Factors Associated With Delayed Graft Function and Their Influence on Outcomes of Kidney Transplantation. Transplant Proc. 2016;48:2267-2271. [PMID: 27742276 DOI: 10.1016/j.transproceed.2016.06.007]

Application of ultrasound in early prediction of delayed graft function after renal transplantation

Kidney transplantation is currently the most effective treatment for end-stage renal disease. Delayed graft function (DGF) is one of the most common complications after renal transplantation and is a significant complication affecting graft function and the survival time of transplanted kidneys. Therefore, early diagnosis of DGF is crucial for guiding post-transplant care and improving long-term patient survival. This article will summarize the pathological basis and clinical characteristics of DGF after kidney transplantation, with a focus on contrast-enhanced ultrasound. It will analyze the current application status of ultrasound technology in DGF diagnosis and provide a comprehensive review of the clinical applications of ultrasound technology in this field, serving as a reference for the further application of ultrasound technology in kidney transplantation.

Kidney Tissue Proteome Profiles in Short Versus Long Duration of Delayed Graft Function - A Pilot Study in Donation After Circulatory Death Donors

Introduction

Delayed graft function (DGF) is often defined as the need for dialysis treatment in the first week after a kidney transplantation. This definition, though readily applicable, is generic and unable to distinguish between "types" of DGF or time needed to recover function that may also significantly affect longer-term outcomes. We aimed to profile biological pathways in donation after circulatory death (DCD) kidney donors that correlate with DGF and different DGF durations.

Methods

A total of N = 30 DCD kidney biopsies were selected from the UK Quality in Organ Donation (QUOD) biobank and stratified according to DGF duration (immediate function, IF n = 10; "short-DGF" (1-6 days), SDGF n = 10; "long-DGF" (7-22 days), LDGF n = 10). Samples were matched for donor and recipient demographics and analyzed by label-free quantitative (LFQ) proteomics, yielding identification of N = 3378 proteins.

Results

Ingenuity pathway analysis (IPA) on differentially abundant proteins showed that SDGF kidneys presented upregulation of stress response pathways, whereas LDGF presented impaired response to stress, compared to IF. LDGF showed extensive metabolic deficits compared to IF and SDGF.

Conclusion

DCD kidneys requiring dialysis only in the first week posttransplant present acute cellular injury at donation, alongside repair pathways upregulation. In contrast, DCD kidneys requiring prolonged dialysis beyond 7 days present minimal metabolic and antioxidant responses, suggesting that current DGF definitions might not be adequate in distinguishing different patterns of injury in donor kidneys contributing to DGF.

Renal Function at Discharge Among Kidney Recipients Experiencing Delayed Graft Function and Its Associations With Long-term Outcomes

Delayed graft function (DGF) after kidney transplantation is associated with higher rates of acute rejection and poor graft survival and outcomes. Current DGF definitions based on posttransplant need for dialysis are not standardized and there are no objective methodologies for quantifying DGF severity.

METHODS

Using Organ Procurement and Transplantation Network data, we examined DGF, and used recipient serum creatinine at discharge as a correlate of renal function and DGF severity (mild: <2.5 mg/dL; severe: ≥2.5 mg/dL). The associations between donor and recipient factors and DGF severity were quantified using logistic regression. We also examined the associations between DGF severity and long-term recipient outcomes, adjusting for potential confounders.

RESULTS

A predictive model using donor and recipient factors had a reasonably good ability to discriminate mild (low creatinine) versus severe (high creatinine) DGF (c-statistic of 0.70). In Cox regression, DGF and creatinine at discharge were both independently associated with long-term outcomes, yet their effects differed depending on the outcome (graft function, death-censored graft function, recipient mortality). Our findings suggest that having DGF, but with relatively good renal function (creatinine <2.5) at discharge, may be less deleterious on graft and recipient survival compared with severe, prolonged DGF, which was associated with a decreased median graft survival of ~2.6 y compared with no DGF with low creatinine at discharge.

