Age is an important predictor of kidney transplantation outcome

ACEI/ARB use within one year of kidney transplant is associated with less AKI and graft loss in elderly recipients

BACKGROUND

Optimizing long-term graft survival remains a major focus in transplant. Elderly kidney transplant recipients are vulnerable to acute kidney injury (AKI) and graft loss. This study assessed the safety and efficacy of ACEI/ARB in elderly kidney transplant recipients and impact on graft outcomes.

METHODS

Retrospective, longitudinal, cohort study of 500 patients age ≥60 years, who underwent kidney transplantation between 2005 and 2015. Demographic, transplant, and outcomes data were collected. Manual chart abstraction was conducted to determine medication use at discharge, one, three, and five years post-transplant. Univariate and multivariable Cox regression modeling were used to analyze outcomes.

RESULTS

Mean age of subjects was 66 years (range 60-81). 59% were males and 50% were African-American. 49% had chronic kidney disease (CKD) due to diabetes mellitus (DM). A total of 38, 134, 167, and 112 elderly kidney transplant recipients were on ACEI/ARB at discharge, one, three, and five years post-transplant respectively. ACEI/ARB initiated within one year of transplant was associated with lower risk of graft loss (HR=0.62, CI 0.38-0.99, p = 0.047). This was driven mainly by a lower risk of death (HR=0.41, CI 0.24-0.71, p = 0.002). ACEI/ARB use was associated with lower risk of AKI after 1 year (HR 0.70, CI 0.52-0.95, p = 0.02). ACEI/ARB was not associated with increased risk of acute rejection or hospitalization.

CONCLUSION

Initiation of ACEI/ARB within one year of transplant is associated with lower risk of AKI and graft loss, driven by lower risk of death in elderly kidney transplant recipients. Clinicians should maximize ACEI/ARB therapy early on after kidney transplant.

Gender differences in cardiovascular outcomes of kidney transplant recipients: A retrospective cohort study

The purpose of this study was to investigate gender differences in cardiovascular outcomes of kidney transplant recipients (KTRs). Here, a retrospective cohort study was conducted, and data from the National Health Insurance Research Database in Taiwan were used. In total, 2904 patients who had end-stage renal disease (ERSD) and received kidney transplantation (KT) were identified by propensity score matching (PSM) and were enrolled from 1997 to 2012, with follow-up ending in 2013. Besides, major adverse cardiovascular events (MACEs) were defined as a composite of all-cause mortality, nonfatal myocardial infarction, and nonfatal strokes. Apart from that, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated by Cox regression, while the Bayesian network model was constructed to assess the importance of risk factors for MACEs. Furthermore, the original cohort was a sensitivity analysis. Women had a lower risk of MACEs compared with men (hazard ratio [HR]: 0.84; 95% CI: 0.72-0.98; P = .024). Beyond that, stratified analysis of age and waiting time for KT showed that the risk of MACEs was significantly lower in women than in men among KTRs aged > 50 years (HR: 0.79; 95% CI: 0.62-1.0; P = .05) or waiting time for KT ≤ 6 years (HR: 0.85; 95% CI: 0.72-0.99; P = .04). Bayesian network indicated that age is an important determinant of cardiovascular outcomes in KTRs, regardless of gender. In Taiwan, women had a lower risk of adverse cardiovascular outcomes than men in KTRs aged > 50 years or with a waiting time for KT ≤ 6 years. Furthermore, age is an important independent determinant for the prognosis of KTRs.

Predicting kidney allograft survival with explainable machine learning

INTRODUCTION

Despite significant progress over the last decades in the survival of kidney allografts, several risk factors remain contributing to worsening kidney function or even loss of transplants. We aimed to evaluate a new machine learning method to identify these variables which may predict the early graft loss in kidney transplant patients and to assess their usefulness for improving clinical decisions.

MATERIAL AND METHODS

A retrospective cohort study was carried out with 627 kidney transplant patients followed at least three months. All these data were pre-processed, and their selected features were used to develop an automatically working a machine learning algorithm; this algorithm was then applied for training and parameterization of the model; and finally, the tested model was then used for the analysis of patients' features that were the most impactful for the prediction of clinical outcomes. Our models were evaluated using the Area Under the Curve (AUC), and the SHapley Additive exPlanations (SHAP) algorithm was used to interpret its predictions.

RESULTS

The final selected model achieved a precision of 0.81, a sensitivity of 0.61, a specificity of 0.89, and an AUC value of 0.84. In our model, serum creatinine levels of kidney transplant patients, evaluated at the hospital discharge, proved to be the most important factor in the decision-making for the allograft loss. Patients with a weight equivalent to a BMI closer to the normal range prior to a kidney transplant are less likely to experience graft loss compared to patients with a BMI below the normal range. The age of patients at transplantation and Polyomavirus (BKPyV) infection had significant impact on clinical outcomes in our model.

CONCLUSIONS

Our algorithm suggests that the main characteristics that impacted early allograft loss were serum creatinine levels at the hospital discharge, as well as the pre-transplant values such as body weight, age of patients, and their BKPyV infection. We propose that machine learning tools can be developed to effectively assist medical decision-making in kidney transplantation.

Multicenter evaluation of complex urinary diversion for renal transplantation: outcomes of complex surgical solutions

PURPOSE

An abnormal lower urinary tract poses significant challenges for transplant surgeons. Besides the ureteral anastomosis to an ileal conduit, there are diverse complex reconstructive solutions. Due to its rarity, standardization and teaching of complex urinary diversion is extremely difficult.

METHODS

The indications and outcomes of complex urinary diversions after kidney transplantation (KT) were retrospectively investigated at eight urologic transplant centers including a current follow-up.

RESULTS

Of 37 patients with 21 (56%) males, vesicoureteral reflux (24%), spina bifida (22%), and glomerulonephritis (12%) were the most common causes of terminal renal failure. In 30 (81%) patients, urinary diversion was performed before KT, at a median of 107.5 (range, 10; 545) months before. Transplantations were held at a median patient age of 43 (10; 68) years, including six (16%) living donations. Urinary diversion was modified during 12 (32%) transplantations. After KT, the ileal conduit was the most common incontinent urinary diversion in 25 (67%) patients; a Mainz pouch I and bladder augmentation were the most frequent continent diversions (each n = 3). At a median follow-up of 120 months (range 0; 444), 12 (32%) patients had a graft failure with a 5-year graft survival of 79% (95%CI 61; 90). The median overall survival was 227 months (168; 286) and the 5-year overall survival 89% (69.3; 96.4).

CONCLUSION

The mid-term kidney transplant function with complex urinary diversion appears to be comparable to transplants with regular urinary diversions. Hence, complex urinary diversion should always be considered as a surgical option, even during transplantation, if necessary.

Trends in kidney transplantation and living donor nephrectomy in Germany: a total population analysis from 2006 to 2021

PURPOSE

To analyze recent trends of surgical access routes, length of hospital stay (LOS), and mortality in kidney transplantation (KT) and living donor nephrectomy (LDN) in Germany.

MATERIALS AND METHODS

We studied the nationwide German hospital billing database and the German hospital quality reports from 2006 to 2021.

