The recovery status from delayed graft function can predict long-term outcome after deceased donor kidney transplantation. Sci Rep. 2017;7:13725. [PMID: 29057921 PMCID: PMC5651849 DOI: 10.1038/s41598-017-14154-w]

Prediction of early recovery of graft function after living donor liver transplantation in children

For end-stage liver disease in children, living donor liver transplantation (LDLT) is often the important standard curative treatment. However, there is a lack of research on early recovery of graft function after pediatric LDLT. This is a single-center, ambispective cohort study. We collected the demographic and clinicopathological data of donors and recipients, and determined the risk factors of postoperative delayed recovery of hepatic function (DRHF) by univariate and multivariate Logistic analyses. 181 cases were included in the retrospective cohort and 50 cases in the prospective cohort. The incidence of DRHF after LDLT in children was 29.4%, and DRHF could well evaluate the early recovery of graft function after LDLT. Through Logistic analyses and AIC score, preoperative liver function of donors, ischemia duration level of the liver graft, Ln (Cr of recipients before operation) and Ln (TB of recipients on the 3rd day after operation) were predictive indicators for DRHF after LDLT in children. Using the above factors, we constructed a predictive model to evaluate the incidence of postoperative DRHF. Self-verification and prospective internal verification showed that this prediction model had good accuracy and clinical applicability. In conclusion, we pointed many risk factors for early delayed recovery of graft function after LDLT in children, and developed a visual and personalized predictive model for them, offering valuable insights for clinical management.

Predicting Long-term Outcomes in Deceased Donor Kidney Transplant Recipients Using Three Short-term Graft Characteristics

Key Points

Delayed graft function is not an ideal measure of graft function, yet is used to assess risk in kidney transplantation. We propose a model that combines it with two other measures of 90-day graft function to identify recipients at incremental risk of inferior long-term outcomes.

Background

Delayed graft function (DGF) in kidney transplant recipients is used to determine graft prognosis, make organ utilization decisions, and as an important end point in clinical trials. However, DGF is not an ideal measure of graft function. We aimed to develop and validate a model that provides incremental risk assessment for inferior patient and graft outcomes.

Methods

We included adult kidney-only deceased donor transplant recipients from 1996 to 2016. In addition to DGF, two short-term measures were used to assess risk: renal function recovery <100% (attaining half the donor's eGFR) and recipient's 90-day eGFR <30. Recipients were at no, low, moderate, or high risk if they met zero, one, two, or all criteria, respectively. Cox proportional hazard models were used to assess the independent relationship between exposure and death-censored graft failure (DCGF) and mortality.

Results

Of the 792 eligible recipients, 24.5% experienced DGF, 40.5% had renal function recovery <100%, and 6.9% had eGFR <30. Over a median follow-up of 7.3 years, the rate of DCGF was 18.7% and mortality was 25.1%. When compared with recipients at no risk, those at low, moderate, and high risk were noted to have an increase in risk of DCGF (adjusted hazard ratio [aHR], 1.53; 95% confidence interval [CI], 1.03 to 2.27; aHR, 2.84; 95% CI, 1.68 to 4.79; aHR, 15.46; 95% CI, 8.04 to 29.71) and mortality (aHR, 1.16; 95% CI, 0.84 to 1.58; aHR, 1.85; 95% CI, 1.13 to 3.07; aHR, 2.66; 95% CI, 1.19 to 5.97). When using a hierarchical approach, each additional exposure predicted the risk of DCGF better than DGF alone and 100 random bootstrap replications supported the internal validity of the risk model. In an external validation cohort deemed to be at lower risk of DCGF, similar nonsignificant trends were noted.

Conclusion

We propose a risk model that provides an incremental assessment of recipients at higher risk of adverse long-term outcomes than DGF alone. This can help advance the field of risk assessment in transplantation and inform therapeutic decision making in patients at the highest spectrum of inferior outcomes.

