirement of hemodialysis within the first week had the best predictive value for GL (AUC 0.77), and DGF based on sCr variation during the first 3 days post-transplant had the best predictive value for three-year death-censored GL (AUC 0.79). Combination of the 48-h sCr reduction ratio and classical DGF can improve the AUC for GL (AUC 0.85) as well as the predictive accuracy for death-censored GL (83.3%).

Conclusion

DGF was an independent risk factor for poor transplant outcome. The combination of need for hemodialysis within the first week and the 48-h serum creatinine reduction rate has a better predictive value for patient and poor graft outcome.

Early Prediction of Graft Outcomes After Kidney Transplantation From Donors After Circulatory Death: Biomarkers and Transplantation Characteristics

BACKGROUND

This study aimed to identify transplantation characteristics and biomarkers that predict outcomes for kidney transplant (KT) patients from donors after circulatory death (DCDs).

METHODS

Consecutive patients receiving a KT from a DCD in our center between 2014 and 2016 were included; the reference population was recipients with a living donor KT. The urinary tubular injury biomarker-to-creatinine ratio and serum lactate dehydrogenase (LDH) were measured at post-transplant days 1 and 3. The primary outcome was the occurrence of delayed graft function (DGF). Descriptive and receiver operating characteristic analyses were performed.

RESULTS

Forty-one patients were included in the analysis: 15 (36.59%) DCD KTs (9 of which suffered from DGF) and 26 (63.41%) living donor KTs. For the primary endpoint, neutrophil gelatinase-associated lipocalin, N-acetyl-beta-D-glucosaminidase, urinary tubular injury biomarker-to-creatinine ratio, and LDH areas under the curve were 1 and 0.96 (95% confidence interval: 0.84-1.0), 1 and 0.92 (95% confidence interval: 0.73-1.0), respectively. Among the transplant characteristics, only the 30-minute resistive index on the perfusion machine was significantly higher in DCD KTs with DGF vs those without DGF (0.26 mm Hg/mL/min [0.20; 0.32] vs 0.14 mm Hg/mL/min [0.12; 0.16], P = .05). Median 3-month creatinine clearance among DGF DCD KTs was 49 mL/min/1.73 m² [IQR: 42; 65] and 65 mL/min/1.73 m² [IQR: 62; 66] among DCD KTs without DGF (P = .22).

CONCLUSION

In the DCD KT population, clinical and biological markers were identified that provided predictive tools for DGF. Thus, systematic measurement of these biomarkers, particularly LDH, could improve the management of kidney graft recipients' immunosuppressive therapy.

Association Between Duration of Delayed Graft Function, Acute Rejection, and Allograft Outcome After Deceased Donor Kidney Transplantation

BACKGROUND

Prolonged duration of delayed graft function (DGF) may be associated with adverse allograft outcomes, but the association between threshold duration of DGF, acute rejection and long-term allograft loss remains undefined. We aimed to determine the impact of DGF duration on allograft outcomes and to assess whether this association was mediated by acute rejection.

METHODS

Using data from the Australian and New Zealand Dialysis and Transplant Registry, Cox proportional modeling was used to determine the association between quartiles of DGF duration, acute rejection at 6 months and death-censored graft loss (DCGL). Mediation analysis was conducted to determine whether acute rejection was a causal intermediate between DGF and DCGL.

RESULTS

Of 7668 deceased donor kidney transplants between 1997 and 2014, 1497 (19.5%) recipients experienced DGF requiring dialysis. The median (interquartile range) duration of DGF was 7 (9) days, with 25% requiring dialysis for 14 days or longer. Among recipients who had experienced a DGF duration of 1 to 4 days, the adjusted hazard ratio for duration of 5 to 7, 8 to 13, and 14 days or longer were 1.13 (95% confidence interval [CI], 0.83-1.55; P = 0.43), 1.44 (95% CI, 1.08-1.91; P = 0.013), and 1.99 (95% CI, 1.50-2.65; P < 0.001), respectively, for acute rejection; and were 1.10 (95% CI< 0.73-1.67; P = 0.64), 1.45 (95% CI, 1.00-2.11; P = 0.05) and 1.60 (95% CI, 1.10-2.31; P = 0.01), respectively, for DCGL. On average, 8% of the effects between DGF duration and DCGL were explained by acute rejection.

CONCLUSIONS

There was a direct dose-dependent effect between DGF duration and DCGL, with acute rejection explaining less than 10% of the effects between DGF duration and DCGL. Future research identifying other potential modifiable mediators that lies in the causal pathway between DGF duration and allograft loss is essential.

