A comparative analysis of survival of patients on dialysis and after kidney transplantation

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.

Impaired kidney function: supporting the safe use of medicines for patients

Due to the increasing incidence of acute kidney injury (AKI) and chronic kidney disease (CKD), nurses in most healthcare settings are likely to care for patients with some degree of impaired kidney function. Impaired kidney function can adversely affect the way the body excretes, absorbs, distributes and metabolises medicines (pharmacokinetics), potentially resulting in a wide range of drug-related complications. This article provides an overview of the effects of impaired kidney function on pharmacokinetics and the importance of accurate drug dose adjustments for patients with related conditions. It also discusses various aspects of medicines use in patients with AKI, the pharmacological management of patients with CKD and the use of immunosuppressive therapy in patients who have had a kidney transplant. The authors consider the role of the nurse in ensuring safe medicines use for patients with impaired kidney function throughout the article.

A nomogram based on contrast-enhanced ultrasound for evaluating the glomerulosclerosis rate in transplanted kidneys

Background

A high rate of glomerulosclerosis serves as an important signal of poor response to treatment and a high risk of disease progression or adverse prognosis in transplanted kidneys. We hypothesized that contrast-enhanced ultrasound (CEUS) could serve as a novel imaging biomarker in the early prediction of glomerulosclerosis rate by evaluating renal allograft microcirculation.

Methods

A retrospective analysis was performed on 143 transplanted kidney recipients with confirmed pathology, including 100 in the training group and 43 in the validation group. All patients underwent conventional ultrasound (CUS) and CEUS examinations. The patients were divided into two groups: those with >50% glomerulosclerosis and those with ≤50% glomerulosclerosis. The nomograms derived from independent predictors identified by multivariate logistic analysis were assessed using receiver operating characteristic (ROC) curve analysis, 1,000 bootstrap resamples, calibration curves, and decision curve analysis (DCA).

Results

The patients with >50% glomerulosclerosis and those with ≤50% glomerulosclerosis showed statistically significant differences in CEUS parameters, including in peak intensity (PI) (25 vs. 30; P<0.001), absolute time to peak (ATTP) (10 vs. 9; P=0.004), and time to peak (TTP) (22 vs. 19.5; P=0.026). Multivariate analysis revealed that PI [odds ratio (OR) =0.852; 95% confidence interval (CI): 0.737-0.986], peak systolic velocity (PSV) of the interlobar artery (OR =0.850; 95% CI: 0.758-0.954), cortical echogenicity (OR =38.429; 95% CI: 3.695-399.641), and time since transplantation (OR =1.017; 95% CI: 1.006-1.028) were independent predictors of whether the glomerulosclerosis rate was >50% and were incorporated into the construction of a nomogram. The area under the curve (AUC) of the nomogram in the training and validation groups was 0.914 (95% CI: 0.840-0.960) and 0.909 (95% CI: 0.781-0.975), respectively, with a bootstrap resampling AUC of 0.877. The calibration curve and DCA confirmed the diagnostic performance of the nomogram model.

Conclusions

The nomogram, which combined CUS, CEUS, and clinical indicators, exhibited notable predictive efficacy for the glomerulosclerosis rate in transplanted kidneys, thereby demonstrating the potential to improve clinical decision-making.

Racialized and Immigrant Status and the Pursuit of Living Donor Kidney Transplant - a Canadian Cohort Study

Introduction

Both immigrant and racialized status may be associated with the pursuit of living donor kidney transplant (LDKT).

Methods

This study was a secondary analysis of a convenience cross-sectional sample of patients with kidney failure in Toronto, obtained from our "Comprehensive Psychosocial Research Data System" research database. The exposures included racialized, immigrant, and combined immigrant and racialized status (White nonimmigrant, racialized nonimmigrant, White immigrant and racialized immigrant). Outcomes include the following: (i) having spoken about LDKT with others, (ii) having a potential living donor (LD) identified, (iii) having allowed others to share the need for LDKT, (iv) having directly asked a potential donor to be tested, and (v) accept a hypothetical LDKT offer. We assessed the association between exposure and outcomes using univariable, and multivariable binary or multinominal logistic regression (reference: White or White nonimmigrant participants).

Results

Of the 498 participants, 281 (56%) were immigrants; 142 (28%) were African, Caribbean, and Black (ACB); 123 (25%) were Asian; and 233 (47%) were White. Compared to White nonimmigrants, racialized immigrants (relative risk ratio [RRR]: 2.98; 95% confidence interval [CI]: 1.76-5.03) and racialized nonimmigrants (RRR: 2.84; 95% CI: 1.22-6.65) were more likely not to have spoken about LDKT with others (vs. having spoken or planning to do so). Both racialized immigrant (odds ratio [OR]: 4.07; 95% CI: 2.50-6.34), racialized nonimmigrants (OR: 2.68; 95% CI: 1.31-5.51) and White immigrants (OR: 2.68; 95% CI: 1.43-5.05) were more likely not to have a potential LD identified.

Conclusion

Both racialized and immigrant status are associated with less readiness to pursue LDKT. Supporting patients to communicate their need for LDKT may improve equitable access to LDKT.

Genetic Diagnosis of Adult Hemodialysis Patients With Unknown Etiology

Introduction

Kidney disease of unknown etiology accounts for 1 in 10 adult end-stage renal disease (ESRD) cases worldwide. The aim of this study is to clarify the genetic background of patients with chronic kidney disease (CKD) of unknown etiology who initiated renal replacement therapy (RRT) in adulthood.

Methods

This is a multicenter cross-sectional cohort study. Of the 1164 patients who attended 4 dialysis clinics in Japan, we first selected patients who started RRT between the ages of 20 and 49 years. After excluding patients with apparent causes of CKD (e.g., diabetic nephropathy, polycystic kidney disease (PKD) with family history, patients who underwent renal biopsy), 90 patients with CKD of unknown cause were included. The 298 genes associated with CKD were analyzed using capture-based targeted next-generation sequencing.

Results

Of the 90 patients, 10 (11.1%) had pathogenic variants in CKD-causing genes and 17 (18.9%) had variant of unknown significance (VUS). Three patients had PKD1 pathogenic variants, and 1 patient had PKD1 and COL4A4 pathogenic variants. In addition, 2 patients were diagnosed with atypical hemolytic uremic syndrome (aHUS) due to C3 or CFHR5. One patient each was diagnosed with Alport syndrome due to COL4A4 and COL4A3 variants, nephronophthisis due to NPHP1 variants, Fabry disease due to GLA variants, and autosomal-dominant tubulointerstitial kidney disease due to UMOD variants. Genetic diagnoses were not concordant with clinical diagnoses, except for patients with PKD1 variant.

Conclusion

This largest study on genetic analysis in hemodialysis-dependent adults revealed the presence of undiagnosed inherited kidney diseases.

Predicting Cellular Rejection of Renal Allograft Based on the Serum Proteomic Fingerprint

Kidney transplantation is an essential medical procedure that significantly enhances the survival rates and quality of life for patients with end-stage kidney disease. However, despite advancements in immunosuppressive therapies, allograft rejection remains a leading cause of organ loss. Notably, predictions of cellular rejection processes primarily rely on biopsy analysis, which is not routinely performed due to its invasive nature. The present work evaluates if the serum proteomic fingerprint, as acquired by Fourier Transform Infrared (FTIR) spectroscopy, can predict cellular rejection processes. We analyzed 28 serum samples, corresponding to 17 without cellular rejection processes and 11 associated with cellular rejection processes, as based on biopsy analyses. The leave-one-out-cross validation procedure of a Naïve Bayes model enabled the prediction of cellular rejection processes with high sensitivity and specificity (AUC > 0.984). The serum proteomic profile was obtained in a high-throughput mode and based on a simple, rapid, and economical procedure, making it suitable for routine analyses and large-scale studies. Consequently, the current method presents a high potential to predict cellular rejection processes translatable to clinical scenarios, and that should continue to be explored.

Knowledge and Attitudes of Dialysis Patients Toward Kidney Transplantation: Preliminary Report from a Pilot Study Preceding a Cross-Sectional Nationwide Evaluation

BACKGROUND

The knowledge and attitudes of dialyzed patients toward the best method of renal replacement treatment (ie, kidney transplantation [KTx]) may be the main factor motivating them to apply and be put on the national kidney transplant waiting list, resulting in a better prognosis.

OBJECTIVE

Assessment of the knowledge and attitudes of dialyzed patients toward KTx.

METHODS

A pilot study is considered an introductory step before the nationwide project, which will cover dialysis centers in Poland from 2023 to 2024. The authorship 4-part questionnaire, including self-assessment knowledge, attitude dimension, pain and mental evaluation section, was made available to 30 patients with hemodialysis aged 30 to 75 years.

