Donation After Cardiac Death Kidneys Research Articles

#1887 Comparison of the efficacy of preservation at 22°C versus 4°C in warm ischemic kidneys from MHC-inbred CLAWN miniature swine

Abstract Background and Aims Static cold preservation, the standard in transplantation, is primarily aimed at reducing metabolic and oxygen demand. Kidney transplantation from donors after cardiac death (DCD) addresses the shortage of donor organs, but these kidneys are susceptible to cold preservation. A previous study using small animal models demonstrated the potential benefits of preserving DCD kidneys at a warmer temperature of 22°C using extracellular-type solutions (Iwai S., PLoS One 2012). Based on this foundational research, our study aimed to evaluate the efficacy of preserving warm ischemic kidneys at temperatures of either 4°C or 22°C using preclinical large animal miniature swine models. Method After 2 hours of warm ischemia, the pig kidneys were preserved for 60 minutes at either 4°C or 22°C with extracellular-type solutions (ETK®). In Experiment 1, these preserved kidneys underwent ex-vivo perfusion for 120 minutes at 37°C with a mean arterial pressure of 85 mmHg. This perfusion used a Ringer's solution supplemented with red blood cells, aiming to determine the early functionality of kidneys subjected to 2-hour warm ischemia in transplantation and to assess whether preservation at 4°C or 22°C could maintain renal function during the acute postoperative period (n = 3 in each group). During this period, both physiological parameters (renal blood flow, intrarenal resistance, and urine output) and metabolic parameters (oxygen consumption) were evaluated. In Experiment 2, kidneys that underwent similar warm ischemia and preservation procedures were transplanted into MHC-matched recipients. These recipients received continuous tacrolimus treatment for 12 days to minimize rejection due to minor antigen differences. After transplantation, renal function was monitored and assessed by serum creatinine levels and renal biopsies for 14 days (n = 3 in each group). Results Experiment 1 demonstrated that kidneys subjected to 2 hours of warm ischemia and then preserved at 22°C had better physiological and metabolic indices during a subsequent 2-hour ex-vivo perfusion compared to those preserved at 4°C. The results were as follows: 22°C vs. 4°C—mean renal blood flow (27 ± 5 vs. 10 ± 0 ml/min), intrarenal resistance (3.5 ± 0.5 vs. 8.7 ± 0.1 mmHg/ml/min), total urine volume (14 ± 5 vs. 5 ± 4 ml), and oxygen consumption (224 ± 39 vs. 93 ± 16 ml/min/g). Importantly, there was no complete cessation of blood flow in either group, indicating the potential for long-term evaluation using a transplantation model. In Experiment 2, kidneys preserved at 22°C resulted in significantly lower peak post-transplant serum creatinine levels compared to those preserved at 4°C (3.9 ± 0.6 mg/dl vs 8.9 ± 0.3 mg/dl, p = 0.0015). There was a marked decrease in the area under the curve of creatinine from day 0 to day 14, with a 36% reduction from 61 mg/dL per day in the 4°C group to 39 mg/dL per day in the 22°C group. Renal biopsies performed on post-operative day 4 revealed extensive necrosis in the renal tubules of kidneys stored at 4°C. In contrast, kidneys preserved at 22°C showed more localized damage. In addition, PCNA staining indicated accelerated regeneration of the tubular epithelium in kidneys preserved at 22°C. Conclusion This study demonstrates that kidneys subjected to 2 hours of warm ischemia from MHC-inbred miniature swine are more effectively preserved at 22°C than at 4°C when using an extracellular-type solution. To our knowledge, this is the first report demonstrating the efficacy of organ preservation at 22°C in clinically relevant, large animal models. From the evaluation of ex-vivo perfusion of preserved kidneys, it was suggested that kidneys preserved at 22°C maintain better blood perfusion to severely ischemic kidneys immediately after transplantation, which leads to the rapid recovery of renal function of acute kidney injury. Future research will focus on elucidating the mechanisms underlying the superior outcomes associated with 22°C preservation. In addition, investigations will be conducted to determine whether similar benefits can be achieved using intracellular-type solutions, which are more commonly used in renal transplantation.

Metabolomic and lipidomic landscape of porcine kidney associated with kidney perfusion in heart beating donors and donors after cardiac death

Transplant centers are currently facing a lack of tools to ensure adequate evaluation of the quality of the available organs, as well as a significant shortage of kidney donors. Therefore, efforts are being made to facilitate the effective use of available organs and expand the donor pool, particularly with expanded criteria donors. Fulfilling a need, we aim to present an innovative analytical method based on solid-phase microextraction (SPME) - chemical biopsy. In order to track changes affecting the organ throughout the entire transplant procedure, porcine kidneys were subjected to multiple samplings at various time points. The application of small-diameter SPME probes assured the minimal invasiveness of the procedure. Porcine model kidney autotransplantation was executed for the purpose of simulating two types of donor scenarios: donors with a beating heart (HBD) and donors after cardiac death (DCD). All renal grafts were exposed to continuous normothermic ex vivo perfusion. Following metabolomic and lipidomic profiling using high-performance liquid chromatography coupled to a mass spectrometer, we observed differences in the profiles of HBD and DCD kidneys. The alterations were predominantly related to energy and glucose metabolism, and differences in the levels of essential amino acids, purine nucleosides, lysophosphocholines, phosphoethanolamines, and triacylglycerols were noticed. Our results indicate the potential of implementing chemical biopsy in the evaluation of graft quality and monitoring of renal function during perfusion.

