[REIN: a tool for the benefit of renal transplantation]

On the occasion of the 20th anniversary of the REIN (French Renal Epidemiology and Information Network), a summary work on the contributions of the national French ESKD register was carried out. On the issue of access to renal transplantation for ESKD patients, the following key messages were retained. The registry of the REIN includes data about kidney transplant and dialysis. It thus allows evaluating the access to kidney transplant in France based on the needs of the population with stage 5 CKD treated by renal replacement therapy. The data produced by the registry is complementary to the data in the report of the Agence de la biomédecine (Agency of Biomedicine) based on the activity of the transplant centres and the population of registered patients waiting for a transplant. The proportion of preemptive transplant (transplant without prior recourse to dialysis) as well as that of preemptive registration (before starting dialysis) have increased since 2012 but remain low. The proportion of preemptive transplant as the first replacement therapy remains low and stable over time at around 3 to 4%. The access to the waiting list and the transplant varies depending on the age and co-morbidities of the patients (diabetes, obesity) as well as on the region. The rates of registration on the kidney transplant waiting list at the time of initiation of dialysis and at 1 year from the start have been increasing since 2012, irrespective of the patients’ characteristics, though it remains low in elderly, diabetic and severely obese patients. This is partly the result related to the publication of the HAS (French National Authority for Health) recommendations in 2015 and the publications on the disparities in access to transplants established thanks to the REIN registry. The causes of non-registration at the time of initiation of dialysis have changed over time with some patients not registering for contraindication steadily decreasing since 2012. Thanks to several studies conducted using data from the registry, the variations in access to the list could be explained, partly, by the health condition of the dialysis population as well as by the socio-economic context and differences in practices according to dialysis networks. The median waiting time for a kidney transplant has been gradually increasing since 2012, with a delta of about 8 months between 2012 and 2020. However, the waiting time between the initiation of dialysis and the transplant has increased less significantly. The probability of receiving a first kidney transplant depends on the age, diabetic status and obesity of the patient, and has remained stable over time.

Diffuse large B-cell lymphoma presenting as an ileocaecal mass in a post-transplant patient

Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin's lymphoma. Extranodal involvement, including the gastrointestinal tract, occurs frequently. However, colorectal involvement is extremely rare. We present a case of a man in his 20s with prior renal transplantation on immunosuppression for 10 years who developed symptoms of gas and bloating associated with unintentional weight loss. Colonoscopy revealed a large fungating mass at the ileocaecal valve, and a biopsy of this lesion confirmed stage IV DLBCL. Endoscopy should be considered for early workup of vague gastrointestinal symptoms, even in younger patients, if they have been on long-standing immunosuppression.

DETERMINATION OF THE PRA POSITIVITY PERCENTAGE IN MALE PATIENTS WITH CHRONIC KIDNEY DISEASE BY USING FLOW CYTOMETRY TECHNIQUE

The antibodies directed against human leukocyte antigen (HLA) molecules, which play a crucial role in allograft histocompatibility, are called anti-HLA antibodies. Anti-HLA antibodies against foreign HLA molecules may be present in patients with chronic kidney disease even before transplantation. The panel reactive antibody (PRA) test is used to measure the renal transplant candidate's immune sensitivity to HLA molecules other than their own HLA molecules by assessing the diversity of anti-HLA antibodies in the blood of these patients. This study aimed to determine the PRA values and the percentage of PRA positivity of Turkish male patients with chronic kidney disease (CKD), who had not been sensitized by the major known causes (those with no history of organ or tissue transplantation, those with no history of blood transfusion), who had not been diagnosed with any autoimmune diseases, and who had not been under immunosuppressive treatment. The study included 60 male patients aged over 18 years. All of the patients were followed up with a diagnosis of CKD at the Nephrology Clinic, Internal Medicine Department, Akdeniz University Medical Faculty Hospital. None of the patients included in the study was sensitized by a known mechanism previously (they did not have blood transfusion or organ transplantation). Glomerular filtration rate (GFR) levels of all patients were below the level of 60 mL/min/1.73 m2. Patient data including their age information, etiology of CKD, accompanying diseases, and information about dialysis modalities were recorded. HLA antibody percentage was determined by the flow cytometry technique. Statistical data analysis was performed by using SPSS 22.0 (Statistical Package for Social Sciences, Version 22.0). The values of p less than 0.05 were considered statistically significant. Twenty patients were receiving dialysis treatment due to end-stage renal disease. Of the 60 patients included in the study, 25% showed PRA positivity; 28.3% of all study patients were found to be positive for anti-HLA class I antibodies and 26.7% of all study patients were found to be positive for anti-HLA class II antibodies on separate analysis for anti-HLA class I and anti-HLA class II antibody positivity. When the patients were categorized as PRA negative and PRA positive in two groups, there were no differences between the groups according to mean age, percentage of hemodialysis patients, percentage of peritoneal dialysis patients and presence of accompanying chronic diseases (such as hypertension, type 2 diabetes mellitus, hyperlipidemia, nephrolithiasis, coronary artery disease). In addition to this, evaluation of the GFR levels showed that the PRA positive group contained a significantly higher percentage of end-stage renal disease patients (GFR <15 mL/min/1.73 m2) as compared with the PRA negative group. Detailed analysis of the percentages of PRA levels in the PRA positive patients, which was carried out to determine the degree of sensitization, showed that the PRA values were over 80% in 11.77% of the patients positive for anti-HLA class I antibodies. On the other hand, PRA values were within the range of 15%-80% in 88.23% of the patients who had anti-HLA class II antibodies. The PRA values were below 80% in all of the patients positive for anti-HLA class II antibodies and those positive for both anti-HLA class I and class II antibodies. In conclusion, PRA levels of the candidates for kidney transplantation should always be measured to assess their state of sensitization before transplantation, even though they have no risk factors known to cause anti-HLA antibody development.

