Delayed graft function

Association of Intraoperative Hypotension With Delayed Graft Function Following Kidney Transplant: A Single Centre Retrospective Cohort Study

BACKGROUND

Intraoperative hypotension is associated with acute kidney injury after surgery. However, the definition (duration and magnitude) of hypotension during kidney transplantation (KT) surgery on early graft function remains unclear.

METHODS

We conducted a retrospective cohort study of KT recipients from December 1, 2009, to December 31, 2019. Exposure to intraoperative hypotension was characterized as the duration (minutes) of mean arterial pressure (MAP) <55, <65, <75, and <85 mmHg. Our co-primary outcomes were DGF-creatinine reduction ratio (DGF-CRR, <30% creatinine reduction, postoperative days 1 and 2), and DGF-dialysis (DGF-D, required dialysis within the week of KT for deceased donor recipients). Logistic regression models were fitted to assess this relationship between MAP and DGF.

RESULTS

We included 1602 KT (939 deceased donors, 663 living donors) and 23 were excluded. DGF-CRR occurred in 33% of patients. DGF-CRR was associated with MAP < 65 (>5 min: OR 1.77, 95% confidence interval [CI]: 1.39-2.30; 6-10 min: OR 1.67, 95% CI: 0.97-2.86; 11-20 min: OR 2.18, 95% CI: 1.31-3.63) in unadjusted and <55 mmHg (5 min: OR 1.85, 95% CI: 1.47-2.32; 5-10 min: OR 2.41, 95% CI: 1.65-3.53; 11-20 min: OR 2.36, 95% CI: 1.60, 3.48) in adjusted models. There was also a signal for increased risk of DGF-CRR at MAP < 75 (>5 min: OR 1.69, 95% CI: 1.02-2.80). DGF-D (incidence 35%) in deceased donor KT was not associated with hypotension.

CONCLUSIONS

We found an association between intraoperative hypotension and DGF-CRR at a threshold MAP of 55 mmHg, with a consistent signal toward increased risk at both 65 and 75 mmHg, as indicated by unadjusted models.

The Association Between Delayed Graft Function and Renal Resistive Index in Kidney Transplant Recipients

Background and objectives

Delayed graft function (DGF) may increase the risk for kidney graft dysfunction. Renal resistive index (RRI) in Doppler ultrasonography is useful in measuring blood flow changes in kidneys which is indicative of tubulointerstitial damage. Most of the diseases in DGF etiology are related to tubulointerstitium and arteries of the kidneys. In this study, we investigated whether there is a relationship between delayed graft function and renal resistive index in kidney transplant recipients (KTR).

Materials and methods

Patients who underwent kidney transplantation were included in this retrospective study. KTR were divided into two groups as DGF (+) and DGF (−). Comparison of RRI values of DGF (+) and DGF (−) groups according to the measurements at different times.

Results

The findings showed that both RRI measurements (post-transplant in the first week and the end of the first year) of the DGF (+) group were higher than DGF (−) group (p=0.001 and p=0.003, respectively). The interaction of measurements and DGF did not have an effect on RRI (p>0.05).

Conclusion

The value of RRI in the DGF (−) group was lower than DGF (+) group in the first week after kidney transplantation.

Quantitative Assessment of Intraoperative Laser Fluorescence Angiography with Indocyanine Green Predicts Early Graft Function after Kidney Transplantation

Objective:

This study was designed to demonstrate the predictive ability of quantitative indocyanine green (ICG) fluorescence angiography for the short-term postoperative outcome, the occurrence of delayed graft function (DGF), and long-term graft survival.

Summary Background Data:

DGF is a relevant problem after kidney transplantation; sufficient microperfusion of the allograft is crucial for postoperative organ function. Fluorescence angiography with ICG can serve as an intraoperative quality control of microperfusion.

Methods:

This prospective diagnostic study, conducted in 2 German transplantation centers from November 2015 to October 2018, included 128 consecutive kidney transplantations. Intraoperative assessment of the allograft microperfusion was performed by near-infrared fluorescence angiography with ICG; a software was used for quantitative analysis. The associations between perfusion parameters (eg, ICG Ingress) and donor, recipient, peri-procedural, and postoperative characteristics were evaluated.

Results:

DGF occurred in 23 (24%) kidney recipients from deceased donors. ICG Ingress (P = 0.0027), donor age (P = 0.0452), recipient age (P = 0.0139), and recipient body mass index (P = 0.0017) were associated with DGF. ICG Ingress correlated significantly with recipient age (r = −0.27662, P = 0.0016), cold and warm ischemia time (r = −0.25204, P = 0.0082; r = −0.19778, P = 0.0283), operating time (r = −0.32208, P = 0.0002), eGFR on postoperative days 1 (r =+0.22674, P = 0.0104) and 7 (r = +0.33189, P = 0.0001). The cutoff value for ICG Ingress was 106.23 AU with sensitivity of 78.3% and specificity of 80.8% (P < 0.0001) for the prediction of DGF.

