Outcome of grafts with long-lasting delayed function after renal transplantation

Impact of Pretransplant Dialysis Modality on Posttransplant Outcomes: A Single-Center Experience

OBJECTIVES

It remains unclear whether posttransplant outcomes differ according to the pretransplant dialysis modality (peritoneal dialysis vs hemodialysis). Our aim was to assess posttransplant outcomes in patients with different predialysis modalities.

MATERIALS AND METHODS

Two thousand two hundred fifty-eight kidney recipients following up in Hamed Alessa Organ transplant center in Kuwait were included and divided into two groups according to pre-transplant dialysis modality: Group 1: those who received hemodialysis (HD) and group 2: those with peritoneal dialysis (PD). Demographics, pretransplant and posttransplant comorbidities, and patient and graft outcomes were studied.

RESULTS

There were 1956 patients on hemodialysis, and 302 patients were on peritoneal dialysis. Most were male patients (1456 vs 802 female patients), with comparable mean age (P = .34). Chronic glomerulonephritis and diabetic nephropathy represented the most common original kidney disease before transplant (27.6% and 21.4%, respectively), with higher prevalence of glomerulonephritis in group 1 and diabetic nephropathy in group 2 (P = .001). The 2 groups were comparable with regard to immunosuppression (induction and maintenance) (P > .05). Posttransplant diabetes and hypertension were significantly higher in the hemodialysis group (P = .004 and P = 003, respectively). There was no significant difference between the 2 groups with regard to the graft outcome (P = .86). However, patient survival was significantly higher in the hemodialysis group (81.2% vs 64.4%).

CONCLUSIONS

Compared with peritoneal dialysis, pretransplant hemodialysis is associated with better posttransplant patient survival despite no difference in the graft outcome. Diabetes-related complications could be attributed to such outcomes.

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.

Peritoneal Dialysis for Potential Kidney Transplant Recipients: Pride or Prejudice?

Kidney transplantation (KT) is recognized as the gold-standard of treatment for patients with end-stage renal disease. Additionally, it has been demonstrated that receiving a pre-emptive KT ensures the best recipient and graft survivals. However, due to an overwhelming discrepancy between the organs available and the patients on the transplant waiting list, the vast majority of transplant candidates require prolonged periods of dialysis before being transplanted. For many years, peritoneal dialysis (PD) and hemodialysis (HD) have been considered competitive renal replacement therapies (RRT). This dualistic vision has recently been questioned by evidence suggesting that an individualized and flexible approach may be more appropriate. In fact, tailored and cleverly planned changes between different RRT modalities, according to the patient’s needs and characteristics, are often needed in order to achieve the best results. While home HD is still under scrutiny in this particular setting, current data seems to favor the use of PD over in-center HD in patients awaiting a KT. In this specific population, the demonstrated advantages of PD are superior quality of life, longer preservation of residual renal function, lower incidence of delayed graft function, better recipient survival, and reduced cost.

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.

ABO Blood Incompatibility Positively Affects Early Graft Function: Single-Center Retrospective Cohort Study

BACKGROUND

We investigated the association between ABO-incompatible (ABO-I) kidney transplantation and early graft function.

METHODS

We retrospectively analyzed 95 patients who underwent living donor kidney transplantation between May 2009 and July 2019. It included 61 ABO-compatible (ABO-C) and 34 ABO-I transplantations. We extracted data on immunologic profile, sex, age, cold ischemic time, type of immunosuppression, and graft function. Two definitions were used for slow graft function (SGF) as follows: postoperative day (POD) 3 serum creatinine level >3 mg/dL and estimated glomerular filtration rate (eGFR) <20 mL/min/1.73 m². Logistic regression analysis was performed to analyze the effect of ABO-I on the incidence of SGF.

RESULTS

The characteristics between the ABO-C and ABO-I were not different. ABO-I received rituximab and plasma exchange. Patients also received tacrolimus and mycophenolate mofetil for 2 weeks and prednisolone for 1 week before transplantation as preconditioning. Of the 95 study patients, 19 (20%) and 21 (22%) were identified with SGF according to POD 3 serum creatinine level or eGFR, respectively. Multivariable analysis revealed that ABO-I significantly reduced the incidence of SGF (odds ratio, 0.15; 95% confidence interval, 0.03-0.7; P = .02), and cold ischemic time >150 min increased the incidence of SGF (odds ratio, 6.5; 95% confidence interval, 1.7-25; P = .006). Similar results were identified in POD 3 eGFR. Inferior graft function in patients with SGF was identified up to 6 months after transplantation.

CONCLUSION

ABO-I reduces the incidence of SGF, which is associated with an inferior graft function up to 6 months.

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.

Association of Slow Graft Function with Long-Term Outcomes in Kidney Transplant Recipients

Background

Whether slow graft function (SGF) represents an intermediate phenotype between immediate graft function (IGF) and delayed graft function (DGF) in kidney transplant recipients is unknown.

Material/Methods

In a retrospective cohort analysis of 1,222 kidney transplant recipients, we classified patients as having IGF, SGF, and DGF using two different schemas. SGF was defined as serum creatinine (Cr) ≥3.0 mg/dL by postoperative day 5 in Schema 1, and in Schema 2, SGF was defined as Cr >1.5 mg/dL plus a creatinine reduction ratio <20% between postoperative days 1 and 3. A complementary log-log model was used to examine the association of graft function with graft survival and patient survival.