RESULTS

The median age of the patients was 59 years. The primary cause of end-stage renal disease (ESRD) was glomerulonephritis (33%). Most of the patients stayed on hemodialysis for 2 years or less (57%); 43% of the patients declared insufficient knowledge in the field of KTx, 41% of the patients were not informed at the nephrology clinic that KTx remains one of the methods of renal replacement therapy, and 65% did not receive information about the possibility of preemptive or early transplantation from a relative donor. Only 34% of the patients considered KTx to be a much better treatment option than dialysis, but only 20% of those were on the national waiting list for KTx.

CONCLUSIONS

The pilot study showed insufficient knowledge of patients with ESRD regarding kidney transplantation as a method of renal replacement therapy. There is a need to introduce an effective educational program.

Direct and indirect impact of the COVID-19 pandemic on the survival of kidney transplant recipients: A national observational study in France

During the pandemic period, health care systems were substantially reorganized for managing COVID-19 cases. Corresponding consequences on persons with chronic diseases remain insufficiently documented. This observational cohort study investigated the direct and indirect impact of the pandemic period on the survival of kidney transplant recipients (KTR). Using the French National Health Data System, incident persons with end-stage kidney disease between 2015 and 2020, and who received a kidney transplant during this period were included and followed up from their transplantation date to December 31, 2021. The survival of KTR during the prepandemic and pandemic periods was investigated using Cox models with time-dependent covariates. There were 10 637 KTR included in the study, with 324 and 430 deaths observed during the prepandemic and pandemic periods, respectively. The adjusted risk of death during the pandemic period was similar to that observed during the prepandemic period (hazard ratio [HR] [95% confidence interval]: 0.92 [0.77-1.11]), COVID-19-related hospitalization was associated with an increased risk of death (HR: 10.62 [8.46-13.33]), and a third vaccine dose was associated with a lower risk of death (HR: 0.42 [0.30-0.57]). The pandemic period was not associated with an indirect higher risk of death in KTR with no COVID-19-related hospitalization.

Clostridioides difficile Infection in Kidney Transplant Recipients

Clostridioides difficile (C. difficile) is a bacterial organism that typically infects the colon, which has had its homeostasis of healthy gut microbiota disrupted by antibiotics or other interventions. Patients with kidney transplantation are a group that are susceptible to C. difficile infection (CDI) and have poorer outcomes with CDI given that they conventionally require long-term immunosuppression to minimize their risk of graft rejection, weakening their responses to infection. Recognizing the risk factors and complex pathophysiological processes that exist between immunosuppression, dysbiosis, and CDI is important when making crucial clinical decisions surrounding the management of this vulnerable patient cohort. Despite the clinical importance of this topic, there are few studies that have evaluated CDI in the context of kidney transplant recipients and other solid organ transplant populations. The current recommendations on CDI management in kidney transplant and solid organ transplant recipients are mostly extrapolated from data relating to CDI management in the general population. We provide a narrative review that discusses the available evidence examining CDI in solid organ transplant recipients, with a particular focus on the kidney transplant recipient, from the epidemiology of CDI, clinical features and implications of CDI, potential risk factors of CDI, and, ultimately, prevention and management strategies for CDI, with the aim of providing areas for future research development in this topic area.

Survival benefit of living donor kidney transplantation in patients on hemodialysis

BACKGROUND

Donors bravely donate their kidneys because they expect that living donor kidney transplantation (LKT) confers benefits to recipients. However, the magnitude of the survival benefit of LKT is uncertain.

METHODS

This prospective cohort study used two Japanese nationwide databases for dialysis and kidney transplantation and included 862 LKT recipients and 285,242 hemodialysis (HD) patients in the main model and 5299 LKT recipients and 151,074 HD patients in the supplementary model. We employed time-dependent model in the main model and assessed the hazard ratio and the difference in the restricted mean survival time (RMST) between LKT recipients and HD patients. In the main analysis of the main model (LKT, N = 675; HD, N = 675), we matched LKT recipients with HD patients by age, sex, dialysis vintage, and cause of renal failure and excluded HD patients with dementia or performance status grades 2, 3, or 4.

RESULTS

The median observational period was 8.00 (IQR 3.58-8.00) years. LKT was significantly associated with a lower risk of mortality (hazard ratios (95% confidence interval (CI)), 0.50 (0.35-0.72)) and an increase in life expectancy (7-year RMST differences (95% CI), 0.48 (0.35-0.60) years) compared with HD. In subgroup analysis, the survival benefit of LKT was greater in female patients than in male patients in the Cox model; whereas older patients gained longer life expectancy compared with younger patients.

CONCLUSIONS

LKT was associated with better survival benefits than HD, and the estimated increase in life expectancy was 0.48 years for 7 years.

Utility of the Interferon-Gamma Enzyme-Linked Immunosorbent Spot Assay to Predict Risk of Cytomegalovirus Infection in Kidney Transplant Recipients

Non-specific interferon-gamma (IFN-γ) enzyme-linked immunosorbent (ELISpot) responses after solid organ transplant (SOT) and their relationship with cytomegalovirus (CMV) reactivation have hardly been investigated. Adult kidney transplant (KT) recipients underwent measurement of IFN-γ-producing T cells using the ELISpot assay before and 1 month after transplantation. Data for CMV infection episodes were collected. Risk factors for post-transplant CMV infection, based on IFN-γ responses, were analyzed using a Cox proportional hazards model. A total of 93 KT recipients were enrolled in the study and 84 evaluable participants remained at 1 month post KT. Thirty-three (39%) recipients developed subsequent CMV infection within 6 months post-transplant. At 1-month post-transplant, IFN-γ-producing T cells with <250 spot-forming units (SFUs)/2.5 × 105 peripheral blood mononuclear cells (PBMCs) were significantly associated with CMV infection (HR 3.1, 95% CI 1.4-7.1, p = 0.007). On multivariable analysis, posttransplant IFN-γ-producing T cells with <250 SFUs/2.5 × 105 PBMCs remained independently associated with CMV infection (HR 3.1, 95% CI 1.2-7.8, p = 0.019). Conclusions: KT recipients with low IFN-γ-producing T cells measured by the ELISpot assay are more likely to develop CMV infection after transplantation. Therefore, measurement of nonspecific cell-mediated immunity ELISpot responses could potentially stratify recipients at risk of CMV infection (Thai Clinical Trials Registry, TCTR20210216004).

COVID-19 and Access to Kidney Transplantation for Older Candidates in the United States: A National Registry Study

Rationale & Objective

Coronavirus disease (COVID)-19 has likely impacted accessibility to transplantation services among older adults (age ≥65 years). We quantified the impact of COVID-19 on kidney transplantation access for older kidney-only candidates registered on the United States (US) kidney waitlist.

Study Design

Retrospective analysis of registry data.

Setting & Participants

57,222 older adults who were part of or added to the US kidney waitlist between January 1, 2016 and February 28, 2022, identified using the Scientific Registry of Transplant Recipients (SRTR).

Exposures

Four COVID-19 waves and one nonwave period based on the national incidence of COVID-19 in the US (initial: March 15-May 30, 2020; winter 2020-2021: December 1, 2020-January 31, 2021; delta: August 1, 2021-September 30, 2021; omicron: December 1, 2021-February 28, 2022; nonwave: inter-wave periods).

Outcomes

Waitlist registrations, deceased-donor kidney transplants, living-donor kidney transplants, waitlist mortality, and waitlist removals due to deteriorating condition (hereafter referred to as removals).

Analytical Approach

Poisson regression for the adjusted incidence rate ratio (aIRR) of each outcome during the COVID-19 waves and the nonwave period relative to reference (January 1, 2016-December 31, 2019), adjusted for seasonality and secular trends.

Results

Waitlist registrations initially declined and increased henceforth. Deceased-donor kidney transplants and living-donor kidney transplants remained below-expected levels during all waves. Waitlist mortality peaked during the winter 2020-2021 wave (aIRR: 1.701.982.30) and has declined since; mortality rates were 139%, 107%, and 251% above expected for Black candidates, men, and candidates aged ≥75 years, respectively, during the winter 2020-2021 wave. Removals increased from 22% below expected levels (initial wave) to 26% above expected levels (omicron wave); removals were nonsignificantly higher than expected during the omicron wave for older Black and Hispanic candidates.

Limitations

The findings are not generalizable to those listed at earlier ages with prolonged waitlist times. Additionally, using national COVID-19 incidence does not consider local policy and health care variations. Lastly, aIRRs must be interpreted cautiously due to smaller daily event counts.

Conclusions

COVID-19 was associated with fewer transplants and increased mortality and removals in older kidney transplant candidates. Transplant providers should consider this impact and implement policies and practices to ensure the continuity of care.

Plain-Language Summary

The proportion of older adults on the kidney transplant waitlist is increasing, but the impact of COVID-19 on this population is not well characterized. In this study, we looked at incident waitlist registrations, deceased- and living-donor kidney transplants, and waitlist mortality and removals due to deteriorating condition over 4 waves of COVID-19. We found that transplantation services did not fully recover to prepandemic levels as of March 2022. Notably, racial/ethnic minorities and older men experienced lower rates of kidney transplants and higher rates of waitlist mortality, respectively, relative to White candidates and older women. Identifying vulnerable subpopulations affected by COVID-19 and its long-term impact is crucial for creating strategies to ensure the continuity of care in this population during public health emergencies.