RESULTS

There were a total of 35.898 KTs. In total, 9044 (25%) were living donor transplantations, while 26.854 (75%) were transplantations after donation after brain death (DBD). The share of open LDN decreased from 82% in 2006 to 22% in 2020 (- 4%/year; p < 0.001). The share of laparoscopic LDN increased from 18% in 2006 to 70% in 2020 (+ 3%/year; p < 0.001). The share of robotic LDN increased from 0% in 2006 to 8% in 2020 (+ 0.6%/year; p < 0.001). Robotic-assisted KT increased from 5 cases in 2016 to 13 procedures in 2019 (p = 0.2). LOS was shorter after living donor KT, i.e., 18 ± 12.1 days versus 21 ± 19.6 days for DBD renal transplantation (p < 0.001). Moreover, LOS differed for open versus laparoscopic versus robotic LDN (9 ± 3.1 vs. 8 ± 2.9 vs. 6 ± 2.6; p = 0.031). The overall in-hospital mortality was 0.16% (n = 5) after LDN, 0.47% (n = 42) after living donor KT and 1.8% (n = 475) after DBD KT.

CONCLUSIONS

There is an increasing trend toward minimal-invasive LDN in recent years. Overall, in-hospital mortality was low after KT. However, 5 deceased healthy donors after LKD caution that the risks of this procedure should also be taken very seriously.

Debiased lasso for stratified Cox models with application to the national kidney transplant data

The Scientific Registry of Transplant Recipients (SRTR) system has become a rich resource for understanding the complex mechanisms of graft failure after kidney transplant, a crucial step for allocating organs effectively and implementing appropriate care. As transplant centers that treated patients might strongly confound graft failures, Cox models stratified by centers can eliminate their confounding effects. Also, since recipient age is a proven non-modifiable risk factor, a common practice is to fit models separately by recipient age groups. The moderate sample sizes, relative to the number of covariates, in some age groups may lead to biased maximum stratified partial likelihood estimates and unreliable confidence intervals even when samples still outnumber covariates. To draw reliable inference on a comprehensive list of risk factors measured from both donors and recipients in SRTR, we propose a de-biased lasso approach via quadratic programming for fitting stratified Cox models. We establish asymptotic properties and verify via simulations that our method produces consistent estimates and confidence intervals with nominal coverage probabilities. Accounting for nearly 100 confounders in SRTR, the de-biased method detects that the graft failure hazard nonlinearly increases with donor's age among all recipient age groups, and that organs from older donors more adversely impact the younger recipients. Our method also delineates the associations between graft failure and many risk factors such as recipients' primary diagnoses (e.g. polycystic disease, glomerular disease, and diabetes) and donor-recipient mismatches for human leukocyte antigen loci across recipient age groups. These results may inform the refinement of donor-recipient matching criteria for stakeholders.

A cross-validation statistical framework for asymmetric data integration

The proliferation of biobanks and large public clinical data sets enables their integration with a smaller amount of locally gathered data for the purposes of parameter estimation and model prediction. However, public data sets may be subject to context-dependent confounders and the protocols behind their generation are often opaque; naively integrating all external data sets equally can bias estimates and lead to spurious conclusions. Weighted data integration is a potential solution, but current methods still require subjective specifications of weights and can become computationally intractable. Under the assumption that local data are generated from the set of unknown true parameters, we propose a novel weighted integration method based upon using the external data to minimize the local data leave-one-out cross validation (LOOCV) error. We demonstrate how the optimization of LOOCV errors for linear and Cox proportional hazards models can be rewritten as functions of external data set integration weights. Significant reductions in estimation error and prediction error are shown using simulation studies mimicking the heterogeneity of clinical data as well as a real-world example using kidney transplant patients from the Scientific Registry of Transplant Recipients.

Physiological Age by Artificial Intelligence-Enhanced Electrocardiograms as a Novel Risk Factor of Mortality in Kidney Transplant Candidates

BACKGROUND

Mortality risk assessment before kidney transplantation (KT) is imperfect. An emerging risk factor for death in nontransplant populations is physiological age as determined by the application of artificial intelligence to the electrocardiogram (ECG). The aim of this study was to examine the relationship between ECG age and KT waitlist mortality.

METHODS

We applied a previously developed convolutional neural network to the ECGs of KT candidates evaluated 2014 to 2019 to determine ECG age. We used a Cox proportional hazard model to examine whether ECG age was associated with waitlist mortality.

RESULTS

Of the 2183 patients evaluated, 59.1% were male, 81.4% were white, and 11.4% died during follow-up. Mean ECG age was 59.0 ± 12.0 y and mean chronological age at ECG was 53.3 ± 13.6 y. After adjusting for chronological age, comorbidities, and other characteristics associated with mortality, each increase in ECG age of >10 y than the average ECG age for patients of a similar chronological age was associated with an increase in mortality risk (hazard ratio 3.59 per 10-y increase; 95% confidence interval, 2.06-5.72; P  < 0.0001).

CONCLUSIONS

ECG age is a risk factor for KT waitlist mortality. Determining ECG age through artificial intelligence may help guide risk-benefit assessment when evaluating candidates for KT.

Sickness Symptoms in Kidney Transplant Recipients: A Scoping Review

Sickness symptoms (depressive symptoms, anxiety, and fatigue) are common among people with chronic illness, often presenting as a symptom cluster. Sickness symptoms persist in many patients with chronic kidney disease, even after kidney transplantation (KT); however, little is known about sickness symptom-induced burden in KT recipients. This scoping review synthesizes available evidence for sickness symptoms in KT recipients, including findings on symptom prevalence, predictors, outcomes, interrelationships, and clustering. Among 38 reviewed studies, none identified sickness symptoms as a cluster, but we observed interrelationships among the symptoms examined. Fatigue was the most prevalent sickness symptom, followed by anxiety and depressive symptoms. Predictors of these symptoms included demographic, clinical, and psychosocial factors, and health-related quality of life was the most researched outcome. Future research should use common data elements to phenotype sickness symptoms, include biological markers, and employ sophisticated statistical methods to identify potential clustering of sickness symptoms in KT recipients.

Management and Outcome After Early Renal Transplant Vein Thrombosis: A French Multicentre Observational Study of Real-Life Practice Over 24 Years

Early (<14 days) renal transplant vein thrombosis posttransplant (eRVTPT) is a rare but threatening complication. We aimed to assess eRVTPT management and the rate of functional renal transplantation. Of 11,172 adult patients who had undergone transplantation between 01/1997 and 12/2020 at 6 French centres, we identified 176 patients with eRVTPT (1.6%): 16 intraoperative (Group 1, G1) and 160 postoperative (Group 2, G2). All but one patient received surgical management. Patients in group G2 had at least one imaging test for diagnostic confirmation (N = 157, 98%). During the operative management of the G2 group, transplantectomy for graft necrosis was performed immediately in 59.1% of cases. In both groups, either of two techniques was preferred, namely, thrombectomy by renal venotomy or thrombectomy + venous anastomosis repair, with no difference in the functional graft rate (FGR) at hospital discharge (p = NS). The FGR was 62.5% in G1 and 8.1% in G2 (p < 0.001). Numerous complications occurred during the initial hospitalization: 38 patients had a postoperative infection (21.6%), 5 experienced haemorrhagic shock (2.8%), 29 exhibited a haematoma (16.5%), and 97 (55.1%) received a blood transfusion. Five patients died (2.8%). Our study confirms the very poor prognosis of early renal graft venous thrombosis.