Results

Mean age of study patients was 51.5±13.3 years, 59.9% were male, and 66.7% were white. In Schema 1, SGF and DGF were associated with comparable increases in risk of graft failure compared to IGF (hazard ratio (HR) 1.46, 95% confidence intervals (CI) 1.02–2.10 for SGF and HR 1.56, CI 1.11–2.22 for IGF); estimates were similar for Schema 2 (HR 1.52, CI 1.05–2.20 for SGF and HR 1.54, CI 1.10–2.17 for IGF). However, for mortality, outcomes for SGF were similarly to IGF, both SGF and IGF were associated with lower risk relative to DGF (HR 0.54, CI 0.36–0.80 for SGF in Schema 1; HR 0.58, CI 0.39–0.85 for SGF in Schema 2).

Conclusions

These findings suggest that SGF may be a marker for graft failure but not for mortality, and SGF may therefore represent a phenotype separate from IGF and DGF.

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.

Outcomes of standard dose EC-MPS with low exposure to CsA in DCD renal transplantation recipients with DGF

AIMS

The lower limit of exposure to cyclosporine A (CsA) has not yet been established in donation after cardiac death (DCD) renal transplantation recipients with delayed graft function (DGF) receiving enteric-coated mycophenolate sodium (EC-MPS) therapy. Stable and adequate mycophenolic acid (MPA) dosing may facilitate lower CsA exposure after DCD renal transplantation in recipients with DGF without compromising safety.

METHODS

A 12-month, single-centre open-label prospective trial was performed in our centre. According to their DGF risk index using the previous DGF prediction models, we divided up the patients on oral CsA into either a DGF group (n = 26) and no DGF group (n = 48). All of the patients initially received the standard EC-MPS dosing (1440 mg/day). The initial dose of CsA in the low risk of DGF group was 4.5 mg/kg/day and in the high risk of DGF group was 2.5 mg/kg/day. Efficacy parameters, safety and tolerability were assessed over a 12-month study period.

RESULTS

The incidence of DGF was 18.5% in the 162 DCD recipients. Between the DGF group and the no DGF group, the 1-year patient survival and graft survival were not significantly different. The incidence of BPAR was higher in the DGF group (26.9% vs. 8.3%, p = 0.032). Most patients in the DGF group had recovery of renal function after 1 month. The adverse events between the two groups were not significantly different. The daily EC-MPS doses of the DGF group were significantly higher than the no DGF group before the 6-month follow-up period. There were no significant differences between the two groups regarding the mean AUC levels during the follow-up period.

CONCLUSIONS

These results show that low expose CsA with standard dosing of EC-MPS and thymoglobulin was efficacious, safe and well-tolerated in DCD renal transplant recipients with DGF in China. Furthermore, stable and adequate MPA exposure helped to reduce the dose of and exposure to CsA. Thus, this may lead to less-induced nephrotoxicity and better renal function recovery.

Prolonged Delayed Graft Function Is Associated with Inferior Patient and Kidney Allograft Survivals

It is unclear if there is an association between the duration of delayed graft function (DGF) and kidney transplant (KT) outcomes. This study investigated the impact of prolonged DGF on patient and graft survivals, and renal function one year after KT. This single center retrospective analysis included all deceased donor KT performed between Jan/1998 and Dec/2008 (n = 1412). Patients were grouped in quartiles according to duration of DGF (1-5, 6-10, 11-15, and >15 days, designated as prolonged DGF). The overall incidence of DGF was 54.2%. Prolonged DGF was associated with retransplantation (OR 2.110, CI95% 1.064-4.184,p = 0.033) and more than 3 HLA mismatches (OR 1.819, CI95% 1.117-2.962,p = 0.016). The incidence of acute rejection was higher in patients with DGF compared with those without DGF (36.2% vs. 12.2%, p<0.001). Compared to patients without DGF, DGF(1-5), DGF(6-10), and DGF(11-15), patients with prolonged DGF showed inferior one year patient survival (95.2% vs. 95.4% vs. 95.5% vs. 93.4% vs. 88.86%, p = 0.003), graft survival (91% vs. 91.4% vs. 92% vs. 88.7% vs. 70.5%, p<0.001), death-censored graft survival (95.7% vs. 95.4% vs. 96.4% vs. 94% vs. 79.3%, p<0.001), and creatinine clearance (58.0±24.6 vs. 55.8±22.2 vs. 53.8±24.1 vs. 53.0±27.2 vs. 36.8±27.0 mL/min, p<0.001), respectively. Multivariable analysis showed that prolonged DGF was an independent risk factor for graft loss (OR 3.876, CI95% 2.270-6.618, p<0.001), death censored graft loss (OR 4.103, CI95% 2.055-8.193, p<0.001), and death (OR 3.065, CI95% 1.536-6.117, p = 0.001). Prolonged DGF, determined by retransplantation and higher HLA mismatches, was associated with inferior renal function, and patient and graft survivals at one year.

The effect of delayed graft function on graft and patient survival in kidney transplantation: an approach using competing events analysis

OBJECTIVE

In kidney transplantation, the impact of delayed graft function (DGF) on long-term graft and patient survival is controversial. We examined the impact of DGF on graft and recipient survival by accounting for the possibility that death with graft function may act as a competing risk for allograft failure.

STUDY DESIGN AND SETTING

We used data from 1281 adult primary deceased-donor kidney recipients whose allografts functioned at least 1 year.