"It's My Life and It's Now or Never"-Transplant Recipients Empowered From a Service-Dominant Logic Perspective

Patient well-being after an organ transplant is a major outcome determinant and survival of the graft is crucial. Before surgery, patients are already informed about how they can influence their prognosis, for example by adhering to treatment advice and remaining active. Overall, effective selfmanagement of health-related issues is a major factor in successful long-term graft survival. As such, organ transplant recipients can be considered as co-producers of their own health status. However, although keeping the graft in good condition is an important factor in the patient's well-being, it is not enough. To have a meaningful life after a solid organ transplant, patients can use their improved health status to once again enjoy time with family and friends, to travel and to return to work -in short to get back on track. Our assertion in this article is twofold. First, healthcare providers should look beyond medical support in enhancing long-term well-being. Second, organ recipients should see themselves as creators of their own well-being. To justify our argument, we use the theoretical perspective of service-dominant logic that states that patients are the true creators of real value-in-use. Or as Bon Jovi sings, "It's my life and it's now or never."

Kidney transplantation and kidney donation do not affect short-term blood pressure variability

PURPOSE

Blood pressure variability (BPV) is an independent cardiovascular risk factor in CKD. Kidney transplantation (KTx) is associated with improved BP levels for kidney transplant recipient (KTRs), without evoking significant changes in donors. The aim of this study was to assess the short- and mid-time effects of KTx and donation on short-term BPV in KTRs and their respective living kidney donors.

MATERIALS AND METHODS

Forty KTRs and their respective donors were evaluated with 24-h ABPM (Mobil-O-Graph-NG) at baseline (1 month before), 3-months and 12-months after KTx. Standard-deviation (SD), weighted-SD (wSD), coefficient-of-variation (CV), average-real-variability (ARV) and variability independent of mean (VIM) for SBP/DBP were calculated with validated formulas.

RESULTS

All 24-h systolic and diastolic BPV indexes studied did not change significantly from baseline to 3-month (SBP-wSD: 12.8 ± 3.0 vs 13.2 ± 3.4 mmHg, p = 0.608; SBP-ARV: 10.3 ± 2.4 vs 10.8 ± 2.6 mmHg, p = 0.463) and 12-month evaluation (SBP-wSD 12.8 ± 3.0 vs 12.1 ± 2.8; p = 0.424 and SBP-ARV: 10.3 ± 2.4 vs 10.2 ± 2.5; p = 0.615) after kidney transplantation in the KTRs.In kidney donors, all 24-h systolic BPV indices displayed a trend towards higher values at 3 months compared to baseline, but without reaching statistical significance (SBP-wSD: 12.2 ± 2.8 vs 13.6 ± 4.2 mmHg, p = 0.107 and SBP-ARV: 10.1 ± 2.1 vs 11.2 ± 3.1 mmHg, p = 0.099), the levels of 24-h systolic SBP indices at 12-months were almost identical to baseline values. 24-h diastolic BPV indices at 3-month and 12-month evaluation were similar to baseline.

CONCLUSION

Short-term BPV did not change significantly 3 and 12 months after kidney transplantation/donation neither in KTRs nor in living kidney donors. Longitudinal studies examining associations of BPV with adverse outcomes in these individuals are needed.

Delayed Graft Function in Kidney Retransplantation: United Network for Organ Sharing Data With Linked Primary and Retransplant

INTRODUCTION

There are several articles exploring the risk factors for primary delayed graft function (DGF). However, current literature does not include many resources on the risk factors for DGF when it is a recipient's second kidney transplant or look at short-term graft and patient survival of DGF retransplants.

METHODS

United Network for Organ Sharing data from January 2008 to June 2021 were analyzed. Pancreas transplants, multi-organ transplants, and lost to follow-up transplants were excluded. Second transplant patients with DGF were identified. Multivariate logistic regression models based on the primary and second transplant characteristics were created. Survival analysis was performed with Kaplan-Meier methodology and assessed with log-rank test.

RESULTS

A total of 2964 second kidney transplants were identified. Rate of DGF in the second transplant was 28.4% (843/2964) and 49.2% of them had a prior DGF in their first transplant (P < 0.001). Multivariate analysis confirmed that occurrence of DGF (odds ratio [OR] 1.5, P < 0.001) and graft loss due to acute rejection (OR 1.2, P < 0.005) in the primary transplant were predictors of reappearing DGF in the second transplant. Dialysis at transplant was the greatest risk factor from the second transplant (OR 3.539, P < 0.001). There was a decreased graft survival after 12 mo (77% versus 49% with log t-test <0.001) in the second transplant. However, DGF was not significantly associated with patient survival.

CONCLUSIONS

This study shows the interaction between primary and second transplant in developing DGF. Survival analysis shows lower graft survival for retransplants in the case of DGF. This study opens the possibility of identifying additional risk factors for patients undergoing retransplant surgeries.

A Comparison Between Saline and Balanced Solutions in Kidney Transplants: A Randomized Clinical Trial

Objective This study aimed to investigate the impact of different types of intravenous fluids - normal saline (NS), lactated Ringer's solution (LR), and PlasmaLyte (PL) - on the acid-base balance and electrolyte concentration following kidney transplant, a common procedure for patients with end-stage renal disease (ESRD). Methodology A randomized controlled trial design was employed, wherein the primary parameters analyzed were postoperative pH and serum potassium levels. Postoperative concentrations of serum bicarbonate, sodium, chloride, and creatinine, as well as graft functionality, were assessed as secondary outcomes. These measurements were performed at the start and end of surgery, as well as 24 and 72 hours postoperatively. Results A total of 53 patients were included in the study and randomized into three cohorts: NS, LR, and PL, each of which showed comparability in terms of demographic and transplantation specifics. Notably, patients in the NS group exhibited a more significant decrease in pH (NS group: 7.285 ±0.098, LR group: 7.324 ±0.075, PL group: 7.7338 ±0.059) and bicarbonate levels (17.0 ±4.2, 20.9 ±2.8, 20.0 ±4.5) post 24 hours after the operation and displayed a similar pattern immediately after the surgery. However, there were no discernible differences in potassium (p=0.460), sodium (p=0.681), and chloride (p=0.321) levels across the groups. Furthermore, the study did not observe any significant differences in postoperative graft functionality. Conclusion The use of NS as the intraoperative fluid of choice led to lower pH and bicarbonate levels following kidney transplant, as compared to LR and PL. However, these results did not correlate with improvements in graft functionality.

Evolving Trends in Kidney Transplant Outcomes Among Older Adults: A Comparative Analysis Before and During the COVID-19 Pandemic

Background

Advancements in medical technology, healthcare delivery, and organ allocation resulted in improved patient/graft survival for older (age ≥65) kidney transplant (KT) recipients. However, the recent trends in these post-KT outcomes are uncertain in light of the mounting burden of cardiovascular disease, changing kidney allocation policies, heterogeneity in candidates' risk profile, and the coronavirus disease 2019 pandemic. Thus, we examined secular trends in post-KT outcomes among older and younger KT recipients over the last 3 decades.

Methods

We identified 73 078 older and 378 800 younger adult (aged 18-64) recipients using Scientific Registry of Transplant Recipients (1990-2022). KTs were grouped into 6 prepandemic eras and 1 postpandemic-onset era. Kaplan-Meier and Cox proportional hazards models were used to examine temporal trends in post-KT mortality and death-censored graft failure.

Results

From 1990 to 2022, a 19-fold increase in the proportion of older KT recipients was observed compared to a 2-fold increase in younger adults despite a slight decline in the absolute number of older recipients in 2020. The mortality risk for older recipients between 2015 and March 14, 2020, was 39% (adjusted hazard ratio [aHR] = 0.61, 95% confidence interval [CI], 0.50-0.75) lower compared to 1990-1994, whereas that for younger adults was 47% lower (aHR = 0.53, 95% CI, 0.48-0.59). However, mortality risk during the pandemic was 25% lower (aHR = 0.75, 95% CI, 0.61-0.93) in older adults and 37% lower in younger adults (aHR = 0.63, 95% CI, 0.56-0.70) relative to 1990-1994. For both populations, the risk of graft failure declined over time and was unaffected during the pandemic relative to the preceding period.

Conclusions

The steady improvements in 5-y mortality and graft survival were disrupted during the pandemic, particularly among older adults. Specifically, mortality among older adults reflected rates seen 20 y prior.