Induction Therapy in Elderly Kidney Transplant Recipients With Low Immunological Risk

BACKGROUND

In nonimmunized patients, similar rejection rates are observed for patients who have undergone thymoglobulin (antithymocyte globulins [ATG]) or basiliximab (BSX) therapy. While ATG may improve delayed graft function, it may also be associated with higher infection rates and malignancy risk. We compared survival and clinical outcomes in elderly recipients with low immunological risk according to their induction therapy.

METHODS

We conducted a multicentric study on nonimmunized patients ≥65 years of age receiving a first kidney transplant between 2010 and 2017. The principal outcome was patient and graft survival. Secondary outcomes were cumulative probabilities of infection, first acute rejection episode, malignancy, de novo donor specific antibody, posttransplant diabetes (PTD), cardiac complications, estimated glomerular filtration rate, and occurrence of delayed graft function. Cox, logistic, or linear statistical models were used depending on the outcome studied, and models were weighted on the propensity scores.

RESULTS

Two hundred and four patients were included in the BSX group and 179 in the ATG group with the average age of 71.0 and 70.5 years, respectively. Patient and graft survival at 3 years posttransplantation were 74% (95% CI, 65%-84%) and 68% (95% CI, 60%-78%) in ATG and BSX group, respectively, without significant difference. Occurrence of PTD was significatively higher in BSX group (23% versus 15%, P = 0.04) due to higher trough levels of Tacrolimus on month 3 (9.48 versus 7.30 ng/mL, P = 0.023). There was no difference in other evaluated outcomes.

CONCLUSIONS

In elderly recipients, ATG does not lead to poorer outcomes compared with BSX and could permit lower trough levels of Tacrolimus, thus reducing occurrence of PTD.

Lower rate of delayed graft function is observed when epidural analgesia for living donor nephrectomy is administered

Background

The beneficial effects of epidural analgesia (EDA) in terms of pain control and postoperative convalescence are widely known and led to a frequent use for patients who underwent living donor kidney nephrectomy. The objective of this study was to determine whether general anesthesia (GA) plus EDA compared to GA only, administered for living donor nephrectomy has effects on postoperative graft function in recipients.

Methods

In this monocentric, retrospective cohort analysis we analyzed the closed files of all consecutive donor- recipient pairs who underwent living donor kidney transplantations from 2008 to 2017. The outcome variable was delayed graft function (DGF), defined as at least one hemodialysis within seven days postoperatively, once hyperacute rejection, vascular or urinary tract complications were ruled out. Statistical analyses of continuous variables were calculated using the two-tail Student’s t test and Fisher exact test for categorical variables with a significance level of p < 0.05, respectively.

Results

The study enclosed 291 consecutive living donor kidney transplantations. 99 kidney donors received epidural analgesia whereas 192 had no epidural analgesia. The groups showed balanced pretransplantational characteristics and comparable donors´ and recipients’ risk factors. 9 out of all 291 recipients needed renal replacement therapy (RRT) during the first 7 days due to delayed graft function; none of these donors received EDA. The observed rate of DGF in recipients whose kidney donors received epidural analgesia was significantly lower (0% vs. 4.6%; p = 0.031).

Conclusions

In our cohort we observed a significantly lower rate of DGF when epidural analgesia for donor nephrectomy was administered. Due to restrictions of the study design this observation needs further confirmation by prospective studies.

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.

Cold Pulsatile Machine Perfusion versus Static Cold Storage in Kidney Transplantation: A Single Centre Experience

Introduction

We present our experience with hypothermic machine perfusion (HMP) versus cold storage (CS) in relation to kidney transplant outcomes.

Methods

Retrospective analysis of 33 consecutive HMP kidney transplant outcomes matched with those of 33 cold stored: delayed graft function (DGF), length of hospital stay (LOS), estimated glomerular filtration rate (eGFR), and patient and graft survival were compared. Renal Resistive Indexes (RIs) during HMP in relation to DGF were also analysed.

Results

In the HMP group, mean HMP time was 5.7 ± 3.9 hours with a mean cold ischaemic time (CIT) of 15 ± 5.6 versus 15.1 ± 5.3 hours in the CS group. DGF was lower in the HMP group (p=0.041), and donation after Circulatory Death (DCD) was a predictor for DGF (p<0.01). HMP decreased DGF in DCD grafts (p=0.036). Patient and graft survival were similar, but eGFR at 365 days was higher in the HMP cohort (p<0.001). RIs decreased during HMP (p<0.01); 2-hours RI ≥ 0.45 mmHg/mL/min predicted DGF in DCD kidneys (75% sensitivity, 80% specificity; area under the curve 0.78); 2-hours RI ≥ 0.2 mmHg/ml/min predicted DGF in DBD grafts (sensitivity 100%, specificity 91%; area under the curve 0.87).