RESULTS

The probability of graft loss occurrence is overestimated using the complement of Kaplan-Meier estimates (1-KM). Both the cause-specific Cox proportional hazard regression model (standard Cox) and the subdistribution hazard regression model proposed by Fine and Gray showed that DGF was associated with shorter time to graft failure (csHR = 2.0, P = 0.002; sHR = 1.57, P = 0.009), independent of acute rejection (AR) and after adjusting for traditional factors associated with graft failure. Regarding patient survival, DGF was a predictor of patient death using the cause-specific Cox model (csHR = 1.57, P = 0.029) but not using the subdistribution model.

CONCLUSIONS

The probability of graft loss from competing end points should not be reported with the 1-KM. Application of a regression model for subdistribution hazard showed that, independent of AR, DGF has a detrimental effect on long-term graft survival, but not on patient survival.

Delayed graft function: risk factors and the effects of early function and graft survival

INTRODUCTION

Delayed graft function (DGF), a well-known immediate postoperative complication is defined as the need for dialysis during the first week after deceased donor kidney transplantation. It affects 25% to 50% of recipients. In this study we identified risk factors for DGF and its impact on patient and graft survivals.

METHODS

We retrospectively analyzed medical records from renal transplant recipients aged above 18 years who received a deceased donor kidney graft between November 2008 and December 2011, excluding kidney losses during the first week.

RESULTS

Among 137 transplantations, 64 (46.5%) displayed DGF. Multivariate analysis showed secondary renal disease (OR 3.7, CI 1.36-10.30; P = .011), HLA mismatches > 3 (OR 4.4, CI 1.53-12.51; P = .006) and donor urine output ≤ 3000 ml/24h (OR 25.8, CI 3.60-185.70; P = .001) to be significant risk factors for DGF. The hospitalization time was longer in the DGF group (38,2 ± 20,75 vs. 25,6 ± 8,18; P < .001). At 1 month, DGF group showed worse graft function based upon serum creatinine: 207.7 ± 148.52 vs 118.1 ± 36.63 μmol/L (P < .001). At 1 year follow-up, incidence of biopsy-proven acute renal rejection episodes was higher in the DGF (28; 51,9%) vs. the non-DGF group (18; 33,3%; P = .05). The 1-year recipient survival in DGF and no DGF groups were 90% vs 97% respectively (P = .124). With 1-year death censored graft survivals of 92% vs 100% respectively (P = .062).

CONCLUSION

Secondary renal disease, HLA mismatches and lower donor urinary output were associated with a greater incidence of DGF, leading to prolonged hospitalizations and an increased risk for an acute rejection episode.

Is delayed graft function causally associated with long-term outcomes after kidney transplantation? Instrumental variable analysis

BACKGROUND

Although some studies have found an association between delayed graft function (DGF) after kidney transplantation and worse long-term outcomes, a causal relationship remains controversial. We investigated this relationship using an instrumental variables model (IVM), a quasi-randomization technique for drawing causal inferences.

METHODS

We identified 80,690 adult, deceased-donor, kidney-only transplant recipients from the Scientific Registry of Transplant Recipients between 1997 and 2010. We used cold ischemia time (CIT) as an instrument to test the hypothesis that DGF causes death-censored graft failure and mortality at 1 and 5 years after transplantation, controlling for an array of characteristics known to affect patient and graft survival. We compared our IVM results with a multivariable linear probability model.

RESULTS

DGF occurred in 27% of our sample. Graft failure rates at 1 and 5 years were 6% and 22%, respectively, and 1-year and 5-year mortality rates were 5% and 20%, respectively. In the linear probability model, DGF was associated with increased risk of both graft failure and mortality at 1 and 5 years (P<0.001). In the IVM, we found evidence suggesting a causal relationship between DGF and death-censored graft failure at both 1 year (13.5% increase; P<0.001) and 5 years (16.2% increase; P<0.001) and between DGF and mortality at both 1 year (7.1% increase; P<0.001) and 5 years (11.0% increase; P<0.01). Results were robust to exclusion of lower quality as well as pumped kidneys and use of a creatinine-based definition for DGF.

CONCLUSION

Instrumental variables analysis supports a causal relationship between DGF and both graft failure and mortality.

Changes in serum and renal vitamin E levels in deoxycorticosterone acetate-salt hypertensive rats

BACKGROUND

Hypertension is an important risk factor for the progression of chronic renal disease, which may result in the development of end-stage renal disease. Since reactive oxygen species are implicated in the induction of hypertension, antioxidants have been used to reduce blood pressure and renal impairment in animal models and in human hypertension. However, the available data are not conclusive.

METHODS

To investigate oxidative stress in hypertension, we evaluated renal and serum vitamin E levels as the most effective antioxidant to reduce lipid peroxidation by high-performance liquid chromatography among rats subjected to deoxycorticosterone acetate (DOCA)-salt treatment for 4 weeks. Renal levels of malondialdehyde (MDA) as a marker of cell lipid peroxidation were also assayed in treated rats. Systolic blood pressure (SBP) was measured in conscious rats by the tail-cuff method using a PowerLab/4sp data acquisition system.

RESULTS

SBP increased significantly in DOCA-salt-treated rats compared to the sham group after 4 weeks of treatment. Serum vitamin E levels were significantly lower and renal MDA concentrations significantly higher in treated compared to sham rats. However, renal vitamin E levels were also significantly higher among treated compared to sham rats.