Effects of Delayed Graft Function on Transplant Outcomes: A Meta-analysis

Delayed graft function (DGF) is a frequent complication of kidney transplantation, but its impact on long- and short-term transplant outcomes is unclear. We conducted a systematic literature search for studies published from 2007 to 2020 investigating the association between DGF and posttransplant outcomes. Forest plots stratified between center studies and registry studies were created with pooled odds ratios. Posttransplant outcomes including graft failure, acute rejection, patient mortality, and kidney function were analyzed. Of the 3422 articles reviewed, 38 papers were included in this meta-analysis. In single-center studies, patients who experienced DGF had increased graft failure (odds ratio [OR] 3.38; 95% confidence interval [CI], 1.85-6.17; P < 0.01), acute allograft rejection (OR 1.84; 95% CI, 1.30-2.61; P < 0.01), and mortality (OR 2.32; 95% CI, 1.53-3.50; P < 0.01) at 1-y posttransplant. Registry studies showed increased graft failure (OR 3.66; 95% CI, 3.04-4.40; P < 0.01) and acute rejection (OR 3.24; 95% CI, 1.88-5.59; P < 0.01) but not mortality (OR 2.27; 95% CI, 0.97-5.34; P = 0.06) at 1-y posttransplant. DGF was associated with increased odds of graft failure, acute rejection, and mortality. These results in this meta-analysis could help inform the selection process, treatment, and monitoring of transplanted kidneys at high risk of DGF.

Clinical indicators of slow graft function and outcome after pediatric kidney transplantation

BACKGROUND

Lesser degrees of perioperative ischemia-reperfusion injury that does not require dialysis may nonetheless influence allograft outcomes, necessitating evaluation of suitable surrogate indicators of perioperative allograft injury.

METHODS

This retrospective analysis of pediatric kidney transplants evaluated two indicators representing pace and completeness of recovery, for association with 12-month estimated glomerular filtration rate (eGFR) and first-year rate of eGFR decline: time to creatinine nadir (TTN) and ratio of recipient/donor unadjusted GFR (uGFR_R/D ) at 1-month post-transplant. Donor, recipient, and perioperative risk factors were tested further for association with these 2 indicators.

RESULTS

179 patients (190 transplants) aged 13 (IQR 7-17) years and 56% male were included. Twelve-month eGFR was strongly associated with unadjusted GFR at 1 month (uGFR_1M , p < .001) and uGFR_R/D (p = .003), but not with TTN. None of the indicators was associated with the rate of subsequent eGFR decline after 1-month post-transplant. As a potential surrogate indicator, uGFR_1M is effectively modeled by TTN and uGFR_R/D (adjusted R²  = 0.57) and is associated with 12-month eGFR (β = 0.81 ± 0.08; p < .001). Clinical factors associated with uGFR_R/D included donor uGFR (p < .001), BSA (p = .026), age (p = .074), and recipient BSA (p < .001). Factors associated with pace of recovery (TTN) included donor uGFR (p = .018), type (p = .019), and recipient BSA (p = .022).

CONCLUSIONS

The uGFR_R/D ratio, but not TTN, is a useful indicator of perioperative allograft damage that is associated with one-year functional outcome; and uGFR_1M is a potential early surrogate outcome. Donor, recipient, and perioperative factors that are associated with slow allograft function are identified.

Bryostatin-1 Attenuates Ischemia-Elicited Neutrophil Transmigration and Ameliorates Graft Injury after Kidney Transplantation

Ischemia reperfusion injury (IRI) is a form of sterile inflammation whose severity determines short- and long-term graft fates in kidney transplantation. Neutrophils are now recognized as a key cell type mediating early graft injury, which activates further innate immune responses and intensifies acquired immunity and alloimmunity. Since the macrolide Bryostatin-1 has been shown to block neutrophil transmigration, we aimed to determine whether these findings could be translated to the field of kidney transplantation. To study the effects of Bryostatin-1 on ischemia-elicited neutrophil transmigration, an in vitro model of hypoxia and normoxia was equipped with human endothelial cells and neutrophils. To translate these findings, a porcine renal autotransplantation model with eight hours of reperfusion was used to study neutrophil infiltration in vivo. Graft-specific treatment using Bryostatin-1 (100 nM) was applied during static cold storage. Bryostatin-1 dose-dependently blocked neutrophil activation and transmigration over ischemically challenged endothelial cell monolayers. When applied to porcine renal autografts, Bryostatin-1 reduced neutrophil graft infiltration, attenuated histological and ultrastructural damage, and improved renal function. Our novel findings demonstrate that Bryostatin-1 is a promising pharmacological candidate for graft-specific treatment in kidney transplantation, as it provides protection by blocking neutrophil infiltration and attenuating functional graft injury.