The side effect profile of sirolimus and its relationship with some variables: A retrospective study of Iranian renal transplant patients

Background

Sirolimus is a potent immunosuppressive in renal transplantation. However, its use is limited by some reported side effects. The objective of this study was to determine the side effect profile of sirolimus in renal transplant patients.

Materials and Methods

In the present study, we retrospectively reviewed the medical records of 116 renal transplant patients treated with sirolimus alone or in combination with other immunosuppressive agents at private therapeutic centers in Isfahan, Iran, between March 2009 and February 2020. A checklist was used to collect data on demographic and clinical variables. Data were analyzed with independent samples t-test and Chi-squared test.

Results

Our findings indicated that the most prevalent sirolimus-related side effects were edema (42.3%), proteinuria (37.5%), cytopenia (26.9%), abnormal level of liver enzymes (11.7%), and pneumonitis (9.7%). Stratification of side effects by sirolimus dose (<2 mg and ≥2 mg) demonstrated their dose-independent occurrence (P > 0.05). Pneumonitis was the most frequent reason for sirolimus cessation (58.7%). No significant differences were observed between males and females regarding the frequency of reasons for sirolimus cessation (P > 0.05).

Conclusion

Edema, proteinuria, cytopenia, abnormal level of liver enzymes, and pneumonitis were the most prevalent sirolimus-related side effects in renal transplant patients. Further prospective cohort studies are warranted to detect underlying mechanisms and determinants of these side effects in renal transplant patients treated with sirolimus.

PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study: protocol for a hybrid type I, mixed method, randomised controlled trial

INTRODUCTION

Kidney transplant candidates (KTCs) need to be in optimal physical and psychological condition prior to surgery. However, KTCs often experience compromised functional capacity which can be characterised as frailty. Prehabilitation, the enhancement of a person's functional capacity, may be an effective intervention to improve the health status of KTCs. The PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study aims to examine the effectiveness of a multimodal prehabilitation programme on the health status of KTCs, and to explore the potential of implementation of prehabilitation in daily clinical practice.

METHODS AND ANALYSIS

This study uses a single centre, effectiveness-implementation hybrid type I study design, comprised of a randomised controlled trial and a mixed-methods study. Adult patients who are currently on the transplant waiting list or are waitlisted during the study period, at a university medical centre in The Netherlands, will be randomly assigned to either prehabilitation (n=64) or care as usual (n=64) groups. The prehabilitation group will undergo a 12-week home-based, tailored prehabilitation programme consisting of physical and/or nutritional and/or psychosocial interventions depending on the participant's deficits. This programme will be followed by a 12-week maintenance programme in order to enhance the incorporation of the interventions into daily life. The primary endpoint of this study is a change in frailty status as a proxy for health status. Secondary endpoints include changes in physical fitness, nutritional status, psychological well-being, quality of life and clinical outcomes. Tertiary endpoints include the safety, feasibility and acceptability of the prehabilitation programme, and the barriers and facilitators for further implementation.

ETHICS AND DISSEMINATION

Medical ethical approval was granted by the Medical Ethics Committee Groningen, Netherlands (M22.421). Written informed consent will be obtained from all participants. The results will be disseminated at international conferences and in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov, NCT05489432.

Therapeutic drug monitoring of mycophenolic acid (MPA) using volumetric absorptive microsampling (VAMS) in pediatric renal transplant recipients: ultra-high-performance liquid chromatography-tandem mass spectrometry analytical method development, cross-validation, and clinical application

BACKGROUND

Mycophenolic acid (MPA) is widely used in posttransplant pharmacotherapy for pediatric patients after renal transplantation. Volumetric absorptive microsampling (VAMS) is a recent approach for sample collection, particularly during therapeutic drug monitoring (TDM). The recommended matrix for MPA determination is plasma (PL), and conversion between capillary-blood VAMS samples and PL concentrations is required for the appropriate interpretation of the results.

METHODS

This study aimed to validate and develop a UHPLC-MS/MS method for MPA quantification in whole blood (WB), PL, and VAMS samples, with cross and clinical validation based on regression calculations. Methods were validated in the 0.10-15 µg/mL range for trough MPA concentration measurement according to the European Medicines Agency (EMA) guidelines. Fifty pediatric patients treated with MPA after renal transplantation were included in this study. PL and WB samples were obtained via venipuncture, whereas VAMS samples were collected after the fingerstick. The conversion from VAMS_MPA to PL_MPA concentration was performed using formulas based on hematocrit values and a regression model.

RESULTS

LC-MS/MS methods were successfully developed and validated according to EMA guidelines. The cross-correlation between the methods was evaluated using Passing-Bablok regression, Bland-Altman bias plots, and predictive performance calculations. Clinical validation of the developed method was successfully performed, and the formula based on regression was successfully validated for VAMS_MPA to PL_MPA concentration and confirmed on an independent group of samples.