Conclusion

HMP decreased DGF compared to CS, offering viability assessment pretransplant and improving one-year renal function of the grafts.

Comparative Assessment of uNGAL, uNAG and Cystatin C As Early Biomarkers in Renal Post-Transplant Patients

Urinary neutrophil gelatinase-associated lipocalin (uNGAL), urinary N-acetyl-bd-glucosaminidase (NAG), urinary α1-microglobulin/creatinine ratio and cystatin C have been suggested as potential early markers of delayed graft function (DGF) following kidney transplantation. We conducted a prospective study in 50 consecutive kidney transplant recipients to evaluate serial changes of these biomarkers within the first week after transplantation and assess their performance in predicting DGF (dialysis requirement during initial post-transplant week) and graft function throughout the first year. Urine samples were collected on post-transplantation days 0, 1, 2, 4, and 7. Statistical analysis: Linear mixed and multivariable regression models, receiver-operating characteristic (ROC), and areas under ROC curves were used. At all-time points, mean urinary NGAL levels were significantly higher in patients developing DGF. Shortly after transplantation (3-6 h), uNGAL and uNAG values were higher in DGF recipients (on average +242 ng/mL; NAG – 6.8 U/mmol creatinine, considering mean dialysis time of 4.1 years) and rose further in the following days, contrasting with prompt function recipients. On Day-1 uNGAL levels accurately predicted DGF (AUC-ROC = 0.93), with a performance higher than serum creatinine (AUC-ROC = 0.76), and similar to cystatin C (AUC-ROC = 0.95). Multivariable analyses revealed that uNGAL levels at days 4 and 7 were strongly associated with one-year serum creatinine level. Urinary NGAL, serum cystatin C is an early marker of graft injury and is independently associated with dialysis requirement within one week after transplantation and one-year graft function.

Outcomes of single kidney transplantation from pediatric donors: A single-center experience

Kidneys from pDDs are increasingly used to narrow the huge gap between incremental demand and static supply. However, there is still controversy on the clinical outcome of SKT from pDDs. We conducted a retrospective cohort study of 452 adult recipients in our center between March 2012 and February 2017. Outcomes of 3 groups, transplants with organs from pDDs (n=50), aDDs (n=207), and LDs (n=195), were compared. The mean age and weight of pDDs were 8.98 years (range 8 months-17 years) and 30.05 kg (range 8.2-55 kg), respectively. There was no difference in 1-year (96.0%, 98.1%, and 99.0%, respectively, P=.277) and 3-year patient survival (96.0%, 98.1%, and 99.0%, respectively, P=.277) or in 1-year (96.0%, 96.6%, and 98.5%, P=.307) and 3-year (96.0%, 96.6% and 97.9%, P=.437) graft survival. SCr, eGFR, and allograft size were similar among the 3 groups at 6th month post-transplant and thereafter. Incidence of DGF was higher in patients of the aDD group than those in the pDD group (22.7% vs 10.0%, P<.001), but there was no difference in AR and infection. SKT from pDDs to adult recipients is effective and safe with acceptable outcomes, and it will be a promising expansion to the donor pool.

The recovery status from delayed graft function can predict long-term outcome after deceased donor kidney transplantation

The effect of delayed graft function (DGF) recovery on long-term graft outcome is unclear. The aim of this study was to examine the association of DGF recovery status with long-term outcome. We analyzed 385 recipients who underwent single kidney transplantation from brain-dead donors between 2004 and 2015. Patients were grouped according to renal function at 1 month post-transplantation: control (without DGF); recovered DGF (glomerular filtration rate [GFR] ≥ 30 mL/min/1.73 m²); and incompletely recovered DGF group (GFR < 30 mL/min/1.73 m²). DGF occurred in 104 of 385 (27%) recipients. Of the DGF patients, 70 recovered from DGF and 34 incompletely recovered from DGF. Death-censored graft survival rates for control, recovered DGF, and incompletely recovered DGF groups were 95.3%, 94.7%, and 80.7%, respectively, at 5 years post-transplantation (P = 0.003). Incompletely recovered DGF was an independent risk factor for death-censored graft loss (HR = 3.410, 95%CI, 1.114-10.437). DGF was associated with increased risk for patient death regardless of DGF recovery status. Mean GFRs at 5 years were 65.5 ± 20.8, 62.2 ± 27.0, and 45.8 ± 15.4 mL/min/1.73 m² for control, recovered, and incompletely recovered DGF groups, respectively (P < 0.001). Control group and recovered DGF patients had similar renal outcomes. However, DGF was associated with increased risk for patient death regardless of DGF recovery status.