Static Cold Storage with Mitochondria-Targeted Hydrogen Sulfide Donor Improves Renal Graft Function in an Ex Vivo Porcine Model of Controlled Donation-after-Cardiac-Death Kidney Transplantation.

The global donor kidney shortage crisis has necessitated the use of suboptimal kidneys from donors-after-cardiac-death (DCD). Using an ex vivo porcine model of DCD kidney transplantation, the present study investigates whether the addition of hydrogen sulfide donor, AP39, to University of Wisconsin (UW) solution improves graft quality. Renal pedicles of male pigs were clamped in situ for 30 min and the ureters and arteries were cannulated to mimic DCD. Next, both donor kidneys were nephrectomized and preserved by static cold storage in UW solution with or without AP39 (200 nM) at 4 °C for 4 h followed by reperfusion with stressed autologous blood for 4 h at 37 °C using ex vivo pulsatile perfusion apparatus. Urine and arterial blood samples were collected hourly during reperfusion. After 4 h of reperfusion, kidneys were collected for histopathological analysis. Compared to the UW-only group, UW+AP39 group showed significantly higher pO2 (p < 0.01) and tissue oxygenation (p < 0.05). Also, there were significant increases in urine production and blood flow rate, and reduced levels of urine protein, serum creatinine, blood urea nitrogen, plasma Na+ and K+, as well as reduced intrarenal resistance in the UW+AP39 group compared to the UW-only group. Histologically, AP39 preserved renal structure by reducing the apoptosis of renal tubular cells and immune cell infiltration. Our finding could lay the foundation for improved graft preservation and reduce the increasingly poor outcomes associated with DCD kidney transplantation.

Pancreas transplantation with grafts obtained from donation after cardiac death or donation after brain death results in comparable outcomes.

Pancreas organ shortages and long recipient waitlist times are critical components that limit recipients from receiving a pancreas transplant. Over the last decade, our center has been using donation after cardiac death (DCD) donors as an adjunct to donation after brain death (DBD) donors to expand the organ pool. The aim of this study was to compare recipient and graft survival between DCD and DBD recipients. A retrospective single center propensity matched analysis (2011-2020) of 32 DCD vs 96 DBD pancreas transplants was performed. 8-year recipient survival was similar between DCD and DBD groups (87.4% vs 92.7%, p=0.35) as was simultaneous kidney and pancreas transplant (SPK) 8-year kidney (88.9 vs 96.9%, p=0.219) and pancreas graft survival (77.4% vs 86.7%, p=0.344). There was no difference in vascular thrombosis rate between DCD and DBD pancreas grafts (3.1% vs 7.3%, p=0.73). DCD kidneys had a higher rate of DGF vs DBD kidneys (28.1% vs 6.3%, p=0.004), without any significant difference in long term kidney failure (12.5% vs 8.3%, p=0.5). Recipients of DCD grafts demonstrate equivalent long-term patient and graft survival compared to DBD recipients for pancreas transplantation. Increased utilization of well selected DCD donors is a safe strategy to increase the donor pool.

Risk factors for BK virus infection in DCD donor kidney transplant recipients.

BK virus infection after kidney transplantation can negatively impact the prognosis of patients. However, current risk factor analyses primarily focus on BK virus nephropathy, while BK viruria and BK viruria progressing to BK viremia receive less attention. This study aims to analyze the risk factors associated with BK viruria and BK viruria progressing to BK viremia in recipients of donation after cardiac death (DCD), with the goal of facilitating early intervention. Donor characteristics and clinical data of recipients before and after transplantation were evaluated, and logistic univariate and multivariate analyses were performed to determine the risk factors associated with BK viruria and the progression of BK viruria to BK viremia. Additionally, machine learning techniques were employed to identify the top five features associated with BK viruria evolving into BK viremia. During a median follow-up time of 1,072 days (range 739-1,418), 69 transplant recipients (15.6% incidence rate) developed BK viruria after transplantation, with 49.3% of cases occurring within 6 months post-transplantation. Moreover, 19 patients progressed to BK viremia. Donor age [OR: 1.022 (1.000, 1.045), p = 0.047] and donor procalcitonin (PCT) levels [0.5-10 ng/ml; OR: 0.482 (0.280, 0.828), p = 0.008] were identified as independent risk factors for BK viruria. High BK viruria [OR: 11.641 (1.745, 77.678), p = 0.011], recipient age [OR: 1.106 (1.017, 1.202), p = 0.018], and immunoinduction regimen [ATG; OR: 0.063 (0.006, 0.683), p = 0.023] were independent risk factors for BK viruria progressing to BK viremia. Machine learning analysis confirmed the importance of high BK viruria, recipient age, and immunoinduction regimen (ATG) in predicting the progression of BK viruria to BK viremia. The development and progression of BK virus in DCD kidney transplant recipients is influenced by multiple factors. Early intervention and treatment could potentially extend the lifespan of the transplanted organ.

