The prognostic value of time needed on dialysis in patients with delayed graft function

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.

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.

The predictive value of urinary kidney injury molecular-1 for long-term graft function in kidney transplant patients: a prospective study

Background

Monitoring allograft function during the early stages is crucial, and therefore requires biomarkers more sensitive than serum creatinine (Scr). Kidney injury molecular-1 (KIM-1) is a potent biomarker; however, disparities exist in the literature concerning its predictive value in allograft function. Therefore, this study aimed to evaluate its predictive value for the long-term prognosis of kidney transplantation patients.

Methods

A prospective study with a cohort comprising 160 patients scheduled for kidney transplantation was conducted to evaluate the predictive power of urinary KIM-1 (uKIM-1) and other renal ischemia-reperfusion biomarkers including urinary L-type fatty acid binding protein (uL-FABP), urinary N-acetyl-β-D glucosaminidase (uNAG), and urinary neutrophil gelatinase-related lipoprotein (uNGAL) for allograft prognosis.

Results

One hundred and forty kidney recipients who were admitted to our hospital between September 2014 and December 2017 with a median follow-up of 30.3 months were included. Thirty-seven recipients had functional delayed graft function (fDGF) in the first week post transplantation, and 42 recipients had progressed to allograft dysfunction [estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m²] by the end of the study, while nine recipients deteriorated into allograft loss (defined by the initiation of dialysis). The levels of uKIM-1 in the fDGF group were higher than those in the immediate graft function (IGF) recipients (P<0.05) at 0 hour post transplantation [5.885 (4.420–7.913) vs. 4.605 (3.417–5.653) ng/mmol], and on the first day post transplantation [5.569 (4.181–6.722) vs. 4.002 (3.222–6.488) ng/mmol]. The levels of uL-FABP in the fDGF group were also higher than those in the IGF group at 0 hour post transplantation (89.818±39.332 vs. 69.187±37.926 µg/mmol) and on the third day post transplantation [77.835 (60.368–100.678) vs. 66.841 (28.815–89.783) µg/mmol]. Multivariate Cox regression analysis demonstrated that recipients with higher uKIM-1 levels on the first day post transplantation had a 23.5% increase in the risk of developing fDGF and a 27.3% increase in the risk of prolonged renal allograft dysfunction.

Conclusions

uKIM-1 on the first day post transplantation can predict short-term graft function and is a potent biomarker for the long-term prognosis of graft function.

Pre-arrest doxycycline protects donation after circulatory death kidneys

Kidney injury during donation after circulatory determination of death (DCDD) includes warm ischemic (WI) injury from around the time of asystole, and cold ischemic (CI) injury during cold preservation. We have previously shown that Matrix Metalloproteinases (MMPs) are involved in CI injury and that Doxycycline (Doxy), an antibiotic and known MMP inhibitor, protects the transplant kidney during CI. The purpose of our study was to determine if Doxy given before asystole can also prevent injury during WI. A rat model of DCDD was used, including Control, Preemptive Doxy (45 mg/kg iv), and Preemptive and Perfusion (100 microM) Doxy groups. Thirty minutes after asystole, both kidneys were removed. The left kidney was perfused at 4 °C for 22 h, whereas the right was used to establish the degree of warm ischemic injury prior to cold preservation. MMP-2 in the perfusate was significantly reduced in both treatment groups [Control 43.7 ± 7.2 arbitrary units, versus Preemptive Doxy group 23.2 ± 5.5 (p = 0.03), and 'Preemptive and Perfusion' group 18.0 ± 5.6 (p = 0.02)]. Reductions in NGAL, LDH, and MMP-9 were also seen. Electron microscopy showed a marked reduction in mitochondrial injury scores in the treatment groups. Pre-arrest Doxy was associated with a reduction in injury markers and morphologic changes. Doxy may be a simple and safe means of protecting transplant kidneys from both WI and CI.

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.

Proteomic Analysis of Perfusate from Machine Cold Perfusion of Transplant Kidneys: Insights Into Protection from Injury

Background

Machine cold perfusion is beneficial to the preservation of kidneys for transplantation. At the end of preservation, the perfusion solution contains many proteins. Using a proteomics approach, we searched for useful biomarkers and potential therapeutic targets in the perfusate. Our program is unique in that all transplant kidneys (even living donor kidneys, LKD) are placed on machine cold perfusion prior to transplantation.