Cost-Effectiveness of Recombinant Zoster Vaccine for the Prevention of Herpes Zoster in Hematopoietic Stem Cell Transplant Recipients and Other Immunocompromised Adults in the United States

INTRODUCTION

Immunocompromised (IC) adults are at increased risk of developing herpes zoster (HZ) and HZ-related complications due to therapy or underlying disease. This study evaluated the cost effectiveness of recombinant zoster vaccine (RZV) versus no vaccine for the prevention of HZ in hematopoietic stem cell transplant (HSCT) recipients and other IC adults aged ≥ 18 years in the United States (US).

METHODS

A static Markov model simulated cohorts of IC individuals using a 1-year cycle length and 30-year time horizon to estimate the cost effectiveness of RZV. Inputs were sourced from clinical trial results and publicly available sources/literature. Modeled populations included US adult HSCT recipients (base case), patients with human immunodeficiency virus (HIV), patients with breast cancer, patients with Hodgkin's lymphoma, and renal transplant recipients. The model reported societal costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). Sensitivity and threshold analyses were conducted.

RESULTS

In the base case of 19,671 US adult HSCT recipients, RZV resulted in total societal cost savings of US$0.1 million and 109 incremental QALYs versus no vaccine. RZV was a 'dominant strategy' versus no vaccine because vaccination resulted in cost savings with QALY gains. RZV was also cost saving in renal transplant recipients, and cost effective at a willingness-to-pay threshold of US$100,000 per QALY gained in patients with HIV, breast cancer, and Hodgkin's lymphoma, with ICERs of US$33,268, US$67,682, and US$95,972 per QALY gained, respectively, versus no vaccine.

CONCLUSIONS

Model results show RZV is potentially cost saving for the prevention of HZ in US adult HSCT recipients and US adults with selected immunocompromising conditions, and cost effective for others, supporting the use of RZV to prevent HZ and HZ-related complications in IC adults.

In Vivo Assessment of Laboratory-Grown Kidney Tissue Grafts

Directed differentiation of stem cells is an attractive approach to generate kidney tissue for regenerative therapies. Currently, the most informative platform to test the regenerative potential of this tissue is engraftment into kidneys of immunocompromised rodents. Stem cell-derived kidney tissue is vascularized following engraftment, but the connection between epithelial tubules that is critical for urine to pass from the graft to the host collecting system has not yet been demonstrated. We show that one significant obstacle to tubule fusion is the accumulation of fibrillar collagens at the interface between the graft and the host. As a screening strategy to identify factors that can prevent this collagen accumulation, we propose encapsulating laboratory-grown kidney tissue in fibrin hydrogels supplemented with candidate compounds such as recombinant proteins, small molecules, feeder cells, and gene therapy vectors to condition the local graft environment. We demonstrate that the AAV-DJ serotype is an efficient gene therapy vector for the subcapsular region and that it is specific for interstitial cells in this compartment. In addition to the histological evaluation of epithelial tubule fusion, we demonstrate the specificity of two urine biomarker assays that can be used to detect human-specific markers of the proximal nephron (CD59) and the distal nephron (uromodulin), and we demonstrate the deposition of human graft-derived urine into the mouse collecting system. Using the testing platform described in this report, it will be possible to systematically screen factors for their potential to promote epithelial fusion of graft and host tissue with a functional intravital read-out.

Impact of pretransplantation malnutrition risk on the clinical outcome and graft survival of kidney transplant patients

BACKGROUND

The prevalence of malnourished patients before transplantation and the influence of malnutrition on graft and patient outcomes remain underestimated, despite being associated with higher postoperative morbidity and mortality. This study aimed to develop an easy nutritional screening tool and evaluate the impact of nutritional status on clinical outcome, graft survival (GS) and mortality risk in kidney transplant patients (KTP).

METHODS

In this retrospective cohort study including 451 KTP, we developed a score by using anthropometric, clinical, and laboratory measures performed in the pretransplant evaluation. The patients were stratified into 3 groups according to the final score: G1 (0 or 1 point)=low risk, G2 (2 to 4 points)=moderate risk, and G3 (>5 points)=high risk of malnutrition. The patients were monitored after transplantation at least 1 to 10 years.

RESULTS

Stratifying the 451 patients based on the pretransplant risk score, G1, G2, and G3 were composed of 90, 292, and 69 patients, respectively. Patients from G1 maintained the lowest serum creatinine levels at hospital discharge when compared with others (p = 0.012). The incidence of infection in the patients from G3 was higher than patients from G1 and G2 (p = 0.030). G3 recipients showed worse GS than G1 patients (p = 0.044). G3 patients showed almost threefold higher risk for graft loss (HR 2.94, 95% CI 1.084-7.996).

CONCLUSIONS

KTP with higher malnutrition risk score were associated with worse outcomes and GS. The nutritional screening tool is easy to be used in clinical practice to evaluate the patient in preparation for kidney transplant.

Breaking Barriers and Bridging Gaps: Advancing Diversity, Equity, and Inclusion in Kidney Transplant Care for Black and Hispanic Patients in the United States

Kidney transplantation offers better mortality and quality of life outcomes to patients with end-stage renal failure compared to dialysis. Specifically, living donor kidney transplantation is the best treatment for end-stage renal disease, since it offers the greatest survival benefit compared to deceased donor kidney transplant or dialysis. However, not all patients from all racial/ethnic backgrounds enjoy these benefits. While black and Hispanic patients bear the predominant disease burden within the United States, they represent less than half of all kidney transplants in the country. Other factors such as cultural barriers that proliferate myths about transplant, financial costs that impede altruistic donation, and even biological predispositions create a complex maze and can also perpetuate care inaccessibility. Therefore, blanket efforts to increase the overall donation pool may not extend access to vulnerable populations, who may require more targeted attention and interventions. This review uses US kidney transplantation data to substantiate accessibility differences amongst racial minorities as well as provides examples of successful institutional and national systemic level changes that have improved transplantation outcomes for all.

In a real-life setting, risk factors, coronary artery calcium score, and coronary stenosis at computed tomography angiography are associated with major adverse cardiovascular events and all-cause mortality among kidney transplant candidates

Kidney failure is associated with an increased risk of cardiovascular disease and death. This single-center, a retrospective study evaluated the association between risk factors, coronary artery calcium score (CACS), coronary computed tomography angiography (CTA), major adverse cardiovascular events (MACEs), and all-cause mortality in kidney transplant candidates. Data on clinical risk factors, MACE, and all-cause mortality were collected from patient records. A total of 529 kidney transplant candidates were included (median follow-up of 4.7 years). CACS was evaluated in 437 patients and CTA in 411. Both the presence of ≥3 risk factors, CACS of ≥400, as well as multiple-vessel stenoses or left main artery disease predicted MACE (hazard ratio, 2.09; [95% confidence interval, 1.35-3.23]; 4.65 [2.20-9.82]; 3.70 [1.81-7.57]; 4.90 [2.40-10.01]) and all-cause mortality (harad ratio, 4.44; [95% confidence interval, 2.54-7.76]; 4.47 [2.22-9.02]; 2.82 [1.34-5.94]; 5.41 [2.81-10.41]) in univariate analyses. Among patients eligible for CACS and CTA (n = 376), only CACS and CTA were associated with both MACE and all-cause mortality. In conclusion, risk factors, CACS, and CTA provide information on the risk of MACE and mortality in kidney transplant candidates. An additional value of CACS and CTA compared with risk factors was observed for the prediction of MACE in a subpopulation undergoing both CACS and CTA.

Complement Binding Anti-HLA Antibodies and the Survival of Kidney Transplantation

Background: Antibody-mediated rejection (AMR) is one of the most important challenges in the context of renal transplantation, because the binding of de novo donor-specific antibodies (dnDSA) to the kidney graft triggers the activation of the complement, which in turn leads to loss of transplant. In this context, the objective of this study was to evaluate the association between complement-fixing dnDSA antibodies and graft loss as well as the possible association between non-complement-fixing antibodies and transplanted organ survival in kidney transplant recipients. Methods: Our study included a cohort of 245 transplant patients over a 5-year period at Virgen de las Nieves University Hospital (HUVN) in Granada, Spain. Results: dnDSA was observed in 26 patients. Of these patients, 17 had non-complement-fixing dnDSA and 9 had complement-fixing dnDSA. Conclusions: Our study demonstrated a significant association between the frequency of rejection and renal graft loss and the presence of C1q-binding dnDSA. Our results show the importance of the individualization of dnDSA, classifying them according to their ability to activate the complement, and suggest that the detection of complement-binding capacity by dnDSA could be used as a prognostic marker to predict AMR outcome and graft survival in kidney transplant patients who develop dnDSA.

