Kidney graft survival in Europe and the United States: strikingly different long-term outcomes

Clinical and histological evolution after de novo donor-specific anti-human leukocyte antigen antibodies: a single centre retrospective study

Background

Donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) can be preformed or de novo (dn). Strategies to manage preformed DSA are well described, but data on the management and outcomes of dnDSA are lacking.

Methods

We performed a retrospective analysis of data from a single centre of the management and outcomes of 22 patients in whom a dnDSA was identified with contemporary and follow up biopsies.

Results

Evolution from baseline to follow up revealed a statistically significant loss of kidney function (estimated glomerular filtration rate: 45.9 ± 16.7 versus 37.4 ± 13.8 ml/min/1.73 m²; p = 0.005) and increase in the proportion of patients with transplant glomerulopathy (percentage with cg lesion ≥1: 27.2% vs. 45.4%; p = 0.04). Nine patients were not treated at the time of dnDSA identification, and 13 patients received various drug combinations (e.g., corticosteroids, plasmapheresis, thymoglobulins and/or rituximab). No significant pathological changes were observed for the various treatment combinations.

Conclusion

Our retrospective analysis of a small sample suggests that dnDSA should be considered a risk factor for the loss of kidney function independent of the baseline biopsy, and multidisciplinary evaluations of the transplant patient are a necessary requirement. Further confirmation in a multicentre prospective trial is required.

Evaluation of the 1000 renal transplants carried out at the University Hospital of the Botucatu Medical School (HCFMB) - UNESP and their evolution over the years

INTRODUCTION

The progress in kidney transplantation has been evident over the years, as well as its benefits for patients.

OBJECTIVES

To evaluate the 1.000 kidney transplants performed at the Botucatu Medical School University Hospital, subdividing the patients in different periods, according to the current immunosuppression, and evaluating the differences in graft and patient survival.

METHODS

Retrospective cohort analysis of the transplants performed between 06/17/87 to 07/31/16, totaling 1,046 transplants, subdivided into four different periods: 1) 1987 to 2000: cyclosporine with azathioprine; 2) 2001 to 2006: cyclosporine with mycophenolate; 3) 2007 to 2014: tacrolimus with antimetabolic; and 4) 2015 to 2016: tacrolimus with antimetabolic, with increased use of the combination of tacrolimus and mTOR inhibitors.

RESULTS

There was an increase in the mean age of recipients and increase in deceased donors and their age in the last two periods. There was a reduction in graft function delay, being 54.3% in the fourth period, compared to 78.8% in the first, p = 0.002. We found a reduction in acute rejection, being 6.1% in the last period compared to 36.3% in the first, p = 0.001. Urological complications and diabetes after transplantation were more frequent in the first two periods. The rates of cytomegalovirus infection were higher in the last two periods. There was an improvement in graft survival, p = 0.003. There was no difference in patient survival, p = 0.77 (Figure 2).

CONCLUSION

There was a significant increase in the number of transplants, with evolution in graft survival, despite the worsening in the profiles of recipients and donors.

AFT survival model to capture the rate of aging and age-specific mortality trajectories among first-allogeneic hematopoietic stem cells transplant patients

Accelerated failure time (AFT) model is commonly applied in engineering studies to address the failure rate of a machine. In humans, survival profile of transplant patients is among the rare scenarios whereby AFT is applicable. To date, it is uncertain whether reliable risk estimates and age-specific mortality trajectories have been published using conventional statistics approach. By investigating mortality trajectory, the rate of aging d(log(μ(x)))/dx of Hematopoietic Stem Cells Transplants (HSCTs) patients who had underwent first-allogeneic transplants can be obtained, and to unveil the possibility of elasticity of human aging rate in HSCTs. A modified parametric frailty survival model was introduced to the survival profiles of 11,160 patients who had underwent first-allogeneic HSCTs in the United States between 1995 and 2006; data was shared by Center for International Bone and Marrow Transplant Research. In comparison to stratification, the modification permits two entities in relation to time to be presented; age and calendar time. To consider its application in empirical studies, the data contains arbitrary right-censoring, a statistical condition which is preferred by choice in many transplant studies. The finalized multivariate AFT model was adjusted for clinical and demographic covariates, and age-specific mortality trajectories were presented by donor source and post-transplant time-lapse intervals. Two unexpected findings are presented: i) an inverse J-shaped hazard in unrelated donor-source t≤100-day; ii) convergence of unrelated-related hazard lines in 100-day365-day) must consider for periodic medical improvements, and transplant year as a standalone time-variable is not sufficient for statistical adjustment in the finalized multivariate model. In relevance to clinical studies, biennial event-history analysis and age-specific mortality trajectories of long-term survivors provide a more relevant intervention audit report for transplant protocols than the popular statistical presentation; i.e. survival probabilities among donor-source.

How to obtain and maintain favorable results after heart transplantation: keys to success?

We compared survival in our heart recipients with survival rates reported by the International Society of Heart and Lung Transplantation (ISHLT) Registry. As recipient and donor characteristics are changing over time, we studied four different eras. In order to differentiate between short- and long-term survival, we analyzed both overall survival and survival at one year. Obviously, this exercise is only relevant when baseline donor and recipient characteristics are comparable, as these differences may affect the outcome in opposite directions. To overcome this potential bias as much as possible, we calculated the Index for Mortality Prediction After Cardiac Transplantation (IMPACT)-scores and the Donor Risk Index (DRI). Looking to our results, we found that our DRIs in the different eras are almost equal to those obtained from the United Network for Organ Sharing database in the very same eras. Our IMPACT-scores, on the other hand, seem higher than those reported by ISHLT. Survival after transplantation and conditional on 1-year survival was higher than the outcome reported by the ISHLT Registry. As our operation technique and post-transplant immunosuppressive schedule did not differ from most centers, we speculated on potential factors that might contribute to our positive results. Patient selection and a relatively short waiting time are important contributors to the overall survival benefit. Our centralized follow-up may also have played an important role. Finally, the indefinite compulsory health insurance coverage in our country and easy access to different screening programs might also have influenced our outcome in a positive way. We are well aware that with challenges like donor organ shortage, more and more patients on mechanical circulatory support (MCS) will affect outcomes in the future.