CONCLUSIONS

This study is the first development of a triple matrix-based LC-MS/MS method for MPA determination in the pediatric population after renal transplantation. For the first time, the developed methods were cross-validated with routinely used HPLC-DAD protocol.

The First Entirely 3D-Printed Training Model for Robot-assisted Kidney Transplantation: The RAKT Box

Background

Robot-assisted kidney transplantation (RAKT) is increasingly performed at selected referral institutions worldwide. However, simulation and proficiency-based progression training frameworks for RAKT are still lacking, making acquisition of the RAKT-specific skill set a critical unmet need for future RAKT surgeons.

Objective

To develop and test the RAKT Box, the first entirely 3D-printed, perfused, hyperaccuracy simulator for vascular anastomoses during RAKT.

Design setting and participants

The project was developed in a stepwise fashion by a multidisciplinary team including urologists and bioengineers via an iterative process over a 3-yr period (November 2019-November 2022) using an established methodology. The essential and time-sensitive steps of RAKT were selected by a team of RAKT experts and simulated using the RAKT Box according to the principles of the Vattituki-Medanta technique. The RAKT Box was tested in the operating theatre by an expert RAKT surgeon and independently by four trainees with heterogeneous expertise in robotic surgery and kidney transplantation.

Surgical procedure

Simulation of RAKT.

Measurements

Video recordings of the trainees' performance of vascular anastomoses using the RAKT Box were evaluated blind by a senior surgeon according to the Global Evaluative Assessment of Robotic Skills (GEARS) and Assessment of Robotic Console Skills (ARCS) tools.

Results and limitations

All participants successfully completed the training session, confirming the technical reliability of the RAKT Box simulator. Tangible differences were observed among the trainees in both anastomosis time and performance metrics. Key limitations of the RAKT Box include lack of simulation of the ureterovesical anastomosis and the need for a robotic platform, specific training instruments, and disposable 3D-printed vessels.

Conclusions

The RAKT Box is a reliable educational tool to train novice surgeons in the key steps of RAKT and may represent the first step toward the definition of a structured surgical curriculum in RAKT.

Patient summary

We describe the first entirely 3D-printed simulator that allows surgeons to test the key steps of robot-assisted kidney transplantation (RAKT) in a training environment before performing the procedure in patients. The simulator, called the RAKT Box, has been successfully tested by an expert surgeon and four trainees. The results confirm its reliability and potential as an educational tool for training of future RAKT surgeons.

Prospective cohort study of Torque Teno Virus (TTV) viral load kinetics and the association with graft rejection in renal transplant patients

INTRODUCTION

Graft survival is mainly determined by rejections and infectious complications in transplant recipients. Torque Teno Virus (TTV), a nonpathogenic and ubiquitous single-stranded DNA virus, has been proposed as a biomarker of the immune status in transplant patients. This study aimed to determine the correlation between a Home-Brew TTV PCR and R-GENE®PCR; the TTV viral load kinetics in renal transplant recipients and the association with graft rejection.

MATERIALS AND METHODS

Prospective cohort study on 107 adult renal transplant recipients. TTV viral load was determined in 746 plasma samples collected before and after renal transplantation by a Home-Brew PCR and a commercial PCR (R-GENE®PCR). Associations of TTV viral load with graft rejections were analyzed.

RESULTS

Agreement of both PCR assays was 93.2% and Pearson correlation coefficient was r: 0.902 (95%CI: 0.8881-0.9149, p < 0.0001). TTV viral load kinetics showed an initial gradual increase reaching a peak at 3 months. This highest value was followed by a slight decrease, reaching a plateau significantly higher than the initial baseline at 6 months (p < 0.0001). Between (181-270) days post-transplantation, TTV median viral load in patients with graft rejection was significantly lower, 3.59 Log₁₀ copies/mL (by Home-Brew PCR) and 3.10 Log₁₀ copies/mL (by R-GENE®PCR) compared to patients without graft rejection (6.14 and 5.96 Log₁₀ copies/mL, respectively).

CONCLUSIONS

Significantly lower TTV viral load was observed in patients with renal rejection occurring at a median of 243 days post-transplantation. Given the dynamic behavior of TTV viral load post-transplantation, cut-off values for risk stratification to predict rejection might be determined in relation to the post-transplant period.

Incidence of and Risk Factors for Recurrent Urinary Tract Infections in Renal Transplant Recipients

Background

Recurrent urinary tract infections (rUTIs) are common after renal transplantation (RTx), and the impact on graft and patient survival remains controversial.

Objective

In this study, we investigate the incidence and risk factors for rUTIs in a cohort of RTx recipients and evaluate the effect on graft and patient survival.

Design setting and participants

A retrospective cohort of adult patients who underwent RTx at Rigshospitalet, Denmark, between 2014 and 2021 was evaluated in this study.

Outcome measurements and statistical analysis

Risk factors for rUTIs were explored with a multivariable cause-specific Cox proportional hazard analysis. The Kaplan-Meier estimate was used to assess overall survival.

Results and limitations

A total of 571 RTx recipients were included. The median age was 52 yr (interquartile range: 42-62 yr). Of the cases, 62% were deceased donor RTx. A total of 103 recipients experienced rUTIs. We found increasing age (hazard ratio [HR]: 1.02 per year increase, 95% confidence interval [95% CI]: 1.00-1.04, p = 0.02), female gender (HR: 2.1, 95% CI: 1.4-3.3, p < 0.001), history of lower urinary tract symptoms (HR: 2.3, 95% CI: 1.4-3.5, p = 0.001), and a UTI within 30 d of surgery (HR: 3.5, 95% CI: 2.1-5.9, p < 0.001) were associated with rUTIs. No influence of rUTIs on overall or graft survival was observed.