Conclusion:

Fluorescence angiography with ICG allows intraoperative quantitative assessment of microperfusion during kidney transplantation. The parameter ICG Ingress reflects recipient and procedure characteristics and is able to predict the incidence of DGF.

Trial registration:

Clinicaltrials.gov: NCT-02775838

Impact of Induction Therapy on Delayed Graft Function Following Kidney Transplantation in Mated Kidneys

BACKGROUND

Delayed graft function (DGF) is defined as the need for dialysis within 1 week of transplantation and occurs in 20%-50% of deceased-donor kidney transplant recipients. Although recovery from DGF often occurs within a few days, many cases may take weeks to months before the transplant function begins. The delay in function increases the complexity of recipient care, makes the diagnosis of acute rejection more difficult, prolongs length of stay, and increases hospital costs. Although several authors have proposed nomograms to predict DGF, there is no identifiable strategy to ameliorate it, except for the possible use of a specific type of induction therapy called Thymoglobulin.

METHODS

In this retrospective analysis we included 407 subjects, of which 76 were mated (left and right kidney transplanted at Montefiore from the same donor). We used conditional logistic regression analysis while adjusting for the mated kidneys. We adjusted for age, gender, and race a priori, as well as cold ischemia time.

RESULTS

There was a 36% decrease in odds of DGF when Thymoglobulin was used as induction when compared with basiliximab in mated kidneys 0.64 (0.10-4.05) (odds ratio [OR] with 95% confidence interval [CI]).

CONCLUSIONS

Thymoglobulin did have a protective effect in these data when analyzed in mated kidneys, however, we need a larger amount of data to concretely conclude this effect.

Prognostic Value of Levels of Urine Neutrophil Gelatinase-associated Lipocalin and Interleukin-18 in Patients With Delayed Graft Function After Kidney Transplantation

OBJECTIVE

The aim of our study was to examine how serial urine neutrophil gelatinase-associated lipocalin (uNGAL) and interleukin (IL)-18 concentrations change over time after kidney transplantation and whether we can use them to predict delayed graft function (DGF).

METHODS

Spot urine samples for the NGAL and IL-18 tests were taken at 4, 12, 24, 48, and 72 hours after transplantation from every patient at hospital presentation. Urine samples were tested for NGAL by a chemiluminescence assay kit on the ARCHITECT I2000 immunology analyzer. IL-18 were measured by a quantitative immunoenzymatic assay kit. Serum samples for the creatinine measurement were taken at 24, 48, and 72 hours after kidney transplantation. Serum samples were tested for creatinine on the Olympus analyzer 5821 by alkaline picric acid method. The patients were divided into 2 groups: DGF group and non-DGF group.

RESULTS

The urine NGAL levels were increased in DGF group at all points over the follow-up period. There are differences (P < .05) in NGAL concentrations between DGF (n = 21) and non-DGF groups (n = 102). However, urine samples from the DGF group (n = 21) had increased IL-18 concentrations at 4, 12, 24, and 48 hours postoperatively compared with non-DGF group samples (n = 102) (P < .05). There were obvious distinctions (P < .05) of serum creatinine (SCr) levels in 24 hours between the DGF (n = 21) and non-DGF groups (n = 102). The specificity and positive predictive value of NGAL in the DGF diagnosis increased with time, but the sensitivity and negative predictive value do not change. The specificity, sensitivity, positive predictive, value and negative predictive value of IL-18 in the DGF diagnosis changed irregularly at multiple time points after transplant. The positive predictive value and negative predictive value of 24-hour SCr were 47.4% and 95.7%, respectively. The positive predictive value and negative predictive value of combination of NGAL, IL-18, and SCr (area under the receiver-operating characteristic curve = 0.984; 95% CI, 0.887-0.994) were 90.9% and 100%, respectively. Overall, the combination of NGAL, IL-18, and SCr was found to have a significantly better positive predictive value than all the other combination assays (P < .05). In addition, there were obvious distinction of the negative predictive value of NGAL and IL-18 combination compared with those of other combinations (P < .05).

CONCLUSIONS

The combination of NGAL, IL-18, and SCr measurements after initiation of treatment may be highly effective for risk stratification in patients with DGF. The combination may be useful to cover the complete diagnostic window of patients presenting with DGF.

Long-term Effects of Delayed Graft Function on Pancreas Graft Survival After Pancreas Transplantation

BACKGROUND

Compared with the impact of delayed graft function (DGF) after renal transplantation, DGF after pancreas transplantation has not been fully evaluated.

METHODS

We retrospectively verified the impact of DGF on long-term pancreas graft survival in surgically successful cases. Pancreas graft failure was defined by the recipient's return to exogenous insulin administration.

