Impact of failed allograft nephrectomy on initial function and graft survival after kidney retransplantation

Kidney Retransplantation in Children

Pediatric kidney transplant recipients will likely require a retransplant in their lifetime. Although the significant advances in clinical management and newer immunosuppressive agents have had a significant effect to improve short-term allograft function, it is apparent that long-term allograft function remains suboptimal. Therefore, it is likely that most pediatric renal allograft recipients will require 1 or more retransplants during their lifetime. In the West, an increasing number of patients on the deceased donor wait list are awaiting a retransplant; in the US, 15% of current annual transplants are retransplants. Unfortunately, the use of a second or subsequent grafts in pediatric recipients has inferior long-term graft survival rates compared with initial grafts, with decreasing rates with each subsequent graft. Multiple issues influence the outcome of retransplant, with the most significant being the cause of the prior transplant failure. Nonadherenceassociated graft loss poses unresolved ethical issues that may affect a patient's access to retransplant. Graft nephrectomy prior to retransplant may benefit selected patients, but the effect of an in situ failed graft on the development of panel reactive antibodies remains to be definitively determined. It is important that these and other factors discussed in this presentation be taken into consideration during the counseling of families on the optimal approach for their child who requires a retransplant.

The Role of Allograft Nephrectomy in the Failing Kidney Transplant

Patients with failed renal allografts have associated increased morbidity and mortality. The individualization of immunosuppression taper is the key element in managing these patients to avoid graft intolerance and sensitization while balancing the risk of continued immunosuppression. Most patients with uncomplicated chronic allograft failure do not require allograft nephrectomy (AN), and there is no clear evidence that it improves outcomes. The AN procedure is associated with variable morbidity and mortality. It is reserved mainly for early technical graft failure or in symptomatic cases associated with allograft infection, malignancy, or graft intolerance syndrome. It may also be considered in those who cannot tolerate immunosuppression and are at high risk for graft intolerance. AN has been associated with an increased risk of sensitization due to inflammatory response from surgery, immunosuppression withdrawal with allograft failure, and retained endovascular tissue. Although it is presumed that for-cause AN after transplant failure is associated with sensitization, it remains unclear whether elective AN in patients who remain on immunotherapy may prevent sensitization. The current practice of immunosuppression taper has not been shown to prevent sensitization or increase infection risk, but current literature is limited by selection bias and the absence of medication adherence data. We discuss the management of failed allografts based on retransplant candidacy, wait times, risk of graft intolerance syndrome, and immunosuppression side effects. Many unanswered questions remain, and future prospective randomized trials are needed to help guide evidence-based management.

Transplant Nephrectomy: Current Concepts

Kidney transplantation is the gold standard treatment option for patients with endstage kidney disease. As the number of waitlisted patients increases, the gap between supply and demand for suitable donor kidneys keeps widening. The adoption of novel strategies that expand the donor pool has attenuated this issue to a certain degree, and this has led to a progressive increase in the number of annual transplants performed. As transplanted kidneys have a finite lifespan, there is a reciprocal rise in the number of patients who return to dialysis once their allograft fails. The clinicians involved in the management of such patients are left with the problem of managing the nonfunctioning allograft. The decision to undertake transplant nephrectomy (TN) in these patients is not straightforward. Allograft nephrectomy is a procedure that is associated with significant morbidity and mortality. It will have implications for the outcomes of the subsequent transplant. In this review, we aimed to compressively discuss the indications, techniques, and outcomes of TN, which is an integral component of the management of a failing allograft.

How to Deal With Kidney Retransplantation-Second, Third, Fourth, and Beyond

Kidney transplantation is the best health option for patients with end-stage kidney disease. Ideally, a kidney transplant would last for the lifetime of each recipient. However, depending on the age of the recipient and details of the kidney transplant, there may be a need for a second, third, fourth, or even more kidney transplants. In this overview, the outcome of multiple kidney transplants for an individual is presented. Key issues include surgical approach and immunologic concerns. Included in the surgical approach is an analysis of transplant nephrectomy, with indications, timing, and immunologic impact. Allograft thrombosis, whether related to donor or recipient factors merits investigation to prevent it from happening again. Other posttransplant events such as rejection, viral illness (polyomavirus hominis type I), recurrent disease (focal segmental glomerulosclerosis), and posttransplant lymphoproliferative disease may lead to the need for retransplantation. The pediatric recipient is especially likely to need a subsequent kidney transplant. Finally, noncompliance/nonadherence can affect both adults and children. Innovative approaches may reduce the need for retransplantation in the future.