Indoxyl Sulphate Retention Is Associated with Microvascular Endothelial Dysfunction after Kidney Transplantation

Kidney transplantation (KTx) is the preferred form of renal replacement therapy in chronic kidney disease (CKD) patients, owing to increased quality of life and reduced mortality when compared to chronic dialysis. Risk of cardiovascular disease is reduced after KTx; however, it is still a leading cause of death in this patient population. Thus, we aimed to investigate whether functional properties of the vasculature differed two years post-KTx (postKTx) compared to baseline (time of KTx). Using the EndoPAT device in 27 CKD patients undergoing living-donor KTx, we found that vessel stiffness significantly improved while endothelial function worsened postKTx vs. baseline. Furthermore, baseline serum indoxyl sulphate (IS), but not p-cresyl sulphate, was independently negatively associated with reactive hyperemia index, a marker of endothelial function, and independently positively associated with P-selectin postKTx. Finally, to better understand the functional effects of IS in vessels, we incubated human resistance arteries with IS overnight and performed wire myography experiments ex vivo. IS-incubated arteries showed reduced bradykinin-mediated endothelium-dependent relaxation compared to controls via reduced nitric oxide (NO) contribution. Endothelium-independent relaxation in response to NO donor sodium nitroprusside was similar between IS and control groups. Together, our data suggest that IS promotes worsened endothelial dysfunction postKTx, which may contribute to the sustained CVD risk.

The Effect of Preoperative Carbohydrate Intake on Length of Stay and Postoperative Recovery Following Laparoscopic Living Donor Nephrectomy

OBJECTIVE

Enhanced Recovery After Surgery (ERAS) protocols are applied in many surgical procedures and often involve preoperative carbohydrate intake. Research surrounding the utility of ERAS in living donor nephrectomy is limited. The objective of this study was to identify whether living kidney donors who received preoperative oral carbohydrates experienced a difference in length of hospital stay (LOS), duration of time required to resume regular oral food and fluid intake, and incidence of gastrointestinal (GI) complications following laparoscopic nephrectomy compared to historical control donors who underwent preoperative fasting.

METHODS

This study was a retrospective analysis of data from adult subjects at one transplant center who underwent laparoscopic living donor nephrectomy. A total of 55 ERAS subjects who received preoperative carbohydrates and 93 historical control subjects who underwent preoperative fasting were included in the final analysis. The following variables were compared between groups: LOS, time to tolerating a regular oral diet postoperatively, time to meeting 50% of estimated fluid needs by oral intake postoperatively, and incidence of postoperative GI complications.

RESULTS

No significant differences between the ERAS and historical control groups in age, weight, body mass index, sex distribution, or estimated fluid needs were identified. Both groups consisted of predominantly female subjects. ERAS subjects experienced a shorter LOS (2.8 days versus 3.9 days, P < .001), time to tolerating a regular oral diet (36.5 hours versus 68.2 hours, P < .001), and time to meeting 50% of estimated fluid needs (25.3 hours versus 44.6 hours, P < .001) after laparoscopic nephrectomy compared to historical control subjects. No significant difference between groups in the incidence of postoperative GI complications (nausea, vomiting, or ileus) was identified.

CONCLUSION

Our findings demonstrate the advantages of ERAS in living kidney donors undergoing laparoscopic nephrectomy and support ERAS implementation within this patient population.

Continuous-flow left ventricular assist devices associated survival awaiting heart and heart-kidney transplant

BACKGROUND

Improvement in continuous-flow left ventricular assist device (CF-LVAD) technology has translated to better outcomes for patients on CF-LVAD support as a bridge-to-transplant. However, data are lacking regarding the subset of CF-LVAD patients with renal failure awaiting simultaneous heart-kidney transplant (HKTx). We sought to better understand the characteristics and outcomes of patients in this group.

METHODS

The United Network for Organ Sharing (UNOS) database was used to identify adult patients listed for heart transplant (HTx) or HKTx from January 1, 2009 to March 31, 2017. Patients were followed from time on waitlist to either removal from waitlist or transplantation. Demographic and clinical data for HTx and HKTx patients were assessed. Kaplan-Meier analysis assessed waitlist and post-transplant survival. For waitlisted patients, both death and removal from the waitlist due to deteriorating medical condition were considered events.

RESULTS

Overall, 26 638 patients registered for transplant were analyzed. 25 111 (94%) were listed for HTx, and 1527 (6%) for HKTx. 7683 (29%) patients listed for HTx had CF-LVAD support. For those listed for HKTx, 441 (28%) underwent dialysis alone, 256 (17%) had CF-LVAD support alone, and 85 (6%) were treated with both CF-LVAD and dialysis. 15 567 (58%) underwent HTx, and 621 (2%) underwent HKTx. In these groups, post-transplant survival was similar (p = 0.06). Patients listed for HKTx treated with both dialysis and CF-LVAD had significantly worse waitlist survival compared to HKTx recipients (p < 0.001).

CONCLUSION

Post-transplant survival is comparable between HTx and HKTx, and early survival is similar between HTx patients and those listed for HTx with CF-LVAD support. However, outcomes on the waitlist for HKTx in CF-LVAD patients on dialysis is significantly worse compared to HKTx recipients. This highlights the need to better account for this patient population when allocating organs.

Economic evaluation of peritoneal dialysis and hemodialysis in Thai population with End-stage Kidney Disease

BACKGROUND

This study aimed to conduct a cost-utility analysis of the "Peritoneal Dialysis (PD)-First" policy in 2008 under a universal health coverage scheme and hemodialysis (HD) in Thai patients with End-stage Kidney Disease (ESKD) using updated real-practice data.

METHODS

Markov model was used to evaluate the cost-utility of two modalities, stratified into five age groups based on the first modality taken at 20, 30, 40, 50, and 60 years old from government and societal perspectives. Input parameters related to clinical aspects and cost were obtained from 15 hospitals throughout Thailand and Thai Renal Replacement Therapy databases. Both costs and outcomes were discounted at 3%, adjusted to 2021, and converted to USD (1 USD = 33.57 Thai Baht). One-way analysis and probabilistic sensitivity analysis were performed to assess the uncertainty surrounding model parameters.

RESULTS

From the government perspective, compared to PD-first policy, the incremental cost-effectiveness ratio (ICER) was between 19,434 and 23,796 USD per QALY. Conversely, from a societal perspective, the ICER was between 31,913 and 39,912 USD per QALY. Both are higher than the willingness to pay threshold of 4,766 USD per QALY.

CONCLUSION

By applying the updated real-practice data, PD-first policy still remains more cost-effective than HD-first policy at the current willingness to pay. However, HD gained more quality-adjusted life years than PD. This information will assist clinicians and policymakers in determining the future direction of dialysis modality selection and kidney replacement therapy reimbursement policies for ESKD patients.

Post‐kidney transplant cancers: Racial and ethnic differences in sun‐exposed skin versus non‐sun‐exposed anogenital skin

BACKGROUND

Transplant recipients have a 2- to 4-fold increased risk of developing malignancies over the general population. Cancer is the second most common cause of death for recipients. The magnitude of the risk depends on the cancer type and increases in viral-related malignancies. Skin cancer is the most common. However, data in most cancer registries is limited to cutaneous melanomas, thereby limiting the epidemiologic examination of cancer risk in non-melanoma skin cancer. Our goal was to evaluate post-kidney transplant cancer cases and sites in our population to guide screening recommendations.

METHODS

Between 2009 and 2015, a retrospective study of adult kidney recipients transplanted at East Carolina University was conducted. The first cancer diagnosis after transplant through February 18, 2020, was captured and analyzed. Patient demographics, cancer sites, and histological diagnoses were analyzed and compared. p16 immunohistochemistry was used as a surrogate marker for high-risk human papillomavirus (HPV) infection.

RESULTS

Retrospectively, kidney transplant recipients were analyzed (N = 439), the majority were non-Hispanic Black (NHB) individuals, 312 (71.1%), and 127 (28.9%) were non-Hispanic White (NHW) individuals. Of these, 59 (13.4%) developed a posttransplant malignancy, with the majority on sun-exposed skin found in NHW. NHB had all anogenital/mucosa skin cancers on non-sun-exposed skin. Of these detected in NHB, all were squamous cell carcinomas, with five out of six (83.3%) being positive for p16.

CONCLUSIONS

Posttransplant malignancy differed significantly by race, site, and potential source of etiology. The majority of malignancies are likely explained by acceleration of precursor lesions from prior exposure to ultraviolet rays or HPV.

Health Belief Model Constructs Affect Influenza Vaccine Uptake in Kidney Transplant Recipients

This secondary analysis explored how the constructs of the health belief model affect influenza vaccine uptake in kidney transplant recipients (KTRs). In the parent study, a total of 180 KTRs were recruited at an organ transplant center in South Korea. A nonlinear path analysis using generalized structural equation modeling was performed. Previous influenza vaccination had a direct effect on their behavior, while cues to action alone did not directly affect their behavior. Perceived benefits played a key role as a mediator in improving influenza vaccine uptake in KTRs. This study highlights the need for health professionals to assess perceived benefits at the individual level and provide patient-centered interventions based on a consideration of theoretical mechanisms. As cues to action, recommendations for recipients’ first vaccination after kidney transplant should focus on changing patients’ perceptions of benefits by emphasizing the positive aspects of the influenza vaccine for immunosuppressed patients.