The prognostic value of the furosemide stress test in predicting delayed graft function following deceased donor kidney transplantation

OBJECTIVES AND METHODS

The Furosemide Stress Test (FST) is a novel dynamic assessment of tubular function that has been shown in preliminary studies to predict patients who will progress to advanced stage acute kidney injury, including those who receive renal replacement therapy (RRT). The aim of this study is to investigate if the urinary response to a single intraoperative dose of intravenous furosemide predicts delayed graft function (DGF) in patients undergoing deceased donor kidney transplant.

RESULTS

On an adjusted multiple logistic regression, a single 100 mg dose of intraoperative furosemide after the anastomosis of the renal vessels (FST) predicted the need for RRT at 2 and 6 h post kidney transplantation (KT). Recipient urinary output was measured at 2 and 6 h post furosemide administration. In receiver-operating characteristic (ROC) analysis, the FST predicted DGF with an area-under-the curve of 0.85 at an optimal urinary output cut-off of <600 mls at 6 h with a sensitivity of and a specificity of 83% and 74%, respectively.

CONCLUSIONS

The FST is a predictor of DGF post kidney transplant and has the potential to identify patients requiring RRT early after KT.

Delayed Graft Function Phenotypes and 12-Month Kidney Transplant Outcomes

BACKGROUND

Ischemia-reperfusion injury (IRI) leading to delayed graft function (DGF), defined by the United Network for Organ Sharing as dialysis in the first week (UNOS-DGF), associates with poor kidney transplant outcomes. Controversies remain, however, about dialysis initiation thresholds and the utility for other criteria to denote less severe IRI, or slow graft function (SGF).

METHODS

Multicenter, prospective study of deceased-donor kidney recipients to compare UNOS-DGF to a definition that combines impaired creatinine reduction in the first 48 hours or greater than 1 dialysis session for predicting 12-month estimated glomerular filtration rate (eGFR). We also assessed 10 creatinine and urine output-based SGF definitions relative to 12-month eGFR.

RESULTS

In 560 recipients, 215 (38%) had UNOS-DGF, 330 (59%) met the combined definition, 14 (3%) died, and 23 (4%) had death-censored graft failure by 12 months. Both DGF definitions were associated with lower adjusted 12-month eGFR (95% confidence interval)-by 7.3 (3.6-10.9) and 7.4 (3.8-11.0) mL/min per 1.73 m, respectively. Adjusted relative risks for 12-month eGFR less than 30 mL/min per 1.73 m were 1.9 (1.2-3.1) and 2.1 (1.1-3.7), with unadjusted areas under the curve of 0.618 and 0.627, respectively. For SGF definitions, postoperative day (POD) 7 creatinine had the strongest association with 12-month eGFR, and POD5 creatinine and creatinine reduction between POD1 and POD2 demonstrated modest separations in 12-month eGFR.

CONCLUSIONS

Although UNOS-DGF does not adequately predict 12-month function on its own, our findings do not support changing the definition. Postoperative day 7 creatinine is correlated with 12-month eGFR, but large translational studies are needed to understand the biological link between IRI severity at transplant and longer-term outcomes.

Association Between Slow and Delayed Graft Function With Graft Outcomes in Pediatric and Adolescent Deceased Donor Kidney Transplant Recipients

BACKGROUND

Delayed graft function (DGF) is associated with an increased risk of graft loss in adult kidney transplant recipients but the association remains inconsistent in pediatric recipients. The aim of this study is to examine the association between DGF and graft loss in pediatric and adolescent deceased donor kidney transplant recipients aged 21 years or younger using Australia and New Zealand Dialysis and Transplant registry.

METHODS

The associations between DGF status, overall and death-censored graft loss (DCGL) were examined using adjusted Cox regression analyses.

RESULTS

There were 367 recipients followed up for a median of 9.7 years between 1990 and 2012, with 82 (22%) experiencing DGF requiring dialysis (DGF-D) in the first 72 hours after transplant. Compared with recipients who did not experienced DGF-D, the adjusted hazard ratios for overall graft loss and DCGL in recipients who have experienced DGF-D was 2.08 (95% confidence interval [95% CI], 1.39-3.11; P < 0.001) and 2.09 (95% CI, 1.38-3.17; P < 0.001), respectively, independent of era, age, and initial immunosuppression. Slow graft function, defined as no immediate function but not requiring dialysis, was associated with adjusted hazard ratios of 2.60 (95% CI, 1.50-4.51; P = 0.001) for overall graft loss and 2.49 (95% CI, 1.39-4.47; P = 0.002) for DCGL.