Association of Nephrectomy of the Failed Renal Allograft With Outcome of the Future Transplant: A Systematic Review

Kidney allograft failure is a significant complication in kidney transplant recipients, and the surgical decision to perform allograft nephrectomy poses a strong dilemma because it is associated with significant morbidity and mortality. There is a debate over the effect of allograft nephrectomy on the development of allosensitization and the impact on potential retransplantation. Moreover, the use of immunosuppression may contribute to antibody allosensitization as allograft nephrectomy and immunosuppression act jointly and interdependently toward antibody formation. Because more and more patients with kidney allograft failure are entering wait lists for repeat transplant procedures, a review of available evidence on the field is required. Here, we performed a literature search using multiple medical databases to identify relevant studies that assessed the effects of allograft nephrectomy on important retransplant endpoints such as allograft and patient survival; furthermore, secondary outcomes such as alloantibody sensitization were also evaluated. A total of 15 studies were identified; all were retrospective, single-center studies. The rate of allograft nephrectomy in patients with retransplant varied widely (from 20% to 80%). The average allograft nephrectomy rate in included studies was 43% (allograft nephrectomy number/number of repeat transplantations: 2351/5431). Most studies did not observe an allograft survival benefit after retransplant for patients with allograft nephrectomy with the exception of 4 studies that found worse allograft survival after allograft nephrectomy. Interestingly, 1 study found that, in the patient subgroup with early kidney allograft failure (<12 months posttransplant), allograft nephrectomy may be associated with better allograft survival. Available data suggested that allograft nephrectomy may be associated with a higher risk of increasing anti-HLA antibody levels. The quality of the included studies suffered from nonrandomized design, potential confounding, and small sample size. To conclude, further randomized controlled trials are required to delineate the role of allograft nephrectomy on retransplant outcomes.

Practice patterns and influence of allograft nephrectomy in pediatric kidney re-transplantation: A pediatric nephrology research consortium study

INTRODUCTION

There are no guidelines regarding management of failed pediatric renal transplants.

MATERIALS & METHODS

We performed a first of its kind multicenter study assessing prevalence of transplant nephrectomy, patient characteristics, and outcomes in pediatric renal transplant recipients with graft failure from January 1, 2006, to December 31, 2016.

RESULTS

Fourteen centers contributed data on 186 pediatric recipients with failed transplants. The 76 recipients that underwent transplant nephrectomy were not significantly different from the 110 without nephrectomy in donor or recipient demographics. Fifty-three percent of graft nephrectomies were within a year of transplant. Graft tenderness prompted transplant nephrectomy in 91% (P < .001). Patients that underwent nephrectomy were more likely to have a prior diagnosis of rejection within 3 months (43% vs 29%; P = .04). Nephrectomy of allografts did not affect time to re-listing, donor source at re-transplant but significantly decreased time to (P = .009) and incidence (P = .0002) of complete cessation of immunosuppression post-graft failure. Following transplant nephrectomy, recipients were significantly more likely to have rejection after re-transplant (18% vs 7%; P = .03) and multiple rejections in first year after re-transplant (7% vs 1%; P = .03).

CONCLUSIONS

Practices pertaining to failed renal allografts are inconsistent-40% of failed pediatric renal allografts underwent nephrectomy. Graft tenderness frequently prompted transplant nephrectomy. There is no apparent benefit to graft nephrectomy related to sensitization; but timing / frequency of immunosuppression withdrawal is significantly different with slightly increased risk for rejection following re-transplant.

Allograft nephrectomy versus nonallograft nephrectomy after failed renal transplantation: a systematic review by updated meta-analysis

There is limited evidence regarding the impact of allograft nephrectomy (AN) on the long-term outcome of subsequent kidney re-transplantation compared with no prior allograft nephrectomy. The aim of the present study was to conduct a systematic review and meta-analysis to estimate the accumulation of evidence over time. Primary outcomes were 5-year graft and patient survival. Cochrane library, Google scholar, PubMed, Medline and Embase were systematically searched. Meta-analysis was conducted using both fixed- and random-effects models. Study quality was assessed in duplicate using the Newcastle-Ottawa scale. Sixteen studies were included, with a total of 2256 patients. All included studies were retrospective and comparative. There was no significant difference in 5-year graft survival (GS) [Hazard Ratio (HR) = 1.11, 95% Confidence Intervals (CI): 0.89, 1.38, P = 0.37, I²  = 10%) or in 5-year patient survival (PS; HR = 0.70, 95% CI: 0.45, 1.10, P = 0.12, I²  = 0%]. Patients in the AN cohort were significantly younger than patients in the nonallograft nephrectomy (NAN) cohort by one year. Prior allograft nephrectomy was associated with a significantly higher risk of delayed graft function (DGF), acute rejection, primary nonfunction (PNF), per cent of panel reactive antibodies (% PRA) and allograft loss of the subsequent transplant. Although, DGF, % PRA, acute rejection and primary nonfunction rates were significantly higher in the AN cohort, allograft nephrectomy prior to re-transplantation had no significant association with five-year graft and patient survival.

Embolization of the renal artery before graft nephrectomy: a comparing study to evaluate the possible benefits

The graft nephrectomy is burdened by immunological and surgical complications. The main surgical complications of graft nephrectomy are hemorrhage, infections, vascular injury and death. The mortality is high, with percentages varying between 1.3 and 38%. Therefore, graft nephrectomy should be recommended only in selected cases. We conducted a retrospective study, comparing the data of 26 patients undergoing an allograft nephrectomy (2009-2013), without embolization of the renal artery (NO EMBO group) with the data of 40 patients undergoing an allograft nephrectomy (2014-2019), with embolization of the renal artery (EMBO group). We included only graft nephrectomies performed at least 6 months after transplantation. The patients included in the study were consecutive because until 2013 we did not perform the embolization of the renal graft artery. Afterwards, from 2014, instead, we routinely carry out embolization to all patients to be subjected to graft nephrectomy. We, therefore, wanted to analyze whether this surgical approach compared to the previous technique can lead to an improvement in morbidity and mortality, reducing the risk of bleeding and operating times. The examination of our data highlights that embolization of renal artery reduces the operating times of the explant, in addition the group subjected to embolization had less changes in hemoglobinemia and less blood loss.