Trends, Social Context, and Transplant Implications of Obesity Among Incident Dialysis Patients in the United States

BACKGROUND

Kidney transplant programs have variable thresholds to accept obese candidates. This study aimed to examine trends and the social context of obesity among United States dialysis patients and implications for kidney transplant access.

METHODS

We performed a retrospective cohort study of 1 084 816 adults who initiated dialysis between January 2007 and December 2016 using the United States Renal Data System data. We estimated national body mass index (BMI) trends and 1-y cumulative incidence of waitlisting and death without waitlisting by BMI category (<18.5 kg/m 2 , ≥18.5 and <25 kg/m 2 [normal weight], ≥25 and <30 kg/m 2 [overweight], ≥30 and <35 kg/m 2 [class 1 obesity], ≥35 and <40 kg/m 2 [class 2 obesity], and ≥40 kg/m 2 [class 3 obesity]). We then used Fine-Gray subdistribution hazard regression models to examine associations between BMI category and 1-y waitlisting with death as a competing risk and tested for effect modification by End Stage Renal Disease (ESRD) network, patient characteristics, and neighborhood social deprivation index.

RESULTS

The median age was 65 (interquartile range 54-75) y, 43% were female, and 27% were non-Hispanic Black. From 2007 to 2016, the adjusted prevalence of class 1 obesity or higher increased from 31.9% to 38.2%. Class 2 and 3 obesity but not class 1 obesity were associated with lower waitlisting rates relative to normal BMI, especially for younger individuals, women, those of Asian race, or those living in less disadvantaged neighborhoods ( pinteraction < 0.001 for all).

CONCLUSIONS

Obesity prevalence is rising among US incident dialysis patients. Relative to normal BMI, waitlisting rates with class 2 and 3 obesity were lower and varied substantially by region, patient characteristics, and socioeconomic context.

Experiences of adults living with a kidney transplant-Effects on physical activity, physical function, and quality of life: A descriptive phenomenological study

BACKGROUND

Although kidney transplantation is the best treatment for kidney failure, scarce research has examined its effects on physical activity, physical function and quality of life.

OBJECTIVES

To investigate the experiences of a group of adults living with advanced kidney disease focusing on quality of life, physical activity and function and to see how findings differ in a group of kidney transplant recipients.

APPROACH

Individual semi-structured interviews were conducted with adults with advanced kidney disease (n = 10; 70.5 ± 8.9 years) and adults who had received a kidney transplant (n = 10; 50.7 ± 11.5 years; transplant age: 42.7 ± 20.9 months). Interviews were transcribed verbatim, thematically analysed and composite vignettes developed.

FINDINGS

Individuals with advanced kidney disease described a sense of loss and alteration to their life plans. Kidney transplant recipients reported increased freedom, independence and a return to near normality, with improved quality of life, physical activity and function compared with their pre-transplant lives. However, transplant recipients also described living with anxiety about the health of their transplant and fear it may fail.

CONCLUSION

Whilst adults living with advanced kidney disease often experience a reduced quality of life, physical activity and function, kidney transplantation can help facilitate a return to pre-disease levels of physical activity, physical function and quality of life. However, transplant recipients also reported living with anxiety around their new kidney failing. This study demonstrates the variability in the lived experiences of adults living with advanced kidney disease or a kidney transplant and highlights the need for patient-centred care.

The psychosocial needs of adolescent and young adult kidney transplant recipients, and associated interventions: a scoping review

Background

Renal transplantation is considered the gold standard treatment for end-stage kidney disease. Adolescent and young adult kidney transplant recipients have the highest rate of graft loss amongst transplanted patients. It is largely accepted this is due to psychosocial and behavioural difficulties, which impact adherence to prescribed therapies. This phenomenon is not isolated to a particular healthcare system having been observed in multiple countries across different continents. It is a global issue of concern. We sought to review the psychosocial needs of these patients, and the interventions designed to meet these needs.

Methods

A scoping review was conducted based on Arksey and O’Malley’s six-stage framework. Eligibility criteria included primary studies of any type that investigated the psychosocial needs of adolescent and/or young adult renal transplant recipients or studies which examined interventions designed to address these needs. Search strategies were developed and conducted on PsycINFO, PubMed, Embase, and CINAHL. Articles meeting the inclusion criteria were critically reviewed using a descriptive-analytical narrative method.

Results

Thirty-nine studies met our inclusion criteria, 30 of which related to psychosocial needs, and the remainder examined psychosocial interventions. Four main themes were derived from our analysis of psychosocial needs literature, as follows: the need for (1) emotional support, (2) acceptance, (3) direction, (4) equality in healthcare. 2 main themes emerged from analysis of psychosocial intervention literature, namely: psychosocial (1) capability, (2) assessment. Despite the evidence that graft health is strongly associated with psychosocial wellbeing, findings revealed a significant lack of literature investigating how best to meet psychosocial needs. Trends were observed amongst intervention studies, namely interventions of novel and non-evidenced based design, with the aim of improving medication adherence through organisational strategies and education. However, literature regarding psychosocial needs showed non-adherence to therapies was not simply a result of disorganisation or lack of understanding, but rather, was founded on a recipient’s idiosyncratic relationship with their prescribed therapies e.g., psychological, social or financial reasons for non-adherence.

Conclusions

Future research should be directed at investigating the efficacy of evidence-based interventions that empower the individual patient to overcome their specific barrier to an optimal relationship with their therapies.

Risks for donors associated with living kidney donation: meta-analysis

BACKGROUND

Living kidney donation risk is likely to differ according to donor's demographics. We aimed to analyse the effects of age, sex, body mass index (BMI) and ethnicity.

METHODS

A systematic review and meta-analysis was undertaken of the effects of preoperative patient characteristics on donor kidney function outcomes, surgical complications, and hypertension.

RESULTS

5129 studies were identified, of which 31 met the inclusion criteria, mainly from the USA and Europe. The estimated glomerular filtration rate (eGFR) in donors aged over 60 years was a mean of 9.54 ml per min per 1.73 m2 lower than that of younger donors (P < 0.001). Female donors had higher relative short- and long-term survival. BMI of over 30 kg/m2 was found to significantly lower the donor's eGFR 1 year after donation: the eGFR of obese donors was lower than that of non-obese patients by a mean of -2.70 (95 per cent c.i. -3.24 to -2.15) ml per min per 1.73 m2 (P < 0.001). Obesity was also associated with higher blood pressure both before and 1 year after donation, and a higher level of proteinuria, but had no impact on operative complications. In the long term, African donors were more likely to develop end-stage renal disease than Caucasians.

CONCLUSION

Obesity and male sex were associated with inferior outcomes. Older donors (aged over 60 years) have a larger eGFR decline than younger donors, and African donors have a higher incidence of ESRD than Caucasians.

The Impact of Human Microbiotas in Hematopoietic Stem Cell and Organ Transplantation

The human microbiota heavily influences most vital aspects of human physiology including organ transplantation outcomes and transplant rejection risk. A variety of organ transplantation scenarios such as lung and heart transplantation as well as hematopoietic stem cell transplantation is heavily influenced by the human microbiotas. The human microbiota refers to a rich, diverse, and complex ecosystem of bacteria, fungi, archaea, helminths, protozoans, parasites, and viruses. Research accumulating over the past decade has established the existence of complex cross-species, cross-kingdom interactions between the residents of the various human microbiotas and the human body. Since the gut microbiota is the densest, most popular, and most studied human microbiota, the impact of other human microbiotas such as the oral, lung, urinary, and genital microbiotas is often overshadowed. However, these microbiotas also provide critical and unique insights pertaining to transplantation success, rejection risk, and overall host health, across multiple different transplantation scenarios. Organ transplantation as well as the pre-, peri-, and post-transplant pharmacological regimens patients undergo is known to adversely impact the microbiotas, thereby increasing the risk of adverse patient outcomes. Over the past decade, holistic approaches to post-transplant patient care such as the administration of clinical and dietary interventions aiming at restoring deranged microbiota community structures have been gaining momentum. Examples of these include prebiotic and probiotic administration, fecal microbial transplantation, and bacteriophage-mediated multidrug-resistant bacterial decolonization. This review will discuss these perspectives and explore the role of different human microbiotas in the context of various transplantation scenarios.

Why Donors Do Not Donate: A Living Donation Program Experience

BACKGROUND

A living donor (LD) kidney transplant is the best therapeutic option for end-stage kidney disease. Potential donors must undergo multiple analyses and the rates of live donation can be as low as 8% to 18%. Here, we report on the live kidney donor program in our unit with emphasis on the reasons why potential donors do not proceed to donation.

METHODS

We performed a single-center retrospective study of all potential kidney donors with a first LD appointment at Centro Hospitalar Universitário do Porto between January 2016 and December 2020.