Outcomes in kidney transplant recipients treated with immediate-release tacrolimus capsules versus extended-release tacrolimus capsules: A cohort study

INTRODUCTION

Prior randomized trials and observational studies have generally reported similar outcomes in kidney transplant recipients (KTRs) treated with immediate-release tacrolimus (IR-TAC) versus extended-release tacrolimus (ER-TAC). However, many of these previous studies focused on patients with low immunological risks, had small sample sizes and brief follow-up periods, and excluded outcomes associated with graft loss, such as chronic rejection.

METHODS

To address these limitations, we conducted a cohort study of 848 KTRs at a single transplantation center who had generally high immunological risks and were treated with either IR-TAC capsules (589 patients, 65.9%) or ER-TAC capsules (289 patients, 34.1%). All patients received their designated maintenance immunosuppressive regimen for at least 3 months post-transplantation. Afterwards, tacrolimus formulation was at the discretion of each patient's transplant nephrologist. For the two treatment groups, we compared the hazards of experiencing a composite outcome of acute or chronic antibody-mediated rejection (AMR), acute or chronic T-cell-mediated rejection, de novo DSA, and/or graft loss over a 3-year period starting at 3 months post-transplantation.

RESULTS

In a multivariable Cox proportional hazards regression model, KTRs treated with IR-TAC capsules had an increased hazard of experiencing the composite outcome when compared to patients treated with ER-TAC capsules; however, this result was not significant (adj HR 1.24, 95% CI .92-1.68, p = .163). Similar results were obtained with inverse probability of treatment weighting (IPTW) using a propensity score (adj HR 1.25, 95% CI .93-1.68, p = .146).

CONCLUSION

These findings suggest that when compared to IR-TAC capsules, ER-TAC capsules do not reduce the hazard of poor outcomes in KTRs with generally high immunological risks.

Quality of Life of Post-renal Transplant Patients in Rawalpindi

Objectives The objective is to assess the overall quality of life (QoL) in patients who had undergone renal transplant within the last three years and correlate this index with various demographic variables such as age, gender, marital status, and education level and to correlate the QoL score calculated vs. the health status perceived by the patients themselves Materials and methods This was an analytical cross-sectional study, carried out over a period of five months. A total of 123 patients were targeted among which data from 79 patients were gathered including all the patients that underwent kidney transplantation in the past three years at a renal transplant center in CMH, Rawalpindi, Pakistan. Non- Probability convenience sampling was used, and data were collected using the WHOQOL-BREF tool that contained 25 questions targeted to four domains (physical, psychological, social, and environmental). The Questionnaire was administered over the phone with proper consent taken beforehand. Data were analyzed using Excel and SPSS version 23. Results A total of 79 patients were administered the questionnaire with the mean age of our study population being 35±11 years out of which 84.5% were male and 15.5% were female. Patients received the kidney from relative donors (98.4%) with the highest percentage being sister donors (30.9%). The majority of patients reported from Punjab (54.4%), with the rest from far-flung rural areas. An estimated 62.5% of the patients presented with other systemic/psychological disorders such as DM+, IHD, HTN, Hepatitis C, depression, etc. The mean global score of these patients was 79.21 which can be broken down into four domains, physical domain 80.40, psychological domain 78.99, social domain 82.70, and environmental domain 74.75. Conclusion In a developing country such as Pakistan, with most of the patients belonging to lower or middle socioeconomic groups, we believe that the patient's own sense of QoL is overshadowed by the mere exuberance of being given a second chance at life which was portrayed by the discrepancies in the perceived vs actual QoL graph. One common recurring theme that was noticed whilst interviewing the patients was that the difficulties they might have faced post-transplant paled in comparison to how grateful they were to live another day. A positive trend was noticed between the time since transplant and the QoL score which could be attributed to various factors such as the use of aggressive immunosuppressants, fear of injury, fear of transplant rejection, etc. in the first-year post-transplant. Demographic variables such as income, age, location, etc. did not affect the scores of these patients on a great scale. The present study aims to guide clinicians in the improvement of long-term outcomes of renal transplantation in Pakistan.

Function and longevity of renal grafts from high-KDPI donors

BACKGROUND

High kidney-donor profile index (KDPI) kidneys have a shorter survival than grafts with lower KDPI values. It is still unclear, however, whether their shorter longevity depends on an inferior baseline function, faster functional decline, or the combination of both.

METHODS

We analyzed the estimated glomerular filtration rate (eGFR) of 605 consecutive recipients of deceased donor kidney transplants (KT) at 1, 3, 6, 12, 18, 24, 36, 48, and 60 months. Comparisons were performed among four groups based on KDPI quartile: Group I-KDPI ≤ 25% (n = 151), Group II-KDPI 26-50% (n = 182), Group III-KDPI 51-75% (n = 176), and Group IV-KDPI 〉 75% (n = 96). Linear mixed model analysis was subsequently used to assess whether KDPI was independently associated with the decline in eGFR during the first 5-years after KT. We also analyzed the incidence of delayed graft function (DGF), rejection within the first year after KT, patient survival, graft survival, and death censored graft survival based on KDPI group.

FINDINGS

High-KDPI grafts had lower eGFR immediately after KT, had a higher incidence of DGF and rejection. However, there were no signifcant differences in the adjusted rate (slope) of decline in eGFR among the four KDPI groups (P = .06). Although patient survival was signigicantly lower for recipients of high-KDPI grafts, death-censored graft survival was similar among the four KDPI groups (P = .33).

CONCLUSIONS

The shorter functional survival of high-KDPI grafts seems to be due to their lower baseline eGFR rather than a more rapid functional decline after KT.

RETRACTED:Predictive Factors of Surgical Complications in the First Year Following Kidney Transplantation

This article has been retracted: please see Elsevier Policy on Article Withdrawal ( https://www.elsevier.com/locate/withdrawalpolicy ). The article has been retracted at the request of the last author, Sebastien Deglise, due to significant violations of research standards during the course of the study which do not ensure the reliability of the published data and of which the author has informed the journal that he was unaware at the time of the publication.

Kidney transplantation waiting times and risk of cardiovascular events and mortality: a retrospective observational cohort study in Taiwan

OBJECTIVES

Patients with end-stage renal disease (ESRD) are at a high risk of cardiovascular events (CVEs), and kidney transplantation (KT) has been reported to improve risk of CVEs and survival. As the association of KT timing on long-term survival and clinical outcomes remains unclear, we investigated the association of different KT waiting times with clinical outcomes.

DESIGN

Retrospective observational cohort study.

SETTING

We conducted an observational cohort study using data from the National Health Insurance Research Database in Taiwan. Adult patients who initiated KT therapy from 1997 to 2013 were included.

PARTICIPANTS

A total of 3562 adult patients who initiated uncomplicated KT therapy were included and categorised into four groups according to KT waiting times after ESRD: group 1 (<1 year), group 2 (1-3 years), group 3 (3-6 years) and group 4 (>6 years).

PRIMARY OUTCOME MEASURES

The main outcomes were composite of all-cause death, non-fatal myocardial infarction or non-fatal stroke, based on the primary diagnosis in medical records during hospitalisation.