MP31-12 ASSOCIATION OF INITIAL POST-TRANSPLANT DONOR-DERIVED CELL-FREE DNA LEVELS WITH PERI-TRANSPLANT OUTCOMES AND DONOR CHARACTERISTICS IN DECEASED DONOR KIDNEY TRANSPLANT RECIPIENTS: A SINGLE-CENTER RETROSPECTIVE STUDY

You have accessJournal of UrologyCME1 Apr 2023MP31-12 ASSOCIATION OF INITIAL POST-TRANSPLANT DONOR-DERIVED CELL-FREE DNA LEVELS WITH PERI-TRANSPLANT OUTCOMES AND DONOR CHARACTERISTICS IN DECEASED DONOR KIDNEY TRANSPLANT RECIPIENTS: A SINGLE-CENTER RETROSPECTIVE STUDY Conner Lombardi, Jacob Lang, Emile Garcia, Mary Lee Brown, Dinkar Kaw, Deepak Malhotra, Shobha Ratnam, Michael Rees, and Obi Ekwenna Conner LombardiConner Lombardi More articles by this author , Jacob LangJacob Lang More articles by this author , Emile GarciaEmile Garcia More articles by this author , Mary Lee BrownMary Lee Brown More articles by this author , Dinkar KawDinkar Kaw More articles by this author , Deepak MalhotraDeepak Malhotra More articles by this author , Shobha RatnamShobha Ratnam More articles by this author , Michael ReesMichael Rees More articles by this author , and Obi EkwennaObi Ekwenna More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003264.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Donor-derived cell-free DNA has been demonstrated as an accurate biomarker and risk predictor for acute rejection in kidney transplantation, but it’s association with other clinical variables implicated in rejection have been mixed. The aim of this study was to assess the clinical association of dd-cfDNA levels that have been associated with peri-transplant outcomes including development of delayed graft function, cold ischemia time (CIT), use of machine perfusion, and donor characteristics, including deceased donor mode of death, kidney donor profile index (KDPI), and donor age. METHODS: Retrospective data from a cohort of 84 deceased donor kidney recipients transplanted from November 2019 to December 2020 with initial dd-cfDNA (ProsperaÔ, Natera, Inc.) levels collected within six months (Median date of collection 19 days; IQR 16-31 days) of undergoing transplantation were included in the study. Pearson’s C2, Wilcoxon rank-sum tests, and linear regression with Pearson’s correlation coefficient were used to measure association with significance determined at p<0.05. RESULTS: When examining peri-transplant characteristics, mean levels of dd-cfDNA were significantly higher in those with DGF (n=20) than non-DGF (n=64) [1.02% (95% CI 0.65-1.39%) vs. 0.65 (95% CI 0.42-0.88%); p=0.002]. Dd-cfDNA levels were not significantly associated with CIT (mean p=.744, r=.036), or machine perfusion (n=45) versus no machine perfusion(n=39) (0.85% (95% CI 0.52%-1.19%) vs. 0.60% (95% CI 0.41%-0.78%); p=.32). When examining donor characteristics, dd-cfDNA levels in were significantly higher in recipients with donation after cardiac death (DCD) kidneys versus donation after brainstem death (DBD) kidneys [1.26% (95% CI 0.75%-1.76%) vs. 0.53% (95% CI 0.36%-0.69%); p=0.000]. Donor age (p=.271, r=0.12) and KDPI (p=0.15, r=0.16) were not significantly associated with dd-cfDNA levels. CONCLUSIONS: Dd-cfDNA levels were significantly elevated in patients who had DGF and in recipients of DCD kidneys in our single center cohort. Notably, machine perfusion, donor age, KDPI, and CIT were not associated with increased levels with of dd-cfDNA. As associations of these variables in the literature are thus far varied, studies with increased sample size are necessary to determine the true associations. Source of Funding: The authors declare no sources of funding © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e434 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Conner Lombardi More articles by this author Jacob Lang More articles by this author Emile Garcia More articles by this author Mary Lee Brown More articles by this author Dinkar Kaw More articles by this author Deepak Malhotra More articles by this author Shobha Ratnam More articles by this author Michael Rees More articles by this author Obi Ekwenna More articles by this author Expand All Advertisement PDF downloadLoading ...

411.6: Inferior Long-term Outcomes of Simultaneous Liver-Kidney Transplantation Using Donation After Cardiac Deaths Donors in the United Network for Organ Sharing Database