RESULTS

Between May 2004 and April 2013, we performed 135 technically successful primary pancreas transplantations. Delayed graft function was defined as a total cumulative insulin requirement of 19 UI or greater within postoperative 7 days. Of the 135 recipients in our study cohort, 47 (34.8%) developed DGF after the pancreas transplantation. By multivariate analysis, DGF was found to be associated with a donor age of 30 years or older (odds ratio, 3.4; 95% confidence interval, 1.50-7.69; P=0.003) and the increased ratio of body mass index in a recipient to a donor (odds ratio, 26.1; 95% confidence interval, 2.53-270.0; P=0.006). There was a trend toward higher acute rejection (P=0.622) and mortality (P=0.49) rates in recipients with versus without DGF, although this did not reach statistical significance. Delayed graft function was found to be associated with a greater risk of overall pancreas graft failure (P=0.016) and death-censored graft failure (P=0.037).

CONCLUSION

Delayed graft function after pancreas transplantation was found to be associated with a greater risk of overall pancreas graft failure and death-censored graft failure.

Anaphylatoxins in organ transplantation

C3a and C5a (also called anaphylatoxins) are inflammatory peptides generated during complement activation. They do not only play important roles in innate immunity through the initiation and regulation of inflammatory responses, but also significantly influence adaptive immune responses. Organ transplantation triggers an initial inflammatory response and subsequent to the specific immune response (also called the alloimmune response), both of which contribute to graft rejection. Emerging evidence suggests that anaphylatoxins, particularly C5a, are significantly involved in both inflammatory and alloimmune responses following organ transplantation, thus influencing graft outcome. This review will provide the information on our current understanding of the roles for anaphylatoxins in ischemia-reperfusion injury, graft rejection, and transplant tolerance, and the therapeutic potential of targeting anaphylatoxin receptors in organ transplantation.

Therapeutic roles of curcumin: lessons learned from clinical trials

Extensive research over the past half century has shown that curcumin (diferuloylmethane), a component of the golden spice turmeric (Curcuma longa), can modulate multiple cell signaling pathways. Extensive clinical trials over the past quarter century have addressed the pharmacokinetics, safety, and efficacy of this nutraceutical against numerous diseases in humans. Some promising effects have been observed in patients with various pro-inflammatory diseases including cancer, cardiovascular disease, arthritis, uveitis, ulcerative proctitis, Crohn's disease, ulcerative colitis, irritable bowel disease, tropical pancreatitis, peptic ulcer, gastric ulcer, idiopathic orbital inflammatory pseudotumor, oral lichen planus, gastric inflammation, vitiligo, psoriasis, acute coronary syndrome, atherosclerosis, diabetes, diabetic nephropathy, diabetic microangiopathy, lupus nephritis, renal conditions, acquired immunodeficiency syndrome, β-thalassemia, biliary dyskinesia, Dejerine-Sottas disease, cholecystitis, and chronic bacterial prostatitis. Curcumin has also shown protection against hepatic conditions, chronic arsenic exposure, and alcohol intoxication. Dose-escalating studies have indicated the safety of curcumin at doses as high as 12 g/day over 3 months. Curcumin's pleiotropic activities emanate from its ability to modulate numerous signaling molecules such as pro-inflammatory cytokines, apoptotic proteins, NF-κB, cyclooxygenase-2, 5-LOX, STAT3, C-reactive protein, prostaglandin E(2), prostate-specific antigen, adhesion molecules, phosphorylase kinase, transforming growth factor-β, triglyceride, ET-1, creatinine, HO-1, AST, and ALT in human participants. In clinical trials, curcumin has been used either alone or in combination with other agents. Various formulations of curcumin, including nanoparticles, liposomal encapsulation, emulsions, capsules, tablets, and powder, have been examined. In this review, we discuss in detail the various human diseases in which the effect of curcumin has been investigated.

Receptor binding mode and pharmacological characterization of a potent and selective dual CXCR1/CXCR2 non-competitive allosteric inhibitor

BACKGROUND AND PURPOSE

DF 2156A is a new dual inhibitor of IL-8 receptors CXCR1 and CXCR2 with an optimal pharmacokinetic profile. We characterized its binding mode, molecular mechanism of action and selectivity, and evaluated its therapeutic potential.

EXPERIMENTAL APPROACH

The binding mode, molecular mechanism of action and selectivity were investigated using chemotaxis of L1.2 transfectants and human leucocytes, in addition to radioligand and [(35) S]-GTPγS binding approaches. The therapeutic potential of DF 2156A was evaluated in acute (liver ischaemia and reperfusion) and chronic (sponge-induced angiogenesis) experimental models of inflammation.

KEY RESULTS

A network of polar interactions stabilized by a direct ionic bond between DF 2156A and Lys(99) on CXCR1 and the non-conserved residue Asp(293) on CXCR2 are the key determinants of DF 2156A binding. DF 2156A acted as a non-competitive allosteric inhibitor blocking the signal transduction leading to chemotaxis without altering the binding affinity of natural ligands. DF 2156A effectively and selectively inhibited CXCR1/CXCR2-mediated chemotaxis of L1.2 transfectants and leucocytes. In a murine model of sponge-induced angiogenesis, DF 2156A reduced leucocyte influx, TNF-α production and neovessel formation. In vitro, DF 2156A prevented proliferation, migration and capillary-like organization of HUVECs in response to human IL-8. In a rat model of liver ischaemia and reperfusion (I/R) injury, DF 2156A decreased PMN and monocyte-macrophage infiltration and associated hepatocellular injury.