RESULTS

Compared with group 1, the adjusted risk of primary outcome events (all-cause death, non-fatal myocardial infarction or non-fatal stroke) increased by 1.67 times in group 2 (95% CI: 1.40 to 2.00; p<0.001), 2.17 times in group 3 (95% CI: 1.73 to 2.71; p<0.001) and 3.10 times in group 4 (95% CI: 2.21 to 4.35; p<0.001). The rates of primary outcome events were 6.7%, 13.4% and 14.0% within 5 years, increasing to 19.5%, 26.3% and 30.8% within 10 years in groups 1, 2 and 3, respectively.

CONCLUSIONS

Our results demonstrate that early KT is associated with superior long-term cardiovascular outcomes compared with late KT in selected patients with ESRD receiving uncomplicated KT, suggesting that an early KT could be a better treatment option for patients with ESRD who are eligible for transplantation.

Pearls and Pitfalls in Pediatric Kidney Transplantation After 5 Decades

Worldwide, over 1,300 pediatric kidney transplantations are performed every year. Since the first transplantation in 1959, healthcare has evolved dramatically. Pre-emptive transplantations with grafts from living donors have become more common. Despite a subsequent improvement in graft survival, there are still challenges to face. This study attempts to summarize how our understanding of pediatric kidney transplantation has developed and improved since its beginnings, whilst also highlighting those areas where future research should concentrate in order to help resolve as yet unanswered questions. Existing literature was compared to our own data of 411 single-center pediatric kidney transplantations between 1968 and 2020, in order to find discrepancies and allow identification of future challenges. Important issues for future care are innovations in immunosuppressive medication, improving medication adherence, careful donor selection with regard to characteristics of both donor and recipient, improvement of surgical techniques and increased attention for lower urinary tract dysfunction and voiding behavior in all patients.

Sequential Organ Failure Assessment (SOFA) and 90-day mortality in patients with kidney transplant status at first ICU admission: a cohort study of 428 patients

PURPOSE

We investigated the prognostic accuracy of scores of SOFA for 90-day mortality in patients with kidney transplant status identified from the public Medical Information Mart for Intensive Care III databank.

METHODS

A total of 428 participants with kidney transplant status who were admitted for the first time to the ICU were included. The target-independent and target-dependent variables were the SOFA scores in the first 3 days of ICU admission and 90-day mortality, respectively.

RESULTS

Fully adjusted binary logistic regression indicated that the day-2 and day-3 SOFA scores were positively associated with a risk of 90-day mortality after adjustment for confounders (odds ratio: 1.196, 95% confidence interval: 1.052-1.360; odds ratio: 1.233, 95% confidence interval: 1.062-1.432). The receiver operating characteristic curve showed areas under the curve for the prediction of 90-day mortality from SOFA scores on days 1, 2 and 3 were 0.524, 0.654, and 0.727, respectively. Further analysis using Kaplan-Meier survival curves and multivariate regression models of 90-day survival showed that patients with low SOFA scores survived longer than those with high scores.

CONCLUSION

The SOFA scores in the early days of ICU admission were positively associated with 90-day outcomes although the first-day score showed no significant correlation.

Multivariate Longitudinal Assessment of Kidney Function Outcomes on Graft Survival after Kidney Transplantation Using Multivariate Joint Modeling Approach: A Retrospective Cohort Study

Background

The performance of a transplanted kidney is evaluated by monitoring variations in the value of the most important markers. These markers are measured longitudinally, and their variation is influenced by other factors. The simultaneous use of these markers increases the predictive power of the analytical model. This study aimed to determine the simultaneous longitudinal effect of serum creatinine and blood urea nitrogen (BUN) markers, and other risk factors on allograft survival after kidney transplantation.

Methods

In a retrospective cohort study, the medical records of 731 renal transplant patients, dated July 2000 to December 2013, from various transplant centers in Mashhad (Iran) were examined. Univariate and multivariate joint models of longitudinal and survival data were used, and the results from both models were compared. The R package joineRML was used to implement joint models. P values <0.05 were considered statistically significant.

Results

Results of the multivariate model showed that allograft rejection occurred more frequently in patients with elevated BUN levels (HR=1.68, 95% CI: 1.24-2.27). In contrast, despite a positive correlation between serum creatinine and allograft rejection (HR=1.49, 95% CI: 0.99-2.22), this relationship was not statistically significant.

Conclusion

Results of the multivariate model showed that longitudinal measurements of BUN marker play a more important role in the investigation of the allograft rejection.

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

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

Kidney transplantation outcomes in lupus nephritis: A 37-year single-center experience from Latin America

OBJECTIVE

We assessed patient and graft outcomes and prognostic factors in kidney transplantation in patients with end-stage kidney disease (ESKD) secondary to lupus nephritis (LN) undergoing kidney transplantation from August 1977 to December 2014 in a Latin American single center.

METHODS

The primary endpoint was patient survival, and the secondary endpoints were death-censored graft survival for the first renal transplant and the rate of recurrent LN (RLN). Kaplan-Meier method was used for survival analysis. Factors predicting patient and death-censored graft survivals were examined by Cox proportional-hazards regression analyses.

RESULTS

185 patients were retrospectively evaluated. Patient survival rates were 88% at one year, 82% at three years, 78% at five years, and 67% at ten years. Death-censored graft survival for the first renal transplant was 93% at one year, 89% at three years, 87% at five years, and 80% at ten years. RLN was diagnosed in 2 patients (1.08%), but no graft was lost because of RLN. Thirty-nine (21.1%) patients died, and 65 (35.1%) patients experienced graft loss during the follow-up. By multivariable analyses, older recipient age and 1-month posttransplantation eGFR <45 ml/min/1.73m² were associated with lower patient survival and an increased risk of graft loss, while induction immunosuppressive therapy exerted a protective effect on patients' survival. In the subgroup of patients in whom disease activity was measured at the time of transplantation, a higher SLEDAI score was also associated with lower patient survival and an increased risk of graft loss.

CONCLUSION

In a mostly Mestizo population, kidney transplantation is an excellent therapeutic alternative in LN patients with ESKD. Older recipient age, an eGFR <45 ml/min/1.73m² at one month posttransplantation, and disease activity at the time of transplantation are predictive of a lower patient and death-censored graft survival, while induction immunosuppressive therapy has a protective effect on patient survival. RLN is rare and does not influence the risk of graft loss.

Clinical Outcomes of Older Kidney Transplant Recipients

BACKGROUND

Older kidney transplant recipients (OKTR) are vulnerable to infections and AKI, often prompting hospitalization. This study elucidates etiology of hospitalizations, AKI, and outcomes in OKTR.

METHODS

Retrospective study of 500 patients age ≥ 60, who underwent kidney transplantation from 2005-2015. Demographic, transplant, and outcomes data were collected.

RESULTS

OKTR had mean age 66 years; 59% males and 50% African Americans. 62% had at least one hospitalization post-transplant. Predictors of hospitalization were DGF, DM, panel reactive antibodies (PRA), dialysis duration. Hospitalization was mostly due to infection and surgical complications. Average length of stay was 6.4 days. OKTR with at least one hospitalization had 84% higher risk for graft loss (p=0.001). 56% of older kidney transplant recipients had at least one AKI episode post-transplant. Predictors of AKI included DGF, older, African American donor, and tacrolimus variability. The most common etiologies for AKI were infection, dehydration, and GI complications. OKTR with at least one AKI episode had 2.6-fold higher risk for graft loss (p<0.001).