Renal allograft rejection, lymphocyte infiltration, and de novo donor-specific antibodies in a novel model of non-adherence to immunosuppressive therapy

Background

Non-adherence has been associated with reduced graft survival. The aim of this study was to investigate the immunological mechanisms underlying chronic renal allograft rejection using a model of non-adherence to immunosuppressive therapy. We used a MHC (major histocompatibility complex) -mismatched rat model of renal transplantation (Brown Norway to Lewis), in which rats received daily oral cyclosporine A. In analogy to non-adherence to therapy, one group received cyclosporine A on alternating days only. Rejection was histologically graded according to the Banff classification. We quantified fibrosis by trichrome staining and intra-graft infiltration of T cells, B cells, and monocytes/macrophages by immunohistochemistry. The distribution of B lymphocytes was assessed using immunofluorescence microscopy. Intra-graft chemokine, chemokine receptor, BAFF (B cell activating factor belonging to the TNF family), and immunoglobulin G transcription levels were analysed by RT-PCR. Finally, we evaluated donor-specific antibodies (DSA) and complement-dependent cytotoxicity using flow cytometry.

Results

After 28 days, cellular rejection occurred during non-adherence in 5/6 animals, mixed with humoral rejection in 3/6 animals. After non-adherence, the number of T lymphocytes were elevated compared to daily immunosuppression. Monocyte numbers declined over time. Accordingly, lymphocyte chemokine transcription was significantly increased in the graft, as was the transcription of BAFF, BAFF receptor, and Immunoglobulin G. Donor specific antibodies were elevated in non-adherence, but did not induce complement-dependent cytotoxicity.

Conclusion

Cellular and humoral rejection, lymphocyte infiltration, and de novo DSA are induced in this model of non-adherence.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12865-017-0236-6) contains supplementary material, which is available to authorized users.

Intragraft Molecular Pathways Associated with Tolerance Induction in Renal Transplantation

The modern immunosuppression regimen has greatly improved short-term allograft outcomes but not long-term allograft survival. Complications associated with immunosuppression, specifically nephrotoxicity and infection risk, significantly affect graft and patient survival. Inducing and understanding pathways underlying clinical tolerance after transplantation are, therefore, necessary. We previously showed full donor chimerism and immunosuppression withdrawal in highly mismatched allograft recipients using a bioengineered stem cell product (FCRx). Here, we evaluated the gene expression and microRNA expression profiles in renal biopsy samples from tolerance-induced FCRx recipients, paired donor organs before implant, and subjects under standard immunosuppression (SIS) without rejection and with acute rejection. Unlike allograft samples showing acute rejection, samples from FCRx recipients did not show upregulation of T cell- and B cell-mediated rejection pathways. Gene expression pathways differed slightly between FCRx samples and the paired preimplantation donor organ samples, but most of the functional gene networks overlapped. Notably, compared with SIS samples, FCRx samples showed upregulation of genes involved in pathways, like B cell receptor signaling. Additionally, prediction analysis showed inhibition of proinflammatory regulators and activation of anti-inflammatory pathways in FCRx samples. Furthermore, integrative analyses (microRNA and gene expression profiling from the same biopsy sample) identified the induction of regulators with demonstrated roles in the downregulation of inflammatory pathways and maintenance of tissue homeostasis in tolerance-induced FCRx samples compared with SIS samples. This pilot study highlights the utility of molecular intragraft evaluation of pathways related to FCRx-induced tolerance and the use of integrative analyses for identifying upstream regulators of the affected downstream molecular pathways.

Kidney transplantation in Romania: two transplant centers experience

PURPOSE

Kidney graft survival rates improved from decade to decade, but data about factors that affect patient and graft survival remain challenging and even controversial.

METHODS

We analyzed retrospectively data from kidney transplanted patients followed in two Romanian transplant centers (Iasi and Bucharest)-new programmes specifically developed after 1989 to cover transplantation requirements for two-thirds of Romania. We used a composite survival outcome defined as 50% reduction in estimated glomerular filtration rate (eGFR), return to dialysis or death. Survival analysis was performed using uni- and multivariable Cox regression with baseline and time-updated covariates.

RESULTS

From the entire cohort of 365 patients, 243 had the outcome of interest. In the univariable Cox survival analysis, age, hemoglobin, eGFR, cholesterol, AST and transplant center were associated with the outcome. The multivariable Cox analysis reveals that only cholesterol (HR 0.97, 95% CI 0.94-0.99 per 10 mg/dL increase) and transplant center (HR 3.64, 95% CI 2.67-4.97) remain associated. For the time-updated Cox survival analysis we found that eGFR (HR 0.91, 95% CI 0.87-0.96 per 10 ml/min/1.73 m² increase) and cholesterol are associated with the outcome in the univariable analysis and only eGFR and transplant center in the multivariable Cox survival analysis.

CONCLUSIONS

Our study reports data from two distinct transplant centers from a developing country. Our results are similar to the current literature data, but also reveal that the approach of a center to the transplantation management is an independent factor associated with graft survival.

Prediction of Kidney Graft Rejection Using Artificial Neural Network

OBJECTIVES

Kidney transplantation is the best renal replacement therapy for patients with end-stage renal disease. Several studies have attempted to identify predisposing factors of graft rejection; however, the results have been inconsistent. We aimed to identify prognostic factors associated with kidney transplant rejection using the artificial neural network (ANN) approach and to compare the results with those obtained by logistic regression (LR).

METHODS

The study used information regarding 378 patients who had undergone kidney transplantation from a retrospective study conducted in Hamadan, Western Iran, from 1994 to 2011. ANN was used to identify potential important risk factors for chronic nonreversible graft rejection.

RESULTS

Recipients' age, creatinine level, cold ischemic time, and hemoglobin level at discharge were identified as the most important prognostic factors by ANN. The ANN model showed higher total accuracy (0.75 vs. 0.55 for LR), and the area under the ROC curve (0.88 vs. 0.75 for LR) was better than that obtained with LR.