Background: Outcomes of simultaneous liver-kidney transplantation (SLKT) in donation after cardiac death (DCD) have improved over the years, but data are limited. Aim of this study was to assess the long-term outcomes of SLKT from DCD organs and then compare them to donation after brain death (DBD) organs. Methods: We analyzed data from the United Network for Organ Sharing (UNOS) from 2002 to 2021. Adult SLKT were included, other multi-organ and re-transplants were excluded from the analysis. Propensity score matching was performed to assess the outcomes between two groups. P<0.05 was considered as significant. Results: In the United States, 8733 SLKT were performed during the study period (499 SLKT from DCD and 8234 from DBD). Recipients of DCD organs, when compared to recipients of DBD organs, were older (median age 59 vs 58 years, P=0.005), had lower prevalence of dialysis (62 vs 68%, P=0.003), lower Model for End-Stage Liver Disease (MELD) score (24 vs 29, P<0.001) and longer wait-time (89 vs 68 days, P=0.009). Donors of DCD organs were younger (median age 33 vs 35 years, P<0.001), had shorter cold ischemia time in liver (5.8 vs 6.0 hours, P<0.001) and in kidney (9.5 vs 10.5 hours, P<0.001), and had similar kidney donor profile index (31 vs 30 %, P=0.18) compared to DBD donor. The most common primary diagnosis for both recipient groups was alcohol-related liver disease, while non-alcoholic steatohepatitis was more common in DCD group (28 vs 21%). Long-term outcomes including five-year overall survival and liver graft survivals were inferior in DCD recipients (71.4 vs 74.8%, P=0.11; 74.0 vs 67.1%, P=0.0011). After propensity score matching, five-year overall survival and liver graft survivals were inferior (71.4 vs 76.4%, P=0.031; 67.1 vs 76.0%, P<0.001). Multivariable cox-regression analysis in the matched-cohort showed that DCD was an independent risk factor of mortality (hazard ratio {HR}- 1.33; 95% Confidence interval{CI}, 1.04-1.68; P=0.021) and liver graft failure (HR- 1.54; 95% CI, 1.24-1.92; P<0.001). For kidney allograft outcomes in matched-cohort, delayed graft function was higher in DCD (36 vs 20%, P<0.001) and five-year kidney graft outcome was inferior in DCD (67.3 vs 74.7%, P=0.0034). The most common listed causes of five-year mortality were infection (21.4%) and multi-organ failure (20.8%) and there were no differences between two groups. Other factors associated with mortality were recipient older age (HR 1.03; 95%CI 1.02-1.04, P<0.001), male recipient (HR 1.32; 95%CI 1.06-1.64, P=0.014), and donor older age (HR 1.01; 95%CI 1.00-1.02, P=0.024). Conclusion: Recipients of SLKT from DCD donors had inferior long-term post-transplant outcomes with decrease in overall survival and allograft survival. Careful identification of risk factors associated with worse outcomes is required to improve utilization of DCD donors for SLKT.

404.7: Study on the Regulatory Effect of iPS-Derived Exosomes on the Local Immune Microenvironment in DCD Kidney Transplanted Rats

Introduction: Ischemia reperfusion injury (IRI) of donation After Cardiac death (DCD) transplanted kidney is the key factor of acute renal injury, acute and chronic rejection of renal transplantation and transplanted kidney disease.The latest researches show that mesenchymal stem cells (MSCs) have the function of protecting damaged tissues and organs and strong immune regulation. Induced pluripotent stem (iPS) cells have higher proliferative capacity and exosome secretion potential than MSCs. In addition to the functions of stem cells, exosomes have the unique ability to cross the blood-brain barrier and deliver remotely, which means that exosomes have better advantages in clinical disease treatment compared with the therapeutic potential of stem cells. Therefore, the main purpose of this study is to clarify the role of IPS derived exosomes in protecting the IRI of DCD transplanted kidney and regulating its local immune microenvironment. Methods: The iPS cells were passaged to the third passage and massively expanded. After 48 hours of culture, 100 mL of cell culture supernatant was collected and exosomes were extracted from the supernatant by the kit method, and the morphology and surface membrane marker proteins of the exosomes were identified. The SD rats were established with DCD renal transplantation model and 10, 50, and 100 μg of exosomes were infused into that SD rats respectively, and a PBS control group was set at the same time. On the 3rd, 5th, 7th, 14th and 28th days after transplantation, the content of cytokines in the serum of the recipient rats, the proportion of lymphocyte subsets CD4+CD25+Foxp3+Tregs in the spleen and the relative expression of Foxp3 mRNA were detected. The proliferation of renal tubular cells was detected by PCNA immunofluorescence. The pathological changes of renal tissue were determined by HE staining, and the apoptosis of renal tubular epithelial cells was detected by Tunel staining. The infiltration of inflammatory cells was detected by immunohistochemistry. The expression changes of regulatory T cells in renal tissue and macrophage phenotypic characteristics were analyzed by flow cytometry. Results: The experimental amount of exosomes was successfully obtained, and the morphology was observed by transmission electron microscope. The exosomes were round or oval membranous vesicles with uniform size, and the edges were clearly visible. The TSG101, CD63, and CD9 proteins were highly expressed on the exosome membrane surface by western-blot. A DCD rat kidney transplantation model was successfully established. The expression levels of IL-12, IL-2, IFN-γ, and TNF-α in the serum of each group were increased to varying degrees from the 3rd day after operation. On the 3rd and 7th days, the levels of IL-12, IL-2, IFN-γ, and TNF-α in the 100 μg exosome infusion group were significantly lower than those in the 10 μg, 50 μg and PBS groups (P<0.05), and the expression level of IL-10 in the 100 μg exosome infusion group was significantly higher than 10μg, 50μg and PBS groups (P<0.05). On the 28th day, the expression level of IL-10 in the 100 μg exosome infusion group was significantly higher than other groups (P<0.01). Compared with other groups, the CD4+CD25+Tregs and CD4+CD25+Foxp3+Tregs accounted for the highest proportion of CD4+T cells in the spleen of the 100μg infusion group (P<0.05). On the 28th day, the expression level of Foxp3 mRNA in the 100 μg infusion group was significantly higher than that in the 50 μg group (P<0.05). The stainings of PCNA, HE and Tunel showed that SD rats infused with 100μg exosomes could significantly reduce the pathological damage, inflammatory response and apoptosis of renal tubular epithelial cells in the transplanted kidney, promote the proliferation of renal tubular epithelial cells, and have a protective effect on IRI kidney. On the 28th day, the expression of CD4+CD25+Foxp3+Tregs cells in the transplanted kidney tissue was significantly increased, which further promoted the differentiation of macrophages into the immunomodulatory M2 subset. Conclusions: The infusion of iPS-derived high-dose exosomes is involved in the protection of the DCD kidney transplant during IRI process, and alleviates the acute and chronic injury of the DCD kidney transplant, and promotes the formation of the local immunosuppressive microenvironment in the DCD kidney transplantation. The National Natural Science Foundation of China (No.81900686).