CONCLUSIONS

This study has shown that DGF, encompassing a spectrum of renal dysfunction after kidney transplantation including those who may or may not require dialysis, is an independent risk factor for long-term graft loss.

Factors Associated With Delayed Graft Function and Their Influence on Outcomes of Kidney Transplantation

BACKGROUND

One of the main postoperative complications of kidney transplant is delayed graft function (DGF), which means absence of graft function after transplant or the need for dialysis during the first week post procedure. The occurrence of DGF currently in our hospital is high and has been attributed to a combination of many factors. The aim of this study was to evaluate the factors associated to DGF and their influence in the outcome of kidney transplants.

METHODS

Historical cohort of 150 patients transplanted with live or deceased donor kidneys from 2011 to 2013.

RESULTS

DGF was associated to time in dialysis and the number of recipient pre-transplant transfusions, donors age, serum creatinine level, use of vasoactive drugs in the donor, distance from place of organ retrieval and transplant center, and duration of cold ischemia time. DGF influenced post-transplantation outcome in regard to length of stay in intensive care, length of hospital stay, acute rejection episodes, and higher creatinine levels at discharge. Patients and graft survival were shorter in the DGF group.

CONCLUSIONS

There are multiple factors related to DGF, the most important being those related to donors, and organ storage. The most important factor related to the recipient was the dialysis vintage. We did not find a correlation between DGF and HLA-compatibility. DGF consequences are important, including worse graft function and survival, as well as impact in recipient morbidity and mortality.

Use of a Targeted Urine Proteome Assay (TUPA) to identify protein biomarkers of delayed recovery after kidney transplant

PURPOSE

Development of delayed graft function (DGF) following kidney transplant is associated with poor outcomes. An ability to rapidly identify patients with DGF versus those with immediate graft function (IGF) may facilitate the treatment of DGF and the research needed to improve prognosis. The purpose of this study was to use a Targeted Urine Proteome Assay to identify protein biomarkers of delayed recovery from kidney transplant.

EXPERIMENTAL DESIGN

Potential biomarkers were identified using the Targeted Urine Proteome (MRM) Assay to interrogate the relative DGF/IGF levels of expression of 167 proteins in urine taken 12-18 h after kidney implantation from 21 DGF, 15 SGF (slow graft function), and 16 IGF patients. An iterative Random Forest analysis approach evaluated the relative importance of each biomarker, which was then used to identify an optimum biomarker panel that provided the maximum sensitivity and specificity with the least number of biomarkers.

CONCLUSIONS AND CLINICAL RELEVANCE

Four proteins were identified that together distinguished DGF with a sensitivity of 77.4%, specificity of 82.6%, and AUC of 0.891. This panel represents an important step toward identifying DGF at an early stage so that more effective treatments can be developed to improve long-term graft outcomes.

Association of Pre-Transplant Dialysis Modality and Post-Transplant Outcomes: A Meta-Analysis

♦ BACKGROUND: It remains unclear whether post-transplant outcomes differ according to the pre-transplant dialysis modality (peritoneal dialysis [PD] versus hemodialysis [HD]). We performed a meta-analysis of studies that assessed either post-transplant mortality, graft survival, or delayed graft function (DGF) in both PD and HD patients. ♦ METHODS: Two independent authors searched English-language literature from January 1, 1980, through August 31, 2014, national conference proceedings, and reference lists. We used combinations of terms related to dialysis (hemodialysis, peritoneal dialysis, or renal replacement therapy), kidney transplant, and outcomes. Studies were included if they measured any of the 3 post-transplant study outcomes in both pre-transplant HD and PD. ♦ RESULTS: A total of 16 studies were included in the final analysis. Of these, 6 studies reported adjusted hazard ratio for mortality, pooled adjusted risk ratio: 0.89 (95% confidence interval [CI] 0.82 - 0.97) in favor of PD (p = 0.006). The same 6 studies reported adjusted hazard ratio for graft survival, pooled adjusted risk ratio: 0.97 (95% CI 0.92 - 1.01, p = 0.16). A total of 13 studies reported unadjusted DGF. Pooled odds ratio: 0.5 (95% CI 0.41 - 0.63) in favor of PD (p < 0.005). Significant heterogeneity observed for all outcomes: I2 = 72.7%, I2 = 59.9%, and I2 = 66.8%, respectively. ♦ CONCLUSIONS: Based on these results, pre-transplant PD is associated with better post-transplant survival than HD. Pre-transplant PD was also associated with decreased risk for DGF compared with HD, although these results were unadjusted. There was no significant difference in graft survival between pre-transplant HD and PD. These results suggest that PD may be the preferred dialysis modality for patients expected to receive a transplant.