CONCLUSIONS

The results of this study indicate that the ANN model outperformed LR in the prediction of kidney transplantation failure. Therefore, this approach is a promising classifier for predicting graft failure to improve patients' survival and quality of life, and it should be further investigated for the prediction of other clinical outcomes.

Ex vivo pretreatment of human vessels with siRNA nanoparticles provides protein silencing in endothelial cells

Human endothelial cells are initiators and targets of the rejection response. Pre-operative modification of endothelial cells by small interfering RNA transfection could shape the nature of the host response post-transplantation. Ablation of endothelial cell class II major histocompatibility complex molecules by small interfering RNA targeting of class II transactivator can reduce the capacity of human endothelial cells to recruit and activate alloreactive T cells. Here, we report the development of small interfering RNA-releasing poly(amine-co-ester) nanoparticles, distinguished by their high content of a hydrophobic lactone. We show that a single transfection of small interfering RNA targeting class II transactivator attenuates major histocompatibility complex class II expression on endothelial cells for at least 4 to 6 weeks after transplantation into immunodeficient mouse hosts. Furthermore, silencing of major histocompatibility complex class II reduces allogeneic T-cell responses in vitro and in vivo. These data suggest that poly(amine-co-ester) nanoparticles, potentially administered during ex vivo normothermic machine perfusion of human organs, could be used to modify endothelial cells with a sustained effect after transplantation.

The use of gene silencing techniques in the treatment of post-transplantation host rejection is not long lasting and can have systemic effects. Here, the authors utilize a nanocarrier for siRNA for treatment of arteries ex vivo prior to implantation subsequently attenuating immune reaction in vivo.

Increase of allosensitization after a kidney graft failure: Predictors and effect on retransplantation outcomes

Patients who are candidates for a second kidney transplant (SKT) frequently have a higher level of panel reactive antibodies (PRA). We assessed the allosensitisation change after a first graft failure (GF), its predictors and impact on retransplantat outcomes. We retrospectively selected 140 adult patients who received a SKT. Recipient and donor characteristics were analyzed. We defined the delta PRA (dPRA) as the difference between peak PRA before the SKT and first one (cohort median value=+10%). Logistic regression analysis was used to determine risk factors for dPRA≥10% and acute rejection (AR) in the SKT. Univariable and multivariable Cox analysis was applied to assess independent predictors of second GF. Risk factors for dPRA≥10% at SKT were AR (OR=2.57; P=0.022), first graft survival <1 year (OR=2.47; P=0.030) and ABDR HLA mismatch (OR=1.38 per each mismatch; P=0.038). AR in the SKT was associated with dPRA≥10% (OR=2.79; P=0.047). Induction with a lymphocyte-depleting agent had a protective effect (OR=0.23; P=0.010). SKT survival was lower (P=0.008) in patients with a dPRA≥10% (75.6%, 60.5% in dPRA≥10%; 88.6%, 88.6% in dPRA<10% patients at 5 and 10 years, post-transplant respectively). Multivariable Cox regression showed that dPRA≥10% (HR=2.38, P=0.042), delayed graft function (HR=2.82, P=0.006) and AR (HR=3.30, P=0.001) in the SKT were independent predictors of retransplant failure. This study shows that an increased allosensitisation at retransplant was associated with the degree of HLA mismatch and led to poorer outcomes. De-emphasis of HLA matching in current allocation policies may be undesirable, particularly in patients with a higher chance of needing a SKT.

The Emerging Role of Nanotechnology in Cell and Organ Transplantation

Transplantation is often the only choice many patients have when suffering from end-stage organ failure. Although the quality of life improves after transplantation, challenges, such as organ shortages, necessary immunosuppression with associated complications, and chronic graft rejection, limit its wide clinical application. Nanotechnology has emerged in the past 2 decades as a field with the potential to satisfy clinical needs in the area of targeted and sustained drug delivery, noninvasive imaging, and tissue engineering. In this article, we provide an overview of popular nanotechnologies and a summary of the current and potential uses of nanotechnology in cell and organ transplantation.

B-Type Natriuretic Peptide and Cardiac Troponin I Are Associated With Adverse Outcomes in Stable Kidney Transplant Recipients

BACKGROUND

Approximately 200 000 kidney transplant recipients are living in the United States; they are at increased risk for cardiovascular and other adverse outcomes. Biomarkers predicting these outcomes are needed. Using specimens collected during the Folic Acid for Vascular Outcome Reduction in Transplantation trial, we determined whether plasma levels of B-type natriuretic peptide (BNP) and cardiac troponin I are associated with adverse outcomes in stable kidney transplant recipients.

METHODS

Five hundred ten subjects were selected randomly from the 4110 Folic Acid for Vascular Outcome Reduction in Transplantation participants. This cohort was then enriched for all additional subjects with adverse outcomes (death, dialysis-dependent kidney failure (DDKF), and cardiovascular outcomes) for a total of 1131 participants studied. Quartiles of BNP and high-sensitivity cardiac troponin I (hs-cTnI) were included in adjusted models. Combinations of normal and elevated hs-cTnI (>26.2 ng/L) and BNP (>100 pg/mL) were also studied.

RESULTS

Median concentrations (interquartile ranges) were 5.6 (3.3-10.5) ng/L for hs-cTnI and 39 (15, 94) pg/mL for BNP. Hazard ratios for each adverse outcome were higher with higher quartiles of BNP after adjustment and remained statistically significant after adding hs-cTnI to the model. The highest quartile hazard ratio for DDKF was 2.47 (95% confidence interval [95% CI], 1.21-5.05). Simultaneous elevations of BNP and hs-cTnI over clinical cutoffs were strongly associated with adverse outcomes with hazard ratios 8.8 (95% CI, 3.4-23.1) for DDKF and 6.3 (95% CI, 2.7-15.0) for cardiovascular outcomes.

CONCLUSIONS

Higher BNP is associated with mortality and cardiovascular and kidney outcomes in stable kidney transplant recipients. Elevated BNP and hs-cTnI identify candidates for targeted risk reduction.