Management of patients with a failed kidney transplant: what should we do?

The number of kidney transplant recipients returning to dialysis after graft failure is steadily increasing over time. Patients with a failed kidney transplant have been shown to have a significant increase in mortality compared with patients with a functioning graft or patients initiating dialysis for the first time. Moreover, the risk for infectious complications, cardiovascular disease and malignancy is greater than in the dialysis population due to the frequent maintenance of low-dose immunosuppression, which is required to reduce the risk of allosensitization, particularly in patients with the prospect of retransplantation from a living donor. The management of these patients present several controversial opinions and clinical guidelines are lacking. This article aims to review the leading evidence on the main issues in the management of patients with failed transplant, including the ideal timing and modality of dialysis reinitiation, the indications for an allograft nephrectomy or the correct management of immunosuppression during graft failure. In summary, retransplantation is a feasible option that should be considered in patients with graft failure and may help to minimize the morbidity and mortality risk associated with dialysis reinitiation.

The Failing Kidney Transplant Allograft. Transplant Nephrectomy: Current State-of-the-Art

PURPOSE OF REVIEW

This review provides a critical literature overview of the risks and benefits of transplantectomy in patients with a failed allograft. Additionally, it offers a summary of related problems, primarily alloantibody sensitization in the event of nephrectomy and immunosuppression weaning.

RECENT FINDINGS

Transplant nephrectomy has high morbidity and mortality rates. The morbidity of transplant nephrectomy (4.3 to 82%) is mostly due to hemorrhage or infection. Mortality rates range from 1.2 to 39%, and most are due to sepsis. Transvascular graft embolization has been described as a less invasive alternative technique for the management of symptomatic graft rejection, with minimal complications compared with transplantectomy. The number of patients with a failed allograft returning to dialysis is increasing. The role of allograft nephrectomy in the management of asymptomatic transplant failure is still controversial and up today continues to depend on the usual clinical practice of each institution. The less invasive transvascular embolization could have applicability in asymptomatic patients with the obvious lower morbidity and mortality rate.

Long-term outcome of third, fourth and fifth kidney transplantation: technical aspects and immunological challenges

Background

The number of patients on waiting lists for repeated kidney transplantation has increased. However, retransplanted patients have a greater surgical and immunological risk than first-time kidney recipients.

Methods

We retrospectively analysed all kidney recipients that underwent third, fourth or fifth kidney transplantation (Group 3+) at the University Hospital Essen, Essen, Germany from October 1973 to January 2017. A historical cohort of recipients retransplanted with a second kidney (Group 2) served as the control. Donor and recipient demographic data, cold ischaemia time (CIT), warm ischaemia time, overall operation time and methods, transplantectomy of previous kidney grafts, incidence of surgical and immunological complications as well as patient- and death-censored survival were analysed.

Results

We identified 108 recipients transplanted with the third, fourth or fifth renal allograft. Patients with more than one transplantation had significantly higher surgical risk due to atherosclerosis (P = 0.002) and higher immunological risk due to higher panel reactive antibody levels preoperatively (current panel reactive antibody P = 0.004; highest panel reactive antibody value P = 0.0001). Group 3+ patients had more often undergone previous transplant nephrectomy (P = 0.0001). There was a significant difference in CIT (P = 0.009), overall operative time (P = 0.0001) and post-transplantation thrombotic events (P = 0.02). We could not demonstrate any differences in graft and patient survival.

Conclusion

Third, fourth and fifth transplant recipients are a high-risk patient cohort. Our results suggest that patient survival after more than three renal transplantations is similar to that of second graft recipients. This supports the concept of repeated kidney retransplantations.

Impact of Transplant Nephrectomy for Patient Survival Over the Past 15 Years: A Single-Center Study

OBJECTIVES

How transplant nephrectomy affects patient survival after return to dialysis is unclear. Here, we compared patient survival after graft loss between patients with and without transplant nephrectomy.

MATERIALS AND METHODS

We divided 171 patients who received transplant between 2000 and 2015 and had graft loss into 3 groups: 64 had graft failure left in situ (without nephrectomy), 51 had nephrectomy < 3 months posttransplant (early nephrectomy), and 56 patients had nephrectomy > 3 months posttransplant (late nephrectomy). The primary endpoint was patient survival. Risk factors for patient death were also analyzed. Secondary endpoints included relisting for transplant and immunosuppressive agent status.

RESULTS

Patient survival rates at 1, 3, and 5 years posttransplant in those without nephrectomy, early nephrectomy, and late nephrectomy were 92.1% /90.5%/86.6%, 96.0%/89.7%/80.4%, and 100.0% /97.9%/ 95.6%, respectively. Rates in patients with early nephrectomy differed significantly from those with late nephrectomy (P = .005). On multivariate analysis, patient survival was affected by relisting for transplant (hazard ratio 0.17; 95% confidence interval, 0.06-0.41; P < .001) and graft survival duration (hazard ratio 0.36, 95% confidence interval, 0.13-0.93; P = .036). Relisting for transplant occurred in 46.9% of patients without nephrectomy, 56.9% of patients with early nephrectomy, and 51.8% of patients with late nephrectomy. Those with late nephrectomy took 14.7 months after graft loss to relist for transplant, with 7.8 months for those without nephrectomy (P = .039) and 6.3 months for those with early nephrectomy (P = .051). Only 10.9% of those without nephrectomy were immunosuppressive free, which was in contrast to 94.1% and 78.6% of those with early and late nephrectomy, respectively.