CONCLUSIONS

Post-transplant hospitalization and AKI in OKTR significantly impact graft survival. Addressing comorbidities and risks in the pre-transplant and outpatient setting may help alleviate burden of hospitalization and risk of AKI in OKTR and improve graft outcomes.

Outcomes in Living Donor Kidney Transplantation: The Role of Donor's Kidney Function

INTRODUCTION

Living donor kidney transplant (LDKT) is one of the best therapeutic options for end-stage kidney disease (ESKD). Guidelines identify different estimated glomerular filtration rate (eGFR) thresholds to determine the eligibility of donors. The aim of our study was to evaluate whether pretransplant donor eGFR was associated with kidney function in the recipient.

METHODS

We retrospectively studied LDKT recipients who received a kidney graft between September 1, 2005, and June 30, 2016 in the same transplant center in France and that had eGFR data available at 3, 12, 24, and 36 months posttransplant.

RESULTS

We studied 90 donor-recipient pairs. The average age at time of transplant was 51.47 ± 10.95 for donors and 43.04 ± 13.52 years for recipients. Donors' average eGFR was 91.99 ± 15.37 mL/min/1.73 m2. Donor's age and eGFR were significantly correlated (p < 0.0001, r2 0.023). Donor's age and eGFR significantly correlated with recipient's eGFR at 3, 12, and 24 months posttransplant (age: p < 0.001 at all intervals; eGFR p = 0.001, 0.003, and 0.016, respectively); at 36 months, only donor's age significantly correlated with recipient's eGFR. BMI, gender match, and year of kidney transplant did not correlate with graft function. In the multivariable analyses, donor's eGFR and donor's age were found to be associated with graft function; correlation with eGFR was lost at 36 months; and donor's age retained a strong correlation with graft function at all intervals (p < 0.001).

CONCLUSIONS

Donor's eGFR and age are strong predictors of recipient's kidney function at 3 years. We suggest that donor's eGFR should be clinically balanced with other determinants of kidney function and in particular with age.

Aorto-Iliac Artery Calcification and Graft Outcomes in Kidney Transplant Recipients

While the association of vascular calcification with inferior patient outcomes in kidney transplant recipients is well-established, the association with graft outcomes has received less attention. With this dual-centre cohort study, we aimed to determine the clinical impact of recipient pre-transplant aorto-iliac calcification, measured on non-contrast enhanced computed tomography (CT)-imaging within three years prior to transplantation (2005–2018). We included 547 patients (61.4% male, age 60 (interquartile range 51–68) years), with a median follow-up of 3.1 (1.4–5.2) years after transplantation. The aorto-iliac calcification score (CaScore) was inversely associated with one-year estimated-glomerular filtration rate (eGFR) in univariate linear regression analysis (standard β −3.3 (95% CI −5.1 to −1.5, p < 0.0001), but not after adjustment for potential confounders, including donor and recipient age (p = 0.077). In multivariable Cox regression analyses, a high CaScore was associated with overall graft failure (p = 0.004) and death with a functioning graft (p = 0.002), but not with death-censored graft failure and graft function decline. This study demonstrated that pre-transplant aorto-iliac calcification is associated with one-year eGFR in univariate, but not in multivariable linear regression analyses. Moreover, this study underlines that transplantation in patients with a high CaScore does not result in earlier transplant function decline or worse death censored graft survival, although ongoing efforts for the prevention of death with a functioning graft remain essential.

Logistic Regression Model in a Machine Learning Application to Predict Elderly Kidney Transplant Recipients with Worse Renal Function One Year after Kidney Transplant: Elderly KTbot

Background

Renal replacement therapy (RRT) is a public health problem worldwide. Kidney transplantation (KT) is the best treatment for elderly patients' longevity and quality of life.

Objectives

The primary endpoint was to compare elderly versus younger KT recipients by analyzing the risk covariables involved in worsening renal function, proteinuria, graft loss, and death one year after KT. The secondary endpoint was to create a robot based on logistic regression capable of predicting the likelihood that elderly recipients will develop worse renal function one year after KT.

Method

Unicentric retrospective analysis of a cohort was performed with individuals aged ≥60 and <60 years old. We analysed medical records of KT recipients from January to December 2017, with a follow-up time of one year after KT. We used multivariable logistic regression to estimate odds ratios for elderly vs younger recipients, controlled for demographic, clinical, laboratory, data pre- and post-KT, and death.

Results

18 elderly and 100 younger KT recipients were included. Pretransplant immune variables were similar between two groups. No significant differences (P > 0.05) between groups were observed after KT on laboratory data means and for the prevalences of diabetes mellitus, hypertension, acute rejection, cytomegalovirus, polyomavirus, and urinary infections. One year after KT, the creatinine clearance was higher (P = 0.006) in youngers (70.9 ± 25.2 mL/min/1.73 m²) versus elderlies (53.3 ± 21.1 mL/min/1.73 m²). There was no difference in death outcome comparison. Multivariable analysis among covariables predisposing chronic kidney disease epidemiology collaboration (CKD-EPI) equation <60 mL/min/1.73 m² presented a statistical significance for age ≥60 years (P = 0.01) and reduction in serum haemoglobin (P = 0.03). The model presented goodness-fit in the evaluation of artificial intelligence metrics (precision: 90%; sensitivity: 71%; and F ₁ score: 0.79).

Conclusion

Renal function in elderly KT recipients was lower than in younger KT recipients. However, patients aged ≥60 years maintained enough renal function to remain off dialysis. Moreover, a learning machine application built a robot (Elderly KTbot) to predict in the elderly populations the likelihood of worse renal function one year after KT.

Outcomes With Age Combinations in Living Donor Kidney Transplantation

INTRODUCTION

Reevaluation of donor criteria, including age, is needed to combat organ shortages, lengthy wait times, and anticipated recipient mortality rates. The purpose of this study was to evaluate donor and recipient (D/R) age combinations and patient and graft survival outcomes.

METHODS

Single-organ, living donor kidney transplantations (LDKTs) from 2012 to 2018 were retrospectively reviewed. Donors and recipients were placed into "older" and "younger" age categories of 50 years and above or below age 50, then analyzed with SPSS version 25.

RESULTS

We performed 347 LDKTs. Younger-to-older pairings had significantly higher rates of smoking in recipient (53.6%) and hepatitis C (5.5%), but shorter hospital stays (5.3 days). Older-to-younger pairings had the longest hospital stays (7.4 days) but the shortest cold ischemic time (2.3 hours). Notably, there was no significant variance in delayed graft function (first-week dialysis) between groups. Regarding complication rates, only bleeding within 30 days, highest in older-to-older pairings (7.7%), and renal complications, highest in older-to-younger pairings, significantly varied between groups. Interestingly, though younger-to-older cases had the longest mean graft survival time, older kidneys lasted 537 days longer in older recipients than in younger recipients.

DISCUSSION

These results indicate there is not a one-size-fits-all approach when considering outcomes of donor/recipient age-pairings in LDKT, as significant correlations did not consistently favor one age-pairing over others. Regardless of age-pairing, LDKT provides gold standard treatment and expands the availability of organs. Future research into the impact of age-pairing on specific variables, national or multicenter studies, and protocol development for evaluating donor/recipient age-pairings is needed.