CONCLUSIONS

Our novel DGF severity stratification identified unique factors associated with DGF severity, along with DGF's association with long-term graft and patient survival. The adverse cost and outcome implications of severe DGF warrant additional investigation to improve kidney transplantation practice.

Effects of an individualized nutritional intervention on kidney function, body composition, and quality of life in kidney transplant recipients: Study protocol for a randomized clinical trial

Background

Proteinuria after kidney transplantation (KTx) has been a frequent problem due to several factors, high protein intake being one of them. Individualized nutritional intervention in the late post-KTx period can promote the improvement or the reduction of risks associated with the parameters of evaluation of kidney function, body composition, and quality of life in individuals submitted to KTx.

Methods

This is a single-center, randomized and stratified clinical trial. The study will be conducted in a university hospital in northeastern Brazil with 174 individuals aged ≥19 years submitted to KTx and followed up for 12 months. Assessments will take place at 3-month intervals (T0, T3, T6, T9, and T12). The patients will be allocated to intervention and control groups by random allocation. The intervention group will receive individualized nutritional interventions with normoproteic diets (1.0 g/kg) after 60 days of KTx whereas the controls will receive the standard nutritional guidance for the post-KTx period. The primary efficacy variable is the change from baseline in log proteinuria assessed with the urinary albumin/creatinine ratio. Secondary efficacy variables include body composition, anthropometry, quality of life assessment and physical activity, lipid profile and glycemic control. Ninety-two subjects per group will afford 70% power to detect a difference of 25% between groups in log proteinuria. Primary efficacy analysis will be on the modified intention-to-treat population with between-groups comparison of the change from baseline in log proteinuria by analysis of covariance.

Discussion

The study will assess the effects of an individualized nutritional intervention on proteinuria 12 months after KTx.

Trial registration

REBEC (RBR-8XBQK5).

Transcriptome Analysis of Kidney Grafts Subjected to Normothermic Ex Vivo Perfusion Demonstrates an Enrichment of Mitochondrial Metabolism Genes

Normothermic ex vivo kidney perfusion (NEVKP) has demonstrated superior outcomes for donation-after-cardiovascular death grafts compared with static cold storage (SCS). To determine the mechanisms responsible for this, we performed an unbiased genome-wide microarray analysis.

METHODS

Kidneys from 30-kg Yorkshire pigs were subjected to 30 min of warm ischemia followed by 8 h of NEVKP or SCS, or no storage, before autotransplantation. mRNA expression was analyzed on renal biopsies on postoperative day 3. Gene set enrichment analysis was performed using hallmark gene sets, Gene Ontology, and pathway analysis.

RESULTS

The gene expression profile of NEVKP-stored grafts closely resembled no storage kidneys. Gene set enrichment analysis demonstrated enrichment of fatty acid metabolism and oxidative phosphorylation following NEVKP, whereas SCS-enriched gene sets were related to mitosis, cell cycle checkpoint, and reactive oxygen species (q < 0.05). Pathway analysis demonstrated enrichment of lipid oxidation/metabolism, the Krebs cycle, and pyruvate metabolism in NEVKP compared with SCS (q < 0.05). Comparison of our findings with external data sets of renal ischemia-reperfusion injury revealed that SCS-stored grafts demonstrated similar gene expression profiles to ischemia-reperfusion injury, whereas the profile of NEVKP-stored grafts resembled recovered kidneys.

CONCLUSIONS

Increased transcripts of key mitochondrial metabolic pathways following NEVKP storage may account for improved donation-after-cardiovascular death graft function, compared with SCS, which promoted expression of genes typically perturbed during IRI.

Effect of Delayed Graft Function on the Outcome and Allograft Survival of Kidney Transplanted Patients from a Deceased Donor

BACKGROUND

In kidney transplantation (KT), delayed graft function (DGF) is a significant early complication observed in the first week. The study aimed to investigate the impact of DGF on the outcome, allograft, and patient survival after KT with organs from deceased donors.