Prediction, prevention, and management of delayed graft function: where are we now?

Delayed graft function (DGF) remains a major barrier to improved outcomes after kidney transplantation. High-risk transplant recipients can be identified, but no definitive prediction model exists. Novel biomarkers to predict DGF in the first hours post-transplant, such as neutrophil gelatinase-associated lipocalin (NGAL), are under investigation. Donor management to minimize the profound physiological consequences of brain death is highly complex. A hormonal resuscitation package to manage the catecholamine "storm" that follows brain death is recommended. Donor pretreatment with dopamine prior to procurement lowers the rate of DGF. Hypothermic machine perfusion may offer a significant reduction in the rate of DGF vs simple cold storage, but costs need to be evaluated. Surgically, reducing warm ischemia time may be advantageous. Research into recipient preconditioning options has so far not generated clinically helpful interventions. Diagnostic criteria for DGF vary, but requirement for dialysis and/or persistent high serum creatinine is likely to remain key to diagnosis until current work on early biomarkers has progressed further. Management centers on close monitoring of graft (non)function and physiological parameters. With so many unanswered questions, substantial reductions in the toll of DGF in the near future seem unlikely but concentrated research on many levels offers long-term promise.

Ex Vivo Normothermic Perfusion Induces Donor-Derived Leukocyte Mobilization and Removal Prior to Renal Transplantation

Introduction

Ex vivo normothermic perfusion offers an alternative method of organ preservation, allowing donor kidneys to be reanimated and evaluated prior to transplantation. Beyond preservation, it can be used to characterize the immunological contribution of the donor kidney in isolation. Furthermore, it has the potential to be used as an immunomodulatory strategy to manipulate donor kidneys prior to transplantation.

Methods

Explanted porcine kidneys underwent 6 hours of perfusion. Sequential perfusate samples were collected and leukocytes characterized via flow cytometry. An inflammatory profile was generated via cytokine quantification. Cell-free DNA was also determined as markers of cell death.

Results

All kidneys functioned within normal parameters and met the criteria for transplantation at the end of perfusion. Throughout perfusion there were continuous increases in pro-inflammatory cytokines, including large concentrations of interferon-γ, suggesting that perfusion drives a significant inflammatory response. Increasing concentrations in cell-free DNA were also observed, suggesting cell death. During perfusion there was a marked cellular diapedesis of T cells, B cells, natural killer (NK) cells, and monocytes from the kidney into the circuit. Minor populations of granulocytes and macrophages were also detected.

Discussion

We demonstrate that ex vivo normothermic perfusion initiates an inflammatory cytokine storm and release of mitochondrial and genomic DNA. This is likely to be responsible for immune cell activation and mobilization into the circuit prior to transplantation. Interestingly this did not have an impact on renal function. These data therefore suggest that normothermic perfusion can be used to immunodeplete and to saturate the pro-inflammatory capacity of donor kidneys prior to transplantation.

The effect of pre-operative methylprednisolone on the incidence of delayed graft function in renal transplantation

Introduction:

This study explores the effect of different corticosteroid administration timings on the incidence of slow/delayed graft function.

Methods:

One hundred and twelve kidney transplants from January 2011 to March 2014 were retrospectively analysed. Thirty-six cases were excluded because they were donor-specific antibody positive ( n=16), received thymoglobulin/plasma exchange ( n=11), were ABO-incompatible ( n=6) or suffered graft loss from vascular thrombosis within the first week post-transplant ( n=3). The study period straddled three eras of corticosteroid administration, from intra-operative intravenous (IV) hydrocortisone (Era 1; n=26), to intra-operative IV methylprednisolone (Era 2; n=38) and pre-operative IV methylprednisolone (Era 3; n=12). The primary endpoint was the incidence of slow/delayed graft function. Secondary outcomes included estimated glomerular filtration rate at discharge and 120 and 365 days, rejection (acute and one-year), wound complications, post-transplant diabetes, increase in low-density lipoprotein or body mass index, and cytomegalovirus or BK viraemia within one year.