Improving HLA matching in living donor kidney transplantation using kidney paired exchange program

BACKGROUND

The inclusion of compatible pairs within kidney paired exchange programs has been described as a way to enhance these programs. Improved immunological matching for the recipient in compatible pair has been described to be a possible benefit.

METHODS

The main purpose of our study was to determine if the introduction of compatible pairs in the Portuguese kidney paired exchange program would result in a better match for these patients, but also to assess if this strategy would increase the number of incompatible pairs with a possible match. We included 17 compatible pairs in kidney paired exchange pool of 35 pairs and performed an in-silico simulation determining HLA eplet mismatch load between the co-registered and matched pairs using HLA MatchMaker, version 3.0.

RESULTS

Our study showed that the inclusion of fully HLA-A, -B, -DR mismatched compatible pairs within the national Portuguese KEP increased matched rate within ICP (0.71%) and improved HLA eplet matching within compatible pairs. 16 of 17 (94.12%) of the CP obtained one or more transplants possibilities and 13 (81.25%) would have been transplanted with significantly lower HLA class I and class II total and antibody-verified eplet mismatch load (83.9 ± 16.9 vs. 59.8 ± 12.2, P = .002 and 30.1 ± 5.5 vs. 21.2 ± 3.0, P = .003, respectively).

CONCLUSIONS

This strategy is a viable alternative for compatible pairs seeking a better matched kidney and Portuguese KEP program should allow them this possibility.

Comparative Analysis of Risk Factors in Declined Kidneys from Donation after Brain Death and Circulatory Death

Background and objectives: Kidneys from donation after circulatory death (DCD) are more likely to be declined for transplantation compared with kidneys from donation after brain death (DBD). The aim of this study was to evaluate characteristics in the biopsies of human DCD and DBD kidneys that were declined for transplantation in order to rescue more DCD kidneys. Materials and Methods: Sixty kidney donors (DCD = 36, DBD = 24) were recruited into the study and assessed using donor demographics. Kidney biopsies taken post cold storage were also evaluated for histological damage, inflammation (myeloperoxidase, MPO), von Willebrand factor (vWF) expression, complement 4d (C4d) deposition and complement 3 (C3) activation using H&E and immunohistochemistry staining, and Western blotting. Results: More DBD donors (16/24) had a history of hypertension compared with DCDs (8/36, p = 0.001). The mean warm ischemic time in the DCD kidneys was 12.9 ± 3.9 min. The mean cold ischemic time was not significantly different between the two groups of kidney donors (DBD 33.3 ± 16.7 vs. DCD 28.6 ± 14.1 h, p > 0.05). The score of histological damage and MPO, as well as the reactivity of vWF, C4d and C3, varied between kidneys, but there was no significant difference between the two donor types (p > 0.05). However, vWF reactivity might be an early indicator for loss of tissue integrity, while C4d deposition and activated C3 might be better predictors for histological damage. Conclusions: Similar characteristics of DCD were shown in comparison with DBD kidneys. Importantly, the additional warm ischemic time in DCD appeared to have no further detectable adverse effects on tissue injury, inflammation and complement activation. vWF, C4d and C3 might be potential biomarkers facilitating the evaluation of donor kidneys.

Donor Age Amplifies the Detrimental Effects of Cold Ischemia Time on Long-Term Kidney Allograft Survival Independently of the Occurrence of Delayed Graft Function or Early Acute Rejection

OBJECTIVES

We investigated the influence of the interaction between donor age and cold ischemia time on allograft survival in the absence of delayed graft function, early acute rejection, or the combination of both.

MATERIALS AND METHODS

We conducted a retrospective analysis of a cohort of patients first transplanted with living-related and deceased-donor allografts between 2001 and 2016. Predictors included cold ischemia time, donor and recipient age and sex, body mass index, renal replacement therapy duration, cause of end-stage renal disease, HLA class I and II mismatches, panel of reactive antibodies score, donor creatinine concentration, development of delayed graft function, and biopsy-proven acute rejection. The response variable was time until return to renal replacement therapy. Patients who died with functioning allografts were censored at the time of death. Analyses included multivariate Cox proportional hazards regression.

RESULTS

The study included 498 patients followed for median of 4.1 years with median cold ischemia time of 17.0 hours. On multivariate analysis, allograft survival was negatively affected by the cold ischemia time-donor age interaction (P = .026), acute rejection (P = .043), delayed graft function (P = .001), and acute rejection combined with delayed graft function (P = .002). Restricted mean allograft survival times in patients who developed neither delayed graft function nor acute rejection decreased from 13.6 to 8.6 years when cold ischemia time increased from 12 to 36 hours and donor age increased from 30 to 60 years.

CONCLUSIONS

Allograft survival was negatively affected by donor age-cold ischemia time interaction independently of the development of delayed graft function, acute rejection, or their combination.

Should kidney allografts from old donors be allocated only to old recipients?

In several deceased donor kidney allocation systems, organs from elderly donors are allocated primarily to elderly recipients. The Eurotransplant Senior Program (ESP) was implemented in 1999, and since then, especially in Europe, the use of organs from elderly donors has steadily increased. The proportion of ≥60-year-old donors reported to the Collaborative Transplant Study (CTS) by European centers has doubled, from 21% in 2000-2001 to 42% in 2016-2017. Therefore, in the era of organ shortage it is a matter of debate whether kidney organs from elderly donors should only be allocated to elderly recipients or whether <65-year-old recipients can also benefit from these generally as "marginal" categorized organs. To discuss this issue, a European Consensus Meeting was organized by the CTS on April 12, 2018, in Heidelberg, in which 36 experts participated. Based on available evidence, it was unanimously concluded that kidney organs from 65- to 74-year-old donors can also be allocated to 55- to 64-year-old recipients, especially if these organs are from donors with no history of hypertension, no increased creatinine, no cerebrovascular death, and no other reasons for defining a marginal donor, such as diabetes or cancer.

Retrospective Analysis of the first 100 Kidney Transplants at the Istanbul Okan University, Health Application and Research Center

Objectives:

The renal transplant program of Istanbul Okan University Hospital started in August 2017. Five cadaveric and 95 living donor kidney transplants have been performed for over 16 months. In this study, we aimed to share our experiences regarding kidney transplantation.

Methods:

In this study, a retrospective analysis of 100 patients who underwent kidney transplantation at the Istanbul Okan University over 16 months, the Health Application and Research Center was carried out. Patients’ demographics, creatinine levels of donors and recipients, co-morbid conditions, postoperative complications, features of arterial anastomosis and arterial variations observed on computed tomography angiography of donor-patient were assessed.

Results:

Mean age of donor patients was 44.05±13.76 (18-71) years. All living donors had computed tomography angiography for assessment of the vascular structure of both kidneys. Accessory right kidney artery was the most dominant vascular variation (16.5%). The primary cause of chronic renal disease was diabetes mellitus (36.4%) and hypertension (15.6%). Mean warm and cold ischemia time was 1.82±0.44 (1-3) and 40.25±6.12 (31-57) minutes, respectively. The most observed postoperative complication was stenosis of ureter anastomosis (4.1%). End-to-end arterial anastomosis between renal and internal iliac arteries was the most preferred anastomosis (57.2%).

Conclusion:

Increasing kidney transplantation, which is the most appropriate treatment in terms of cost-effectiveness, will be beneficial for patient health and economy of the country.