CONCLUSIONS

After graft failure, patients without nephrectomy did not have inferior survival versus patients who received early or late nephrectomy. Graft survival time and relisting for transplant were associated with patient survival regardless of having transplant nephrectomy.

Prediction of rat liver transplantation outcomes using energy metabolites measured by microdialysis

BACKGROUND

Warm ischemia jeopardizes graft quality and recipient survival in donation after cardiac death (DCD) transplantation. Currently, there is no system to objectively evaluate the liver quality from DCD. The present study tried to use energy metabolites to evaluate the donor liver quality.

METHODS

We divided 195 Sprague-Dawley rats into five groups: the control (n = 39), warm ischemic time (WIT) 15 min (n = 39), WIT 30 min (n = 39), WIT 45 min (n = 39), and WIT 60 min (n = 39) groups. Three rats from each group were randomly selected for pretransplant histologic evaluation of warm ischemia-related damage. The remaining 36 rats were randomly divided into donors and recipients of 18 liver transplantations, and were subjected to postoperative liver function and survival analyses. Between cardiac arrest and cold storage, liver energy metabolites including glucose, lactate, pyruvate, and glycerol were measured by microdialysis. The lactate to pyruvate ratio (LPR) was calculated.

RESULTS

The changes in preoperative pathology with warm ischemia were inconspicuous, but the trends in postoperative pathology and aminotransferase levels were consistent with preoperative energy metabolite measurements. The 30-day survival rates of the control and WIT 15, 30, 45, and 60 min groups were 100%, 81.82%, 76.92%, 58.33%, and 25.00%, respectively. The areas under the receiver operating characteristic curves of glucose, lactate, glycerol, and LPR were 0.87, 0.88, 0.88, and 0.92, respectively.

CONCLUSION

Glucose, lactate, glycerol, and LPR are predictors of graft quality and survival outcomes in DCD transplantation.

Transplant nephrectomy after graft failure: is it so risky? Impact on morbidity, mortality and alloimmunization

PURPOSE

To determine the impact of transplant nephrectomy on morbidity and mortality and HLA immunization.

METHODS

All patients who underwent transplant nephrectomy in our centre between 2000 and 2016 were included in this study. A total of 2822 renal transplantations and 180 transplant nephrectomies were performed during this period.

RESULTS

The indications for transplant nephrectomy were graft intolerance syndrome: 47.2%, sepsis: 22.2%, vascular thrombosis: 15.5%, tumour: 8.3% and other 6.8%. Transplant nephrectomies were performed via an intracapsular approach in 61.7% of cases. The blood transfusion rate was 50%, the morbidity rate was 38% and the mortality rate was 3%. Transplant nephrectomies more than 12 months after renal transplant failure were associated with more complications (p = 0.006). Transfusions in the context of transplant nephrectomy had no significant impact on alloimmunization.

CONCLUSION

The risk of bleeding, and therefore of transfusion, constitutes the major challenge of this surgery in patients eligible for retransplantation. Even if transfusions in this context of transplant nephrectomy had no significant impact on alloimmunization, this high-risk surgery, whenever possible, must be performed electively in a well-prepared patient.

Impact of Allograft Nephrectomy on Second Renal Transplant Outcome

OBJECTIVES

The impact of allograft nephrectomy on the outcome of a subsequent renal transplant is unclear. This study was conducted to assess the effects of the first allograft nephrectomy on outcomes of a second transplant.

MATERIALS AND METHODS

This study included 118 patients who received a second transplant between 1994 and 2015. Before the second transplant, 59 patients did not undergo a first allograft nephrectomy (group A). Group B comprised 59 patients who had undergone a first allograft nephrectomy. We compared sensitization, acute rejection, and survival of the second graft between groups. The risk factors of a second graft loss were assessed.

RESULTS

The first graft survival was significantly longer in group A than in group B (100.6 vs 3.7 months; P < .001). Prevalence of preformed donor-specific antibodies before the second allograft was similar between both groups (28.8% vs 39.0% for group A vs group B; P = .243). Numerically higher acute rejection rates occurred in group B than in group A (23.7% vs 15.3%; P = .245). In group A, graft survival rates at 1, 3, and 5 years were 93.0%, 87.0%, and 82.3% and were significantly higher than for group B (76.7%, 69.1%, and 62.5%; P ⟨ .05). On multivariate analysis, survival of the second graft was affected by acute rejection (hazard ratio = 2.24; 95% confidence interval, 1.10-4.45; P = .027) and the interval from first graft loss to second transplant (hazard ratio = 1.11; 95% confidence interval, 1.02-1.19; P = .008).

CONCLUSIONS

A first allograft nephrectomy was associated with inferior second graft survival. We recommend that recipients of second transplants should be considered as high risk if they had undergone prior allograft nephrectomy.