DISCUSSION

Decreased plasma vitamin E levels and increased renal MDA levels show systemic and local oxidative stress in DOCA-salt-treated rats. However, the higher renal vitamin E level suggested a local compensatory mechanism. Vitamin E administration might be appropriate, as significant decreases in vitamin E levels were observed in the serum of DOCA-salt-treated rats.

IL-18 and urinary NGAL predict dialysis and graft recovery after kidney transplantation

Current methods for predicting graft recovery after kidney transplantation are not reliable. We performed a prospective, multicenter, observational cohort study of deceased-donor kidney transplant patients to evaluate urinary neutrophil gelatinase-associated lipocalin (NGAL), IL-18, and kidney injury molecule-1 (KIM-1) as biomarkers for predicting dialysis within 1 wk of transplant and subsequent graft recovery. We collected serial urine samples for 3 d after transplant and analyzed levels of these putative biomarkers. We classified graft recovery as delayed graft function (DGF), slow graft function (SGF), or immediate graft function (IGF). Of the 91 patients in the cohort, 34 had DGF, 33 had SGF, and 24 had IGF. Median NGAL and IL-18 levels, but not KIM-1 levels, were statistically different among these three groups at all time points. ROC curve analysis suggested that the abilities of NGAL or IL-18 to predict dialysis within 1 wk were moderately accurate when measured on the first postoperative day, whereas the fall in serum creatinine (Scr) was not predictive. In multivariate analysis, elevated levels of NGAL or IL-18 predicted the need for dialysis after adjusting for recipient and donor age, cold ischemia time, urine output, and Scr. NGAL and IL-18 quantiles also predicted graft recovery up to 3 mo later. In summary, urinary NGAL and IL-18 are early, noninvasive, accurate predictors of both the need for dialysis within the first week of kidney transplantation and 3-mo recovery of graft function.

Association between delayed graft function and allograft and patient survival: a systematic review and meta-analysis

BACKGROUND

Delayed graft function (DGF) is a common complication of renal transplantation. The short-term consequences of DGF are well known, but the long-term relationship between DGF and patient and graft survival is controversial in the published literature. We conducted a systematic review and meta-analysis to precisely estimate these relationships.

METHODS

We performed a literature search for original studies published through March 2007 pertaining to long-term (>6 months) outcomes of DGF. The primary outcome was graft survival. Secondary outcomes were patient survival, acute rejection and kidney function.

RESULTS

When compared to patients without DGF, patients with DGF had a 41% increased risk of graft loss (RR 1.41, 95% CI 1.27-1.56) at 3.2 years of follow-up. There was no significant relationship between DGF and patient survival at 5 years (RR 1.14, 95% CI 0.94-1.39). The mean creatinine in the non-DGF group was 1.6 mg/dl. Patients with DGF had a higher mean serum creatinine (0.66 mg/dl, 95% CI 0.57-0.74) compared to patients without DGF at 3.5 years of follow-up. DGF was associated with a 38% relative increase in the risk of acute rejection (RR 1.38, 95% CI 1.29-1.47).

CONCLUSION

The results of this meta-analysis emphasize and quantify the long-term detrimental association between DGF and important graft outcomes like graft survival, acute rejection and renal function. Efforts to prevent and treat DGF should be aggressively investigated in order to improve graft survival given the deficit in the number of kidney donors.

Long-term renal outcomes after delayed graft function

Delayed graft function (DGF) describes dysfunction of the kidney allograft immediately after transplantation and is the most common complication in the immediate posttransplantation period. Although a standardized definition for DGF is lacking, it is most commonly defined as the need for dialysis within the first week after transplant. DGF is caused by a variety of factors related to the donor and recipient as well as organ procurement techniques. The occurrence of DGF affects both allograft and patient outcomes. In addition to prolonging hospital stay and increasing the costs associated with transplantation, DGF is associated with an increased incidence of acute rejection after transplantation and is associated with poorer long-term graft outcomes. Both immunologic and nonimmunologic mechanisms contribute to DGF. The risk factors for DGF that have been identified are reviewed as well as the impact of DGF on long-term outcomes.

Marked variation in the definition and diagnosis of delayed graft function: a systematic review

BACKGROUND

The term delayed graft function (DGF) is commonly used to describe the need for dialysis after receiving a kidney transplant. DGF increases morbidity after transplantation, prolongs hospitalization and may lead to premature graft failure. Various definitions of DGF are used in the literature without a uniformly accepted technique to identify DGF.

METHODS

We performed a systematic review of the literature to identify all of the different definitions and diagnostic techniques to identify DGF.

RESULTS

We identified 18 unique definitions for DGF and 10 diagnostic techniques to identify DGF.

CONCLUSIONS

The utilization of heterogeneous clinical criteria to define DGF has certain limitations. It will lead to delayed and sometimes inaccurate diagnosis of DGF. Hence a diagnostic test that identifies DGF reliably and early is necessary. Heterogeneity, in the definitions used for DGF, hinders the evolution of a diagnostic technique to identify DGF, which requires a gold standard definition. We are in need of a new definition that is uniformly accepted across the kidney transplant community. The new definition will be helpful in promoting better communication among transplant professionals and aids in comparing clinical studies of diagnostic techniques to identify DGF and thus may facilitate clinical trials of interventions for the treatment of DGF.