Effect of Perioperative Dexmedetomidine on Delayed Graft Function Following a Donation-After-Cardiac-Death Kidney Transplant

Delayed graft function (DGF) is a risk factor for acute rejection and graft failure after kidney transplant. Previous studies have suggested that dexmedetomidine may be renoprotective, but whether the use of dexmedetomidine would improve kidney allograft function is unknown. To investigate the effects of perioperative dexmedetomidine on DGF following a donation-after-cardiac-death (DCD) kidney transplant. This single-center, double-blind, placebo-controlled randomized clinical trial was conducted at The First Affiliated Hospital of Soochow University in Suzhou, China. Adults (18 years or older) who were scheduled for DCD kidney transplant were enrolled between September 1, 2019, and January 28, 2021, and then randomized to receive either dexmedetomidine or normal saline (placebo). One-year postoperative outcomes were recorded. All analyses were based on the modified intention-to-treat population. Patients who were randomized to the dexmedetomidine group received a 24-hour perioperative dexmedetomidine intravenous infusion (0.4 μg/kg/h intraoperatively and 0.1 μg/kg/h postoperatively). Patients who were randomized to the normal saline group received an intravenous infusion of the placebo with the same dose regimen as the dexmedetomidine. The primary outcome was the incidence of DGF, defined as the need for dialysis in the first posttransplant week. The prespecified secondary outcomes were in-hospital repeated dialysis in the first posttransplant week, in-hospital acute rejection, and serum creatinine, serum cystatin C, estimated glomerular filtration rate, need for dialysis, and patient survival on posttransplant day 30. Of the 114 patients enrolled, 111 completed the study (mean [SD] age, 43.4 [10.8] years; 64 male patients [57.7%]), of whom 56 were randomized to the dexmedetomidine group and 55 to the normal saline group. Dexmedetomidine infusion compared with normal saline reduced the incidence of DGF (17.9% vs 34.5%; odds ratio [OR], 0.41; 95% CI, 0.17-0.98; P = .04) and repeated dialysis (12.5% vs 30.9%; OR, 0.32; 95% CI, 0.13-0.88; P = .02, which was not statistically significant after multiple testing corrections), without significant effect on other secondary outcomes. Dexmedetomidine vs normal saline infusion led to a higher median (IQR) creatinine clearance rate on postoperative days 1 (9.9 [4.9-21.2] mL/min vs 7.9 [2.0-10.4] mL/min) and 2 (29.6 [9.7-67.4] mL/min vs 14.6 [3.8-45.1] mL/min) as well as increased median (IQR) urine output on postoperative days 2 (106.5 [66.3-175.6] mL/h vs 82.9 [27.1-141.9] mL/h) and 7 (126.1 [98.0-151.3] mL/h vs 107.0 [82.5-137.5] mL/h) and at hospital discharge discharge (110.4 [92.8-121.9] mL/h vs 97.1 [77.5-113.8] mL/h). Three patients (5.5%) from the normal saline group developed allograft failure by the post hoc 1-year follow-up visit. This randomized clinical trial found that 24-hour perioperative dexmedetomidine decreased the incidence of DGF after DCD kidney transplant. The findings support the use of dexmedetomidine in kidney transplants. Chinese Clinical Trial Registry Identifier: ChiCTR1900025493.

Antibacterial and antioxidant chitosan nanoparticles improve the preservation effect for donor kidneys in vitro

Hypothermic machine perfusion (HMP) is a preferable measure to preserve kidneys from donation after cardiac death (DCD), while the current standard perfusate is imperfect. We synthesized amphiphilic chitosan, N-alkylated-O-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (N-alkyl-O-HTCC) as additive in the perfusate, which can self-assembly into micelles in water (size 133 ± 8.48 nm) (ζ-potential 43.9 ± 2.06 mV), with good antibacterial activity for Escherichia coli and Staphylococcus aureus. The derivates can also deliver hydrophobic drug Alda-1 into kidneys through HMP, with drug loading ratio (~42.14%). The delivery system specifically activated mitochondrial acetaldehyde dehydrogenase 2 in kidneys and reduced the ischemic injury. What's more, the addition of N-alkyl-O-HTCC in HMP also activated mitochondria superoxide dismutase 2, presented nice antioxidant activity. These all helped to improve the quality of DCD kidneys. This study provides a feasible amphiphilic carrier for hydrophobic drugs, and provides efficient guidance for perfusate improvement.

Impact of the use of vasoactive drugs in cardiac death donors on the early postoperative renal function and related complications in renal transplant recipients.

