BACKGROUND Mechanical preservation (MP) of deceased donor kidney transplants showed a 30% to 50% reduction in delayed graft function (DGF) as defined by dialysis in the first week, when compared with cold storage. DGF is associated with longer hospital stays and increased costs. In this study, we sought to understand the impact of MP on rates of DGF and length of hospital stays in a contemporary cohort of deceased donor kidney transplants in the United States. MATERIAL AND METHODS All single deceased donor kidney transplants performed between January 1, 2010, and September 2, 2020, were identified in the Scientific Registry of Transplant Recipients database. Donor kidneys were considered pumped if the transplant center received the kidney on the pump. RESULTS Multivariate logistic regression showed that MP had similar odds of reduction of DGF for all subsets of donors. The unadjusted rate of DGF for pumped brain-dead standard criteria donor (BDSCD) recipients was similar to that of donors stored on ice. The rate of DGF for expanded criteria donors (ECD) and donors after cardiac death (DCD) was lower in the recipients who received MP. The similar DGF rates in BDSCD donor recipients were due to longer cold ischemia times in MP kidneys. The lower DGF rates seen in ECD and DCD recipients of pumped kidneys did not translate into a shortened length of hospitalization after transplant. CONCLUSIONS As currently deployed, only DCD and ECD donor recipients of MP kidneys experienced a lower DGF rate. In all subsets of patients, MP did not appreciably shorten the hospital length of stay.

UNASSIGNED: The implication of gut microbiota in the gut-kidney axis affects the pathophysiology of chronic kidney disease (CKD). Gut microbiota composition changes during CKD. We aimed to determine the relative frequency of important gut microbiota members in end-stage renal disease (ERSD) patients before and after renal transplantation compared to healthy subjects.
UNASSIGNED: Fifteen kidney transplant patients and 10 healthy subjects were recruited in this case-control prospective study. Fecal samples were taken sequentially from all patients before kidney transplantation, 1 week, and 1 month after it. The relative frequency of Lactobacillus spp., Bifidobacterium spp., Akkermansia muciniphila, Bacteroides fragilis, Escherichia coli, and Faecalibacterium pruasnitzii were determined through quantitative PCR. The obtained data was statistically analyzed by Stata software (Stata Corporation, USA).
UNASSIGNED: The mean log number of all bacteria was significantly higher in healthy individuals than kidney transplant recipients (p < 0.001) except for Lactobacillus where the mean levels were almost identical in the two groups (p = 0.67). Moreover, 20% (3) of patients developed a urinary tract infection. Besides, 2 (13.33%) patients were diagnosed with delayed graft function. There were no statistically significant differences regarding changing trends in bacteria log number of Akkermansia muciniphila (p = 0.12), Bacteroid fragilis (p = 0.75), Bifidobacterium (p = 0.99), Escherichia coli (p = 0.5), Faecalibacterium (p = 0.98), and Lactobacilli (p = 0.93) between patients with and without delayed graft function (DGF).
UNASSIGNED: Gut microbiota composition in patients with ESRD was significantly different from those without it. However, the microbiota profile did not significantly differ in patients with and without DGF.

As the global incidence of diabetes rises and diagnoses among younger patients increase, transplant centers worldwide are encountering more organ donors with diabetes. This study examined 80 donors and 160 recipients, including 30 donors with diabetes (DD) and their 60 recipients (DDR). The control group comprised 50 non-diabetic donors (ND) and 100 recipients (NDR). We analyzed clinical, biochemical, and pathological data for both diabetic and control groups, using logistic regression to identify risk factors for delayed graft function (DGF) after kidney transplantation. Results showed that pre-procurement blood urea nitrogen levels were significantly higher in DD [18.20 ± 10.63 vs. 10.86 ± 6.92, p = 0.002] compared to ND. Renal pathological damage in DD was notably more severe, likely contributing to the higher DGF incidence in DDR compared to NDR. Although DDR had poorer renal function during the first three months post-transplant, both groups showed similar renal function thereafter. No significant differences were observed in 1-year or 3-year mortality rates or graft failure rates between DDR and NDR. Notably, according to the Renal Pathology Society (RPS) grading system, kidneys from diabetic donors with a grade > IIb are associated with significantly lower postoperative survival rates. Recipient gender [OR: 5.452 (1.330-22.353), p = 0.013] and pre-transplant PRA positivity [OR: 34.879 (7.698-158.030), p < 0.001] were identified as independent predictors of DGF in DDR. In conclusion, transplant centers may consider utilizing kidneys from diabetic donors, provided they are evaluated pathologically, without adversely impacting recipient survival and graft failure rates.