Conclusions

One in six patients experience rUTIs after RTx. Pre- and postoperative variables affect the risk of rUTIs, but none are easily modifiable. In this cohort, rUTIs did not affect the graft function or survival. The etiology of rUTIs remains poorly understood, and there is a continuous need to study how rUTIs can be reduced and treated optimally.

Patient summary

In this study, we looked at the risk factors for recurrent urinary tract infections in patients after kidney transplantation. We conclude that 21.5% of patients experience recurrent urinary tract infections 5 years after kidney transplantation. Multiple risk factors were found and should be taken into consideration by clinicians.

Paving the way for solutions improving access to kidney transplantation: a qualitative study from a multistakeholder perspective

OBJECTIVES

The aim of this study was to obtain an in-depth perspective from stakeholders involved in access to kidney transplantation to pave the way for solutions in improving access to kidney transplantation. This study qualitatively explored factors influencing optimal access to kidney transplantation from a broad stakeholder perspective.

DESIGN

A qualitative study was performed using semistructured interviews both in focus groups and with individual participants. All interviews were recorded, transcribed and coded according to the principles of grounded theory.

SETTING

Participants were healthcare providers (geographically spread), patients and (former living) kidney donors, policy-makers and insurers.

PARTICIPANTS

Stakeholders (N=87) were interviewed regarding their perceptions, opinions and attitudes regarding access to kidney transplantation.

RESULTS

The problems identified by stakeholders within the domains-policy, medical, psychological, social and economic-were acknowledged by all respondents. According to respondents, more efforts should be made to make healthcare providers and patients aware of the clinical guideline for kidney transplantation. The same opinion applied to differences in medical inclusion criteria used in the different transplantation centres. Stakeholders saw room for improvement based on psychological and social themes, especially regarding the provision of information. Many stakeholders described the need to rethink the current economic model to improve access to kidney transplantation. This discussion led to a definition of the most urgent problems for which, according to the respondents, a solution must be sought to optimise access to kidney transplantation.

CONCLUSIONS

Stakeholders indicated a high sense of urgency to solve barriers in patient access to kidney transplantation. Moreover, it appears that some barriers are quite straightforward to overcome; according to stakeholders, it is striking that this process has not yet been overcome. Stakeholders involved in kidney transplantation have provided directions for future solutions, and now it is possible to search for solutions with them.

Kidney transplant access for children and young adults with congenital anomalies of the kidney and urinary tract

PURPOSE

Although congenital anomalies of the kidney and urinary tract (CAKUT) are among the leading causes of end-stage kidney disease (ESKD) in children and young adults, kidney transplantation access for this population has not been well studied in the US. We compared transplantation access in the US based on whether the etiology of kidney disease was secondary to CAKUT, and additionally by CAKUT subgroups (anatomic vs. inherited causes of CAKUT).

METHODS

Using the United States Renal Data System, we conducted a retrospective cohort study of 80,531 children and young adults who started dialysis between 1995 and 2015. We used adjusted Cox models to examine the association between etiology of kidney disease (CAKUT vs. non-CAKUT, anatomic vs. inherited) and receipt of kidney transplantation, and secondarily, receipt of a living vs. deceased donor kidney transplant.

RESULTS

Overall, we found an increased likelihood of kidney transplantation access for participants with CAKUT compared to those without CAKUT (HR 1.23; 95% CI 1.20-1.27). Among the subset of individuals with CAKUT as the attributed cause of ESKD, we found a lower likelihood of kidney transplantation in those with anatomic causes of CAKUT compared to those with inherited causes of CAKUT (adjusted HR 0.85; 0.81-0.90).

CONCLUSION

There are notable disparities in kidney transplantation rates among CAKUT subgroups. Those with anatomic causes of CAKUT started on dialysis have significantly reduced access to kidney transplantations compared to individuals with inherited causes of CAKUT who were initiated on dialysis. Further studies are needed to understand barriers to transplantation access in this population.

Unique case of colovesical fistula in a renal allograft recipient

Colovesical fistula is commonly suspected in cases of diverticular disease, malignancy, trauma, iatrogenic injury or radiotherapy. In a case of allogenic live related transplant, this is rarely expected, especially after 20 years. The presence of gas in the bladder in the absence of history of instrumentation of urinary tract should prompt us to evaluate for colovesical fistula. Pneumaturia, faecaluria and recurrent urinary tract infection are tell-tale features of colovesical fistula, and when patients who are renal allograft recipient present with them, it should prompt a proper workup and swift surgical management, since the outcome is uniformly favourable. From our knowledge in this realm, we know that these are immunocompromised patients and have a high tendency to develop risk factors like malignancy and/or diverticular disease and eventually form colovesical fistula. An expected time period could be from 2 months to 6 years. But in our case, fistula formation occurred long after peak corticosteroid action, in the absence of conventional aetiologies.