To explore the impact of the use of vasoactive drugs in donation after cardiac death (DCD) donors on graft function, with an attempt to guide the clinical practices of organ preservation and DCD kidney transplantation. The clinical data of 187 DCD donors and 304 recipients who were operated on in our center from February 2018 to May 2019 were retrospectively analyzed. Based on whether vasoactive drugs were used for maintaining blood pressure in DCD donors, the renal donors and recipients were divided into a high-dose group (norepinephrine ≥1.3 µg/kg/min or in combination with dopamine), a low-dose group (norepinephrine <1.3 µg/kg/min or in conjunction with dopamine), and a no-medication group (without the use of vasoactive drugs). The clinical features, post-transplant renal function, and complications were compared among these three groups. The early renal function 1 and 7 days after surgery was significantly superior in the high-dose group and no-medication group (P<0.05) but showed no significant difference between the low-dose group and the no-medication group (P>0.05). Blood urea nitrogen (BUN) on the 1st postoperative days was significantly higher in the high-dose group than in the low-dose group and the no-medication group (P<0.05). Renal function indicators, including serum creatinine (CRE), BUN, and blood uric acid (UA) on the 30th postoperative day, showed no significant difference among these three groups (P>0.05). The incidence of delayed graft function (DGF) after renal transplantation was significantly higher in the high-dose group than in the low-dose group and the no-medication group (P<0.05), whereas there was no significant difference between the groups in the incidences of graft rejection and infections (P>0.05). The use of vasoactive drugs in DCD donors can affect the early recovery of renal function in renal transplant recipients, particularly for those donors who are administered a high dose of vasoactive drugs. Therefore, donor maintenance should be performed cautiously with vasoactive drugs.

Molecular Pathways Underlying Adaptive Repair of the Injured Kidney: Novel Donation After Cardiac Death and Acute Kidney Injury Platforms.

To test the hypothesis that gene expression profiling in peripheral blood from patients who have undergone kidney transplantation (KT) will provide mechanistic insights regarding graft repair and regeneration. Renal grafts obtained from living donors (LD) typically function immediately, whereas organs from donation after cardiac death (DCD) or acute kidney injury (AKI) donors may experience delayed function with eventual recovery. Thus, recipients of LD, DCD, and AKI kidneys were studied to provide a more complete understanding of the molecular basis for renal recovery. Peripheral blood was collected from LD and DCD/AKI recipients before transplant and throughout the first 30 days thereafter. Total RNA was isolated and assayed on whole genome microarrays. Comparison of longitudinal gene expression between LD and AKI/DCD revealed 2 clusters, representing 141 differentially expressed transcripts. A subset of 11 transcripts was found to be differentially expressed in AKI/DCD versus LD. In all recipients, the most robust gene expression changes were observed in the first day after transplantation. After day 1, gene expression profiles differed depending upon the source of the graft. In patients receiving LD grafts, the expression of most genes did not remain markedly elevated beyond the first day post-KT. In the AKI/DCD groups, elevations in gene expression were maintained for at least 5 days post-KT. In all recipients, the pattern of coordinate gene overexpression subsided by 28 to 30 days. Gene expression in peripheral blood of AKI/DCD recipients offers a novel platform to understand the potential mechanisms and timing of kidney repair and regeneration after transplantation.

Transplanting kidneys from donation after cardiac death donors with acute kidney injury.

Donation after cardiac death (DCD) and acute kidney injury (AKI) donors have historically been considered independent risk factors for delayed graft function (DGF), allograft failure, and inferior outcomes. With growing experience, updated analyses have shown good outcomes. There continues to be limited data, however, on outcomes specific to DCD donors who have AKI. Primary outcomes for this study were post-kidney transplant patient and allograft survival comparing two donor groups: DCD AKIN stage 2-3 and DBD AKIN stage 2-3. In comparing these groups, there were no short- or long-term differences in patient (hazard ratio [HR] 1.07, 95% confidence interval [CI] 0.54-1.93, P=.83) or allograft survival (HR 1.47, 95% CI 0.64-2.97, P=.32). In multivariate models, the DCD/DBD status had no significant impact on the estimated GFR (eGFR) at 1 (P=.38), 2 (P=.60), and 3 years (P=.52). DGF (57.9% vs 67.9%, P=.09), rejection (12.1% vs 13.9%, P=.12), and progression of interstitial fibrosis/tubular atrophy (IFTA) on protocol biopsy (P=.16) were similar between the two groups. With careful selection, good outcomes can be achieved utilizing severe AKI DCD kidneys. Historic concerns regarding primary nonfunction, DGF resulting in interstitial fibrosis and rejection, and inferior outcomes were not observed. Given the ongoing organ shortage, increased effort should be undertaken to further utilize these donors.

Should Donation after Cardiac Death Donor Organs be Used in the Pediatric Patient Population?