BACKGROUND: Taurine is one of the most abundant amino acids in humans. Low taurine levels are associated with cellular senescence, mitochondrial dysfunction, DNA damage, and inflammation in mouse, all of which can be reversed by supplementation. It is unknown whether taurine metabolism is associated with kidney allograft function and survival.
METHODS: We performed urine metabolomic profiling of kidney transplant recipients in the early and late phases after transplantation combined with transcriptomic analysis of human kidney allografts. Single-nucleus RNA sequencing data sets of mouse kidneys after ischemia-reperfusion injury were analyzed. We analyzed the association of urinary taurine levels and taurine metabolism genes with kidney function, histology, and graft survival.
RESULTS: Urine taurine concentrations were significantly lower in kidney transplant recipients who experienced delayed graft function. In a mouse model of ischemia-reperfusion injury, the taurine biosynthesis gene, CSAD , but not the taurine transporter SLC6A6 , was repressed. In the late stage of transplantation, low level of taurine in urine was associated with impaired kidney function and chronic structural changes. Urine taurine level in the lowest tertile was predictive of graft loss. Expression of the taurine transporter SLC6A6 in the upper median, but not CSAD , was associated with chronic kidney injury and was predictive of graft loss.
CONCLUSIONS: Low urine taurine level is a marker of injury in the kidney allograft, is associated with poor kidney function, is associated with chronic histological changes, and is predictive of graft survival. The differential expression of CSAD and SLC6A6 , depending on the time after transplantation and marks of injury, highlights different mechanisms affecting taurine metabolism.

BACKGROUND: Delayed graft function (DGF) after kidney transplantation is associated with adverse patients and allograft outcomes. A longer duration of DGF is predictive of worse graft outcomes compared to a shorter duration. Posttransplant serum β2-microglobulin (B2M) is associated with long-term graft outcomes, but its relationship with DGF recovery is unknown.
METHODS: We included all kidney-only transplant recipients with DGF enrolled in the E-DGF trial. Duration of DGF was defined as the interval between the transplant and the last dialysis session. We analyzed the association of standardized serum creatinine (Scr) and B2M on postoperative Days (POD) 1-7 during the subsequent days of DGF with the recovery of DGF.
RESULTS: A total of 97 recipients with DGF were included. The mean duration of DGF was 11.0 ± 11.2 days. Higher Scr was not associated with the duration of DGF in unadjusted or adjusted models. Higher standardized B2M, in contrast, was associated with a prolonged duration of DGF. This association remained in models adjusting for baseline characteristics from POD 2 (3.19 days longer, 95% CI: 0.46-5.93; p = 0.02) through Day 6 of DGF (4.97 days longer, 95% CI: 0.75-9.20; p = 0.02). There was minimal change in mean Scr (0.01 ± 0. 10 mg/dL per day; p = 0.32), while B2M significantly decreased as the time to recovery approached (-0.14 ± 0.05 mg/L per day; p = 0.006), among recipients with DGF.
CONCLUSIONS: B2M is more strongly associated with DGF recovery than Scr. Posttransplant B2M may be an important biomarker to monitor during DGF.
BACKGROUND: ClinicalTrials.gov identifier: NCT03864926.

BACKGROUND: The study purpose was to review retrospectively our single-center experience transplanting kidneys from deceased donors (DD) with acute kidney injury (AKI) according to terminal serum creatinine (tSCr) level.
METHODS: AKI kidneys were defined by a doubling of the DD\'s admission SCr and a tSCr ≥ 2.0 mg/dL.
RESULTS: From 1/07 to 11/21, we transplanted 236 AKI DD kidneys, including 100 with a tSCr ≥ 3.0 mg/dL (high SCr AKI group, mean tSCr 4.2 mg/dL), and the remaining 136 from DDs with a tSCr of 2.0-2.99 mg/dL (lower SCr AKI group, mean tSCr 2.4 mg/dL). These two AKI groups were compared to 996 concurrent control patients receiving DD kidneys with a tSCr < 1.0 mg/dL. Mean follow-up was 69 months. Delayed graft function (DGF) rates were 51% versus 46% versus 29% (p < 0.0001), and 5-year patient and death-censored kidney graft survival rates were 96.8% versus 83.5% versus 82.2% (p = 0.002) and 86.7% versus 77.8% versus 78.8% (p = 0.18) in the high tSCr AKI versus lower tSCr AKI versus control groups, respectively.
CONCLUSIONS: Despite a higher incidence of DGF, patients receiving kidneys from DDs with tSCr levels ≥3.0 mg/dL have acceptable medium-term outcomes compared to either AKI DDs with a lower tSCr or DDs with a tSCr < 1.0 mg/dL.