METHODS

This retrospective study was conducted using 304 KT patients who received an organ from deceased donors from 2008 to 2018. The patients were divided into 2 groups, DGF positive (DGF⁺) and DGF negative (DGF^-). The database containing the clinical, laboratory, and immunologic information of donors and recipients was statistically analyzed using the SSPS program.

RESULTS

In this study, 189 (62.17%) were DGF⁺ and 115 (37.83%) were DGF^-. Until 6 months after KT, the estimate glomerular filtration rate was better in group DGF^-, but it was similar between the groups during 10-year follow-up. Graft losses were higher in DGF⁺ group than in the DGF^- (P = .046). The serum creatinine level was persistently higher in DGF⁺ group until the sixth month (P ≤ .05). Allograft survival rates were better in patients who were DGF^- (P = .033). Those who had DGF for more than 15 days had a worse graft survival (P = .003), but in 10 year follow-up, patient survival rates were similar (P = .705).

CONCLUSION

DGF⁺ patients were associated with dialysis time before KT, ischemia time, and the donors' clinical status, such as age, organ quality, and serum creatinine. All these factors had a great impact on graft survival but not on patient survival.

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.

African American polycystic kidney patients receive higher risk kidneys, but do not face increased risk for graft failure or post-transplant mortality

African Americans (AA) are disproportionately affected by end-stage renal disease (ESRD) and have worse outcomes following renal transplantation. Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic condition leading to ESRD necessitating transplant. We explored this population with respect to race by conducting a retrospective analysis of the UNOS database between 2005 and 2019. Our study included 10,842 (AA n = 1661; non-AA n = 9181) transplant recipients whose primary diagnosis was ADPKD. We further stratified the AA ADPKD population with respect to blood groups (AA blood type B n = 295 vs AA non-B blood type n = 1366), and also compared this cohort to AAs with a diagnosis of DM (n = 16,706) to identify unique trends in the ADPKD population. We analyzed recipient and donor characteristics, generated survival curves, and conducted multivariate analyses. African American ADPKD patients waited longer for transplants (924 days vs 747 days P < .001), and were more likely to be on dialysis (76% vs 62%; p < .001). This same group was also more likely to have AA donors (21% vs 9%; p < .001) and marginally higher KDPI kidneys (0.48 vs 0.45; p < .001). AA race was a risk factor for delayed graft function (DGF), increasing the chance of DGF by 45% (OR 1.45 95% CI 1.26-1.67; p < .001). AA race was not associated with graft failure (HR 1.10 95% CI 0.95-1.28; p = .21) or patient mortality (HR 0.84 95% CI 0.69-1.03; p = .09). Racial disparities exist in the ADPKD population. They should be continually studied and addressed to improve transplant equity.

Significant Dysfunction of Kidney Grafts Exposed to Prolonged Warm Ischemia Is Minimized Through Normothermic Ex Vivo Kidney Perfusion

Supplemental Digital Content is available in the text.

Normothermic ex vivo kidney perfusion (NEVKP) is an emerging technique for renal graft preservation. We investigated whether NEVKP could improve early function of severely injured grafts and reduce the incidence of significant renal dysfunction (SRD) similar to delayed graft function in a model of donation after circulatory death.

Validation of the Kidney Donor Profile Index in Argentina

Kidney Donor Profile Index (KDPI), derived from donor characteristics, was developed in the United States in an effort to devise an objective means of assessing donor organ suitability based on predicted graft survival. The objective of this study is to analyze the utility of KDPI to predict renal graft survival in Argentina. We conducted a retrospective national cohort study of adult patients who received a deceased donor renal transplantation in Argentina between January 2008 and December 2017. The graft survival was estimated according to the KDPI stratified by quartiles. A Kaplan-Meier analysis was used to calculate survival. A Cox regression was performed to estimate the probability of graft loss for each quart of the KDPI adjusted by receptor variables (age, diabetes, sex, and dialysis time) and cold ischemia time. In a Kaplan-Meier analysis, the graft survival decreases as the quartile of KDPI increases. Multivariate analysis shows that the increase in KDPI quartile and recipient's characteristics-such as age ≥60 years, diabetes, and dialysis time-were related to the probability of graft loss. In conclusion, the KDPI system could provide a guide to objectively assess the quality of organs offered for transplantation in Argentina.