Clinical use of controlled oxygenated rewarming of kidney grafts prior to transplantation by ex vivo machine perfusion. A pilot study

BACKGROUND

Sudden restoration of normothermic conditions upon reperfusion of cold-stored grafts has been suggested to entail a massive energy demand not yet met by the cells that still suffer from hypothermic torpor. An adapted and gentle rise of graft temperature by ex-vivo machine perfusion has, therefore, been proposed. This should now be tested in the clinical setting.

METHODS

In a first clinical series, six ECD-kidneys were subjected to controlled oxygenated rewarming (COR) during short term pre-implantation machine perfusion. Matched kidneys that were conventionally kept on ice served as controls.

RESULTS

Early allograft function after transplantation was significantly improved by COR. On post-operative day 7, clearance of creatinine was more than twofold higher after COR and fractional excretion of sodium in the normal range, while significantly elevated in control kidneys. Good correlations were seen between ulterior graft function and real-time parameters obtained during pre-transplant machine perfusion (Lactate: r²  = .9; TIMP2: r²  = .74). Conventional denominators of graft viability like kidney donor risk index KDRI were far less predictive (r²  = .26).

CONCLUSION

It is concluded that COR can be safely applied to renal grafts and appears to be a valuable tool to predict and improve early renal function after transplantation.

The value of cystatin C in predicting perioperative and long-term prognosis of renal transplantation

This study aimed to evaluate the value of cystatin C (Cys C) in predicting the perioperative and long-term prognosis of renal transplantation (RT). The clinical data of 198 RT recipients were collected. Blood samples were obtained daily until 7 d after transplantation and then discharge day to determine the serum levels of Cys C. The receiver-operating characteristic (ROC) analysis and the area under the curve (AUC) were used to determine the diagnostic accuracy of Cys C for delayed graft function (DGF). The presence of shrunken pore syndrome (SPS) with a cystatin C-based estimate of glomerular filtration rate less than 70% of a creatinine-based estimate, was also evaluated as a prognostic factor for the development of DGF. The serum Cys C levels of patients with DGF were higher than those of the non-DGF group. Cys C showed a higher AUC (0.928) in the ROC analysis than did sCr (0.862). Compared to the non-SPS group, there were more patients diagnosed with SPS in the DGF group (p < .05). The follow-up data showed that patients diagnosed with SPS had higher levels of sCr and Cys C compared to other patients, suggesting a poor long-term prognosis. Our findings suggest that Cys C is a sensitive indicator of renal function during the perioperative period. Cys C at a concentration of 4.9 mg/L had the highest sum of sensitivity and specificity for prediction of DGF, with a sensitivity of 0.889 and a specificity of 0.8. SPS is associated with the development of DGF and the poor long-term prognosis of RT.

Risk factors and outcomes for delayed kidney graft function in simultaneous heart and kidney transplant recipients: A UNOS/OPTN database analysis

There are no prior studies assessing the risk factors and outcomes for kidney delayed graft function (K-DGF) in simultaneous heart and kidney (SHK) transplant recipients. Using the OPTN/UNOS database, we sought to identify risk factors associated with the development of K-DGF in this unique population, as well as outcomes associated with K-DGF. A total of 1161 SHK transplanted between 1998 and 2018 were included in the analysis, of which 311 (27%) were in the K-DGF (+) group and 850 in the K-DGF (-) group. In the multivariable analysis, history of pretransplant dialysis (OR: 3.95; 95% CI: 2.94 to 5.29; p < .001) was significantly associated with the development of K-DGF, as was donor death from cerebrovascular accident and longer cold ischemia time of either organ. SHK recipients with K-DGF had increased mortality (HR: 1.99; 95% CI: 1.52 to 2.60; p < .001) and death censored kidney graft failure (HR: 3.51; 95% CI: 2.29 to 5.36; p < .001) in the multivariable analysis. Similar outcomes were obtained when limiting our study to 2008-2018. Similar to kidney-only recipients, K-DGF in SHK recipients is associated with worse outcomes. Careful matching of recipients and donors, as well as peri-operative management, may help reduce the risk of K-DGF and the associated detrimental effects.