Delayed graft function (DGF) after kidney transplantation heralds a worse prognosis. In patients with hyperoxaluria, the incidence of DGF is high. Oxalic acid is a waste product that accumulates when kidney function decreases. We hypothesize that residual diuresis and accumulated waste products influence the DGF incidence. Patients transplanted between 2018-2022 participated in the prospective cohort study. Pre-transplant concentrations of oxalic acid and its precursors were determined. Data on residual diuresis and other recipient, donor or transplant related variables were collected. 496 patients were included, 154 were not on dialysis. Oxalic acid, and glyoxylic acid, were above upper normal concentrations in 98.8%, and 100% of patients. Residual diuresis was ≤150 mL/min in 24% of patients. DGF occurred in 157 patients. Multivariable binary logistic regression analysis demonstrated a significant influence of dialysis type, recipient BMI, donor type, age, and serum creatinine on the DGF risk. Residual diuresis and glycolic acid concentration were inversely proportionally related to this risk, glyoxylic acid directly proportionally. Results in the dialysis population showed the same results, but glyoxylic acid lacked significance. In conclusion, low residual diuresis is associated with increased DGF incidence. Possibly accumulated waste products also play a role. Pre-emptive transplantation may decrease the incidence of DGF.

BACKGROUND: Ischemic-reperfusion injury resulting from kidney transplantation declines the post-transplant graft function. Remote ischemic conditioning (RIC) is known to be able to reduce the criticality of ischemic reperfusion injury. This study aimed to meta-analyze whether the application of remote ischemic conditioning to kidney transplantation patients improves clinical outcomes.
METHODS: Researchers included randomized controlled studies of the application of RIC to either kidney donors or recipients. Articles were retrieved from PubMed, Embase, Web of Science, and Cochrane Library. The risk of bias was evaluated using RoB 2.0. The primary outcome was mortality after transplantation. Secondary outcomes were the incidence of delayed graft function, graft rejection, and post-transplant laboratory results. All outcomes were integrated by RevMan 5.4.1.
RESULTS: Out of 90 papers, 10 articles (8 studies, 1977 patients) were suitable for inclusion criteria. Mortality collected at all time points did not show a significant difference between the groups. Three-month mortality (RR, 3.11; 95% CI, 0.13-75.51, P = 0.49) tended to increase in the RIC group, but 12-month (RR, 0.70; 95% CI, 0.14-3.45, P = 0.67) or final-reported mortality (RR, 0.49; 95% CI, 0.23-1.06, P = 0.07) was higher in the sham group than the RIC group. There was no significant difference between the RIC and sham group in delayed graft function (RR, 0.64; 95% CI, 0.30-1.35, P = 0.24), graft rejection (RR, 1.13; 95% CI, 0.73-1.73, P = 0.59), and the rate of time required for a 50% reduction in baseline serum creatinine concentration of less than 24 h (RR, 0.98; 95% CI, 0.61-1.56, P = 0.93).
CONCLUSIONS: It could not be concluded that the application of RIC is beneficial to kidney transplantation patients. However, it is noteworthy that long-term mortality tended to decrease in the RIC group. Since there were many limitations due to the small number of included articles, researchers hope that large-scale randomized controlled trials will be included in the future.
BACKGROUND: PROSPERO CRD42022336565.

BACKGROUND: With the rising prevalence of end-stage kidney disease, the use of expanded criteria donor allografts, seen as essential for meeting organ demand, still proves challenging due to their higher risk of graft loss, delayed function, and rejection. Machine perfusion, a technique in preserving allografts, offers improved allograft outcomes compared to static cold storage while allowing for the noninvasive measurement of kidney injury biomarkers in the perfusate solution. This offers an objective method to assess graft function at various preservation stages.
METHODS: We conducted a narrative review of the databases PubMed and Scopus, including studies written in the English language and published after 2010.
RESULTS: In this narrative review, we identified biomarkers, like 4-hydroxyproline, taurine, and glutathione transferase, as predictive markers of delayed graft function. Additionally, biomarkers, like extracellular histone h3, vascular cell adhesion protein, and matrix metalloprotease protein, have shown correlation with decreased graft function, although their predictive ability remains inconclusive.
CONCLUSIONS: The review outlines various suggestions for potential areas of research focus to enhance future expanded criteria donor allograft utilization. However, limitations exist, including the absence of a singular reliable biomarker and the challenges of validating biomarker effectiveness across diverse outcomes.

Therapeutic measures aimed at optimising organ function prior to transplantation-whether by conditioning the donor after determination of brain death or by improving organ preservation after kidney removal-have the potential to enhance outcomes after transplantation. The particular advantage is that, unlike any optimised immunosuppressive therapy, a favourable effect can be achieved without side effects for the organ recipient. In recent years, several such measures have been tested in controlled clinical trials on large patient cohorts following kidney transplantation. Hypothermic pulsatile machine perfusion, in particular, has become the focus of interest, but interventions in the donor prior to organ removal, such as the administration of low-dose dopamine until the start of cold perfusion as an example of conditioning antioxidant therapy and therapeutic donor hypothermia in the intensive care unit after brain death confirmation, have also significantly reduced the frequency of dialysis after transplantation with far less effort and cost. With regard to benefits for graft survival, the database for all procedures is less clear and controversial. The aim of this review article is to re-evaluate the available clinical evidence from large multicentre controlled trials, which have also significantly influenced later meta-analyses, and to assess the significance for use in routine clinical practice.