Material/Methods

Perfusates from donation after neurological and circulatory determination of death (DNDD and DCDD respectively) and LKD were collected (n=41) and analyzed for LDH, neutrophil gelatinase-associated lipocalin (NGAL), and matrix metalloproteinase-2 (MMP-2) as markers of injury. Perfusate from each kidney was subjected to 2-dimensional gel electrophoresis, then analyzed using software to identify those spots which are significantly different between the 3 groups. Mass spectrometry was used to identify the proteins and their identity was confirmed with Western blot.

Results

The highest levels of MMP-2, LDH, and NGAL were seen for the DCDD kidneys, followed by the DNDD kidneys and then LDK. Peroxiredoxin-2, NGAL, and alpha-1-antitrypsin were identified as significantly different between the different types of donor kidneys, and their role and possible therapeutic strategies are discussed. Collagen fragments, albumin, and immunoglobulin were also identified as possible byproducts of the injury and may be useful is assessing the degree of injury.

Conclusions

Comparison of the perfusates from the different types of kidneys has allowed us to identify proteins that will be useful in future research into reducing injury in transplant kidneys.

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.

Early post-transplant conversion from tacrolimus to belatacept for prolonged delayed graft function improves renal function in kidney transplant recipients

Prolonged delayed graft function (DGF) in kidney transplant recipients imparts a risk of poor allograft function; tacrolimus may be detrimental in this setting. We conducted a retrospective single center analysis of the first 20 patients converted to belatacept for prolonged DGF as part of a clinical protocol as a novel treatment strategy to treat prolonged DGF. Prior to conversion, patients underwent an allograft biopsy to rule out rejection and confirm tubular injury. The primary outcome was the estimated glomerular filtration rate (eGFR) at 12 months post-transplant; secondary outcome was the change in eGFR 30 days post-belatacept conversion. At 1 year post-transplant, the mean eGFR was 54.2 (SD 19.2) mL/min/1.73 m² . The mean eGFR on the day of belatacept conversion was 16 (SD 12.7) mL/min/1.73 m² and rose to 43.1 (SD 15.8) mL/min/1.73 m² 30 days post-conversion (P<.0001). The acute rejection rate was 20% with 100% patient survival at 12 months post-transplant. There was one graft loss in the setting of an invasive Aspergillus infection that resulted in withdrawal of immunosuppression and transplant nephrectomy. Belatacept conversion for prolonged DGF is a novel treatment strategy that resulted in an improvement in eGFR. Additional follow-up is warranted to confirm the long-term benefits of this strategy.

An Improved Classification of Kidney Function Recovery Using Estimated Glomerular Filtration Rate Slope Post-transplantation

BACKGROUND

The impact of renal function recovery on graft survival was examined using estimated glomerular filtration rate (eGFR) slope after kidney transplantation (GAP classification); this was compared to the conventional classification of immediate graft function (IGF), slow graft function (SGF), and delayed graft function (DGF).

MATERIALS AND METHODS

Overall, 541 cases of cadaveric renal transplants were reviewed from a prospective transplant database. eGFR and its slope were measured using the harmonic mean over the first week post-transplantation. Next, 495 kidney transplant recipients from an independent institution were assessed to determine the prognostic value of graft function based on the eGFR slope.

RESULTS

The main discrimination of eGFR slopes occurred within the first 7 days. Three groups in the GAP classification (Good graft function, Average graft function, Poor graft function) were defined based on eGFR slope tertiles: good graft function (GGF), average graft function (AGF), and poor graft function (PGF) were defined based on the ΔCrCL per day over the first 7 days: <1 mL/min, 1-4 mL/min, and >4 mL/min, respectively. When applied to the validation cohort, the 5-year graft failure was 20% for the PGF group, 4% for the AGF group, and 3% for the GGF group. Multivariable Cox regression analysis demonstrated better prediction of long-term graft function with the new classification (C statistic 0.49 [old)] vs 0.61 [new]).

CONCLUSION

The new GAP criteria were better at predicting long-term graft survival and renal function compared to the conventional classification system, and deserve further consideration in future studies.