Perioperative risk factors associated with delayed graft function following deceased donor kidney transplantation: A retrospective, single center study

BACKGROUND

There is an abundant need to increase the availability of deceased donor kidney transplantation (DDKT) to address the high incidence of kidney failure. Challenges exist in the utilization of higher risk donor organs into what appears to be increasingly complex recipients; thus the identification of modifiable risk factors associated with poor outcomes is paramount.

AIM

To identify risk factors associated with delayed graft function (DGF).

METHODS

Consecutive adults undergoing DDKT between January 2016 and July 2017 were identified with a study population of 294 patients. The primary outcome was the occurrence of DGF.

RESULTS

The incidence of DGF was 27%. Under logistic regression, eight independent risk factors for DGF were identified including recipient body mass index ≥ 30 kg/m², baseline mean arterial pressure < 110 mmHg, intraoperative phenylephrine administration, cold storage time ≥ 16 h, donation after cardiac death, donor history of coronary artery disease, donor terminal creatinine ≥ 1.9 mg/dL, and a hypothermic machine perfusion (HMP) pump resistance ≥ 0.23 mmHg/mL/min.

CONCLUSION

We delineate the association between DGF and recipient characteristics of pre-induction mean arterial pressure below 110 mmHg, metabolic syndrome, donor-specific risk factors, HMP pump parameters, and intraoperative use of phenylephrine.

Clinical impact of serum bilirubin levels on kidney transplant outcomes

Serum bilirubin, a potent endogenous antioxidant, has been associated with decreased risks of cardiovascular disease, diabetes, and kidney disease. However, the effects of serum bilirubin on kidney transplant outcomes remain undetermined. We analyzed 1628 patients who underwent kidney transplantations between 2003 and 2017. Patients were grouped into sex-specific quartiles according to mean serum bilirubin levels, 3–12 months post-transplantation. Median bilirubin levels were 0.66 mg/dL in males and 0.60 mg/dL in females. The intra-individual variability of serum bilirubin levels was low (9%). Serum bilirubin levels were inversely associated with graft loss, death-censored graft failure, and all-cause mortality, independent of renal function, donor status, and transplant characteristics. Multivariable analysis revealed that the lowest serum bilirubin quartile was associated with increased risk of graft loss (HR 2.64, 95% CI 1.67–4.18, P < 0.001), death-censored graft failure (HR 2.97, 95% CI 1.63–5.42, P < 0.001), and all-cause mortality (HR 2.07, 95% CI 1.01–4.22, P = 0.046). Patients with lower serum bilirubin were also at greater risk of rejection and exhibited consistently lower glomerular filtration rates than those with higher serum bilirubin. Serum bilirubin levels were significantly associated with transplantation outcomes, suggesting that bilirubin could represent a therapeutic target for improving long-term transplant outcomes.

Delayed Graft Function and Acute Rejection in Kidney Transplant Patients with Positive Panel-Reactive Antibody and Negative Donor-Specific Antibodies

Background: Delayed graft function (DGF) and acute rejection (AR) are common complications in kidney transplant patients. Objectives: The study evaluated DGF and AR in highly sensitized patients and their effects on kidney function for six months post-transplantation. Methods: We enrolled 95 patients with kidney transplants from living donors who were divided into two groups. Group 1 included 47 highly sensitized patients with panel reactive antibody (PRA) < 20.0% and negative donor-specific antigen, and group 2 included 48 patients with negative PRA. All patients were followed for the state of DGF, AR, and kidney function for six months. Results: Group 1 showed a significantly higher proportion of DGF and AR than group 2 (27.7% versus 2.1%, P < 0.001 and 14.9% versus 2.1%, P = 0.031, respectively). The rates of positive PRA in DGF and AR patients were significantly higher than those in non-DGF and non-AR patients (92.9% versus 42.0%, P < 0.001 and 87.5% versus 46.0%, P = 0.031, respectively). Transplanted kidney function was significantly worse in patients with PRA and DGF and/or AR than in patients with negative PRA and non-DGF and non-AR only in the seventh-day post-transplantation. Conclusions: Kidney transplant in highly sensitized patients with positive PRA was related to the increased ratio of DGF and AR.