Do outcomes after kidney transplantation differ for black patients in England versus New York State? A comparative, population-cohort analysis

OBJECTIVES

Inferior outcomes for black kidney transplant recipients in the USA may not be generalisable elsewhere. In this population cohort analysis, we compared outcomes for black kidney transplant patients in England versus New York State.

DESIGN

Retrospective, comparative, population cohort study utilising administrative data registries.

SETTINGS AND PARTICIPANTS

English data were derived from Hospital Episode Statistics, while New York State data were derived from Statewide Planning and Research Cooperative System. All adults receiving their first kidney-alone allograft between 2003 and 2013 were eligible for inclusion.

MEASURES

The primary outcome measure was mortality post kidney transplantation (including inhospital death, 30-day mortality and 1-year mortality). Secondary outcome measures included postoperative admission length of stay, risk of rehospitalisation, development of cardiac events, stroke, cancer or fracture and finally transplant rejection/failure. Cox proportional hazards regression was used to investigate relationship between ethnicity, country and outcome.

RESULTS

Black patients comprised 6.5% of the English cohort (n=1215/18 493) and 23.0% of the New York State cohort (n=2660/11 602). Compared with New York State, black kidney transplant recipients in England were more likely younger, male, living-donor kidney recipients and had dissimilar medical comorbidities. Inpatient mortality was not statistically different, but death within 30 days, 1 year or kidney transplant rejection/failure was lower among black patients in England versus black patients in New York State. In adjusted regression analysis, with black ethnicity the reference group, white patients had reduced risk for 30-day mortality (OR 0.62 (95% CI 0.44 to 0.86)) and 1-year mortality (OR 0.79 (95% CI 0.63 to 0.99)) in New York State but no difference was observed in England. Compared with England, black kidney transplant patients in New York State had increased HR for kidney transplant rejection rejection/failure by median follow-up (HR 2.15, 95% CI 1.91 to 2.43).

CONCLUSIONS

Outcomes after kidney transplantation for black patients may not be translatable between countries.

Practical Recommendations for Long-term Management of Modifiable Risks in Kidney and Liver Transplant Recipients: A Guidance Report and Clinical Checklist by the Consensus on Managing Modifiable Risk in Transplantation (COMMIT) Group

Short-term patient and graft outcomes continue to improve after kidney and liver transplantation, with 1-year survival rates over 80%; however, improving longer-term outcomes remains a challenge. Improving the function of grafts and health of recipients would not only enhance quality and length of life, but would also reduce the need for retransplantation, and thus increase the number of organs available for transplant. The clinical transplant community needs to identify and manage those patient modifiable factors, to decrease the risk of graft failure, and improve longer-term outcomes.COMMIT was formed in 2015 and is composed of 20 leading kidney and liver transplant specialists from 9 countries across Europe. The group's remit is to provide expert guidance for the long-term management of kidney and liver transplant patients, with the aim of improving outcomes by minimizing modifiable risks associated with poor graft and patient survival posttransplant.The objective of this supplement is to provide specific, practical recommendations, through the discussion of current evidence and best practice, for the management of modifiable risks in those kidney and liver transplant patients who have survived the first postoperative year. In addition, the provision of a checklist increases the clinical utility and accessibility of these recommendations, by offering a systematic and efficient way to implement screening and monitoring of modifiable risks in the clinical setting.

Infectious complications as the leading cause of death after kidney transplantation: analysis of more than 10,000 transplants from a single center

AIM

To identify specific causes of graft failure in a large sample of kidney transplant patients from a middle-income, developing country.

METHODS

Retrospective cohort study analyzing all consecutive single kidney transplants (KTs) performed at a single center in Brazil between January 1st 1998 and December 31st 2013. The database closing date was December 31st 2014.

RESULTS

Out of 10,400 KTs, there were 1191 (11.45%) deaths with a functioning graft, 40 cases (0.38%) of primary non-function (PNF) and 1417 cases (13.62%) of graft loss excluding death and PNF as the cause. Infectious complications (404 cases, 34% of all deaths) were the major cause of death. Most deaths due to infection occurred within the first year after transplantation (157 deaths, 38.86%). Immunologic mechanisms, comprising acute rejection and immune-mediated interstitial fibrosis/tubular atrophy (IF/TA), were responsible for 52% of all cases of graft failure not involving recipient death. Half of the losses by acute rejection occurred late after transplantation.

CONCLUSION

Contrary to what is observed in developed countries, infectious complications are the main challenge with kidney transplantation in Brazil. Non-adherence to treatment also appears to contribute significantly to long-term kidney graft loss. Strategies for improvement should focus on better compliance and a greater safety profile of immunosuppressive treatment.

Mortality after Renal Allograft Failure and Return to Dialysis

INTRODUCTION

The outcomes of patients who fail their kidney transplant and return to dialysis (RTD) has not been investigated in a nationally representative sample. We hypothesized that variations in management of transplant chronic kidney disease stage 5 leading to kidney allograft failure (KAF) and RTD, such as access, nutrition, timing of dialysis, and anemia management predict long-term survival.

METHODS

We used an incident cohort of patients from the United States Renal Data System who initiated hemodialysis between January 1, 2003 and December 31, 2008, after KAF. We used Cox regression analysis for statistical associations, with mortality as the primary outcome.

RESULTS

We identified 5,077 RTD patients and followed them for a mean of 30.9 ± 22.6 months. Adjusting for all possible confounders at the time of RTD, the adjusted hazards ratio (AHR) for death was increased with lack of arteriovenous fistula at initiation of dialysis (AHR 1.22, 95% CI 1.02-1.46, p = 0.03), albumin <3.5 g/dL (AHR 1.33, 95% CI 1.18-1.49, p = 0.0001), and being underweight (AHR 1.30, 95% CI 1.07-1.58, p = 0.006). Hemoglobin <10 g/dL (AHR 0.96, 95% CI 0.86-1.06, p = 0.46), type of insurance, and zip code-based median household income were not associated with higher mortality. Glomerular filtration rate <10 mL/min/1.73 m2 at time of dialysis initiation (AHR 0.83, 95% CI 0.75-0.93, p = 0.001) was associated with reduction in mortality.