Results:

On univariate analysis, pre-operative methylprednisolone was associated with lower incidence of slow/delayed graft function (17%, 55%, 58% in Eras 3, 2, 1 respectively; p=0.041), superior estimated glomerular filtration rate at discharge (median 56, 37 and 43 ml/min for Eras 3, 2, 1 respectively; p=0.033) and at 120 days (median 60, 52, and 46 ml/min for Eras 3, 2, 1 respectively; p=0.017). On multivariate analysis, pre-operative IV methylprednisolone ( vs. Eras 1 and 2 combined; odds ratio 4.79 (90% confidence interval 1.16–19.80); p=0.07) and living donor type ( vs. deceased; odds ratio 5.56 (90% confidence interval 2.25–13.77); p=0.002) were associated with lower incidence of slow/delayed graft function.

Conclusion:

Pre-operative methylprednisolone was associated with reduced slow/delayed graft function and improved early estimated glomerular filtration.

Using an Integrated -Omics Approach to Identify Key Cellular Processes That Are Disturbed in the Kidney After Brain Death

In an era where we are becoming more reliant on vulnerable kidneys for transplantation from older donors, there is an urgent need to understand how brain death leads to kidney dysfunction and, hence, how this can be prevented. Using a rodent model of hemorrhagic stroke and next-generation proteomic and metabolomic technologies, we aimed to delineate which key cellular processes are perturbed in the kidney after brain death. Pathway analysis of the proteomic signature of kidneys from brain-dead donors revealed large-scale changes in mitochondrial proteins that were associated with altered mitochondrial activity and morphological evidence of mitochondrial injury. We identified an increase in a number of glycolytic proteins and lactate production, suggesting a shift toward anaerobic metabolism. Higher amounts of succinate were found in the brain death group, in conjunction with increased markers of oxidative stress. We characterized the responsiveness of hypoxia inducible factors and found this correlated with post-brain death mean arterial pressures. Brain death leads to metabolic disturbances in the kidney and alterations in mitochondrial function and reactive oxygen species generation. This metabolic disturbance and alteration in mitochondrial function may lead to further cellular injury. Conditioning the brain-dead organ donor by altering metabolism could be a novel approach to ameliorate this brain death-induced kidney injury.

Early cytomegalovirus-specific T-cell response and estimated glomerular filtration rate identify patients at high risk of infection after renal transplantation

BACKGROUND

Assessing the risk of cytomegalovirus (CMV) viremia in kidney transplant recipients (KTR) may be helpful to indicate in which patient it is worth starting antiviral treatment during preemptive strategy.

METHODS

In 40 CMV-seropositive KTR preemptively treated with ganciclovir, we used interferon (IFN)-γ ELISpot test to evaluate whether monitoring T cells directed against phosphoprotein (pp) 65 and immediate early (IE)-1 antigens could predict the onset of viremia.

RESULTS

CMV viremia occurred in 24 patients (60%) within 120 days after transplantation. Non-viremic patients had higher anti-pp65, anti-IE-1 T cells, and estimated glomerular filtration rate (eGFR) in the first 90 days after transplantation. At logistic regression, anti-pp65, anti-IE-1 T cells, and eGFR measured at day 30 were significantly associated with CMV infection. Cutoff values of 15 spot-forming cells (SFCs)/200,000 peripheral blood mononuclear cells (PBMCs) for anti-IE, 40 SFCs/200,000 PBMCs for anti-pp65, and 46.6 mL/min/1.73 m(2) for eGFR, respectively, predicted the risk of CMV infection with high sensitivity and specificity (area under the receiver operating characteristic curve >0.75). Using a classification tree model, we identified as high-risk patients those showing anti-pp65 <42 SFCs/200,000 PBMCs and eGFR <62 mL/min/1.73 m(2) , as well as anti-pp65 ≥42 and anti-IE-1 <6.5 SFCs/200,000 PBMCs.

CONCLUSION

Monitoring CMV-specific T-cell responses and eGFR in the first month post transplant can identify patients at high risk of CMV infection, for whom preemptive antiviral therapy is recommended.

Combined predictive value of the expanded donor criteria for long-term graft survival of kidneys from donors after cardiac death: A single-center experience over three decades

OBJECTIVES

Kidneys procured from the deceased hold great potential for expanding the donor pool. The aims of the present study were to investigate the post-transplant outcomes of renal allografts recovered from donors after cardiac death, to identify risk factors affecting the renal prognosis and to compare the long-term survival from donors after cardiac death according to the number of risk factors shown by expanded criteria donors.

METHODS

A total of 443 grafts recovered using an in situ regional cooling technique from 1983 to 2011 were assessed. To assess the combined predictive value of the significant expanded criteria donor risk criteria, the patients were divided into three groups: those with no expanded criteria donor risk factors (no risk), one expanded criteria donor risk factor (single-risk) and two or more expanded criteria donor risk factors (multiple-risk).