Evaluation of the effect of high dose intravenous vitamin C on delayed allograft function in deceased donor kidney transplantation: a preliminary report

Background

Delayed graft function (DGF) can affect short- and long-term allograft outcomes in kidney transplant recipients. One of the pathophysiological pathways in the occurrence of DGF is ischemia-reperfusion injury (IRI). High dose intravenous vitamin C has proven efficacy in decreasing IRI consequences. Accordingly, we designed this study to assess the effect of high dose intravenous vitamin C on the incidence and duration of DGF.

Methods

This is a pilot, single-center, double-blinded, randomized, placebo-controlled trial. In the treatment group, kidney transplant recipients received vitamin C infusion at the dose of 70 mg/kg diluted in 0.45% saline, and in another study arm, only the diluent solution was administered. Data regarding allograft function and other clinical information was recorded.

Results

This preliminary study on 19 patients (9 cases in the vitamin C and 10 cases in the placebo group) showed that after administration of single, high dose vitamin C the incidence of DGF was not significantly different between the groups, but the duration of DGF was substantially shorter in the vitamin C group than the placebo group (7.33 ± 5.68 versus 19.66 ± 0.57 days; P = 0.02). Acute rejection episodes were more seen in the vitamin C group than in the placebo group. Although this data was not statistically significant (P = 0.37), it led to the termination of the study.

Conclusion

A high dose of intravenous vitamin C before allograft implantation was effective in decreasing DGF duration but not DGF incidence.

Trial registration

The trial was registered in the Iranian registry of clinical trials encoded IRCT20100111003043N13 on June 24, 2019.

Assessment of Organ Quality in Kidney Transplantation by Molecular Analysis and Why It May Not Have Been Achieved, Yet

Donor organ shortage, growing waiting lists and substantial organ discard rates are key problems in transplantation. The critical importance of organ quality in determining long-term function is becoming increasingly clear. However, organ quality is difficult to predict. The lack of good measures of organ quality is a serious challenge in terms of acceptance and allocation of an organ. The underlying review summarizes currently available methods used to assess donor organ quality such as histopathology, clinical scores and machine perfusion characteristics with special focus on molecular analyses of kidney quality. The majority of studies testing molecular markers of organ quality focused on identifying organs at risk for delayed graft function, yet without prediction of long-term graft outcome. Recently, interest has emerged in looking for molecular markers associated with biological age to predict organ quality. However, molecular gene sets have not entered the clinical routine or impacted discard rates so far. The current review critically discusses the potential reasons why clinically applicable molecular quality assessment using early kidney biopsies might not have been achieved yet. Besides a critical analysis of the inherent limitations of surrogate markers used for organ quality, i.e., delayed graft function, the intrinsic methodological limitations of studies assessing organ quality will be discussed. These comprise the multitude of unpredictable hits as well as lack of markers of nephron mass, functional reserve and regenerative capacity.

Increased soluble fms-like tyrosine kinase 1 after ischemia reperfusion contributes to adverse clinical outcomes following kidney transplantation

Renal ischemia reperfusion injury (IRI) adversely affects clinical outcomes following kidney transplantation. Understanding the cellular mechanisms and the changes in gene/protein expression following IRI may help to improve these outcomes. Serum soluble fms-like tyrosine kinase 1 (sFlt-1), a circulating antiangiogenic protein, is increased in the first week following kidney transplantation. We evaluated the casual relationship of elevated sFlt-1 levels with renal microvascular dysfunction following IRI in a longitudinal study of 93 kidney transplant recipients and in several animal models. Transplant recipients with higher sFlt-1 levels had higher odds of delayed graft function, graft rejection, impaired graft function, and death. In a subgroup of 25 participants who underwent kidney biopsy within 4 months of kidney transplantation, peritubular capillary area was lower in those with elevated serum sFtl-1 levels. The administration of recombinant sFlt-1 into rodents resulted in significant structural and functional changes of the renal microvasculature, including reduced peritubular capillary density and intracapillary blood volume, and lead to increased expression of inflammatory genes and increased fibrosis. In a murine model of IRI, the kidney was a site of sFlt-1 production, and systemic neutralization of sFlt-1 preserved peritubular capillary density and alleviated renal fibrosis. Our data indicate that high sFlt-1 levels after IRI play an important role in the pathogenesis of microvascular dysfunction, thereby contributing to adverse clinical outcomes following kidney transplantation.