CONCLUSIONS

Excess mortality risk observed in patients starting dialysis after KAF is multifactorial, including nutritional issues and vascular access. Adequate preparation of patients with failing kidney transplants prior to resuming dialysis may improve outcomes.

Development of an immune function assay by measuring intracellular adenosine triphosphate (iATP) levels in mitogen-stimulated CD4+ T lymphocytes

We developed an immune function assay for monitoring CD4+ T cells activity based on changes in intracellular adenosine triphosphate (iATP) levels after phytohemagglutinin (PHA) stimulation. Blood samples were obtained from 40 healthy subjects and 30 RTRs and incubated with 5 µg/mL of PHA for 15-18 hr at 37°C and 5% CO2. Afterward, the CD4+ T cells were separated by antibody-coated magnetic beads and lysed. Then, iATP content in unstimulated and stimulated conditions was measured by luciferin-luciferase reaction using a log-log standard curve. The iATP levels showed significant increase in CD4+ T cells in both healthy persons (mean: 550 ± 142 ng/mL vs. 109 ± 54 ng/mL) and RTRs (mean: 394 ± 160 ng/mL vs. 52 ± 37 ng/mL) after PHA stimulation (P < 0.001). However, the iATP production in RTRs was significantly lower than that in healthy individuals; both prior to and after stimulation with PHA (P < 0.001). No gender-specific difference in iATP production was observed between women and men subjects. This rapid and low-cost assay reflects the degree of immune cell function through assessment of CD4+ T cells activation. Thus, it can be used for evaluation of immune system status in immunodeficient individuals as well as in immunosuppressed transplant recipients who needs drug adjustment.

More Than 1000 Kidney Transplants Performed in Pamplona, Navarra: Data From the Collaborative Transplant Study

INTRODUCTION

The Kidney Transplant Program started at the Clinica Universidad de Navarra (Pamplona, Spain) in September of 1969. The 1000th kidney transplant was performed in September 2015. Data from kidney transplants have been included in the Collaborative Transplant Study since 1983.

MATERIALS AND METHODS

Data on patient and graft survival of the 635 kidney transplants (557 first kidney transplants and 78 second kidney transplants) performed in the Clinica Universidad de Navarra between 1990 and 2014, as well as the estimated average life of the grafts are described and compared with data from the more than 150,000 European kidney transplants included in the Collaborative Transplant Study in the same period.

RESULTS

Data of our patient and graft survival are statistically significantly better (P < .05) than those of the over 150,000 European transplants analyzed in the Collaborative Transplant Study in the same period. The estimated half-life of the kidney transplants performed in our Center is 18.5 years for first transplants and 15.7 years for second transplants, compared to 13.9 and 11.2 years, respectively, calculated for the European transplants.

CONCLUSIONS

Data obtained from the Collaborative Transplant Study confirm excellent graft survival in our Center with an estimated half-life higher than that of the European transplants included in this study.

Multiparametric Functional MRI: A Tool to Uncover Subtle Changes following Allogeneic Renal Transplantation

PURPOSE

To investigate multiparametric functional MRI to characterize acute rejection in a murine allogeneic renal transplant model and evaluate the effect of novel therapeutics.

MATERIAL AND METHODS

We performed allogeneic and syngeneic orthotopic transplantations (Balb/c to C57Bl/6 and C57Bl/6 to C57Bl/6). Allogeneic Groups (n = 5) were either treated with the anti-CCL2-Spiegelmer (mNOX-E36) in monotherapy or in combination with low doses of Ciclosporin-A (10mg/kgBW/d) for 10 days. Controls received equivalent doses of a non-functional spiegelmer (revmNOX-E36) or low dose Ciclosporin-A. Diffusion-weighted (DWI) and Dynamic-contrast-enhanced (DCE-) MRI-scans were performed using a clinical 3T-scanner. DWI analysis (b-values from 0-800 s/mm2) was performed mono- and biexponentially, while DCE-MRI was assessed with deconvolution analysis. Therapy effects were assessed ex vivo with histopathology, immunohistochemistry and RT-PCR. Statistical analysis was performed with unpaired t-tests and Spearman´s correlation coefficient.

RESULTS

DWI showed a significant diffusion restriction in allogeneic compared to syngeneic transplants (ADC: 0.63±0.08 vs. 1.29±0.12 mm2/s*103) with decreasing diffusion restriction under therapy. DCE-MRI showed restored organ perfusion under Ciclosporin A alone and combination therapy (Plasma Flow: 43.43±12.49; 38.75±7.53ml/100ml/min) compared to syngeneic controls (51.03±12.49ml/100ml/min). Ex vivo analysis showed reduced monocytic infiltrates, attenuated levels of inflammatory cytokines under mNOX-E36 monotherapy with an additive effect of low dose Ciclosporin A. There was a significant (p<0.05) negative correlation between ADC and interstitial inflammation (r = -0.73) or macrophage infiltration (r = -0.81) and between organ perfusion and intimal arteritis (r = -0.63).

CONCLUSION

Multiparametric functional MRI is suited to detect renal allograft rejection in an experimental murine model and allows to characterize effects of immunosuppressive therapy alleviating acute rejection processes in allogeneic transplantation.

Progress in Transplantation: Will It Be Achieved in Big Steps or by Marginal Gains?

A wish for progress in transplantation assumes that there are needs not met by the currently available therapy and that the barriers to resolving the problems can be surmounted. There are 5 major unmet needs: the potential to avoid transplantation either by prevention of disease or provision of an alternative to natural biological organ replacement; geographic heterogeneity of access to, and quality of, transplantation; availability of transplantation to those in need of it; survival of the patient and the transplant; and the avoidance of adverse effects of immunosuppression. During the past 50 years, there have been advances on at least 4 of these 5 fronts that illustrate the interplay of "big steps" and "marginal gains" in the following areas: surgical technique, testing the immunologic barriers, introduction of chemical and biological immunosuppression, and prophylaxis for microbial infections. The potential for further improvement comes in 5 major areas: blood biomarkers for monitoring of rejection, drug-free transplantation through the development of stable tolerance, eliminating the impact of ischemia-reperfusion injury, xenotransplantation of porcine kidneys, and finally, the possibility of autologous regeneration of functioning kidney tissue to treat advanced kidney disease.