Introduction Multiple strategies exist to increase the organ pool for pediatric recipients, including using high risk donor organs or donation after cardiac death (DCD) organs. Despite the organ shortage, there still remains a relative reluctance to use livers and kidneys from DCD donors. We examined if this reluctance is warranted by evaluating long term patient and allograft outcomes in pediatric liver and kidney transplant recipients. Materials and Methods The United Network for Organ Sharing database was queried to examine outcomes in all liver and kidney transplant recipients from 1996 to 2017. The patients were then divided upon adult and pediatric (under age 18 years) status and donation after brainstem death (DBD) vs. DCD allograft status. Donor and recipient demographic data were examined, and patient and allograft survival were calculated. Categorical differences were compared using the unpaired Student's t-test and nominal variables using either the Chi Square or Fischer's exact test. A p-value of <0.05 was considered to be significant. Results and Discussion 55 pediatric patients received a DCD liver. The donors in the two groups were similar in age (11.5 vs. 12.0 years, p=NS, DCD vs. DBD). The average time from withdrawal to aortic flush was 17 minutes in the DCD group. The cold storage times were 7.9 vs. 7.7 hours, p=NS, in the DCD vs. DBD groups. Those who received DCD organs were older in age (7.9 vs. 5.1 years, p<0.05). The average Pediatric End-Stage Liver Disease score was 18 vs. 14, p=NS in the DCD vs. the DBD group. Patients were of comparable illness in both groups when comparing need for life support at the time of transplant in the DCD vs. DBD groups (12.5% vs. 9.7%, p=NS). There was no significant difference in patient or allograft survival between the two groups. 276 pediatric recipients recieved a DCD kidney. The DCD donors had similar ages (21.7 vs. 22.0 years, p=NS), a higher KDPI (27% vs. 23%, p<0.05), longer cold storage time (15.4 vs. 14.9 hours, p=NS), and had a time from withdrawal to aortic flush of 16.6 minutes. Those who received DCD organs were older (12.9 vs 11.0 years, p<0.05), had a shorter length of stay (10.6 vs. 15.2 days, p<0.05), and no significant difference in rejection within the first year (18.1% vs. 21.7%). There were no significant differences in patient or allograft survival between the two groups. DCD livers and kidneys have similar to if not improved patient and allograft survival, and are an underutilized source of organs in the pediatric population. Conclusion When chosen well, DCD organs can be used safely with good outcomes in the pediatric patient population.

Outcome of Kidney Transplantation From Donor After Cardiac Death: Reanalysis of the US Mycophenolic Renal Transplant Registry

BackgroundKidney transplantation is limited by the shortage of donor kidneys. Donation after cardiac death (DCD) has been explored to alleviate this problem. To better understand the outcome of DCD kidney transplantation, we reanalyzed the Mycophenolic Renal Transplant (MORE) Registry. MethodsWe compared delayed graft function (DGF), biopsy-proved acute rejection (BPAR), graft loss, and patient death between DCD and donation after brain death (DBD) kidney transplantations. Recipients were further stratified into depleting and nondepleting induction groups for exploratory analysis. ResultsThere were 548 patients who received kidney transplants from deceased donor in the MORE Registry. Among them, 133 received grafts from DCD donors and 415 received from DBD donors. The incidence of DGF was 29.4% and 23.5% in the DCD group and the DBD group, respectively (P = .1812), and the incidence of BPAR at 12 months was 9.0% and 9.9% respectively (P = .7713). The 1-year graft loss rate in the DCD group was higher than that in the DBD group (7.5% vs 3.1%, P = .0283), and the 4-year graft loss rate and patient death rate were not significantly different between the 2 groups. ConclusionsThe DCD kidney transplant group had acceptable short-term outcomes and good long-term outcomes as compared with the DBD kidney transplant group.

Predictive Score Model for Delayed Graft Function Based on Easily Available Variables before Kidney Donation after Cardiac Death.

Background:How to evaluate the quality of donation after cardiac death (DCD) kidneys has become a critical problem in kidney transplantation in China. Hence, the aim of this study was to develop a simple donor risk score model to evaluate the quality of DCD kidneys before DCD.Methods:A total of 543 qualified kidneys were randomized in a 2:1 manner to create the development and validation cohorts. The donor variables in the development cohort were considered as candidate univariate predictors of delayed graft function (DGF). Multivariate logistic regression was then used to identify independent predictors of DGF with P < 0.05. Date from validation cohort were used to validate the donor scoring model.Results:Based on the odds ratios, eight identified variables were assigned a weighted integer; the sum of the integer was the total risk score for each kidney. The donor risk score, ranging from 0 to 28, demonstrated good discriminative power with a C-statistic of 0.790. Similar results were obtained from validation cohort with C-statistic of 0.783. Based on the obtained frequencies of DGF in relation to different risk scores, we formed four risk categories of increasing severity (scores 0–4, 5–9, 10–14, and 15–28).Conclusions:The scoring model might be a good noninvasive tool for assessing the quality of DCD kidneys before donation and potentially useful for physicians to make optimal decisions about donor organ offers.

Hypothermic oxygenated perfusion (HOPE) for fatty liver grafts in rats and humans

Pretreatment of marginal organs by perfusion is a promising opportunity to make more organs available for transplantation. Protection of human donation after cardiac death (DCD) livers by a novel machine perfusion technique, hypothermic oxygenated perfusion (HOPE), was recently established. Herein, we tested whether HOPE is also useful for fatty liver grafts, using a rodent transplant model. Rats were fed over three weeks with a special methionine-choline-deficient diet (MCDD) to induce severe hepatic macrosteatosis (≥60%). Afterwards, livers were transplanted with either minimal or 12h cold storage. Additional liver grafts were treated after 12h cold storage with 1h HOPE before transplantation. Graft injury after orthotopic liver transplantation (OLT) was assessed in terms of oxidative stress, damage-associated molecular patterns release, toll-like receptor-4 activation, cytokine release, endothelial activation, and the development of necrosis and fibrosis. Implantation of cold stored macrosteatotic liver grafts induced massive reperfusion injury after OLT, compared to controls (non-fatty livers). HOPE treatment after cold storage failed to change the degree of steatosis itself, but markedly decreased reperfusion injury after OLT, as detected by less oxidative stress, less nuclear injury, less Kupffer- and endothelial cell activation, as well as less fibrosis within one week after OLT. Protective effects were lost in the absence of oxygen in the HOPE perfusate. HOPE after cold storage of fatty livers prevents significant reperfusion injury and improves graft function, comparable to the effects of HOPE in DCD livers and DCD kidneys. HOPE treatment is easy and may become a universal concept to further expand the donor pool. An increasing number of donor livers contain fat. It is important to harness marginal livers, which may contain fat, as the stock of donor livers is limited. Hypothermic oxygenated perfusion (HOPE) prevents reperfusion injury and improves liver graft function. HOPE offers a simple and low-cost option for treating liver grafts in transplant centers, even after cold storage, instead of transporting machines to the place of procurement. HOPE could be used globally to expand the donor pool.