Early recurrence of focal segmental glomerulosclerosis in a kidney transplant recipient with APOL1 one risk variant

Apolipoprotein 1 (APOL1) risk variants (G1 and G2) are associated with focal segmental glomerulosclerosis (FSGS) in patients of African ancestry. The prevalence of APOL1 two risk variants is lower in Hispanics and very rare in European and Asian populations. APOL1 two risk variants in donor kidneys is associated with recipient kidney graft loss, however the effect of recipient risk variant in the kidney transplant outcome is unclear. Here, we present a late adolescent male with FSGS and end stage renal disease with one APOL1 risk variant (G2) who had immediate recurrence of FSGS in the post-KT period. There was an excellent response to few sessions of plasmapheresis and Rituximab with no further recurrence of FSGS in the 1 year follow-up period. It needs to be seen whether the recipient APOL1 single risk variant causes increased susceptibility to kidney graft loss on a long run via recurrent or de novo pathologies.

Youngest en-bloc kidney transplant recipient in India: defying the barriers and challenges with teamwork

We received a call from a transplant coordinator about the availability of a consented deceased donor. En-bloc kidneys with the aorta and IVC (inferior vena cava) were harvested from a toddler weighing 8 kg. The recipient was of early childhood weighing 14 kg who had been on haemodialysis for the last 3 years for end-stage kidney disease. He received anti-thymocyte globulin as an induction immunosuppressant. The kidneys were transplanted en bloc in the right lower quadrant retroperitoneal region; an anastomosis was performed to the recipient's aorta and IVC, and two separate neocystoureterostomies were created. His serum creatinine reached 0.5 mg/dL on the seventh postoperative day, following a few days of delayed graft function. In this study, we describe the surgical and non-surgical challenges that we faced while performing en-bloc kidney transplant to the youngest recipient and how a multidisciplinary team approach helped us overcome them.

Evaluation of drug interaction between cyclosporine and lercanidipine: a descriptive study

OBJECTIVES

Cyclosporine is an immunosuppressive drug with a high potential for drug interactions that is frequently used in renal transplant patients. The purpose of this study was to assess the change in cyclosporine concentration in patients taking cyclosporine and lercanidipine concurrently.

METHODS

The potential drug interactions in renal transplant patients who received lercanidipine and cyclosporine concurrently in a university hospital between January 2008 and January 2018 were evaluated retrospectively. Patients had renal transplantation from deceased donors or living related donors. The Drug Interaction Probability Scale (DIPS) criteria were used to assess the causality of cyclosporine and lercanidipine drug interaction.

RESULTS

The study included six renal transplant patients. The median cyclosporine concentration before lercanidipine use was 325 ng/mL (min-max 101-356) and 592.5 ng/mL (min-max 198-799) thereafter (p=0.028). Serum creatinine and proteinuria levels did not change significantly during lercanidipine treatment (p=0.686 and p=0.116, respectively). According to the DIPS evaluation, cyclosporine and lercanidipine interaction was classified as "possible (score 3)".

CONCLUSIONS

Concomitant use of cyclosporine and lercanidipine increases the concentration of cyclosporine, which may result in side effects during effective treatment in renal transplant patients. Therefore, cyclosporine concentrations should definitely be monitored while patients are taking lercanidipine.

Intrarenal Anti-Leptin Treatment Attenuates Ischemia and Reperfusion Injury

INTRODUCTION

Renal ischemia and reperfusion (IR) injury introduces cellular stress and is the main cause of acute kidney damage. Renal cells exposed to noxious stress induce the expression of the pleiotropic hormone leptin. As we have previously revealed a deleterious stress-related role for leptin expression, these results suggested that leptin is also involved in pathological renal remodeling. The systemic functions of leptin preclude the study of its local effects using conventional approaches. We have therefore designed a method to locally perturb leptin activity in specific tissues without affecting its systemic levels. This study explores whether local anti-leptin strategy is renoprotective in a post-IR porcine kidney model.

METHODS

We induced renal IR injury in pigs by exposing kidneys to ischemia and revascularization. Upon reperfusion, kidneys instantly received an intra-arterial bolus of either a leptin antagonist (LepA) or saline solution. Peripheral blood was sampled to assess systemic leptin, IL-6, creatinine, and BUN levels, and postoperative tissue samples were analyzed by hematoxylin and eosin histochemistry and immunohistochemistry.

RESULTS

Histology of IR/saline kidneys exhibited extensive necrosis of proximal tubular epithelial cells, as well as elevated levels of apoptosis markers and inflammation. In contrast, IR/LepA kidneys showed no signs of necrosis or inflammation with normal IL-6 and tall-like receptor 4 levels. LepA treatment led to upregulation in mRNA levels of leptin, leptin receptor, ERK1/2, STAT3, and transport molecule Na/H exchanger-3.

CONCLUSIONS

Local, intrarenal postischemic LepA treatment at reperfusion prevented apoptosis and inflammation and was renoprotective. Selective intrarenal administration of LepA at reperfusion may provide a viable option for clinical implementation.

Classification of imbalanced data using machine learning algorithms to predict the risk of renal graft failures in Ethiopia

INTRODUCTION

The prevalence of end-stage renal disease has raised the need for renal replacement therapy over recent decades. Even though a kidney transplant offers an improved quality of life and lower cost of care than dialysis, graft failure is possible after transplantation. Hence, this study aimed to predict the risk of graft failure among post-transplant recipients in Ethiopia using the selected machine learning prediction models.