CONCLUSION AND IMPLICATIONS

DF 2156A is a non-competitive allosteric inhibitor of both IL-8 receptors CXCR1 and CXCR2. It prevented experimental angiogenesis and hepatic I/R injury in vivo and, therefore, has therapeutic potential for acute and chronic inflammatory diseases.

Delayed graft function in the kidney transplant

Acute kidney injury occurs with kidney transplantation and too frequently progresses to the clinical diagnosis of delayed graft function (DGF). Poor kidney function in the first week of graft life is detrimental to the longevity of the allograft. Challenges to understand the root cause of DGF include several pathologic contributors derived from the donor (ischemic injury, inflammatory signaling) and recipient (reperfusion injury, the innate immune response and the adaptive immune response). Progressive demand for renal allografts has generated new organ categories that continue to carry high risk for DGF for deceased donor organ transplantation. New therapies seek to subdue the inflammatory response in organs with high likelihood to benefit from intervention. Future success in suppressing the development of DGF will require a concerted effort to anticipate and treat tissue injury throughout the arc of the transplantation process.

Risk factors for delayed graft function after hand-assisted laparoscopic donor nephrectomy

BACKGROUND

Delayed graft function (DGF) has a negative effect on the results of living-donor kidney transplantation.

OBJECTIVE

To investigate potential risk factors for DGF.

METHODS

This prospective study included 200 consecutive living donors and their recipients between January 2002 and July 2007. Delayed graft function was defined as need for dialysis within the first postoperative week.

RESULTS

Delayed graft function was diagnosed in 12 patients (6%). Intraoperative complications occurred in 10 donors (5%), and postoperative complications in 24 donors (13.5%). One-year kidney graft survival with vs without DGF was 52% and 98%, respectively (P < .002). In donors, 2 univariate risk factors for DGF identified were lower counts per second at peak activity during scintigraphy, and multiple renal veins. In recipients, only 2 or more kidney transplantations and occurrence of an acute rejection episode were important factors. At multivariate analysis, increased risk of DGF was associated with the presence of multiple renal veins (odds ratio, 151.57; 95% confidence interval, 2.53-9093.86) and an acute rejection episode (odds ratio, 78.87; 95% confidence interval, 3.17-1959.62).

CONCLUSION

Hand-assisted laparoscopic donor nephrectomy is a safe procedure. The presence of multiple renal veins and occurrence of an acute rejection episode are independent risk factors for DGF.

Complement in organ transplantation

PURPOSE OF REVIEW

The aim of this review is to bring to attention the most recent advances made in understanding the role of complement components in both innate and adaptive immune responses in solid organ transplantation with emphasis on the kidney.

RECENT FINDINGS

Alongside recent findings related to the role of anaphylatoxins in modulating adaptive immune responses, there has been a genomic study to assess the expression of inflammatory markers in kidney transplantation, showing significant involvement of some complement molecules in predicting graft function. Modulators of complement pathway activity such as decay accelerating factor (CD55) and CD59 have also been shown to have a role in graft rejection. Potential new therapeutic targets related to complement proteins are being investigated.

SUMMARY

The mechanism of rejection in solid organ transplantation is influenced by the initial inflammatory response and subsequent adaptive allo-immune response, both of which have been shown to be affected by various complement components. Due to limitations of existing treatments, new approaches are needed to better control these responses to improve graft survival. Built on an expanding knowledge of complement involvement, targeted blocking of the effector complement molecules and modulating the expression of complement inhibitors has suggested potentially useful approaches for reducing the effect of inflammatory damage from cold ischaemia as well as reducing the activation of the adaptive immune system related to complement.

Posttransplant ischemia-reperfusion injury in transplanted heart is prevented by a minibody to the fifth component of complement

BACKGROUND

Complement activation has been implicated in the development of posttransplant ischemia-reperfusion (I/R) which is responsible for the delayed function of 20% to 30% of grafts. C5a and the terminal complement complex (TCC) are the complement activation products mainly involved in tissue injury caused by I/R.

METHODS

To control activation of the terminal step of the complement activation pathways, we used a neutralizing minibody to C5 containing a human single-chain fragment variable (scFv) linked to the hinge region, CH2, and CH3 domains of rat IgG1.

RESULTS

The minibody acts on C5 inhibiting the release of C5a and the assembly of TCC and depletes circulating C5 in Sprague-Dawley rats with a therapeutic activity of 4 hr. Administration of the minibody to rats 30 min before heart allotransplantation prevented tissue deposition of TCC, apoptosis, and necrosis of the graft and increase in the levels of serum creatine phosphokinase and tumor necrosis factor-alpha observed in control transplanted rats.