Kidney retransplantation in children following rejection and recurrent disease

Retransplantation accounts for approximately 15 % of the annual transplants performed in the USA, and in the recent International Collaborative Transplant Study report on pediatric patients 15.2 % of the 9209 patients included in the report were retransplant recipients. Although the significant advances in clinical management and newer immunosuppressive agents have had a significant impact on improving short-term allograft function, it is apparent that long-term allograft function remains suboptimal. Therefore, it is likely that the majority of pediatric renal allograft recipients will require one or more retransplants during their lifetime. Unfortunately, a second or subsequent graft in pediatric recipients has inferior long-term graft survival rates compared to initial grafts, with decreasing rates with each subsequent graft. Multiple issues influence the outcome of retransplantation, with the most significant being the cause of the prior transplant failure. Non-adherence-associated graft loss poses unresolved ethical issues that may impact access to retransplantation. Graft nephrectomy prior to retransplantation may benefit selected patients, but the impact of an in situ failed graft on the development of panel-reactive antibodies remains to be definitively determined. It is important that these and other factors discussed in this review be taken into consideration during the counseling of families on the optimal approach for their child who requires a retransplant.

Dynamics and epitope specificity of anti-human leukocyte antibodies following renal allograft nephrectomy

BACKGROUND

A considerable proportion of patients awaiting kidney transplantation is immunized by previous transplantation(s). We investigated how allograft nephrectomy (Nx) and withdrawal of maintenance immunosuppression (WD-MIS) in patients with a failed renal allograft contribute to allosensitization.

METHODS

HLA antibodies (HLAabs) were analyzed before and after Nx and/or WD-MIS using a single antigen bead assay. Patients were grouped as follows: (A) Nx and concomitant WD-MIS (n = 28), (B) Nx (n = 14) and (C) WD-MIS (n = 12). In a subgroup of patients, the epitope specificity of HLAabs was determined by adsorption and elution of sera with recombinant single HLA allele-expressing cell lines.

RESULTS

Following Nx and/or WD-MIS, HLAabs were detectable in 100, 100 and 92% of patients in Groups A, B and C, respectively. In patients of all groups, de novo donor-specific HLAabs (DSAs) were found. After Nx, an increase in the breadth [percent panel reactive antibody (%PRA)] and mean fluorescence intensity of class I HLAabs was predominant. In contrast, an increase of class II HLAabs prevailed following WD-MIS. Experimental analysis of the epitope specificities revealed that 64% of the class I HLAabs classically denoted as non-DSA were donor epitope-specific HLAabs (DESA).

CONCLUSIONS

Both Nx and WD-MIS contribute to alloimmunization with differing patterns concerning class I and II HLAabs. Nx preferentially increased class I HLAabs and most of the observed class I HLAabs were DESA. Considering that class I, but not class II, HLA molecules are constitutively expressed, our results support the hypothesis that the increase of HLAabs following Nx might have been caused by removal of the adsorbing donor tissue (sponge hypothesis).

Impact of CYP3A5 and MDR-1 gene polymorphisms on the dose and level of tacrolimus among living-donor liver transplanted patients: single center experience

AIM OF WORK

To assess the impact of Cytochrome P450 3A5 (CYP3A5) and multidrug resistance-1 gene (MDR-1) single nucleotide polymorphisms on the dose and blood level of tacrolimus among liver transplanted patients.

PATIENTS AND METHODS

We enrolled a prospective study of 41 liver transplanted patients. Dose-adjusted trough blood concentration (C/D ratio) was calculated. Polymerase chain reaction-restriction fragment length polymorphism followed by sequencing was done for genotyping of CYP3A5*3 (6986A > G).

RESULTS

At 1 week, 1 and 3 months C/D ratio were significantly lower in CYP3A5 expressers *1/*1 patients compared to non-expressers *3/*3.

CONCLUSION

CYP3A5 (6986A > G) genotype, rather than MDR-1 (2677G > A/T) variant, has an impact on tacrolimus pharmacokinetics.

Kidney retransplantation: removal or persistence of the previous failed allograft?

A significant percentage of patients with failed renal graft are candidates for retransplantation. The outcomes of retransplantation are poorer than those of primary transplantation and sensitization is documented to be a major reason. The management of a failed allograft that is not immediately symptomatic is still very controversial. The aim of this study was to determine the impact of the failed allograft nephrectomy on a subsequent transplantation and its importance in the sensitization. We performed a retrospective analysis of the local prospective transplantation registry of the outcome of 126 second kidney transplantations among 2438 transplantations performed in our unit between June 1980 and March 2013, comparing those who underwent allograft nephrectomy prior to retransplantation with those who retained the failed graft. Primary endpoints were graft and patient survival. The levels of panel-reactive antibodies (PRA) and rate of acute rejections on retransplantation outcomes were also studied. Among the 126 patients who underwent a second renal transplantation, 76 (60.3%) had a prior graft nephrectomy (Group A), whereas 50 (39.7%) kept their failed graft (Group B). Group A showed significantly more positive PRA levels when compared with the other group (38% vs 10%; P < .001), as measured before the most recent transplantation, and a higher rate of acute rejection (19% vs 5.6%; P = .016). There were 28 (36%) renal allograft losses for Group A and 18 (36%) for those who had not had transplantectomy (P = not significant [NS]). One-, 3-, and 5-year graft survival rates were 96.6%, 90.7%, and 83.4%, respectively, in Group A and 95%, 82%, and 68.4%, respectively, in Group B, with no statistical differences (P = .19). Five-year actuarial patient survival rates in the 2 groups was 89.3% and 82.8%, respectively (P = .55). Multivariate analysis showed that PRA level and delayed graft function (DGF) had a statistically significant influence on graft survival (P = .028; odds ratio [OR] = 1.029; and P = .024; OR = 8.6), irrespective of whether the patient had graft nephrectomy or not. The allosensitization indicated by PRA increases after transplantectomy and leads to a higher incidence of acute rejection after retransplantation. Nephrectomy of failed allograft does not seem to significantly influence the survival of a subsequent graft. The decision to remove or retain a failed graft in the context of retransplantation should thus be based on known clinical indications for the procedure.