Identification of Factors Associated With Acute Tubular Necrosis Following Kidney Transplant in Northern Mexico: Increased Risk With Cold Ischemia After 8 Hours

AIM

To identify potential risk factors associated with the incidence of acute tubular necrosis (ATN) following kidney transplant in a sample of patients from northern Mexico.

METHODS

Secondary analysis of data extracted from clinical files of patients who underwent a kidney transplant between 2000 and 2017 at Christus Muguerza Hospital in the city of Chihuahua. The final sample with complete data included 485 patients. ATN was diagnosed in 13.2% of patients using pathologic, clinical, and laboratory criteria. Adjusted odds ratio (ORs) with 95% CIs from multivariate binary logistic regression were used to identify predictors of ATN.

RESULTS

Only 4 of 21 variables analyzed remained statistically significant in the final adjusted model. Cold and warm ischemia followed time-trend patterns with higher odds with longer ischemia times. For cold ischemia, compared with 0 to 240 minutes, ORs were 1.32 (95% CI, 0.49-3.51) for 241-480 minutes, 4.87 (95% CI, 2.29-10.3) for 481-960 minutes, and 10.0 (95% CI, 2.86-35.0) for > 960 minutes; for warm ischemia, compared with 40 to 59 minutes, these were 6.27 (95% CI, 1.95-20.8) for 60-70 minutes and 10.32 (95% CI, 1.95-54.4) for 71-110 minutes. Hypotension during surgery was associated with a higher chance of ATN (OR, 15.9; 95% CI, 4.97-50.9). When the recipients' age was 30 years or older, the probability also increased significantly (OR, 2.88; 95% CI, 1.09-7.57). The final model fitted well and explained 27% of the probability to develop ATN after a kidney transplant.

CONCLUSION

Shortening the duration of ischemia and avoiding hypotension during surgery is essential to prevent ATN following a kidney transplant.

Modifiable Risk Factors for Delayed Graft Function After Deceased Donor Kidney Transplantation

PURPOSE

Delayed graft function is a major complication after kidney transplantation affecting patients' long-term outcome. The aim of this study was to identify modifiable risk factors for delayed graft function after deceased donor kidney transplantation.

METHODS

This is a single-center retrospective cohort study of a university transplantation center. Univariate and multivariate step-wise logistic regression analysis of patient-specific and procedural risk factors were conducted.

RESULTS

We analyzed 380 deceased donor kidney transplantation patients between October 30, 2008 and December 30, 2017. The incidence of delayed graft function was 15% (58/380). Among the patient-specific risk factors recipient diabetes (2.8 [1.4-5.9] odds ratio [OR] [95% confidence interval [CI]]), American Society of Anesthesiologist score of 4 (2.7 [1.2-6.5] OR [95% CI]), cold ischemic time >13 hours (2.8 [1.5-5.3] OR [95% CI]) and donor age >55 years (1.9 [1.01-3.6] OR [95% CI]) revealed significance. The significant intraoperative, procedural risk factors included the use of colloids (3.9 [1.4-11.3] OR [95% CI]), albumin (3.0 [1.2-7.5] OR [95% CI]), crystalloids >3000 mL (3.1 [1.2-7.5] OR [95% CI]) and mean arterial pressure <80 mm Hg at the time of reperfusion (2.4 [1.2-4.8] OR [95% CI]).

CONCLUSION

Patients undergoing deceased donor kidney transplantation with a mean arterial pressure >80 mm Hg at the time of transplant reperfusion without requiring excessive fluid therapy in terms of colloids, albumin or crystalloids >3000 mL are less likely to develop delayed graft function.