CONCLUSIONS

These data suggest that an anti-C5 therapy is effective in preventing graft injury caused by I/R. A minibody containing the human scFv linked to the hinge region and the CH2 and CH3 domains of human IgG1 is ready for use in clinical transplantation.

[Solutions for organ preservation and other cardioplegic liquid formulations. Role of the hospital pharmacist]

Solid organ transplantation is an increasing need and a well-established activity which requires maintaining the quality of the transplant from procurement through the entire, storage, transport and graft procedure. Solutions for organ preservation play a key role in this procedure, by minimizing the deleterious effects of both ischemia and reperfusion. As such, their qualitative and quantitative compositions have to be optimized and validated. The development strategy and formulations proposed for these solutions are analyzed in this review as well as the results of the clinical studies which have set up the relevant pharmacological and physicochemical criteria. The French regulatory status of these products is also discussed. A clear distinction has to be made between solutions for organ preservation which are classified as produits thérapeutiques annexes (therapeutic ancillary products) and cardioplegic liquid formulations which are considered as medicinal products and are subject to marketing approval. Finally, the roles of the hospital pharmacist in the evaluation, selection, purchase and proper use of these products are described.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Early onset proteinuria after renal transplantation: a marker for allograft dysfunction

The objective of this study was to determine whether early proteinuria after renal transplantation affected long-term allograft survival. The 130 patients included 105 men and 25 women of overall mean age, 29.6 +/- 9.6 years. There were 105 living related and, 25 cadaveric donor transplants. Proteinuria was defined as a level in of more than 300 mg/d. Donor and recipient age at transplantation, duration of pretransplant dialysis, donor type (living related or cadaveric), the presence of delayed graft function or acute rejection, panel-reactive antibodies, the number of human leukocyte antigen mismatches, and the systolic blood pressure level were retrospectively recorded for the study subjects. Cox regression analysis was used to determine the effects of proteinuria on allograft survival. Patients with proteinuria demonstrated significantly lower graft survival rates than did those without proteinuria (54.17% vs 82.62%, respectively; P<.002). Proteinuria at the third month after transplantation (P<.004, odds ratio [OR]=3.26, confidence interval [CI]=1.46 to 7.29), donor age (P<.001, OR=1.06, CI=1.02 to 109), and panel-reactive antibodies (P<.041, OR=1.06, CI=1.00 to 1.12) were significantly associated with decreased allograft survival. Early proteinuria after renal transplantation was indicative of a high risk for allograft dysfunction. A reduction of proteinuria may be associated with improved graft survival.

Pretransplantation Systolic Blood Pressure and the Risk of Delayed Graft Function in Young Living-Related Renal Allograft Recipients

Delayed graft function (DGF) is associated with decreased long-term renal allograft survival, however, the entire mechanism of action of DGF has not yet been established. The goal of this study was to determine possible risk factors for DGF in young living-related renal allograft recipients. We retrospectively analyzed the outcome of 142 renal transplant recipients (115 men and 27 women; mean age, 29.7 +/- 9.43 years; 114 living-related donors and 28 cadaveric donors). Data recorded for each patient and donor included gender, age at transplantation, duration of pretransplantation dialysis (recipients only), body mass index, number of human leucocyte antigen mismatches, panel-reactive antibodies, donor creatinine clearance, body weight, systolic and diastolic blood pressure levels, lipid profile, and biochemical parameters. Having obtained the transplant from a cadaveric donor (P<.000, odds ratio [OR]=17.556, confidence interval [CI]=5.961-51.743) and a pretransplantation systolic blood pressure level in the recipient of <120 mm Hg (P<.021, OR=3.600, CI=1.214-10.672) were possible risk factors for DGF. When only living-related recipients were considered, the systolic blood pressure level was significantly associated with DGF. We concluded that a pretransplantation systolic blood pressure level <120 mm Hg is a risk factor for DGF and that preoperative blood pressure control and intervention may help to decrease the risk of DGF.

Evaluation of the Effects of Ischemic Injury and Ureteral Obstruction on Delayed Graft Function in Cats After Renal Autotransplantation

OBJECTIVE

To determine the relative importance of ischemic injury to delayed graft function (DGF) in cats.

STUDY DESIGN

Experimental study.

ANIMALS

Six intact female cats.

METHODS

Cats had renal autograft transplantation without ureteral transection and reimplantation and a contralateral nephrectomy. Serum creatinine and blood urea nitrogen (BUN) concentrations were measured regularly and abdominal ultrasound was performed before surgery, the day after surgery and twice weekly thereafter. Ultrasound-guided renal biopsy was performed on day 7. Cats were euthanatized on day 21. Histology of the autograft, ureter, bladder, vascular anastomoses sites, and contralateral kidney were performed. Observations were compared with those from an historic group of research cats that had extravesicular ureteroneocystostomy and contralateral nephrectomy.