Outcome of nonheart-beating donor kidneys with prolonged delayed graft function after transplantation

Nonheart-beating donor (NHBD) kidneys are frequently associated with delayed graft function (DGF), with a deleterious effect on kidney function and allograft survival. The influence and the duration of DGF on the outcome of NHBD kidneys are assessed. All recipients of an NHBD kidney in the period 1993-2003 were reviewed. Excluded from analysis were patients with primary nonfunction (PNF). One hundred and five patients with a functioning NHBD graft were reviewed: 23 (22%) had immediate function (group 1), 40 (38%) had DGF < or = 2 weeks (group 2), 31 (30%) had DGF 15 days to 4 weeks (group 3) and 11 (10%) had DGF for > 4 weeks (group 4). Creatinine clearance at 3 months was higher in groups 1 and 2 versus group 4 (p = 0.015 and p = 0.006, respectively) and was higher in group 2 versus group 4, at 1 year (p = 0.01). Graft survival was 95%, 98%, 97% and 89%, respectively, at 1 year and 95%, 85%, 77% and 89%, respectively, at 5 years, which was not significantly different. The duration of DGF in NHB kidneys has a negative effect on creatinine clearance, but no effect on graft survival.

Delayed renal graft function: the influence of immunosuppression

INTRODUCTION

We evaluated the influence of different immunosuppressive regimens on delayed renal graft function and progression of renal function in the first year after transplantation.

PATIENTS AND METHODS

Patients were divided into four groups according to the immunosuppressive regimen received: (1) rapamycin (Rap) + mycophenolate mofetil (MMF) + methylprednisolone (MP) + daclizumab (Dmab); (n = 44); (2) tacrolimus (Tac) + MMF + MP + Dmab (n = 39); (3) cyclosporine (CsA) + MMF + MP + basiliximab (Bmab); (n = 30); (4) antithymocyte globulin (ATG) + MMF + MP and CsA after ATG withdrawal (n = 40). Data were analyzed using ANOVA and linear regression. Delayed graft function was defined as the need for hemodialysis posttransplantation.

RESULTS

There were no statistically significant differences between the four groups in terms of gender, time on dialysis before transplantation, histocompatibility, donor age, and cold ischemia time. However, age (49.8, 50.4, 49.8, and 43.5 years, P < .05), panel reactive antibodies (22%, 39%, 27%, 34%, P < .05) and time of delayed graft function (12, 7, 3, 6 days, P < .05) were significantly different between the four groups. The time of delayed graft function depended on the immunosuppressive regimen, as well as donor and recipient age (P < .05). The creatinine clearance demonstrated a statistically significant difference between the four groups in the first month after transplantation (45, 46, 61, 53 mL/min, P < .05), though no further difference was observed at the month 12th.

CONCLUSIONS

The type of immunosuppressive therapy seems to substantially influence the time of recovery from delayed renal graft function, even though it does not seem to affect future graft function. Especially Rap, probably due to its potent antiproliferative effects, seems to prolong the length of graft recovery after renal transplantation.

Comparison of Outcomes after Delayed Graft Function: Sirolimus-Based Versus Other Calcineurin-Inhibitor Sparing Induction Immunosuppression Regimens

BACKGROUND

Sirolimus (SRL) may increase the incidence of or prolong delayed graft function (DGF) after cadaveric renal transplantation. This study compares transplant outcomes of SRL-based induction immunosuppression (IS) with other calcineurin-inhibitor (CNI) sparing regimens in the DGF setting.

METHODS

Adult cadaveric renal-transplant recipients who received transplants between January 1, 1997 and June 30, 2001 and experienced DGF (n=132) were divided into three groups by induction IS: A, depleting antibody (n=41); B, SRL (n=49); and C, neither (n=42). All recipients also received steroids and mycophenolate mofetil with delayed initiation of CNIs when good renal function returned. Patient survival, graft survival, and time to rejection within 1 year of transplantation were assessed by Kaplan-Meier analysis. One-year graft function was compared using Kruskal-Wallis and Fisher's exact tests.

RESULTS

The SRL group had longer DGF duration (P=0.01). The three groups had comparable patient (P=0.27) and graft survival (P=0.69), but the depleting antibody group experienced less rejection (P=0.004). There were no clinically significant differences in 1-year graft function.

CONCLUSIONS

In our analysis of a large and modern cohort of adult cadaveric transplant recipients with DGF, induction immunosuppression with a depleting antibody preparation reduced rejection, whereas SRL prolonged DGF duration. All three CNI-sparing induction IS regimens resulted in comparable patient survival, graft survival, and graft function.

Comparative study on two kidney graft rinsing and preservation solutions in terms of the post-transplantation risk of delayed graft function and cost

OBJECTIVE

To determine whether Belzer solution (Viaspan, Bristol-Myers Squibb, Brussels, Belgium), which is more expensive than Eurocollins solution, was better at preventing delayed graft function (DGF) and whether it was cost-effective as it could potentially reduce post-transplantation complications.

METHOD

The risk of occurrence of complications associated with the use of these two rinsing and preserving solutions was estimated from a survey of 106 patients undergoing renal transplantation between 1 January 1993 and 31 March 1998. Both efficacy and adverse outcomes were recorded along with the costs directly associated with the transplantation procedure in the hospital setting: hospitalization, rinsing and preserving solutions, medical and technical interventions and diagnostic tests.