Time of Cold Ischemia and Delayed Graft Function in a Cohort of Renal Transplant Patients in a Reference Center

There are many factors involved in the delayed graft function of a renal graft, with prolonged cold ischemia time being one of the most relevant. The aim of this study is to evaluate the relationship between the time of cold ischemia and the delayed graft function, and acute rejection and graft loss at 1 year of follow-up. A retrospective cohort of 347 renal transplant patients were evaluated during the years 2009-2013. The incidence of delayed graft function was 18.4% (n = 65). The cold ischemia time was an independent risk factor for delayed graft function (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.04-1.16). By grouping the time of cold ischemia by intervals, the risk of delayed graft function was greater in the 12-18 hours group (OR 2.06, 95% CI 1.02-4.15) and in the >18 hours group (OR 3.38, 95% CI 1.57-7.27). The risk of acute rejection did not increase with longer cold ischemia (p = 0.69), and cold ischemia time was not a risk factor for renal graft loss at 1-year follow-up (hazard ratio 0.97, 95% CI 0.88-1.06). In conclusion the time of cold ischemia (>12 hours) in renal transplant recipients of optimal deceased donors increases the risk of delayed graft function; however, this does not negatively impact the results in acute rejection or graft loss in the first year of the transplant.

Influence of pretransplant midodrine use on outcomes after kidney transplantation

Evaluation of potential kidney transplant recipients is important to identify and treat conditions that may influence graft or patient survival after transplantation. We performed a single-center, observational cohort study to determine whether pretransplant midodrine use influences outcomes after kidney transplantation. We analyzed graft and patient outcomes for adult patients who underwent a kidney-only transplantation at Barnes-Jewish Hospital from January 1999 to December 2015. We quantified adjusted associations of pretransplant midodrine use with post-transplant complications by multivariable Cox regression. Among the 2621 kidney transplant recipients analyzed, 37 (1.4%) were taking midodrine immediately prior to transplantation. Midodrine users were more commonly older (56.5 vs 50.4 years) and obese (67.6% vs 33.6%). Midodrine users were also more likely to be on hemodialysis (86.5% vs 59.2%), to have a longer duration of dialysis dependence (646 months vs 577 months), and to have higher levels of sensitization (peak panel reactive antibody >20%, 32.4% vs 15.8%) compared to nonusers. Pretransplant midodrine users had significantly higher rates of delayed graft function (DGF) (32.4% vs 6.7%, P < 0.001). No difference in the incidence of DGF was observed based on the midodrine dosing regimen. After multivariable adjustment for recipient and donor characteristics, pretransplant midodrine use was independently associated with graft failure at 1 year (adjusted hazard ratio, 5.11; 95% confidence interval, 2.09-12.49).

Evaluation of predictive models for delayed graft function of deceased kidney transplantation

Background

This study aimed to evaluate the predictive power of five available delayed graft function (DGF)-prediction models for kidney transplants in the Chinese population.

Results

Among the five models, the Irish 2010 model scored the best in performance for the Chinese population. Irish 2010 model had an area under the receiver operating characteristic (ROC) curve of 0.737. Hosmer-Lemeshow goodness-of-fit test showed that the Irish 2010 model had a strong correlation between the calculated DGF risk and the observed DGF incidence (p = 0.887). When Irish 2010 model was used in the clinic, the optimal upper cut-off was set to 0.5 with the best positive likelihood ratio, while the lower cut-off was set to 0.1 with the best negative likelihood ratio. In the subgroup of donor aged ≤ 5, the observed DGF incidence was significantly higher than the calculated DGF risk by Irish 2010 model (27% vs. 9%).

Materials and Methods

A total of 711 renal transplant cases using deceased donors from China Donation after Citizen's Death Program at our center between February 2007 and August 2016 were included in the analysis using the five predictive models (Irish 2010, Irish 2003, Chaphal 2014, Zaza 2015, Jeldres 2009).

Conclusions

Irish 2010 model has the best predictive power for DGF risk in Chinese population among the five models. However, it may not be suitable for allograft recipients whose donor aged ≤ 5-year-old.