RESULTS

Five cats completed the study. Serum creatinine and BUN concentrations increased after surgery, peaking at 3.2+/-0.8 and 77.6+/-15.9 mg/dL, respectively, 1-2 days after surgery. Serum creatinine concentration returned to the reference interval by 6 days after surgery. BUN gradually decreased in all cats but did not return to the reference interval by study end. Serum creatinine and BUN concentrations were consistently lower but not significantly so (P=.29 and .56, respectively) compared with the historic ureteroneocystostomy group. No ultrasonographic abnormalities or renal biopsy histologic abnormalities were observed. At necropsy, 1 autograft had generalized interstitial fibrosis.

CONCLUSION

Harvesting the renal graft and the ischemia before revascularization causes impaired renal function after engraftment.

CLINICAL RELEVANCE

The process of harvesting and reimplanting the renal graft can contribute to DGF in cats, independent of ureteral obstruction.

Comparative efficacy of renal preservation solutions to limit functional impairment after warm ischemic injury

In kidney transplantation, cold storage is the dominant modality used to prolong organ viability ex vivo, but is inevitably followed by a period of warm ischemia. Preservation fluids limit tissue damage during the ischemic period, but there is little information on the influence of preservation fluids on the physiologic consequences of warm ischemia alone, or on the comparative ability of such preservation fluids to limit warm ischemic injury. In this study, warm ischemia was induced in rat kidneys by crossclamping the left renal pedicle for 45 min with contralateral nephrectomy. The ischemic kidneys were flushed with Euro-Collins (EC), hyper osmolar citrate (HOC), University of Wisconsin (UW), or phosphate buffered sucrose (PBS)140 solution. Over a period of 2 h after reperfusion, urine and blood samples were collected and physiological parameters related to the function of the postischemic kidneys were assessed. The data show that postischemic renal function can be influenced by the choice of preservation fluid. Essentially, the continued use of EC as a renal preservation solution finds little support in these data, and, while HOC and UW solutions were better able to limit the decline in renal function after warm ischemia than EC, the solution most able to limit functional impairment after warm ischemia was PBS140. This analysis compares the efficacies of the commonly used preservation solutions and could form the basis for future solid-organ transplant studies that may ultimately allow us to propose best-practice guidelines and an optimum platform for improved preservation solutions.

Beneficial effects of the bioflavonoids curcumin and quercetin on early function in cadaveric renal transplantation: a randomized placebo controlled trial

BACKGROUND

The bioflavonoids quercetin and curcumin are renoprotective natural antioxidants. We wished to examine their effects on early graft function (EF).

METHODS

Between September 2002 and August 2004, 43 dialysis dependent cadaveric kidney recipients were enrolled into a study using Oxy-Q which contains 480 mg of curcumin and 20 mg of quercetin, started after surgery and taken for 1 month. They were randomized into three groups: control (placebo), low dose (one capsule, one placebo) and high dose (two capsules). Delayed graft function (DGF) was defined as first week dialysis need and slow function (SGF) as Cr >2.5 mg/dl by day 10. Category variables were compared by chi squared and continuous variables by Kruskal-Wallis.

RESULTS

There were four withdrawals: one by patient choice and three for urine leak. The control group had 2/14 patients with DGF vs. none in either treatment group. Incidence of EF was control 43%, low dose 71% and high dose 93% (P=0.013). Serum creatinine was significantly lower at 2 days (control 7.6+/-2.1, low 5.4+/-0.6, high 3.96+/-.35 P=0.0001) and 30 days (control 1.82+/-.16, low 1.65+/-.09, high 1.33 +/-.1, P=0.03). Acute rejection incidence within 6 months was control 14.3%, low dose 14.3% and high dose 0%. Tremor was detected in 13% of high dose patients vs. 46% of others. Urinary HO-1 was higher in bioflavonoid groups.

CONCLUSION

Bioflavonoid therapy improved early graft function. Acute rejection and neurotoxicity were lowest in the high dose group. These bioflavonoids improve early outcomes in cadaveric renal transplantation, possibly through HO-1 induction.

Cyclosporine Prolongs Delayed Graft Function in Kidney Transplantation: Are Rabbit Anti-Human Thymocyte Globulins the Answer?

BACKGROUND

Cyclosporine (CsA) nephrotoxicity may prolong duration of anuria in renal transplant patients with delayed graft function (DGF). Thus, many Transplant Centers tend to delay CsA treatment in order to accelerate renal function recovery.

METHODS

In this single-center, retrospective analysis we compared the outcomes of 40 renal transplant patients with DGF given a CsA-based (n = 17) regimen since the day of transplant or a CsA-sparing regimen (n = 23) based on early treatment with rabbit anti-human thymocyte globulin (RATG) and delayed CsA administration. We studied all patients with DGF who received a first or second graft at the Bergamo Transplant Center from January 1992 to March 2000.

RESULTS

Patients given RATG as compared to those on CsA had significantly shorter duration of anuria (11.0 +/- 5.6 vs. 19.6 +/- 8.9 days; p < 0.005) and of initial hospitalization (17.4 +/- 4.3 vs. 27.4 +/- 10.4 days; p < 0.001). Throughout the whole study period, 4 patients on RATG as compared to 6 on CsA had an acute rejection episode (p > 0.05). However, no patient on RATG as compared to 4 on CsA had an acute rejection during the anuria period (p < 0.05). Costs including hospitalization, dialysis treatment and study drugs were significantly lower in RATG than in CsA patients (EUR 29,944 +/- 7,281 vs. 36,795 +/- 13,656; p < 0.05).