RESULTS

Among the donor factors, age ≥50 years, hypertension, maximum serum creatinine level ≥1.5 mg/dL and a warm ischemia time ≥30 min were identified as independent predictors of long-term graft failure on multivariate analysis. Regarding the expanded criteria donors criteria for marginal donors, cerebrovascular disease, hypertension and maximum serum creatinine level ≥1.5 mg/dL were identified as significant predictors on univariate analysis. The single- and multiple-risk groups showed 2.01- and 2.40-fold higher risks of graft loss, respectively.

CONCLUSIONS

Renal grafts recovered from donors after cardiac death donors have a good renal function with an excellent long-term graft survival. However, an increased number of expanded criteria donors risk factors increase the risk of graft loss.

Risk factors and long-term outcomes of delayed graft function in deceased donor renal transplantation

Purpose

The purpose of this study was to analyze the risk factors for delayed graft function (DGF) and determine its impact on the outcomes of deceased donor (DD) kidney transplantation (KT).

Methods

Between January 2000 and December 2011, we performed 195 DD renal transplants. After the exclusion of primary nonfunctional grafts (n = 4), the study recipients were divided into two groups-group I, DGF (n = 31, 16.2%); group II, non-DGF (n = 160, 83.8%). The following variables were compared: donor and recipient characteristics, patient and graft survival, postoperative renal function, acute rejection (AR) episodes, and the rates of surgical and infectious complications.

Results

Donor-related variables that showed significant differences included hypertension (P = 0.042), diabetes (P = 0.025), and prerecovery serum creatinine levels (P < 0.001). However, there were no significant differences in recipient-related factors. One significantly different transplant-related factor was positive panel reactive antibody (PRA > 20%, P = 0.008). On multivariate analysis, only the prerecovery serum creatinine level (P < 0.001; hazard ratio [HR], 1.814) was an independent risk factor for the development of DGF. A Cox multivariate analysis of risk factors for graft survival identified these independent risk factors for graft survival: nephron mass (donor kidney weight to recipient body weight ratio) index (P = 0.026; HR, 2.328), CMV infection (P = 0.038; HR, 0.114), and AR episode (P = 0.038; HR, 0.166).

Conclusion

In DD KT, an independent risk factor for DGF was the prerecovery serum creatinine level. Although there was a significant difference in graft survival between the DGF and non-DGF groups, DGF was not an independent risk factor for graft failure in this study.

PREventing Delayed Graft Function by Driving Immunosuppressive InduCtion Treatment (PREDICT-DGF): study protocol for a randomized controlled trial

Background

In kidney transplantation, the use of Anti-Thymocyte Globulins (ATG) as induction therapy has been described as a possible treatment for reducing the prevalence of Delayed Graft Function (DGF). ATG possesses pharmaceutical proprieties that could help control the lesions caused by ischemia reperfusion injury. However, other studies have questioned this potential protective effect. We hypothesized that the benefits related to ATG for reducing DGF prevalence may be higher and more consistently recognized if only patients with high DGF risk are considered. We recently proposed a scoring system entitled DGFS (Delayed Graft Function Score) for such stratification of kidney transplant recipients according to their risk of DGF. Using the DGFS calculation, we aim to determine whether a short course of ATG can decrease the incidence of DGF in comparison with Basiliximab in kidney transplant recipients with low immunological risk but high DGF risk.

Methods

We conduct a phase IV, open label, randomized, multicentric and prospective study, to compare ATG in parallel with a control group treated by Basiliximab. The 1:1 randomized allocation of patients between groups is stratified on the clinical center, and on the hypothermic machine-perfusion device. We aimed to include a total of 384 patients to achieve a statistical power at 0.80. The study was initiated at the Nantes University hospital in July 2014, with data collection continuing until April 2018, and publication of the results proposed for 2019.

Discussion

The main expected benefits of this study are i) the reduction of unjustified ATG over-prescriptions associated with serious adverse events, ii) the reduction of chance losses related to ATG under-prescription, iii) the decrease in the incidence of DGF which was described as a risk factor of graft failure and patient death, and iv) the reduction in hospitalization duration and number of post transplantation dialysis sessions, both being associated with reduced medical costs. In conclusion, the current study is innovative by proposing a more efficient and personalized induction therapy.

Trial registration

The study was registered in the Clinical Trials Registry (#NCT02056938, February 5, 2014), and in the European Clinical Trials Database (EudraCT #2014-000332-42, January 30, 2014).