Risk factors for death in kidney transplant patients: analysis from a large protocol biopsy registry

BACKGROUND

Identification and quantification of the relevant factors for death can improve patients' individual risk assessment and decision-making. We used a well-documented patient cohort (n = 892) in a renal transplant programme with protocol biopsies to establish multivariable Cox models for risk assessment at 3 and 12 months post-transplantation.

METHODS

Patients transplanted between 2000 and 2007 were observed up to 11 years (total observation 5227 patient-years; median 5.9 years). Loss to follow-up was negligible (n = 15). A total of 2251 protocol biopsies and 1214 biopsies for cause were performed. All rejections and clinical borderline rejections in protocol biopsies were treated.

RESULTS

Overall 10-year patient survival was 78%, with inferior survival of patients with graft loss and superior survival of patients with living-donor transplantation. Eight factors were common in the models at 3 and 12 months, including age, pre-transplant heart failure and a score of cardiovascular disease and type 2 diabetes, post-transplant urinary tract infection, treatment of rejection, new-onset heart failure, coronary events and malignancies. Additional variables of the model at 3 months included deceased donor transplantation, transplant lymphocele, BK virus nephropathy and severe infections. Graft function and graft loss were significant factors of the model at 12 months. Internal validation and validation with a separate cohort of patients (n = 349) demonstrated good discrimination of the models.

CONCLUSIONS

The identified factors indicate the important areas that need special attention in the pre- and post-transplant care of renal transplant patients. On the basis of these models, we provide nomograms as a tool to weigh individual risks that may contribute to decreased survival.

Deceased donor organ transplantation potential: A peep into an untapped gold mine

Organ transplantation is the gold standard for treating end-stage organ diseases, many of whom are on waiting lists. The reasons for this include the nonavailability of suitable organs to be transplanted. In many nations, most of these challenges have been surmounted by the adoption of deceased donor program, which is not so in sub-Saharan countries such as Nigeria. This study is to audit the potentially transplantable organs available from potential deceased donors from a Nigerian tertiary hospital. This is a study of deaths in the intensive care unit (ICU) and the accident and emergency units of the University of Ilorin Teaching Hospital, Nigeria. Data included the biodata, social history, diagnosis or indications for admission, time of arrival and death, causes of death, associated comorbidities, potential organs available, social history, and availability of relations at the time of death. There were 104 deaths in the ICU and 10 patients in the accident and emergency unit. There were 66 males (57.9%) and 48 females (42.1%). Eighty patients were Muslims (70.2%) and 34 were Christians (19.8%). A total of 33 participants were unmarried (28.9%),whereas 81 (71.1%) were married. The tribes of the patients were Yoruba (105, 92.1%), Igbo (7, 6.1%), Hausa (1, 0.9%), and Nupe (1, 0.9%). The age range was 0.08-85 years. Twenty-two (19.3%) had primary and the remaining had at least secondary education. The causes of death were myriad, and there were relatives available at the times of all deaths. The Maastricht classification of the deaths were Class I - 1 (0.9%), Class II - 37 (32.2%), Class III - 9 (7.8%), Class IV - 20 (17.4%), and Class V - 47(40.9%). There were no transplantable organs in 42 (36.5%), one organ in eight (7%), two organs in two (7%), three organs in one (0.9%), four organs in 13 (11.3%), five organs in six (5.2%), six organs in 11 (9.6%), seven organs in 11 (9.6%), eight organs in five (13%), and nine organs in five (4.3%). Deceased donor sources of organs are worthy of being exploited to improve organ transplantation in Nigeria.

Kidneys From Elderly Deceased Donors-Is 70 the New 60?

There is a growing shortage of kidney donors leading to extended transplant waiting times associated with increased mortality. To expand the donor pool, clinicians nowadays regularly accept organs from elderly donors, including those aged ≥70 years. There is only limited and conflicting data whether kidneys from these elderly donors allow for satisfactory allograft outcome rates. To asses this question, the 5-year death censored graft survival of 116,870 adult first deceased donor kidney allograft recipients that were transplanted at European centers between 1997 and 2016 and reported to the “Collaborative Transplant Study” were analyzed using Kaplan–Meier analysis and country stratified Cox regression. The combinations of the two transplant periods 1997–2006 and 2007–2016 with the donor age categories 18–49, 50–59, 60–69, and ≥70 years were considered. From 1997–2006 to 2007–2016, the median donor age increased from 50 to 55 years and the proportion of kidneys from ≥60-year-old donors rose from 24.1 to 38.8%. At the same time, the proportion of kidneys from ≥70-year-old donors more than doubled (6.7 vs. 15.4%). Between 1997–2006 and 2007–2016, the 5-year graft survival improved in all donor age categories. During 2007–2016, the 5-year death censored graft survival of kidneys from ≥70-year-old donors was comparable to that of kidneys from 60 to 69-year-old donors during 1997–2006. This was true both for younger recipients (18–64 years) and older recipients (≥65 years). Among the younger recipients, 45–64-year-old recipients showed the best death censored graft survival rates for kidneys from old donors. In the country-stratified Cox regression analysis, compared to the reference of grafts from 18 to 49-year-old donors, the hazard ratio for grafts from ≥70-year-old donors during 2007–2016 was 1.92, exactly the same as the hazard ratio for grafts from 60 to 69-year-old donors during 1997–2006. Our analysis indicates that within only one further decade (1997–2006 vs. 2007–2016) the 5-year death censored graft survival of kidneys from ≥70-year old donors improved to the level of kidneys from 60 to 69-year-old donors in the previous decade.

Unveiling the Role of DNA Methylation in Kidney Transplantation: Novel Perspectives toward Biomarker Identification

The burden of chronic kidney disease is dramatically rising, making it a major public health concern worldwide. Kidney transplantation is now the best treatment for patients with end-stage renal disease. Although kidney transplantation may improve survival and quality of life, its long-term results are hampered by immune- and/or non-immune-mediated complications. Thus, the identification of transplanted patients with a higher risk of posttransplant complications has become a big challenge for public health. However, current biomarkers of posttransplant complications have a poor predictive value, rising the need to explore novel approaches for the management of transplant patient. In this review we summarize the emerging literature about DNA methylation in kidney transplant complications, in order to highlight its perspectives toward biomarker identification. In the forthcoming future the monitoring of DNA methylation in kidney transplant patients could become a plausible strategy toward the prevention and/or treatment of kidney transplant complications.