RESULTS

In our cohort there were 395 potential donors. From the potential donors who finished assessment, 131 were approved for donation and 239 dropped out. After assessment, 104 (28.1%) recipients received a living kidney transplant, 24 of which received a living kidney transplant through the kidney paired exchange program. The individuals who did not proceed to the surgery (n = 239) had a median age of 46.5 years, 64.4% were female, and 34 pairs were ABO-incompatible. The most frequent donor-recipient relationships were spouses, siblings and parents. The 2 most important causes of dropout were due to medical, surgical or psychological contraindications and the donor's voluntary withdrawal. When we evaluated the variables most related to dropout, they were not because of being a spouse and ABO incompatibility.

CONCLUSIONS

When compared to other studies, we showed a relatively higher rate of successful live donations, possibly aided by the presence of cross-over transplantation. Targeted education and support at an earlier stage of the donor assessment process may lead to a better engagement and lower probability of early dropout.

A parallel evaluation of short- and mid-term changes of ambulatory blood pressure in kidney transplant recipients and kidney donors

Introduction

Kidney transplantation (KTx) is associated with improved blood pressure (BP) levels for kidney transplant recipients (KTRs) without evoking significant changes in donors. However, there is a paucity of studies offering simultaneous detailed evaluation of BP profiles over time in transplant donor-recipient pairs. The aim of the present study was the parallel evaluation of ambulatory BP levels and trajectories in KTRs and their respective living kidney donors in the short and mid-term following KTx.

Methods

The study enrolled 40 prospective adult KTRs and their 40 respective donors. All participants were evaluated with 24-h ambulatory BP monitoring (Mobil-O-Graph NG device) at three time points: baseline (1 month before KTx), 3 months and 12 months after KTx.

Results

In KTRs, 3-month 24-h systolic BP (SBP) was marginally reduced and 12-month 24-h SBP significantly reduced compared with baseline [131.9 ± 13.3 versus 126.4 ± 11.9 mmHg (P = .075) and 123.9 ± 10.3 mmHg (P = .009),  respectively]. At both the 3- and 12-month time points, 24-h diastolic BP (DBP) was significantly reduced [86.7 ± 11.5 versus 82.2 ± 8.1 mmHg (P = .043) and 80.3 ± 8.5 mmHg (P = .009)]. Similar observations were made for day- and night time SBP and DBP. Repeated-measures analysis of variance (ANOVA) showed a significant gradual decrease over time in mean 24-h SBP [F(1.463, 39.505) = 3.616; P = .049, partial η ² = 0.118] and DBP [F(1.374, 37.089) = 11.34; P = .055, partial η ² = 0.116]. In contrast, in kidney donors, 24-h SBP [118.5 ± 11.6 versus 118.2 ± 12.8 mmHg (P = .626) and 119.2 ± 11.4 mmHg (P = .748)] and DBP did not change at 3 or 12 months compared with baseline; repeated measures ANOVA showed no differences in the mean 24-h SBP and DBP levels over time. The number of antihypertensive agents decreas in KTRs and remained stable in donors.

Conclusions

KTx reduces ambulatory BP levels and trajectories in KTRs at 3 months and further so at 12 months post-surgery. Kidney donation does not affect the ambulatory BP levels and trajectories of donors at the same intervals.

Dialysis, Distress, and Difficult Conversations: Living with a Kidney Transplant

Background: Providing holistic care to kidney patients is important; however, without full consideration of the perspectives of people living with a kidney transplant, the provision of truly ‘holistic healthcare’ cannot be possible. It is imperative to understand patient experiences by including kidney patients in key strategies and future renal service planning. Ignoring these important patient views means that there is a significant risk of inappropriate renal service provision and lack of adequate support, impacting overall health. The aim of this study was to develop an in-depth understanding of the lived experiences of kidney transplant recipients. Methods: A total of 23 participants were recruited between two regional nephrology units within the United Kingdom via clinical gatekeepers. In-depth interviews were undertaken. Interviews were digitally recorded, transcribed verbatim, and subjected to interpretative phenomenological analysis. Results: Two themes emerged: “managing ongoing fears of dialysis, distress, and COVID-19” and “dealing with difficult conversations”. Conclusions: Renal healthcare professionals need to understand more than the biological impact of receiving a kidney transplant. Understanding the holistic and multidomain experiences that these participants experience will help healthcare professionals to recognize the needs of this group and ensure more responsive psychosocial care.

New Approaches to Cardiovascular Disease and Its Management in Kidney Transplant Recipients

Cardiovascular events, including ischemic heart disease, heart failure, and arrhythmia, are common complications after kidney transplantation and continue to be leading causes of graft loss. Kidney transplant recipients have both traditional and transplant-specific risk factors for cardiovascular disease. In the general population, modification of cardiovascular risk factors is the best strategy to reduce cardiovascular events; however, studies evaluating the impact of risk modification strategies on cardiovascular outcomes among kidney transplant recipients are limited. Furthermore, there is only minimal guidance on appropriate cardiovascular screening and monitoring in this unique patient population. This review focuses on the limited scientific evidence that addresses cardiovascular events in kidney transplant recipients. Additionally, we focus on clinical management of specific cardiovascular entities that are more prevalent among kidney transplant recipients (ie, pulmonary hypertension, valvular diseases, diastolic dysfunction) and the use of newer evolving drug classes for treatment of heart failure within this cohort of patients. We note that there are no consensus documents describing optimal diagnostic, monitoring, or management strategies to reduce cardiovascular events after kidney transplantation; however, we outline quality initiatives and research recommendations for the assessment and management of cardiovascular-specific risk factors that could improve outcomes.

The Use of Machine Learning Algorithms and the Mass Spectrometry Lipidomic Profile of Serum for the Evaluation of Tacrolimus Exposure and Toxicity in Kidney Transplant Recipients

Tacrolimus has a narrow therapeutic window; a whole-blood trough target concentration of between 5 and 8 ng/mL is considered a safe level for stable kidney transplant recipients. Tacrolimus serum levels must be closely monitored to obtain a balance between maximizing efficacy and minimizing dose-related toxic effects. Currently, there is no specific tacrolimus toxicity biomarker except a graft biopsy. Our study aimed to identify specific serum metabolites correlated with tacrolinemia levels using serum high-precision liquid chromatography–mass spectrometry and standard laboratory evaluation. Three machine learning algorithms were used (Naïve Bayes, logistic regression, and Random Forest) in 19 patients with high tacrolinemia (8 ng/mL) and 23 patients with low tacrolinemia (5 ng/mL). Using a selected panel of five lipid metabolites (phosphatidylserine, phosphatidylglycerol, phosphatidylethanolamine, arachidyl palmitoleate, and ceramide), Mg2+, and uric acid, all three machine learning algorithms yielded excellent classification accuracies between the two groups. The highest classification accuracy was obtained by Naïve Bayes, with an area under the curve of 0.799 and a classification accuracy of 0.756. Our results show that using our identified five lipid metabolites combined with Mg2+ and uric acid serum levels may provide a novel tool for diagnosing tacrolimus toxicity in kidney transplant recipients. Further validation with targeted MS and biopsy-proven TAC toxicity is needed.

A qualitative exploration of the facilitators and barriers to self-management in kidney transplant recipients

Background

Understanding the behaviours that facilitate or impede one’s ability to self-manage is important to improve health-related outcomes in kidney transplant recipients (KTRs). Previous studies exploring the self-management experiences of KTRs have focused on specific tasks (e.g., medication adherence), age groups (e.g., adolescent or older recipients), or have been conducted outside of the UK where transferability of findings is unknown. Our study aimed to explore the perceptions and experiences of self-management in UK KTRs to identify facilitators and barriers associated with self-management tasks.

Methods

Semi-structured interviews were conducted with eleven KTRs. Topics explored included experiences of self-management tasks (diet, exercise, medications, stress management), perceived healthcare role, and future interventional approaches. Thematic analysis was used to identify and report themes.

Results

Eight themes were identified which were mapped onto the three self-management tasks described by Corbin and Strauss: medical, role and emotional management. Perceived facilitators to self-management were: gathering health-related knowledge, building relationships with healthcare professionals, creating routines within daily life, setting goals and identifying motivators, establishing support networks, and support from family and friends. Complexity of required treatment and adjusting to a new health status were perceived barriers to self-management.

Conclusions

Participants described the importance of collaborative consultations and continuity of care. Tailored interventions should identify individualised goals and motivators for participating in self-management. Education on effective strategies to manage symptoms and comorbidities could help alleviate KTRs’ perceived treatment burden. Family and peer support could emotionally support KTRs; however, managing the emotional burden of transplantation warrants more attention.

Graphic abstract

Polish attitudes towards unspecified kidney donation: a cross-sectional study

BACKGROUND

Chronic kidney disease effects about 4.2 million people in Poland, yet Polish organ donation research is rare. In addition, compared to other countries in the world, Poland has a relatively low living donation rate. Still, little is known about how Poles would react to the possibility of living kidney donation to strangers. A study was conducted to examine public opinion about living kidney donation, as well as their knowledge about it, willingness to donate to a stranger, and support for a possible expansion of existing Polish organ donation legislation to include living donation to strangers.