HLA sensitisation: can it be prevented?

Human leukocyte antigen (HLA) sensitisation occurs after transfusion of blood products and transplantation. It can also happen spontaneously through cross-sensitisation from infection and pro-inflammatory events. Patients who are highly sensitised face longer waiting times on organ allocation programmes, more graft rejection and therefore more side effects of immunosuppression, and poorer graft outcomes. In this review, we discuss these issues, along with the limitations of modern HLA detection methods, and potential ways of decreasing HLA antibody development. We do not discuss the removal of antibodies after they have developed.

Ischemic injury of the liver in a porcine model of cardiac death assessed by in vivo microdialysis

This study aims to evaluate the ischemic injury of the liver in a porcine model of cardiac death assessed by in vivo microdialysis. A porcine model of cardiac death was established by the suffocation method. Metabolic indicators were monitored using the microdialysis technique during warm ischemia time (WIT) and cold ischemia time (CIT). Pathological changes in ischemic-injured livers were observed by haematoxylin-eosin staining. The predictive values of biochemical parameters regarding the liver donor were evaluated by receiver operating characteristic curve analysis. All statistical analyses were conducted using the SPSS 18.0 software (SPSS Inc, Chicago, Illinois, USA). The degree of warm ischemic injury of the livers increased with prolonged WIT. Serum glucose, glycerol, pyruvate, lactic acid levels and lactate-to-pyruvate (L/P) ratio increased gradually during WIT. Results from Pearson correlation analyses indicated that serum lactate level and L/P ratio were positively associated with the degree of warm ischemic injury of the livers. The degree of cold ischemic injury of the livers gradually increased after 12 h CIT. Serum glucose, lactic acid and L/P ratio achieved a peak after 6-8 h of CIT, but gradually decreased with prolonged CIT. The peak of glycerol occurred after 8 h of CIT, while no changes were found with prolonged CIT. Serum pyruvate level exhibited an increasing trend after 12 h CIT. Our results confirmed that serum glucose and lactate levels were negatively correlated with cold ischemic injury of the liver. However, serum glycerol and pyruvate levels showed positive correlations with cold ischemic injury of the liver. The liver donor was unavailable after 30 min WIT and 24 h CIT. The cut-off value of serum lactate level for warm ischemic injury of the livers was 2.374 with a sensitivity (Sen) of 90 % and specificity (Spe) of 95 %; while the L/P radio was 0.026 (Sen = 80 %, Spe = 83 %). In addition, the cut-off values of serum glucose, lactate, glycerol and pyruvate levels for cold ischemic injury of the livers were 0.339 (Sen = 100 %, Spe = 77 %), 1.172 (Sen = 100 %, Spe = 61 %), 56.359 (Sen = 100 %, Spe = 65 %) and 0.020 (Sen = 100 %, Spe = 67 %), respectively. Our findings provide empirical evidences that serum glucose, lactate levels and L/P ratio may be good indicators for the degree of warm ischemic injury of the livers after cardiac death; while serum glucose, lactate, glycerol and pyruvate levels may be important in predicting cold ischemic injury.

Impact of transplant nephrectomy on peak PRA levels and outcome after kidney re-transplantation

AIM: To determine the impact of transplant nephrectomy on peak panel reactive antibody (PRA) levels, patient and graft survival in kidney re-transplants.

METHODS: From 1969 to 2006, a total of 609 kidney re-transplantations were performed at the University of Freiburg and the Campus Benjamin Franklin of the University of Berlin. Patients with PRA levels above (5%) before first kidney transplantation were excluded from further analysis (n = 304). Patients with graft nephrectomy (n = 245, NE+) were retrospectively compared to 60 kidney re-transplants without prior graft nephrectomy (NE-).

RESULTS: Peak PRA levels between the first and the second transplantation were higher in patients undergoing graft nephrectomy (P = 0.098), whereas the last PRA levels before the second kidney transplantation did not differ between the groups. Age adjusted survival for the second kidney graft, censored for death with functioning graft, were comparable in both groups. Waiting time between first and second transplantation did not influence the graft survival significantly in the group that underwent nephrectomy. In contrast, patients without nephrectomy experienced better graft survival rates when re-transplantation was performed within one year after graft loss (P = 0.033). Age adjusted patient survival rates at 1 and 5 years were 94.1% and 86.3% vs 83.1% and 75.4% group NE+ and NE-, respectively (P < 0.01).