RESULTS

For the 45 kidney grafts rinsed and preserved with Eurocollins (strategy S1: n1 = 45) the cost/graft was estimated at 40 euros. With Viaspan (strategy S2: n2 = 61) the corresponding cost/graft was 424 euros. Logistic regression analysis showed that Viaspan was better than Eurocollins solution (ebeta = 0.437; P = 0.05) in preventing DGF. Overall, S2 was less expensive than S1, from the hospital's perspective. The mean difference per patient was 278 euros, which amounts to a saving of 2% of the total cost per renal transplantation. For rinsing and preserving kidney grafts Belzer solution is therefore preferable to Eurocollins solution.

Sirolimus prolongs recovery from delayed graft function after cadaveric renal transplantation

Sirolimus, lacking known nephrotoxicity, appeared to be an ideal immunosuppressive agent in the setting of delayed graft function (DGF) after renal transplantation. Coincident with our use of sirolimus however, we noticed prolongation of DGF. To investigate possible causes of prolonged DGF, extensive donor, recipient, transplant, and post-transplant data were collected on 132 consecutive cases of DGF at the University of California, San Francisco between 1/1/97 and 6/30/01. Cox proportional hazards analysis of time to graft function was used in univariate and multivariate models to identify factors that prolong DGF. Sirolimus had a large and highly significant effect on time to graft function (hazard ratio 0.48, p = 0.0007). The hazard ratio indicates that a recipient on sirolimus is half as likely to resolve DGF or twice as likely to remain on dialysis as a recipient without sirolimus. Two other factors had less potent but still significant association with DGF duration: recipient sensitization (hazard ratio 0.66, p = 0.037), and Novartis score (hazard ratio 0.93 per 1.0 increase; p = 0.034). Sirolimus retained its profound negative association with time to graft function in all multivariate models. Because sirolimus appears to prolong DGF, it may not be the optimal immunosuppressive choice in the DGF setting.

Long-term renal function in kidneys from non-heart-beating donors: A single-center experience

BACKGROUND

Cadaveric kidneys from brain-stem-dead donors continue to be limited because the number of donors has reached a plateau. Wide recruitment of non-heart-beating donors (NHBD) could significantly increase the donor pool. NHBD renal transplants are underused because of the concern of poor quality graft function from such donors. In response to this perception, we reviewed 46 NHBD renal transplants performed in our center since 1998.

METHODS

All NHBD kidneys were machine-perfused using the Newcastle continuous-hypothermic pulsatile preservation system before transplantation. A control heart-beating-donor (HBD) group was taken as the next consecutive HBD renal transplant to the NHBD transplant. The outcome and quality of function of the groups of renal transplants were analyzed for short-term and long-term performance.

RESULTS

The renal transplant patients were matched for donor and recipient factors. Survival rates for allografts and patients were similar for 1 to 3 years. There was an increased incidence of delayed graft function in the NHBD renal transplants in the perioperative period. The creatinine clearance was 22.8+/-2.3 mL/minute for NHBD patients and 44.4+/-2.9 mL/minute for HBD patients at the time of discharge from hospital. This difference equalized after 3 months and the creatinine clearance for NHBD was 44.2+/-2.4 mL/minute and for HBD 49.2+/-3.4 mL/minute.

CONCLUSIONS

Our results for NHBD renal transplants confirm that such grafts suffer primary warm ischemic injury, shown by the increased incidence of acute tubular necrosis and consequent delayed graft function. This produced poor renal function at the time of hospital discharge. After 3 months, the renal function of NHBD cases improved to the level seen in HBD patients.

Regulation of renal tubular cell apoptosis and proliferation after ischemic injury to a solitary kidney

The time course and regulation of apoptosis and cellular regeneration after 30 minutes of acute ischemic injury to a single kidney was elucidated in rats at five time points over 20 weeks. The fraction of apoptotic cells was most prominent at 1 day after the insult in the distal tubule (8% +/- 4% vs 0% +/- 0%, acute renal failure [ARF] vs sham, respectively) and was still elevated at 7 days (2% +/- 2% vs 0% +/- 0%). At that time, the whole kidney mRNA expression of the apoptosis inhibitory genes bcl-xL and bcl-2, as well as that of the apoptosis promotor bax, was significantly reduced. Immunohistochemistry of kidney specimen showed suppression of bcl-2 in the distal tubule but up-regulation in the proximal tubule, whereas bax protein was more strongly expressed in the distal tubule. Cellular proliferation started at day 1 and continued over the following 20 weeks, leading to severe tubular dilation and kidney failure. These data indicate that differential regulation of bcl-2 family members contributes to the early apoptotic clearance of lethally injured tubular epithelial cells after ischemic injury to a solitary kidney.

Apoptosis of tubular epithelial cells in donor kidney biopsies predicts early renal allograft function

Acute renal failure (ARF) is a serious complication in the early postoperative period after kidney transplantation. In an effort to identify subjects at risk, several donor-, recipient-, and procedure-related factors have been studied. Because no morphologic parameter predictive of delayed graft function has been identified to date, this study was conducted to determine whether the number of apoptotic cells in donor biopsies obtained before engraftment is predictive of the development of posttransplant ARF. Donor biopsies of patients with "biopsy-proven" acute tubular damage but no signs of rejection (n = 23) showed significantly higher counts of apoptotic tubular epithelial cells when compared to patients with immediate transplant function (n = 44) or early rejection (n = 22). In all groups, a significantly higher percentage of apoptotic cells was found in the distal compared to the proximal tubule. The expression of bcl-2 and proliferating cell nuclear antigen was not different among the groups. Late allograft function was not affected by early ARF as serum creatinine values were similar in all three groups after 6 mo. These data suggest that the number of apoptotic renal tubular epithelial cells in donor biopsies before engraftment is predictive of the early postoperative course in patients undergoing kidney transplantation.