CONCLUSIONS

In renal transplant patients with DGF, early RATG treatment with delayed CsA administration accelerated renal function recovery and patient discharge, prevented occult rejections throughout the anuria period and significantly decreased the treatment costs.

Randomized clinical trial of daclizumab induction and delayed introduction of tacrolimus for recipients of non-heart-beating kidney transplants

Background

Kidneys from non-heart-beating donors (NHBDs) have high rates of delayed graft function (DGF). Use of calcineurin inhibitors is associated with a reduction in renal blood flow, which may delay graft recovery from ischaemic acute tubular necrosis.

Methods

To assess whether daclizumab (DZB) could safely replace tacrolimus in the immediate postoperative period, patients were randomized to receive DZB induction and daily mycophenolate mofetil with steroids (DZB group) or standard tacrolimus-based triple therapy (control group). Tacrolimus was given to patients in the DZB group when the serum creatinine level dropped below 350 µmol/l.

Results

Fifty-one patients were recruited at two centres over a 2-year interval between 2000 and 2003. The overall rate of immediate function was 28 per cent (13 of 46 grafts), with the highest rate in recipients of machine-perfused kidneys treated with DZB (eight of 15 patients).

Conclusion

Induction with DZB and delayed introduction of tacrolimus reduced the incidence of DGF in recipients of machine-perfused NHBD kidneys.

Delayed graft function in kidney transplantation

Delayed graft function is a form of acute renal failure resulting in post-transplantation oliguria, increased allograft immunogenicity and risk of acute rejection episodes, and decreased long-term survival. Factors related to the donor and prerenal, renal, or postrenal transplant factors related to the recipient can contribute to this condition. From experimental studies, we have learnt that both ischaemia and reinstitution of blood flow in ischaemically damaged kidneys after hypothermic preservation activate a complex sequence of events that sustain renal injury and play a pivotal part in the development of delayed graft function. Elucidation of the pathophysiology of renal ischaemia and reperfusion injury has contributed to the development of strategies to decrease the rate of delayed graft function, focusing on donor management, organ procurement and preservation techniques, recipient fluid management, and pharmacological agents (vasodilators, antioxidants, anti-inflammatory agents). Several new drugs show promise in animal studies in preventing or ameliorating ischaemia-reperfusion injury and possibly delayed graft function, but definitive clinical trials are lacking. The goal of monotherapy for the prevention or treatment of is perhaps unattainable, and multidrug approaches or single drug targeting multiple signals will be the next step to reduce post-transplantation injury and delayed graft function.

Correction of base deficits in deceased organ donors: Effects on immediate renal allograft function

Fluid status in the brain-dead donor is often difficult to assess. We hypothesized that using base deficit as a measure of tissue perfusion will facilitate fluid management in these donors, thereby improving renal allograft function. Consecutive donors over a 12-month period were prospectively studied. In Group I, resuscitation was based on maintaining normal blood pressure and urine output. In Group II, additional parameters of resuscitation included the correction of base deficit. Immediate renal allograft function was examined in the 48 recipients. Delayed graft function occurred in 48% of Group I, and in 19% of Group II recipients. Creatinine clearance on day 7, calculated by the Cockroft-Gault formula, was 29 +/- 6 mL/min in Group I versus 41 +/- 8 mL/min in Group II. We conclude that correcting base deficit is an extremely useful approach to expedite organ recovery and potentially improve function of transplanted kidneys.

Risk factors and impact of delayed graft function after pancreas transplants

Delayed graft function (DGF) occurs after many pancreas transplants (PTx), but is poorly characterized. We studied its incidence, course, and impact in a series of 531 pancreas transplants. Between January 1997 and September 2002, we performed 531 technically successful primary PTx. Of these 531 recipients, 176 (33%) had DGF, defined by their need for exogenous insulin at the time of hospital discharge. The incidence of DGF was roughly equivalent in the three transplant categories: SPK (36%), PAK (32%), and PTA (31%) (p = NS). By 3 months posttransplant, only 19 (3.5%) of all recipients remained on insulin. Only three recipients (0.56%) did not achieve insulin independence. The mean donor age of recipients with DGF was 35.1 years vs. 28.8 years without DGF (p = 0.003). By multivariate analysis, the most significant risk factor for DGF was donor age > 45 years (RR = 4.3, p = 0.0001). For SPK recipients with DGF, graft survival was 87% at 1 year and 82% at 3 years posttransplant; without DGF, 94% at 1 year and 87% at 3 years (p = 0.07). For PAK and PTA recipients, no difference was noted. Acute rejection rates were somewhat higher in recipients with DGF, but this did not reach statistical significance.