[Infectious diseases in immunocompromised patients]

Immunkompromittierung birgt immer ein erhöhtes Risiko für die Entwicklung infektiöser Komplikationen. Patienten nach solider Organtransplantation sind besonders gefährdet – in dieser Patientengruppe bilden Infektionen die zweithäufigste Todesursache. Prophylaxe und Impfungen sollten daher konsequent eingesetzt werden. Infektionen bei Immunsupprimierten können mit atypischen klinischen Symptomen einhergehen, was die Diagnose und Therapie für den behandelnden Arzt erschwert. Vor allem virale und opportunistische Infektionen stellen dabei eine Herausforderung dar. Umso mehr ist eine Überwachung der Patienten hinsichtlich Infektionserkrankungen notwendig, um frühzeitig die erforderlichen Maßnahmen einleiten zu können.

[Chronic kidney disease and kidney transplantation]

OBJECTIVES

To report epidemiology and characteristics of end-stage renal disease (ESRD) patients and renal transplant candidates, and to evaluate access to waiting list and results of renal transplantation.

MATERIAL AND METHODS

An exhaustive systematic review of the scientific literature was performed in the Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of the following keywords: "chronic kidney disease, epidemiology, kidney transplantation, cost, survival, graft, brain death, cardiac arrest, access, allocation". French legal documents have been reviewed using the government portal (http://www.legifrance.gouv.fr). Articles were selected according to methods, language of publication and relevance. The reference lists were used to identify additional historical studies of interest. Both prospective and retrospective series, in French and English, as well as review articles and recommendations were selected. In addition, French national transplant and health agencies (http://www.agence-biomedecine.fr and http://www.has-sante.fr) databases were screened using identical keywords. A total of 3234 articles, 6 official reports and 3 newspaper articles were identified; after careful selection 99 publications were eligible for our review.

RESULTS

The increasing prevalence of chronic kidney disease (CKD) leads to worsen organ shortage. Renal transplantation remains the best treatment option for ESRD, providing recipients with an increased survival and quality of life, at lower costs than other renal replacement therapies. The never-ending lengthening of the waiting list raises issues regarding treatment strategies and candidates' selection, and underlines the limits of organ sharing without additional source of kidneys available for transplantation.

CONCLUSION

Allocation policies aim to reduce medical or geographical disparities regarding enrollment on a waiting list or access to an allotransplant.

High Intrapatient Variability of Tacrolimus Concentrations Predicts Accelerated Progression of Chronic Histologic Lesions in Renal Recipients

High intrapatient variability (IPV) of tacrolimus concentrations is increasingly recognized as a predictor of poor outcome in solid organ recipients. How it relates to evolution of histology has not been explored. We analyzed tacrolimus IPV using the coefficient of variability (CV) from months 6-12 after transplantation in a cohort of 220 renal recipients for whom paired protocol biopsies at 3 mo and 2 years were available. Recipients in the highest CV tertile had an increased risk of moderate to severe fibrosis and tubular atrophy by 2 years compared with the low-IPV tertile (odds ratio [OR] 2.47, 95% confidence interval [CI] 1.09-5.60, p = 0.031; and OR 2.40, 95% CI 1.03-5.60, p = 0.043, respectively). Other predictors were donor age, severity of chronic lesions at 3 mo, and presence of borderline or subclinical rejection at 3 mo. Chronicity score increased significantly more in the high CV tertile group than in the middle and low tertiles (mean increase 1.97 ± 2.03 vs. 1.18 ± 2.44 and 1.12 ± 1.80, respectively; p < 0.05). CV did not predict evolution of renal function, which did not deteriorate within the 2-year follow-up period. These results indicate that high IPV is related to accelerated progression of chronic histologic lesions before any evidence of renal dysfunction.

Exome Sequencing and Prediction of Long-Term Kidney Allograft Function

Current strategies to improve graft outcome following kidney transplantation consider information at the human leukocyte antigen (HLA) loci. Cell surface antigens, in addition to HLA, may serve as the stimuli as well as the targets for the anti-allograft immune response and influence long-term graft outcomes. We therefore performed exome sequencing of DNA from kidney graft recipients and their living donors and estimated all possible cell surface antigens mismatches for a given donor/recipient pair by computing the number of amino acid mismatches in trans-membrane proteins. We designated this tally as the allogenomics mismatch score (AMS). We examined the association between the AMS and post-transplant estimated glomerular filtration rate (eGFR) using mixed models, considering transplants from three independent cohorts (a total of 53 donor-recipient pairs, 106 exomes, and 239 eGFR measurements). We found that the AMS has a significant effect on eGFR (mixed model, effect size across the entire range of the score: -19.4 [-37.7, -1.1], P = 0.0042, χ2 = 8.1919, d.f. = 1) that is independent of the HLA-A, B, DR matching, donor age, and time post-transplantation. The AMS effect is consistent across the three independent cohorts studied and similar to the strong effect size of donor age. Taken together, these results show that the AMS, a novel tool to quantify amino acid mismatches in trans-membrane proteins in individual donor/recipient pair, is a strong, robust predictor of long-term graft function in kidney transplant recipients.

Current Status of Kidney Transplant Outcomes: Dying to Survive

Kidney transplantation is associated with improved survival compared with maintenance dialysis. In the United States, post-transplant outcomes have steadily improved over the last several decades, with current 1-year allograft and patient survival rates well over 90%. Although short-term outcomes are similar to those in the international community, long-term outcomes appear to be inferior to those reported by other countries. Differences in recipient case mix, allocation polices, and health care coverage contribute to the long-term outcome disparity. This review presents the current status of kidney transplant outcomes in the United States and compares them with the most recent outcomes from Australia and New Zealand, Europe, and Canada. In addition, early trends after implementation of the new kidney allocation system in the United States and its potential impact on post-transplant outcomes are discussed.