Predictors of renal transplant histology at three months

BACKGROUND

The quality of a damaged kidney, the complexity of the surgery, and the events in the first weeks after transplantation, such as delayed graft function (DGF) and acute rejection, may influence its histological appearance and long-term survival. The aim of this study was to evaluate the importance of these factors in predicting renal allograft histology at 3 months.

METHODS

Prospective, protocol kidney biopsy specimens (n=112), obtained 3 months after transplantation, were scored for chronic damage by the Banff schema and evaluated by multivariate analysis against donor factors, implantation histology, prior recipient sensitization, ischemia, perioperative factors, and subsequent clinical events, such as DGF and acute rejection.

RESULTS

Adequate samples were obtained in 102 of 112 biopsies and classified as chronic Banff grade 0 (n=22), grade I (n=56), grade II (n=23), or grade III (n=1). Acute Banff scores were minimal. DGF occurred in 49% and was the strongest predictor of tubulointerstitial damage at 3 months. DGF correlated with acute tubular necrosis on the implantation biopsy specimen and with the number of acute rejection episodes; DGF also correlated with the Banff grades of chronic glomerulitis, chronic interstitial fibrosis, and tubular atrophy scores (P<0.05-0.001) in the 3-month biopsy specimen. By multivariate analysis, chronic tubular atrophy was independently predicted by the presence of vascular disease in the donor biopsy specimen, DGF, and vascular rejection occurring within the first 3 months (P<0.05-0.001). Chronic interstitial fibrosis was unrelated to fibrosis in the donor biopsy specimen but was independently predicted by DGF, donor age, and vascular rejection (P<0.05-0.001). Vascular disease in the donor biopsy specimen correlated with chronic intimal thickening (r=0.36, P<0.01) and arteriolar hyalinosis score (r=0.54, P<0.001) on the 3-month biopsy specimen. Banff chronic intimal vascular thickening was independently predicted by donor biopsy specimen vascular grade, prior vascular rejection episodes, and renal cold ischemia time (P<0.05-0.01). There were no correlates with the mean cyclosporine (CsA) dose, blood levels, diagnosis of CsA toxicity, or cellular rejection within the first 3 months.

CONCLUSIONS

This study has demonstrated that the quality of the donor organ at implantation was strongly predictive of subsequent renal histology in grafts functioning at 3 months. Vascular rejection and DGF had a significant long-term effect on graft damage, but cellular rejection and simple measures of CsA exposure did not.

Early proteinuria in renal transplant recipients treated with cyclosporin

PURPOSE

To establish the risk profile for the development of proteinuria in the first months after renal transplantation and to disclose the prognostic significance of this finding.

DESIGN

We conducted an observational historic cohort study.

SETTING

We conducted the study in a tertiary care hospital renal transplantation unit covering a potential population of approximately 2 million. We made extensive use of suboptimal donors.

POPULATION

In our unit, 560 cadaveric renal transplants were performed between January 1988 and June 1997, under Cyclosporine immunosuppression, with a minimum follow up of 1 year.

METHOD

The risk profile analysis explored early clinical factors reported to be related to the late course of renal transplantation. The study of the prognostic significance of proteinuria included survival analysis and correlation with late markers of graft dysfunction, taking into consideration the intensity and persistence of early proteinuria. A multivariate approach was used in all cases.

RESULTS

Early proteinuria was strongly associated with delayed graft function (odds ratio [OR] 1.03/day of dialysis), acute rejection (OR 1.7 for steroid-sensitive and 6.2 for steroid-resistant rejection), renal transplant to a hypersensitized recipient (OR 2.5), and pediatric (<5 years)(OR 4.1) or older (>60 years)(OR 3.0) donors. The predictive model for persistency of proteinuria was very similar, whereas transient proteinuria could not be adequately modeled. Increasing intensity of proteinuria was strongly associated with poor patient and graft survival. Persistent, but not transient, proteinuria supported this relationship.

CONCLUSIONS

Proteinuria appearing early after renal transplantation is strongly associated with delayed graft function, acute rejection, and the use of pediatric or older donors. Whatever its background, proteinuria is a strong predictor of poor patient and graft survival. This effect is directly related to the intensity and persistence of the disorder.

Early graft function and patient survival following cadaveric renal transplantation

BACKGROUND

The influence of events that occur early following renal transplantation such as delayed graft function (DGF) and acute rejection on long-term graft survival has been widely reported, but its association with patient survival has received less attention.

METHODS

We studied 589 patients who received their first cadaveric transplants between 1984 and 1993, all of whom received cyclosporine-based immunosuppression and who had a median follow-up of seven years. The following factors were identified, and both univariate and multivariate analyses were used to determine their association with long-term patient and graft survival: age, sex, duration of pretransplant dialysis, primary renal disease, immediate graft function (IGF), DGF, primary nonfunction (PNF), acute rejection, and serum creatinine at 3, 6, and 12 months.

RESULTS

Patients with PNF had a poorer survival than those with DGF and IGF (P = 0.01), but there was no difference in survival between DGF and IGF (P = 0.54). Good graft function (serum creatinine of less than 200 mumol/liter) at three months was predictive of better long-term patient survival (P = 0.03). Other factors associated with poor patient outcome were older age, diabetes, adult polycystic kidney disease, male gender, and acute rejection. Cardiovascular disease was the most common cause of death (51.8%). Good graft function at three months (P < 0.001) and an absence of rejection episodes (P = 0.01) were associated with better graft survival.