Induction immunosuppressive therapy stratified according to risk categories in renal transplantation

BACKGROUND

Immunosuppressive therapy is critical during the induction phase for it directly affects graft outcome. Many centers use uniform regimens, although not all patients represent similar risks. The purpose of this study was to evaluate a prospective protocol of immunosuppression according to 2 significant risks in kidney transplant: acute rejection (AR) and delayed graft function (DGF).

METHODS

This study included 35 patients (group I) stratified before starting the immunosuppression as follows: (1) standard risk, (2) increased risk of AR, and (3) augmented risk of DGF. Standard risk patients were treated with Cyclosporine (CsA) and Prednisone (Pred) (n = 18). Patients with increased risk of AR were treated with CsA plus Pred plus Mycophenolate Mofetil (n = 4) or sequential induction with antithymocyte globulin (n = 5). Patients with augmented risk of DGF were started on sequential induction with late inception of CsA (n = 8). Comparisons were made with a series of 20 patients (group II) who received a uniform regimen including CsA plus Pred plus Azathioprine.

RESULTS

AR and DGF rates were 6% and 16% for group I versus 39% and 39% for group II (P =.01 and P =.1, respectively). Serum creatinine values at 30 and 360 days were 1.43 +/- 0.45 and 1.29 +/- 0.40 in group I and 1.99 +/- 1.05 and 1.60 +/- 0.42 in group II (P <.05 for each comparison). Adverse effects, graft survival, and average costs were similar in both groups.

CONCLUSION

The use of differentiate protocols was associated with better graft function and a reduced frequency of AR and DGF. Although 50% of patients required sequential or triple-drug induction, the adverse events and costs were similar. These results encourage the use of individualized immunosuppression.

Prognostic significance of microvascular thrombosis in donor kidney allograft biopsies

BACKGROUND

With a continuing demand for donor kidneys for organ transplantation, it is important to understand the significance of pathologic findings in the donor organ before transplantation. Microvascular thrombosis is sometimes encountered in association with disseminated intravascular coagulation in the donor, and it is unclear whether this finding may affect immediate allograft function and long-term graft survival. To further elucidate this question, we examined our experience with microvascular thrombosis in donor biopsies in the kidney transplant program at our institution.

METHODS

Donor kidney biopsies showing microvascular thrombosis were identified from consecutive donor biopsies in the Duke University Medical Center transplant file database between January 1, 1995 and December 31, 2000. These biopsies and all other kidney biopsies and specimens from the recipients of these kidneys thus identified were reviewed. Sections were stained using a variety of methods, including hematoxylin-eosin, periodic acid-Schiff, methenamine silver, and Masson trichrome methods. Clinical records of the transplant recipients of these kidneys were also reviewed to assess allograft performance and survival.

RESULTS

From 230 consecutive donor kidney biopsies, we identified eight cases exhibiting donor-microvascular thrombosis. Mean follow-up times were 27.5 months for the thrombi group and 35 months for the non-thrombi group. Recipients of grafts with donor thrombi were more likely to exhibit delayed graft function, but graft function at 1 and 2 years and graft survival were similar between the two groups. Subsequent posttransplantation biopsies in five of eight cases showed no evidence of residual thrombosis.

CONCLUSIONS

These data suggest that the presence of donor microvascular thrombosis does not portend poor outcome in renal transplantation.

The influence of Duffy blood group on renal allograft outcome in African Americans

BACKGROUND

African American patients demonstrate higher rates of acute allograft rejection and lower kidney-graft survival compared with white patients. Duffy antigen receptor for chemokines (DARC) on red blood cells has been suggested to have an anti-inflammatory role by acting as a "chemokine sink." We investigated the relationship of Duffy blood group type to renal allograft outcome in African American patient population.

METHODS

A total of 163 African American kidney-transplant recipients were studied for Duffy blood group status. Patient outcomes were assessed at 6 to 42 months after transplantation and monitored for acute rejection episodes, graft function, and graft survival.

RESULTS

A total of 117 (71.8%) patients were Duffy (a-b-), 14 (8.6%) Duffy (a+b-), 21 (12.9%) Duffy (a-b+), and 11 (6.8%) Duffy (a+b+). No significant differences were observed among the groups with respect to median serum-creatinine values or the incidence of biopsy-confirmed acute-rejection episodes. Although only 15.4% of the patients had Duffy (a+) antigen, none lost their allograft during the study period, and Kaplan-Meier graft survival was not significantly different compared to Duffy (a-) group (log-rank test, P=0.12). Duffy (a-b-) patients demonstrated lower allograft survival compared with the other three groups, although statistical significance was not reached (log-rank test P=0.15). Delayed graft function (DGF) was strongly associated with graft failure for only Duffy (a-b-) patients (log-rank test P=0.003).

CONCLUSIONS

Duffy (a-b-) patients have lower allograft survival in the presence of DGF. DARC may attenuate the inflammatory effects of DGF by acting as a "chemokine sink," and DARC-negative patients may be more vulnerable to DGF.