CONCLUSION: Transplant nephrectomy leads to a temporary increase in PRA levels that normalize before kidney re-transplantation. In patients without nephrectomy of a non-viable kidney graft timing of re-transplantation significantly influences graft survival after a second transplantation. Most importantly, transplant nephrectomy is associated with a significantly longer patient survival.

Nephrectomy for the failed renal allograft in children: predictors and outcomes

BACKGROUND

There are no guidelines for the removal of a failed renal allograft, and its impact on subsequent dialysis and retransplantation has not yet been described.

METHODS

We performed a 10-year review of allograft failure to study the factors that determined an outcome of transplant nephrectomy and choice of subsequent renal replacement therapy in children with or without nephrectomy.

RESULTS

A total of 34 children developed graft failure over the 10-year study period, of whom 18 (53 %) required transplant nephrectomy. The median graft survival was 1.1 (range 0.2-10.6) versus 7.5 (1.5-15.0) years in the nephrectomy and non-nephrectomy groups, respectively (p = 0.011). Children with graft failure within 1 year of transplantation were four-fold more likely to require transplant nephrectomy than those with graft failure after 1 year (p = 0.04). Renal biopsy performed at ≤ 8 weeks prior to graft loss showed Banff grade II acute rejection in 13 of the 18 children who required subsequent nephrectomy versus three of the 13 children who did not need nephrectomy (p = 0.01). Inflammation (fever, graft tenderness and raised C-reactive protein (CRP) in the 2 weeks preceding graft failure) was seen in 66 % of nephrectomized children, but not in any in the non-nephrectomy group (p = 0.0003 for CRP between groups). Banff II rejection, an inflammatory response and the time post-transplantation significantly and independently predicted the outcome of nephrectomy (p = 0.008, R (2) = 67 %). Human leukocyte antigen (HLA) antibody levels after graft failure were higher in the nephrectomy group (p = 0.0003), but there was no difference between groups in terms of the presence or class of donor-specific antibodies. Of the children with graft failure, 82 % required dialysis (61 % hemodialysis) and 35 % have to date been successfully retransplanted.

CONCLUSIONS

Children with Banff II rejection, an inflammatory response and early graft loss are more likely to require transplant nephrectomy. Nephrectomy may be associated with higher circulating HLA antibody levels.

Residual renal function in peritoneal dialysis with failed allograft and minimum immunosuppression

Immunosuppression (IS) is often withdrawn in patients with end stage renal disease secondary to a failed renal allograft, and this can lead to an accelerated loss of residual renal function (RRF). As maintenance of RRF appears to provide a survival benefit to peritoneal dialysis (PD) patients, it is not clear whether this benefit of maintaining RRF in failed allograft patients returning to PD outweigh the risks of maintaining IS. A 49 year-old Caucasian male developed progressive allograft failure nine years after living-donor renal transplantation. Hemodialysis was initiated via tunneled dialysis catheter (TDC) and IS was gradually withdrawn. Two weeks after IS withdrawal he developed a febrile illness, which necessitate removal of the TDC and conversion to PD. He was maintained on small dose of tacrolimus (1 mg/d) and prednisone (5 mg/d). Currently (1 year later) he is doing exceedingly well on cycler-assisted PD. Residual urine output ranges between 600-1200 mL/d. Total weekly Kt/V achieved 1.82. RRF remained well preserved in this patient with failed renal allograft with minimal immunosuppressive therapy. This strategy will need further study in well-defined cohorts of PD patients with failed allografts and residual RRF to determine efficacy and safety.

[Kidney nephrectomy after allograft failure]

The number of kidney-transplant patients that return to dialysis therapy after a failed kidney allograft is increasing sharply. These patients differ from patients treated with chronic dialysis, but who have never received a transplant; i.e., former transplanted patients display a higher risk of morbidity-mortality, particularly from cardiovascular and infectious complications. The management of immunosuppression has not been codified for patients with a failed kidney allograft: immunosuppressive therapy can be either abruptly stopped or progressively reduced. In addition, nephrectomy of the failed allograft is debatable. Some advocate this procedure only when there is intolerance, e.g., gross hematuria, local pain, or unexplained inflammatory syndrome. In contrast, others propose a systematic nephrectomy, mainly to reveal anti-HLA antibodies within peripheral blood that may have been adsorbed within the failed allograft, and are not detected, even using sensitive techniques. Prospective studies are warranted to answer these issues.

Impact of renal graft nephrectomy on second kidney transplant survival

PURPOSE

To determine the impact of non-functional renal graft nephrectomy on second kidney transplantation survival.

METHODS

We performed a retrospective study on patients managed in our department from April 1989 to April 2011. We compared the number of acute graft rejections and graft survival between patients undergoing second transplantation with (Group I) or without (Group II) prior graft nephrectomy.

RESULTS

A total of ninety-one patients received a second renal graft: 43 underwent graft nephrectomy and 48 kept their non-functional renal graft. There were 5 episodes of acute graft rejection in Group I and 12 in Group II (p = 0.3). Six (13.9 %) grafts failed in Group I and eight (16.6 %) in Group II. Five and 10 years actuarial graft survival in Group I were, respectively, 91 and 85 %, while in Group II were 82.7 % and 69 % (p = 0.2). PRA level and number of acute rejection episodes did not have a statistically significant influence on graft survival, whether the patient had a nephrectomy or not (p = 0.2).