Delayed Cytotoxic T Lymphocyte-Associated Protein 4-Immunoglobulin Treatment Reverses Ongoing Alloantibody Responses and Rescues Allografts From Acute Rejection

Antibody-mediated rejection has emerged as the leading cause of late graft loss in kidney transplant recipients, and inhibition of donor-specific antibody production should lead to improved transplant outcomes. The fusion protein cytotoxic T lymphocyte-associated protein 4-immunoglobulin (CTLA4-Ig) blocks T cell activation and consequently inhibits T-dependent B cell antibody production, and the current paradigm is that CTLA4-Ig is effective with naïve T cells and less so with activated or memory T cells. In this study, we used a mouse model of allosensitization to investigate the efficacy of continuous CTLA4-Ig treatment, initiated 7 or 14 days after sensitization, for inhibiting ongoing allospecific B cell responses. Delayed treatment with CTLA4-Ig collapsed the allospecific germinal center B cell response and inhibited alloantibody production. Using adoptively transferred T cell receptor transgenic T cells and a novel approach to track endogenous graft-specific T cells, we demonstrate that delayed CTLA4-Ig minimally inhibited graft-specific CD4(+) and T follicular helper responses. Remarkably, delaying CTLA4-Ig until day 6 after transplantation in a fully mismatched heart transplant model inhibited alloantibody production and prevented acute rejection, whereas transferred hyperimmune sera reversed the effects of delayed CTLA4-Ig. Collectively, our studies revealed the unexpected efficacy of CTLA4-Ig for inhibiting ongoing B cell responses even when the graft-specific T cell response was robustly established.

Low-Activity Kidney Transplant Center, A Single-Center Experience: Early Care as a Major Challenge

OBJECTIVES

In many countries, some kidney transplants are performed in small centers, from which clinical data are rarely specifically reported. The aim of this study was to describe patient and graft survival rates and their correlates in a low-activity kidney transplant center.

MATERIALS AND METHODS

We performed a retrospective cohort study of all patients who underwent transplant between January 2002 and May 2012 at a university hospital. Patient, graft, and death-censored graft survival rates were assessed with Kaplan-Meier analyses and compared by log-rank test, with associated factors analyzed by Cox proportional hazards modeling.

RESULTS

Among a total of 162 patients, the mean age was 41.8 ± 13.5 years, and 92% received a living-donor graft. At 1, 3, and 5 years, patient survival was 88.6%, 86%, and 82.9%. Graft survival was 86.9%, 83%, and 77%, and death-censored graft survival was 98.1%, 96.6%, and 92.9% at the same time points. Most graft losses were due to patient death from infection and occurred within the first year after transplant. After adjustment, age over 42 years (hazard ratio of 3.94; 95% confidence interval, 1.39-11.13), deceased donor graft (hazard ratio of 11.41; 95% confidence interval, 1.2-108.35), and higher average education (hazard ratio of 4.96; 95% confidence interval, 1.01-24.32) were independently associated with graft loss.

CONCLUSIONS

The observed patient and graft survival rates were similar to those described in large databases; however, early mortality remains a major challenge. Improving posttransplant care is a key issue to increasing survival in small transplant centers.

Long-Term Outcomes of Kidney and Simultaneous Pancreas-Kidney Transplantation in Recipients With Type 1 Diabetes Mellitus: Silesian Experience

BACKGROUND

Kidney transplantation (KTx) markedly reduces mortality in patients with end-stage kidney disease (ESKD) caused by type 1 diabetes mellitus (T1DM). The outstanding issue is whether transplantation should be limited only to KTx, with further insulinotherapy, or combined with pancreas transplantation in patients with ESKD/T1DM. The goal of this study was to compare the results of simultaneous pancreas-kidney transplantation (SPKTx) and deceased donor KTx and to identify factors affecting patient and kidney graft survival in patients with ESKD/T1DM.

METHODS

Eighty-seven deceased donor KTx and 66 SPKTx operated on in the Silesia region of Poland between 1998 and 2013 were included in the retrospective analysis.

RESULTS

During the mean 6.7 ± 3.6 years of follow-up, fewer cardiovascular episodes were observed in SPKTx recipients than in KTx recipients (1.5% vs 12.6%; P < .05). Five-year patient survival (80.7% in SPKTx vs 77.5% in KTx) and kidney graft survival (66.1% in SPKTx vs 70.4% in KTx) did not differ between study groups. There were no differences in patient survival (log-rank test, P = .99) or kidney graft survival (P = .99) based on Kaplan-Meier curves. Multivariable Cox proportional hazard analysis failed to identify factors explaining patient and kidney graft survival. Five-year pancreas graft survival was 58.9%. SPKTx recipients had significantly higher estimated glomerular filtration rates during the 7-year posttransplant period and less frequently developed proteinuria (6.1% vs 23%; P < .01).

CONCLUSIONS

Pancreas transplantation reduced cardiovascular risk and prevented the development of proteinuria but did not improve patient and kidney graft survival in recipients with T1DM in the 7-year follow-up period.

Kidney Transplant Outcomes After Primary, Repeat and Kidney After Nonrenal Solid Organ Transplantation: A Single-Center Experience

Background

Improvements in renal allograft outcomes have permitted kidney transplantation after prior kidney allograft failure as well as after nonrenal solid organ transplantation. This study compares renal allograft outcomes in the 3 groups, that is, primary, repeat, and kidney after nonrenal solid organ transplantation, where transplant group was coded as a time-dependent variable.

Methods

We retrospectively reviewed registry data for kidney transplant recipients at University of Pittsburgh Medical Center from January 2000 to December 2011. We compared overall graft survival between the 3 groups using Cox regression modeling. We calculated 1-, 3-, and 5-year graft survival and half-lives for each group where feasible.

Results

The study cohort (N = 2014) consisted of group A (primary kidney transplant, n = 1578, with 7923.2 years of follow-up time), group B (repeat kidney transplant, n = 314, with 1566.7 years of follow-up time) and group C (kidney post-nonrenal solid organ transplant, n = 176, with 844.8 years of follow-up time). Of the 1578 patients in the primary kidney transplant group, 74 later received a repeat transplant and thus also have follow-up counted in the repeat kidney transplant group. The median follow-up was 56, 53, and 55 months, respectively. The 5-year actuarial and death-censored graft survival was 68.69%, 68.79%, and 66.48% and 65.53%, 67.68%, and 62.92%, respectively (P = 0.70). There was no difference in overall graft survival in the Cox-adjusted analysis (group B: odds ratio, 1.02; 95% confidence interval, 0.84-1.26; P = 0.79; group C: odds ratio, 0.96; 95% confidence interval, 0.75-1.23; P = 0.76).