METHODOLOGY

The data was extracted from the retrospective cohort of kidney transplant recipients at the Ethiopian National Kidney Transplantation Center from September 2015 to February 2022. In response to the imbalanced nature of the data, we performed hyperparameter tuning, probability threshold moving, tree-based ensemble learning, stacking ensemble learning, and probability calibrations to improve the prediction results. Merit-based selected probabilistic (logistic regression, naive Bayes, and artificial neural network) and tree-based ensemble (random forest, bagged tree, and stochastic gradient boosting) models were applied. Model comparison was performed in terms of discrimination and calibration performance. The best-performing model was then used to predict the risk of graft failure.

RESULTS

A total of 278 completed cases were analyzed, with 21 graft failures and 3 events per predictor. Of these, 74.8% are male, and 25.2% are female, with a median age of 37. From the comparison of models at the individual level, the bagged tree and random forest have top and equal discrimination performance (AUC-ROC = 0.84). In contrast, the random forest has the best calibration performance (brier score = 0.045). Under testing the individual model as a meta-learner for stacking ensemble learning, the result of stochastic gradient boosting as a meta-learner has the top discrimination (AUC-ROC = 0.88) and calibration (brier score = 0.048) performance. Regarding feature importance, chronic rejection, blood urea nitrogen, number of post-transplant admissions, phosphorus level, acute rejection, and urological complications are the top predictors of graft failure.

CONCLUSIONS

Bagging, boosting, and stacking, with probability calibration, are good choices for clinical risk predictions working on imbalanced data. The data-driven probability threshold is more beneficial than the natural threshold of 0.5 to improve the prediction result from imbalanced data. Integrating various techniques in a systematic framework is a smart strategy to improve prediction results from imbalanced data. It is recommended for clinical experts in kidney transplantation to use the final calibrated model as a decision support system to predict the risk of graft failure for individual patients.

Birc3 and Tip1 are upregulated in renal ischemia reperfusion injury

Identification of ischemia-reperfusion injury (I/R)-associated genes is essential for exploring I/R novel mechanisms. Previously, we screened differentially expressed genes in renal I/R mouse models and found that Tax1 binding protein 3 (Tip1) and baculoviral IAP repeat containing 3 (Birc3) are two upregulated genes in I/R. In the present study, we analyzed the expression of Tip1 and Birc3 in I/R models. We found that the expression of Tip1 and Birc3 was upregulated in I/R-treated mice, whereas Tip1 was downregulated and Birc3 was upregulated in oxygen-glucose deprivation/reoxygenation (OGD/R) in vitro models. By inhibiting Birc3 with AT-406 in I/R-treated mice, we observed that the serum creatinine or blood urea nitrogen did not vary. However, inhibition of Birc3 enhanced apoptosis of kidney tissues induced by I/R treatment. Consistently, we found that inhibition of Birc3 also increased the apoptosis rate in tubular epithelial cells induced by OGD/R. These data demonstrated that Tip1 and Birc3 were upregulated in I/R injury. The upregulation of Birc3 may protect against renal I/R injury.

Exercise and Prediabetes After Renal Transplantation (EXPRED-I): A Prospective Study

BACKGROUND

Post-transplant diabetes mellitus (PTDM) beyond 12 months (late PTDM) is a severe complication after renal transplantation. Late PTDM develops mostly in subjects with prediabetes. Although exercise may have a potential role in preventing late PTDM, there are no previous data on the effect of exercise in patients with prediabetes.

MATERIAL AND METHODS

The design was a 12-month exploratory study to test the capacity of exercise in reverting prediabetes in order to prevent late-PTDM. The outcome was the reversibility of prediabetes, assessed every 3 months with oral glucose tolerance tests (OGTT). The protocol included an incremental plan of aerobic and/or strength training as well as an active plan for promoting adherence (telephone calls, digital technology, and visits). A priori, a sample size cannot be calculated which makes this an exploratory analysis. Based on previous studies, the spontaneous reversibility of prediabetes was 30% and the reversibility induced by exercise will account for another 30%, a total reversibility of 60% (p value < 0.05, assuming a potency of 85%). Ad interim analysis was performed during follow-up to test the certainty of this sample calculation. Patients beyond 12 months after renal transplantation with prediabetes were included.

RESULTS

The study was interrupted early due to efficacy after the evaluation of the follow-up of 27 patients. At the end of follow-up, 16 (60%) patients reverted to normal glucose levels at fasting (from 102.13 mg/dL ± 11 to 86.75 ± 6.9, p = 0.006) and at 120 min after the OGTTs (154.44 mg/dL ± 30 to 113.0 ± 13.1, p = 0.002) and 11 patients had persistent prediabetes (40%). Also, insulin sensitivity improved with the reversibility of prediabetes, compared to those with persistent prediabetes: 0.09 [0.08-0.11] versus 0.04 [0.01-0.07], p = 0.001 (Stumvoll index). Most needed at least one increment in the prescription of exercise and compliance. Finally, measures aimed at the improvement of compliance were successful in 22 (80%) patients.

CONCLUSION

Exercise training was effective to improve glucose metabolism in renal transplant patients with prediabetes. Exercise prescription must be conducted considering both the clinical characteristics of the patients and pre-defined strategy to promote adherence. The trial registration number of the study was NCT04489043.