Association Between Delayed Graft Function and Graft Loss in Donation After Cardiac Death Kidney Transplants-A Paired Kidney Registry Analysis.

Delayed graft function (DGF) is an established complication after donation after cardiac death (DCD) kidney transplants, but the impact of DGF on graft outcomes is uncertain. To minimize donor variability and bias, a paired donor kidney analysis was undertaken where 1 kidney developed DGF and the other did not develop DGF using data from the Australia and New Zealand Dialysis and Transplant Registry. Using paired DCD kidney data from the Australia and New Zealand Dialysis and Transplant Registry, we examined the association between DGF, graft and patient outcomes between 1994 and 2012 using adjusted Cox regression models. Of the 74 pairs of DCD kidneys followed for a median of 1.9 years (408 person-years), a greater proportion of recipients with DGF had experienced overall graft loss and death-censored graft loss at 3 years compared with those without DGF (14% vs 4%, P = 0.04 and 11% vs 0%, P < 0.01, respectively). Compared with recipients without DGF, the adjusted hazard ratio for overall graft loss at 3 years for recipients with DGF was 4.31 (95% confidence interval [95% CI], 1.13-16.44). The adjusted hazard ratio for acute rejection and all-cause mortality at 3 years in recipients who have experienced DGF were 0.98 (95% CI, 0.96-1.01) and 1.70 (95% CI, 0.36-7.93), respectively, compared with recipients without DGF. Recipients of DCD kidneys with DGF experienced a higher incidence of overall and death-censored graft loss compared with those without DGF. Strategies aim to reduce the risk of DGF could potentially improve graft survival in DCD kidney transplants.

Effect of Hypothermic Machine Perfusion on the Preservation of Kidneys Donated After Cardiac Death: A Single-Center, Randomized, Controlled Trial.

To assess the application of a hypothermic machine perfusion device (LifePort) in kidney transplantation from donation after cardiac death (DCD) donors, 24 pairs of DCD kidneys were randomly divided into two groups: one of the paired kidneys from the same donor was perfused with the LifePort machine (hypothermic machine perfusion [HMP]), and the contralateral kidney was prepared using common static cold preservation (CCP). The two groups were compared with respect to the incidence of delayed graft function (DGF), level of graft function, and pathological changes in time-zero biopsy specimens. The incidence of DGF was 16.7 and 37.5% in the HMP and CCP groups, respectively; the difference between the two groups was statistically significant (P < 0.05). The incidence of acute rejection was 4.1 (1/24) and 8.3% (2/24) in the HMP and CCP groups, respectively; this difference was not statistically significant (P > 0.05). Forty-eight kidney patients were followed up for 6 months, and the two groups of recipients all survived, yielding a survival rate of 100%. The mean 6-month serum creatinine levels were 98.7 ± 23.6 µmol/L in the HMP group and 105.3 ± 35.1 µmol/L in the CCP group; there was no significant difference between the two groups. HMP can reduce the incidence of DGF in DCD kidneys, and this effect is greater for expanded criteria donors kidneys. HMP can also improve early renal function.

Experiences of rescuing infective arterial hemorrhage and pseudoaneurysm in DCD kidney transplantation

Objective: To summarize experiences of rescuing arterial hemorrhage and pseudoaneurysm caused by infection in donation after cardiac death (DCD) kidney transplantation. Methods: A total of 198 consecutive DCD kidney transplantations between 1 June 2013 and 30 July 2016 in the Third Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. The means of rescuing infective arterial hemorrhage and pseudoaneurysm after operation and their therapeutic effects were summarized. Results: A total of 5 infective arterial hemorrhage, 2 infective pseudoaneurysm with hemorrhage, and 1 infective pseudoaneurysm developed in 198 DCD kidney transplantation recipients with total morbidity of 4.0%, and the morbidity of fungal infection accounted for 2.5%. One case received open surgical therapy. Two cases were treated with endovascular interventional therapy. Five cases received combined treatments of open surgery and endovascular intervention. Selective antibiotics were used based on drug sensitivity test postoperation. The wound was drained, and the drainage was repeatedly cultured to monitor the pathogen till the results turned to negative. Five patients received graft nephrectomy and were restored to hemodialysis. Two patients were successfully rescued with stable graft function. One case died. The mortality of patient was 1/8. Graft loss rate was 5/8. Both patients with stable graft function were mainly treated by intervention. Conclusions: Infective arterial hemorrhage and pseudoaneurysm were primary risk factors causing patient/graft death postoperation in DCD kidney transplantation. Endovascular therapy can be used as an effective rescuing method under the circumstance of infection. The measure allows opportunity of successfully rescuing kidney graft and deserves recommendation.