Conclusions

The adjusted kidney graft survivals in the 3 groups were similar.

Renal transplantation in infants

Renal transplantation (RTx) has become an accepted mode of therapy in infants with severe renal failure. The major indications are structural abnormalities of the urinary tract, congenital nephrotic syndrome, polycystic diseases, and neonatal kidney injury. Assessment of these infants needs expertise and time as well as active treatment before RTx to ensure optimal growth and development, and to avoid complications that could lead to permanent neurological defects. RTx can be performed already in infants weighing around 5 kg, but most operations occur in infants with a weight of 10 kg or more. Perioperative management focuses on adequate perfusion of the allograft and avoidance of thrombotic and other surgical complications. Important long-term issues include rejections, infections, graft function, growth, bone health, metabolic problems, neurocognitive development, adherence to medication, pubertal maturation, and quality of life. The overall outcome of infant RTx has dramatically improved, with long-term patient and graft survivals of over 90 and 80 %, respectively.

Design and rationale of the ATHENA study--A 12-month, multicentre, prospective study evaluating the outcomes of a de novo everolimus-based regimen in combination with reduced cyclosporine or tacrolimus versus a standard regimen in kidney transplant patients: study protocol for a randomised controlled trial

Background

Immunosuppression with calcineurin inhibitors remains the mainstay of treatment after kidney transplantation; however, long-term use of these drugs may be associated with nephrotoxicity. In this regard, the current approach is to optimise available immunosuppressive regimens to reduce the calcineurin inhibitor dose while protecting renal function without affecting the efficacy. The ATHENA study is designed to evaluate renal function in two regimens: an everolimus and reduced calcineurin inhibitor-based regimen versus a standard treatment protocol with mycophenolic acid and tacrolimus in de novo kidney transplant recipients.

Method/Design

ATHENA is a 12-month, multicentre, open-label, prospective, randomised, parallel-group study in de novo kidney transplant recipients (aged 18 years or older) receiving renal allografts from deceased or living donors. Eligible patients are randomised (1:1:1) prior to transplantation to one of the following three treatment arms: everolimus (starting dose 1.5 mg/day; C0 3–8 ng/mL) with cyclosporine or everolimus (starting dose 3 mg/day; C0 3–8 ng/mL) with tacrolimus or mycophenolic acid (enteric-coated mycophenolate sodium at 1.44 g/day or mycophenolate mofetil at 2 g/day) with tacrolimus; in combination with corticosteroids. All patients receive induction therapy with basiliximab. The primary objective is to demonstrate non-inferiority of renal function (eGFR by the Nankivell formula) in one of the everolimus arms compared with the standard group at month 12 post transplantation. The key secondary objective is to assess the incidence of treatment failure, defined as biopsy-proven acute rejection, graft loss, or death, among the treatment groups. Other objectives include assessment of the individual components of treatment failure, incidence and severity of viral infections, incidence and duration of delayed graft function, incidence of indication biopsies, slow graft function and wound healing complications, and overall safety and tolerability. Exploratory objectives include evaluation of left ventricular hypertrophy assessed by the left ventricular mass index, evolution of human leukocyte antigen and non-human leukocyte antigen antibodies, and a cytomegalovirus substudy.

Discussion

As one of the largest European multicentre kidney transplant studies, ATHENA will determine whether a de novo everolimus-based regimen can preserve renal function versus the standard of care. This study further assesses a number of clinical issues which impact long-term outcomes post transplantation; hence, its results will have a major clinical impact.

Trial registration

Clinicaltrials.gov: NCT01843348, date of registration – 18 April 2013; EUDRACT number: 2011-005238-21, date of registration – 20 March 2012

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-016-1220-9) contains supplementary material, which is available to authorized users.

Genotype-guided tacrolimus dosing in African-American kidney transplant recipients

Tacrolimus is dependent on CYP3A5 enzyme for metabolism. Expression of the CYP3A5 enzyme is controlled by several alleles including CYP3A5*1, CYP3A5*3, CYP3A5*6 and CYP3A5*7. African Americans (AAs) have on average higher tacrolimus dose requirements than Caucasians; however, some have requirements similar to Caucasians. Studies in AAs have primarily evaluated the CYP3A5*3 variant; however, there are other common nonfunctional variants in AAs (CYP3A5*6 and CYP3A5*7) that do not occur in Caucasians. These variants are associated with lower dose requirements and may explain why some AAs are metabolically similar to Caucasians. We created a tacrolimus clearance model in 354 AAs using a development and validation cohort. Time after transplant, steroid and antiviral use, age and CYP3A5*1, *3, *6 and *7 alleles were significant toward clearance. This study is the first to develop an AA-specific genotype-guided tacrolimus dosing model to personalize therapy.

Long-term effects of paediatric kidney transplantation

Renal transplantation in paediatric patients usually provides excellent short-term and medium-term results. Early diagnosis of chronic kidney disease and active therapy of end-stage renal disease before and after transplantation enables the majority of children to grow and develop normally. The adverse effects of immunosuppressive medication and reduced graft function might, however, hamper long-term outcomes in these patients and can lead to metabolic complications, cardiovascular disease, reduced bone health, and malignancies. The neurocognitive development and quality of life of paediatric transplant recipients largely depend on the primary diagnosis and on graft function. Poor adherence to immunosuppression is an important risk factor for graft loss in adolescents, and controlled transition to adult care is of utmost importance to ensure a continued normal life. In this Review, we discuss the outcomes and long-term effects of renal transplantation in paediatric recipients, including consequences on growth, development, bone, metabolic, and cardiovascular disorders. We discuss the key problems in the care of paediatric renal transplant recipients and the remaining challenges that should be the focus of future research.