Implementation of a culturally competent APOL1 genetic testing programme into living donor evaluation: A two-site, non-randomised, pre-post trial design

INTRODUCTION

While living donor (LD) kidney transplantation is the optimal treatment for patients with kidney failure, LDs assume a higher risk of future kidney failure themselves. LDs of African ancestry have an even greater risk of kidney failure post-donation than White LDs. Because evidence suggests that Apolipoprotein L1 (APOL1) risk variants contribute to this greater risk, transplant nephrologists are increasingly using APOL1 genetic testing to evaluate LD candidates of African ancestry. However, nephrologists do not consistently perform genetic counselling with LD candidates about APOL1 due to a lack of knowledge and skill in counselling. Without proper counselling, APOL1 testing will magnify LD candidates' decisional conflict about donating, jeopardising their informed consent. Given cultural concerns about genetic testing among people of African ancestry, protecting LD candidates' safety is essential to improve informed decisions about donating. Clinical 'chatbots', mobile apps that provide genetic information to patients, can improve informed treatment decisions. No chatbot on APOL1 is available and no nephrologist training programmes are available to provide culturally competent counselling to LDs about APOL1. Given the shortage of genetic counsellors, increasing nephrologists' genetic literacy is critical to integrating genetic testing into practice.

METHODS AND ANALYSIS

Using a non-randomised, pre-post trial design in two transplant centres (Chicago, IL, and Washington, DC), we will evaluate the effectiveness of culturally competent APOL1 testing, chatbot and counselling on LD candidates' decisional conflict about donating, preparedness for decision-making, willingness to donate and satisfaction with informed consent and longitudinally evaluate the implementation of this intervention into clinical practice using the Reach, Effectiveness, Adoption, Implementation and Maintenance framework.

ETHICS AND DISSEMINATION

This study will create a model for APOL1 testing of LDs of African ancestry, which can be implemented nationally via implementation science approaches. APOL1 will serve as a model for integrating culturally competent genetic testing into transplant and other practices to improve informed consent. This study involves human participants and was approved by Northwestern University IRB (STU00214038). Participants gave informed consent to participate in the study before taking part.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04910867. Registered 8 May 2021, https://register.

CLINICALTRIALS

gov/prs/app/action/SelectProtocol?sid=S000AWZ6&selectaction=Edit&uid=U0001PPF&ts=7&cx=-8jv7m2 ClinicalTrials.gov Identifier: NCT04999436. Registered 5 November 2021, https://register.

CLINICALTRIALS

gov/prs/app/action/SelectProtocol?sid=S000AYWW&selectaction=Edit&uid=U0001PPF&ts=11&cx=9tny7v.

Higher tacrolimus trough levels and time in the therapeutic range are associated with the risk of acute rejection in the first month after renal transplantation

BACKGROUND

Tacrolimus trough levels (C₀) are used in most transplant centres for therapeutic drug monitoring (TDM) of tacrolimus (Tac). The target range of Tac C₀ has been remarkably changed, with a target as low as 3-7 ng/ml in the 2009 European consensus conference and a target of 4-12 ng/ml (preferably to 7-12 ng/ml) following the second consensus report in 2019. Our aim was to investigate whether reaching early Tac therapeutic targets and maintaining time in the therapeutic range (TTR) according to the new recommendations may be necessary for preventing acute rejection (AR) during the first month after transplantation.

METHODS

A retrospective study including 160 adult renal transplant patients (113 men and 47 women) with a median age of 36.3 (20-44) years was conducted between January 2018 and December 2019 at 103 Military Hospital (Vietnam). Tac trough levels were recorded in the first month, and episodes of AR were confirmed by kidney biopsy. Tac TTR was calculated as the percentage of time within the target range of 7-12 ng/ml, according to the 2019 second consensus report. Multivariate Cox analysis was performed to identify the correlation between the Tac target range and TTR with AR.

RESULTS

In the first month after RT, 14 (8.8%) patients experienced AR. There was a significant difference in the incidence of AR between the Tac level groups of < 4, 4-7 and > 7 ng/ml (p = 0.0096). In the multivariate Cox analysis, after adjusting for related factors, a mean Tac level > 7 ng/ml was associated with an 86% decreased risk of AR compared with that of 4-7 ng/ml in the first month (HR, 0.14; 95% CI, 0.03-0.66; p = 0.0131). Every 10% increase in TTR was associated with a 28% lower risk of AR (HR, 0.72; 95% CI, 0.55-0.94; p = 0.014).

CONCLUSION

Gaining and maintaining Tac C₀ according to the 2019 second consensus report might reduce the risk of AR in the first month following transplantation.

Kidney Transplant Outcomes in Elderly Population: A Systematic Review and Meta-analysis

Context

Owing to population ageing, a growing number of kidney transplants (KTs) in elderly population are being performed. KT is the best treatment for patients with end-stage renal disease (ESRD). However, in older patients, the decision between dialysis and KT can be difficult due to potential inferior outcomes. Few studies have been published addressing this issue, and literature outcomes are controversial.

Objective

To conduct a systematic review and meta-analysis to appraise the evidence about outcomes of KT in elderly patients (>70 yr).

Evidence acquisition

A systematic review and meta-analysis (PROSPERO registration: CRD42022337038) was performed. Search was conducted on PubMed and LILACS databases. Comparative and noncomparative studies addressing outcomes (overall survival [OS], graft survival [GS], complications, delayed graft function [DGF], primary nonfunction, graft loss, estimated glomerular filtrate rate, or acute rejection) of KT in people older than 70 yr were included.