CONCLUSION

Nephrectomy of a failed allograft did not significantly improve the survival of a subsequent graft. Graft nephrectomy should be indicated in case of graft-related pain or a chronic inflammation syndrome.

Impact of transplant nephrectomy on retransplantation: a single-center retrospective study

PURPOSE

Kidney retransplantation is the best treatment option for transplanted patients returning to dialysis. The aim of this study was to explore the effect of removal of a failed graft on the outcome of a subsequent transplant.

METHODS

We identified 140 patients who underwent retransplantation at our institution. Retrospective comparison was performed between patients undergoing kidney retransplantation with (group A, n = 28) and without (group B, n = 112) preliminary nephrectomy. Graft and patient survival were calculated by the Kaplan-Meier method.

RESULTS

After a mean follow-up of 64.5 months, patients survival was comparable between the two groups (group A = 68.6 vs. group B = 63.5 months; p = 0.6). Mean graft survival was 65.5 versus 56.0 months in group A and B, respectively (p = 0.14). Surgical complications after retransplantation were significantly higher in group A compared to group B (57.1 vs. 19.6 %; p = 0.0002). There was no significant difference between the two groups in the panel reactive antibody level at the time of retransplantation (group A = 20 % vs. group B = 32 %; p = 0.22). The acute rejection rate was 35.7 % in group A and 25 % in group B (p = 0.36). The risk of delayed graft function was not significantly increased in group A (p = 0.63). Finally, 2 years after retransplantation, patients who had not undergone nephrectomy had lower serum creatinine concentrations (1.3 vs. 1.7 mg/dl; p = 0.01) and higher estimated GFR (77.9 vs. 59.3 ml/min/1.73 m(2); p = 0.02).

CONCLUSION

Our experience shows that there is no advantage in performing allograft nephrectomy before retransplantation, and that this procedure does not seem to significantly influence the survival of a subsequent graft.

Donor-specific antibodies after ceasing immunosuppressive therapy, with or without an allograft nephrectomy

BACKGROUND AND OBJECTIVES

Within the last few years, anti-human leukocyte antigen detection assays have significantly improved. This study asked, using the Luminex single-antigen assay, whether an allograft nephrectomy allowed donor-specific alloantibodies to appear that were not previously detected in the serum when the failed kidney was still in place.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

After losing the kidney allograft and stopping immunosuppressive therapy, the proportions of donor-specific alloantibodies and nondonor-specific alloantibodies were compared in patients who had (n=48; group I) and had not (n=21; group II) undergone an allograft nephrectomy. Allograft nephrectomies were performed at 150 days after kidney allograft loss, and the time between allograft nephrectomy and last follow-up was 538 ± 347 days.

RESULTS

At kidney allograft loss, donor-specific alloantibodies were detected in three group II patients (14.2%) and six group I patients (12.5%). At last follow-up, donor-specific alloantibodies were detected in 11 patients (52.4%) without and 39 patients (81%) with an allograft nephrectomy (P=0.02). Anti-human leukocyte antigen class I donor-specific alloantibodies were positive in 23.8% of group II and 77% of group I patients (P<0.001); anti-human leukocyte antigen class II donor-specific alloantibodies were positive in 42.8% of group II and 62.5% of group I patients. Independent predictive factors for developing donor-specific alloantibodies after losing kidney allograft and stopping immunosuppressants were number of anti-human leukocyte antigen A/B mismatches at transplantation (zero versus one or more) and allograft nephrectomy.

CONCLUSIONS

The development of donor-specific alloantibodies was significantly greater in patients with a failed kidney who had undergone an allograft nephrectomy compared with those patients who had not undergone allograft nephrectomy.

Transplant nephrectomy

About 10% of all renal allografts fail during the first year of transplantation and thereafter approximately 3%-5% yearly. Given that approximately 69 400 renal transplants are performed worldwide annually, the number of patients returning to dialysis following allograft failure is increasing. A failed transplant kidney, whether maintained by low dose immunosuppression or not, elicits an inflammatory response and is associated with increased morbidity and mortality. The risk for transplant nephrectomy (TN) is increased in patients who experienced multiple acute rejections prior to graft failure, develop chronic graft intolerance, sepsis, vascular complications and early graft failure. TN for late graft failure is associated with greater morbidity and mortality, bleeding being the leading cause of morbidity and infection the main cause of mortality. TN appears to be beneficial for survival on dialysis but detrimental to the outcome of subsequent transplantation by virtue of increased level of antibodies to mismatched antigens, increased rate of primary non function and delayed graft function. Many of the studies are characterized by a retrospective and univariate analysis of small numbers of patients. The lack of randomization in many studies introduced a selection bias and conclusions drawn from such studies should be applied with caution. Pending a randomised controlled trial on the role of TN in the management of transplant failure patients, it is prudent to remove failed symptomatic allografts and all grafts failing within 3 mo of transplantation, monitor inflammatory markers in patients with retained failed allografts and remove the allograft in the event of a significant increase in levels.