Effect of polyoma viremia on 3-year allograft kidney function

BACKGROUND

Polyoma viremia is associated with damage to renal tubular and urothelial cells. This may imply that a certain level of viremia, even cleared thereafter, could be associated with long-term renal dysfunction.

METHODS

We, retrospectively, analyzed 390 first renal transplants adult recipients (≥18 years) who were monitored for BK viremia in the first 12 months and evaluated estimated GFR (MDRD-4 equation) at 1 month and at the last follow-up (959 ± 392 days).

RESULTS

One hundred and ninety-nine patients (51%) developed at least one positive viremia: 105 (53%) low viremia (<10⁴  copies/mL), 36 (18%) high viremia (4 × 10⁴  > viremia ≥ 10⁴  copies/mL) and 58 (15%) viremia (≥4 × 10⁴  copies/mL) consistent with polyoma virus associated nephropathy (PyVAN). Out of these 58 patients, 24 (6%) developed bx-proven (SV40+) PyVAN and 34(8.7%) presumptive PyVAN (SV40-). Baseline characteristics, immunosuppression, KDRI, rejection episodes, etc., did not differ among groups but there were more deceased donors and ATG induction therapy in the high viremia group. At last follow-up, all patients in the low, high viremia and presumptive PyVAN (except 2) had cleared BK viremia. Bx-proven PyVAN led to 14 graft losses, 10 due to PyVAN. In the presumptive PyVAN there was only one graft loss registered as due to PyVAN. eGFR, at 1 month after KTx, did not differ among groups (51 ± 22 vs 48 ± 24 vs 45 ± 27 vs 43 ± 18 vs 46 ± 22 mL/min/1.73 m² ), for no, low and high viremia as well for presumptive PyVAN and bx-proven PyVAN groups, respectively. At the last follow-up, eGFR did not differ between the no, low, and high viremia compared to baseline and to each other but was statistically lower in the presumptive and bx-proven PyVAN (38 ± 15 and 17 ± 7 mL/min/1.73 m² ) either compared to baseline or to the other groups.

CONCLUSIONS

This study shows that low and high levels of BK viremia do not lead to GFR changes although very high viremia levels, compatible with presumptive or bx-proven PyVAN, even if cleared thereafter, lead to allograft damage and decreased GFR.

Long-term effects of delayed graft function duration on function and survival of deceased donor kidney transplants

Introduction:

Delayed graft function (DGF) is a frequent complication after deceased donor kidney transplantation with an impact on the prognosis of the transplant. Despite this, long-term impact of DGF on graft function after deceased donor kidney transplantation has not been properly evaluated.

Objective:

The main objective of this study was to evaluate risk factors for DGF and the impact of its occurrence and length on graft survival and function.

Methods:

A retrospective cohort study was performed in 517 kidney transplant recipients who received a deceased donor organ between January 2008 and December 2013.

Results:

The incidence of DGF was 69.3% and it was independently associated with donor's final serum creatinine and age, cold ischemia time, use of antibody induction therapy and recipient's diabetes mellitus. The occurrence of DGF was also associated with a higher incidence of Banff ≥ 1A grade acute rejection (P = 0.017), lower graft function up to six years after transplantation and lower death-censored graft survival at 1 and 5 years (P < 0.05). DGF period longer than 14 days was associated with higher incidence of death-censored graft loss (P = 0.038) and poorer graft function (P < 0.001). No differences were found in patient survival.

Conclusions:

The occurrence of DGF has a long-lasting detrimental impact on graft function and survival and this impact is even more pronounced when DGF lasts longer than two weeks.