Evidence synthesis

Of the 10 357 yielded articles, 19 met the inclusion criteria (18 observational studies, one prospective multicentre study, and no randomised controlled trials), enrolling a total of 293 501 KT patients. Comparative studies reporting enough quantitative data for target outcomes were combined. There were significant inferior 5-yr OS (relative risk [RR], 1.66; 95% confidence interval [CI], 1.18-2.35) and 5-yr GS in the elderly group (RR, 1.37; 95% CI, 1.14-1.65) to those in the <70-yr group. Short-term GS at 1 and 3 yr was similar between groups, and similar findings occurred with DGF, graft loss, and acute rejection rates. Few data about postoperative complications were reported.

Conclusions

Elderly recipients have worse OS at all time points and long-term GS compared with younger recipients (<70 yr). Postoperative complications were under-reported and could not be assessed. The DGF, acute rejection, death with functioning graft, and graft loss were not inferior in elderly recipients. Geriatric assessment in this setting might be useful for selecting better elderly candidates for KT.

Patient summary

Compared with younger population, kidney transplant in elderly patients has inferior patient and graft survival outcomes in the long term.

Factors Associated With Persistent Post-transplant Hyperparathyroidism After Index Renal Transplantation

INTRODUCTION

Secondary hyperparathyroidism (SHP) is common in end-stage renal disease and may progress to persistent post-transplant hyperparathyroidism (PTHP) following renal transplantation (RT). We sought to describe the frequency and determine factors associated with the incidence of PTHP for patients undergoing RT at a single institution that restricts RT for patients with uncontrolled SHP with a parathyroid hormone (PTH) of >800pg/mL at time of initial transplant evaluation.

METHODS

We conducted a single-institution retrospective study of adults undergoing index RT from 2012 to 2020 who had a calcium and PTH level within 12 mo prior to RT and at least 6 mo following RT. PTHP was defined as calcium of >10 mg/dL with an elevated PTH > 88pg/mL at six or more months following RT. Univariate analysis and multivariable logistic regression were performed for factors associated with developing PTHP.

RESULTS

We identified 1110 patients with RT, 65 were excluded for prior RT, 549 did not have a pre-RT and post-RT calcium, and PTH laboratories for inclusion, yielding 496 for analysis. Following RT, 39 patients (7.9%) developed PTHP, compared to those who did not develop PTHP; these patients had significantly higher pre-RT PTH, pre-RT calcium, and frequency of calcimimetic therapy. In multivariable logistic regression factors significantly associated with PTHP were pre-RT calcium of more than 10 mg/dL with an odds ratio (OR) of 3.57 (95% confidence interval [CI] 1.52-8.39, P = 0.003) and pre-RT calcimimetic therapy with an OR 1.30 (95% CI 1.06-2.85, P = 0.041). Compared with patients who had a pre-RT PTH of less than 200 pg/mL, a PTH of 200-399 pg/mL increased risk of PTHP with an OR of 4.52 (95% CI 1.95-21.5, P = 0.048) and a PTH of > 400 pg/mL increased risk of PTHP with an OR of 7.17 (95% CI 1.47-34.9, P = 0.015). In this cohort, 11 patients (28.2%) with PTHP underwent parathyroidectomy (PTx) at a mean of 1.4 y post-RT (standard deviation 0.87).

CONCLUSIONS

For patients required to have a PTH < 800pg/mL for initial transplant candidacy, the subsequent incidence of PTHP is relatively low at 7.9%. Risk factors for PTHP include higher pre-RT calcium and PTH levels and pre-RT calcimimetic therapy. PTx remains underused in the treatment of PTHP. Further study is warranted to determine the optimal PTH cutoff for transplant candidacy and recommendation for PTx in patients requiring calcimimetic therapy for SHP.

Kidney transplant in the next decade: Strategies, challenges and vision of the future

Although the results of kidney transplantation (KT) have improved substantially in recent years, a chronic and inexorable loss of grafts mainly due to the death of the patient and chronic dysfunction of the KT, continues to be observed. The objectives, thus, to optimize this situation in the next decade are fundamentally focused on minimizing the rate of kidney graft loss, improving patient survival, increasing the rate of organ procurement and its distribution, promoting research and training in health professionals and the development of scientific registries providing clinical and reliable information that allow us to optimize our clinical practice in the field of KT. With this perspective, this review will deep into: (1) strategies to avoid chronic dysfunction and graft loss in the medium and long term; (2) to prolong patient survival; (3) strategies to increase the donation, maintenance and allocation of organs; (4) promote clinical and basic research and training activity in KT; and (5) the analysis of the results in KT by optimizing and merging scientific registries.

[Tic douloureux sustained by an eye tumor]

Cancer is a major cause of morbidity and mortality in solid organ transplantation. Nonmelanoma skin cancer (NMSC) such as basocellular (BCC) and spinocellular (SCC) carcinoma, are common in renal transplant recipients. We report a case of an SCC affecting a lacrimal gland in a subject with kidney transplantation. A man aged 75 years who had suffered from glomerulopathy since 1967 and subsequently started haemodialysis, in 1989 was transplanted from a living donor. In 2019, he suffered paresthesia and pain in his right eyebrow arch and he was diagnosed to have neuralgia of the fifth cranial nerve. The failure of medical treatment and the development of a mass in his eyelid plus exophthalmos induced healthcare professionals to perform a magnetic resonance. The latter showed a retrobulbar mass measuring 39×22×16 mm3. Biopsy revealed an SCC and the patient underwent eye exenteration. Although NMSC of the eye is an extremely rare condition, risk factors such as male sex, history of glomerulopathy, and duration of immunosuppression should be taken into consideration at the time of the onset of eye symptoms.