Perioperative Goal-Directed Therapy during Kidney Transplantation: An Impact Evaluation on the Major Postoperative Complications

Background: Kidney transplantation is considered the first-choice therapy in end-stage renal disease (ESRD) patients. Despite recent improvements in terms of outcomes and graft survival in recipients, postoperative complications still concern the health-care providers involved in the management of those patients. Particularly challenging are cardiovascular complications. Perioperative goal-directed fluid-therapy (PGDT) and hemodynamic optimization are widely used in high-risk surgical patients and are associated with a significant reduction in postoperative complication rates and length of stay (LOS). The aim of this work is to compare the effects of perioperative goal-directed therapy (PGDT) with conventional fluid therapy (CFT) and to determine whether there are any differences in major postoperative complications rates and delayed graft function (DGF) outcomes. Methods: Prospective study with historical controls. Two groups, a PGDT and a CFT group, were used: The stroke volume (SV) optimization protocol was applied for the PGDT group throughout the procedure. Conventional fluid therapy with fluids titration at a central venous pressure (CVP) of 8–12 mmHg and mean arterial pressure (MAP) >80 mmHg was applied to the control group. Postoperative data collection including vital signs, weight, urinary output, serum creatinine, blood urea nitrogen, serum potassium, and assessment of volemic status and the signs and symptoms of major postoperative complications occurred at 24 h, 72 h, 7 days, and 30 days after transplantation. Results: Among the 66 patients enrolled (33 for each group) similar physical characteristics were proved. Good functional recovery was evident in 92% of the CFT group, 98% of the PGDT group, and 94% of total patients. The statistical analysis showed a difference in postoperative complications as follows: Significant reduction of cardiovascular complications and DGF episodes (p < 0.05), and surgical complications (p < 0.01). There were no significant differences in pulmonary or other complications. Conclusions: PGDT and SV optimization effectively influenced the rate of major postoperative complications, reducing the overall morbidity and thus the mortality in patients receiving kidney transplantation.

Predictors of Early and Late Mortality in Older Kidney Transplant Recipients

BACKGROUND

Older kidney patients with chronic kidney disease benefit significantly from kidney transplantation. However, these older transplant recipients have greater mortality after transplantation than younger transplant recipients. Understanding the impact of comorbidities on post-transplant mortality can improve risk stratification and patient selection.

METHODS

A single-center analysis of 3105 kidney transplant recipients was performed over a 12-year period. Comorbidities associated with death were evaluated in older and younger transplant recipients.

RESULTS

The 2 most important factors associated with increased mortality in the first 100 days after transplant were recipient age ≥60 and receipt of deceased donor organs (adjusted odds ratios, 3.29 and 5.80, respectively), with no statistically significant impact of recipient comorbidities. In the later post-transplant period (after the first 100 days), recipient age ≥60 and receipt of deceased donor organs (adjusted hazard ratios [HR] of 2.14 and 2.29, respectively) remained predictors of mortality. We also found that donor age ≥60 and the recipient having cardiovascular disease and diabetes were independent predictors of increased mortality. There was a statistically significant interaction between diabetes and heart disease and recipient age ≥60, with a lesser impact on late mortality in older patients compared to younger patients.

CONCLUSIONS

This analysis suggests that comorbidities have a larger impact later after transplantation, with less effect on older recipients. These observations suggest that certain comorbid conditions should be evaluated differently in older patients compared to younger ones.

Living donor risk model for predicting kidney allograft and patient survival in an emerging economy

AIM

Living donor kidney is the main source of donor organs in low to middle income countries. We aimed to develop a living donor risk model that predicts graft and patient survival in an emerging economy.

METHODS

We used data from the Sindh Institute of Urology and Transplantation (SIUT) database (n = 2283 recipients and n = 2283 living kidney donors, transplanted between 1993 and 2009) and conducted Cox proportional hazard analyses to develop a composite score that predicts graft and patient survivals.

RESULTS

Donor factors age, creatinine clearance, nephron dose (estimated by donor/recipient body weight ratio) and human leukocyte antigen (HLA) match were included in the living donor risk model. The adjusted hazard ratios (HRs) for graft failures among those who received a kidney with living donor scores (reference to donor score of zero) of 1, 2, 3 and 4 were 1.14 (95%CI: 0.94-1.39), 1.24 (95%CI:1.03-1.49), 1.25 (95%CI:1.03-1.51) and 1.36 (95%CI:1.08-1.72) (P-value for trend =0.05). Similar findings were observed for patient survival.

CONCLUSIONS

Similar to findings in high income countries, our study suggests that donor characteristics such as age, nephron dose, creatinine clearance and HLA match are important factors that determine the long-term patient and graft survival in low income countries. However, other crucial but undefined factors may play a role in determining the overall risk of graft failure and mortality in living kidney donor transplant recipients.

Cytomegalovirus viraemia and mortality in renal transplant recipients in the era of antiviral prophylaxis. Lessons from the western Australian experience

Background

Cytomegalovirus (CMV) establishes a lifelong infection that is efficiently controlled by the immune system; this infection can be reactivated in case of immunosuppression such as following solid organ transplantation. CMV viraemia has been associated with CMV disease, as well as increased mortality and allograft failure. Prophylactic antiviral medication is routinely given to renal transplant recipients, but reactivation during and following cessation of antiviral prophylaxis is known to occur. The aims of this study were to assess the incidence, timing and impact of CMV viraemia in renal transplant recipients and to determine the level of viraemia associated with adverse clinical outcomes.

Methods

Data from all adult (18 years and over) Western Australian renal transplant recipients transplanted between 1 January 2007 and 31 December 2012 were obtained from the Australia and New Zealand Dialysis and Transplant registry and were supplemented with data obtained from clinical records. Potential risk factors for detectable CMV viraemia (≥600 copies/ml) and all-cause mortality were assessed using univariable analysis and Cox Proportional Hazards Regression.

Results

There were 438 transplants performed on 435 recipients. The following factors increased the risk of CMV viraemia with viral loads ≥600 copies/ml: Donor positive/Recipient negative status; receiving a graft from a deceased donor; and receiving a graft from a donor aged 60 years and over. CMV viraemia with viral loads ≥656 copies/ml was a risk factor for death following renal transplantation, as was being aged 65 years and above at transplant, being Aboriginal and having vascular disease. Importantly 37% of the episodes of CMV viraemia with viral loads ≥656 copies/ml occurred while the patients were expected to be on CMV prophylaxis.

Conclusions

CMV viraemia (≥656 copies/ml) was associated with all-cause mortality in multivariable analysis, and CMV viraemia at ≥656 copies/ml commonly occurred during the period when renal transplant recipients were expected to be on antiviral prophylaxis. A greater vigilance in monitoring CMV levels if antiviral prophylaxis is stopped prematurely or poor patient compliance is suspected could protect some renal transplant recipients from adverse outcomes such as premature mortality.

Is Brain-Dead Donor Fluid Therapy With Colloids Associated With Better Kidney Grafts?

OBJECTIVES

Fluid therapy is required to maintain perfusion to donor organs. Recent reviews on the choices of fluids have emphasized the safety of using crystalloids, as opposed to fluid therapy with colloids, which has been reported to be either unequivocally or potentially harmful in a number of studies on various patient populations. We aimed to analyze whether the type of fluid administered to donors is connected with kidney transplant outcomes.

MATERIALS AND METHODS

A total of 100 consecutive brain-dead multiorgan donors and their respective 181 kidney recipients were studied retrospectively. Data concerning donor fluid therapy, the characteristics of the donors and the recipients, and outcomes after kidney transplant were extracted from organ retrieval and patient records. Cases with early graft function were compared with cases with delayed graft function.

RESULTS

Donors had received both crystalloids and colloids in most cases (84%). Fluid therapy with crystalloids alone was more common among the 40 recipients with delayed (30%) than in the 103 recipients with early graft function (11%) (P = .005). Donor age, time on renal replacement therapy before transplant, and donor fluid therapy with crystalloids alone were independent risk factors for delayed graft function in multivariate analysis.

CONCLUSIONS

Our results suggest that donor fluid therapy including colloids could be beneficial instead of harmful compared with treatment with crystalloids alone. This finding needs to be evaluated in prospective studies.

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.