CONCLUSION

Patients with poor levels of early graft function (but not DGF) and those with either acute rejection episodes or early graft loss are at an increased risk of early death. These high-risk groups should be targeted for interventional studies in an attempt to improve patient survival.

Delayed graft function: predictive factors and impact on outcome in living-related kidney transplantations

The aim of this study was to determine the incidence and possible causes of delayed graft function (DGF) and its impact on outcome in living-related kidney transplantations. We analyzed 158 consecutive living-related kidney transplant recipients. DGF is described as the failure of serum creatinine to fall below pretransplant levels within 1 week of the operation, regardless of urine output. Of the 158 patients studied, 14 (8.8%) fit this criterion. Donor and recipient factors such as age, gender, body weight, recipient/donor weight ratio, HLA match, cyclosporine level, blood group, and anastomosis time of patients with DGF were compared to those of patients without DGF. Apart from donor gender, body weight, and recipient/donor body weight ratio, these parameters were similar in the two groups. In the DGF group the majority of the donors were female (11/14), whereas this was not the case in the controls (64/144; p < 0.02). Mean donor weight in patients experiencing DGF (59.6 +/- 9.2 kg) was significantly lower than in those without DGF (67.8 +/- 10.4 kg; p < 0.05). The mean recipient/donor weight ratio for the DGF group (1.26) was significantly higher than that of the control group (1.03, p < 0.02). The 5-year graft survival rates for patients with and without DGF were 74% and 77%, respectively (NS). On the other hand, the 5-year graft survival rate for patients with DGF complicated by an acute rejection episode (n = 6, 61%) was significantly lower than that of control group patients who experienced acute rejection (n = 43, 74%; p < 0.02). These results indicate that female donor gender and higher recipient/donor weight ratio are major predictive factors in the development of DGF following living-related kidney transplantation. Although DGF alone did not affect the outcome, long-term graft survival was significantly reduced when DGF was associated with acute rejection episodes.

Renal transplantation: surgical aspects, complications and results

Despite the fact that kidney transplants have routinely been successfully performed for over 30 years there continues to be challenges for the transplant surgeon. These include a static donor pool, growing recipient list, declining number of ideal donors and greater reliance on marginal donors. Innovative methods to deal with these problems continue to be sought.

When should expanded criteria donor kidneys be used for single versus dual kidney transplants?

BACKGROUND

To increase the utilization of cadaveric donor kidneys, we have recently expanded our acceptable criteria to include aged donors (frequently with a history of hypertension), by selectively using both donor kidneys (dual transplant) into a single recipient.

METHODS

To define when these expanded criteria donor (ECD) kidneys should be used as a single versus a dual kidney transplant, we retrospectively reviewed 52 recipients of ECD kidneys that had been turned down by all other local centers between 1/1/95 and 11/15/96. Fifteen patients received dual transplants, whereas the remaining 37 received single kidneys. Of the dual kidney recipients, 14 of 15 ECD were > or = 59 years of age, 10 of 15 were hypertensive, and 9 of 15 were both. Of the single recipients, 11 of 37 ECD were > or = 59 years of age, 11 of 37 were hypertensive, and 7 of 37 were both. All patients received cyclosporine-based triple-drug therapy. We compared seven donor (D) and sixteen recipient outcome variables in single versus dual kidney transplants as subgrouped by: (1) donor admission creatinine clearance (D-AdC(Cr)) < 90 ml/min; (2) D-age > or = 59 years; and (3) cold storage (Cld Stg) < or > 24 hr.

RESULTS

In the group with D-AdC(Cr) < 90, there was a significantly higher incidence of delayed graft function (DGF) in single versus dual recipients (9 of 20 [45%] vs. 1 of 11 [9%]; P=0.04) and worse early graft function based upon mean serum creatinine at 1 and 4 weeks (5.3+/-3.3 and 2.8+/-2.0 vs. 1.7+/-0.6 and 1.4+/-0.5 mg] dl; P<0.05). In the group with D-age > or = 59, recipients of single kidneys had significantly higher mean serum creatinine at 1, 4, and 12 weeks versus recipients of dual kidneys (5.1+/-3.3, 3.4+/-2.1, 2.8+/-1.5 versus 2.8+/-2.5, 1.5+/-0.6, 1.6+/-0.5 mg/dl; P<0.05). Cld Stg time also had an impact on DGF and early outcome. Recipients of dual kidneys stored less than 24 hr had a significantly lower incidence of DGF versus single kidneys stored more than 24 hr (10% vs. 46%; P<0.05) and better early graft function based on mean serum creatinine at 1, 4, and 12 weeks (1.9+/-0.8, 1.3+/-0.4, 1.5+/-0.2 vs. 6.6+/-3.4, 3.0+/-1.6, 2.9+/-1.9 mg/dl; P<0.05). The overall 1-year patient and graft survivals were 96% and 81% vs. 93% and 87% (P=NS) in recipients of single ECD versus dual ECD kidneys.

CONCLUSIONS

In conclusion, we believe that kidneys from ECD with D-AdC(Cr) < 90 ml/min and D-age > or = 59 should be used as dual kidney transplants, keeping the Cld Stg time at < 24 hr to minimize the effect of Cld Stg on early graft function.