METHODS

A self-report questionnaire, which included a socio-demographic datasheet (9 questions), 16 questions about attitudes towards living donation, and 1 question about knowledge concerning transplantation law was sent to the respondents from December 2020 - February 2021. Logistic regression was used to assess factors affecting the support of the legalization of unspecified kidney donation amongst the participants.

RESULTS

More than sixty percent (62.1) of respondents supported legalization of unspecified living kidney donation. Such legalization would be accepted by people who accept a choice of a family member to donate a kidney to a stranger (OR = 3.50; Cl 95%: 1.49 to 4.85), who think bone-marrow transplant is safe (OR = 2.65; Cl 95%: 1.80 to 3.91), recognize the benefit of carrying out tests before donating a kidney (OR = 2.56; Cl 95%: 1.79 to 3.69), would agree to receive a kidney from another person (OR = 2.24; Cl 95%: 2.53 to 3.13), or would agree to donate organs after death (OR = 2.06; Cl 95%: 1.45 to 2.95). However, support for unspecified living kidney donation would not be given by respondents fearing the risk of organ trafficking (OR = 0.54; Cl 95%: 0.38 to 0.79).

CONCLUSIONS

In Poland there is strong support for legalization of unspecified living kidney donation. It is vital that future legislation define organ trafficking as a crime with serious punishment so that legal unspecified living kidney donation is not hindered.

TRIAL REGISTRATION

The study was registered with ClinicalTrials.gov (ID: NCT04789122 ) on 08/03/2021.

Pulmonary Arterial Hypertension and Adverse Outcomes after Kidney Transplantation: A Systematic Review and Meta-Analysis

Pulmonary arterial hypertension (PH) has a high prevalence in chronic kidney disease (CKD) patients, especially those undergoing kidney transplantation (KT). We aimed to systematically review and calculate the pooled effect size of the literature evaluating the association between pre-existing PH documented by transthoracic echocardiography (TTE) or invasively and adverse outcomes following KT. The primary composite outcome extracted from the included studies was represented by the mortality from any cause following KT and delayed graft function (DGF), graft dysfunction, or graft failure. The secondary outcomes were represented by individual components of the primary composite outcome. Twelve studies meeting the inclusion criteria were selected. The main finding is that pre-existing PH was associated with increased mortality and a higher rate of DGF, kidney graft dysfunction, or failure in KT recipients. The effect remained significant for all outcomes irrespective of PH evaluation, invasively or using TTE. Consequently, patients with PH defined only by TTE were at higher risk of death, DGF, or graft failure. Our findings support the routine assessment of PH in patients on the KT waitlist. PH might represent an extensively available and valuable tool for risk stratification in KT patients. These data should be confirmed in large prospective clinical trials.

How Should Acute T-cell Mediated Rejection of Kidney Transplants Be Treated: Importance of Follow-up Biopsy

Background.

Limited published data exist to guide patient monitoring after the treatment of T-cell mediated rejection (TCMR) of kidney allografts.

Methods.

We reviewed the kidney function and histological outcomes after treatment of 163 first episodes of biopsy-proven TCMR between January 1‚ 2015‚ and July 31‚ 2020.

Results.

Of the 146 patients treated with steroid pulse alone, complete histological response was seen in 83% of patients with borderline rejection, 82.5% with grade 1A, 67% with grade 1B, and 50% with grade IIA. Of the 17 patients treated with steroids plus antithymocyte globulin, the complete histological response rate was 100% with grade 1A, 75% with grade 1B, 100% with grade IIA, and 57% with grade IIB. Among the patients with complete response as assessed by kidney function, 14% only had a partial or no response histologically. Among patients with no kidney function response, 68% had a complete response histologically.

Conclusion.

We thus find that responses based on kidney function alone do not correlate well with histological responses. If further treatment had been based solely on changes in estimated glomerular filtration rate, a significant number of patients would have been subsequently undertreated or overtreated. These results support the use of protocol follow-up biopsies after the treatment of TCMR.

Survival for waitlisted kidney failure patients receiving transplantation versus remaining on waiting list: systematic review and meta-analysis

OBJECTIVES

To investigate the survival benefit of transplantation versus dialysis for waitlisted kidney failure patients with a priori stratification.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Online databases MEDLINE, Ovid Embase, Web of Science, Cochrane Collection, and ClinicalTrials.gov were searched between database inception and 1 March 2021.

INCLUSION CRITERIA

All comparative studies that assessed all cause mortality for transplantation versus dialysis in patients with kidney failure waitlisted for transplant surgery were included. Two independent reviewers extracted the data and assessed the risk of bias of included studies. Meta-analysis was done using the DerSimonian-Laird random effects model, with heterogeneity investigated by subgroup analyses, sensitivity analyses, and meta-regression.

RESULTS

The search identified 48 observational studies with no randomised controlled trials (n=1 245 850 patients). In total, 92% (n=44/48) of studies reported a long term (at least one year) survival benefit associated with transplantation compared with dialysis. However, 11 of those studies identified stratums in which transplantation offered no statistically significant benefit over remaining on dialysis. In 18 studies suitable for meta-analysis, kidney transplantation showed a survival benefit (hazard ratio 0.45, 95% confidence interval 0.39 to 0.54; P<0.001), with significant heterogeneity even after subgroup/sensitivity analyses or meta-regression analysis.

CONCLUSION

Kidney transplantation remains the superior treatment modality for most patients with kidney failure to reduce all cause mortality, but some subgroups may lack a survival benefit. Given the continued scarcity of donor organs, further evidence is needed to better inform decision making for patients with kidney failure.

STUDY REGISTRATION

PROSPERO CRD42021247247.

Time to Move on: HLA Matching Should Be Reconsidered in Modern Deceased Donor Kidney Allocation

HLA matching has been the cornerstone of deceased donor kidney allocation policies worldwide but can lead to racial inequity. Although HLA matching has been shown to improve clinical outcomes, the long-term impacts of nonallogenic factors are being increasingly recognized. This has led some transplant programs to include points for nonallogenic factors, for example, age. Our study looks at long-term graft and patient outcomes based on allocation cohorts rather than individual number of HLA mismatches.

Early steps to kidney transplantation among persons with HIV and end-stage renal disease in ESRD network 6

INTRODUCTION

End-stage renal disease is a significant cause of morbidity and mortality in persons with HIV (PWH). Limited data exist on access to kidney transplantation for this population.

METHODS

A dataset inclusive of incident dialysis patients between 2012 and 2016 with follow-up through December 2017 that identifies PWH and the general dialysis population of Network 6 (Georgia, North Carolina, South Carolina) was created through merging the United States Renal Data System with the southeastern early transplant access registry. Early steps to kidney transplantation and patient and dialysis facility-level characteristics that serve as barriers to transplantation were described.

RESULTS

Twenty-three thousand four hundred fourteen patients were identified; 469 were PWH. Compared to non-HIV individuals, PWH were younger (49 vs. 58 years, p < 0.001), predominantly Black (87% vs. 56% p < 0.001) and male (72% vs. 56% p < 0.001). PWH were less likely to be referred to kidney transplant within 1 year of starting dialysis (36% vs. 41% p < 0.001) and waitlisted within 1 year of evaluation-start (14% vs. 30%, p = 0.05). PWH (vs. non-PWH) waited longer for referral, evaluation-start, and waitlisting and in multivariable analysis; HIV positivity was associated with a lower probability of referral (hazard ratios [HR]: 0.70; 95% confidence intervals [CIs]: 0.62-0.80), evaluation (HR 0.66; 95% CI: 0.55-0.80), and waitlisting (HR 0.29; 95% CI: 0.20-0.41).

CONCLUSIONS

Targeted interventions are needed to improve access to kidney transplants, particularly in waitlisting, for PWH.

How much should we be concerned about cumulative effective doses in medical imaging?

The International Atomic Energy Agency issued a statement calling for action to strengthen the radiation protection of patients undergoing recurrent imaging. This followed reports of patients receiving cumulative effective doses over 100 mSv from multiple computed tomography examinations. In order to evaluate excess risks of cancer incidence among UK patients, data from an exposure management system covering three hospitals within one trust have been studied over 5½ years. Cumulative effective doses for 105 757 patients, from whom 719 (0.68%) received effective dose over 100 mSv, have been analysed using age and sex specific risk factors for stochastic effects. Two cancers might be expected to be initiated in the patients receiving over 100 mSv, while five might be expected to develop cancer among patients receiving 50-100 mSv. However, the calculations ignore health conditions for which the patients are being treated that may shorten their lives, and rely on the linear-no-threshold dose-effect model which is a subject of debate, so they are likely to overestimate cancer incidence. If health of the patients receiving >100 mSv is taken into account, the risk of mortality from cancer initiated by medical exposure might be the order of 1 in 2000. Recommendations on further strengthening of optimisation should be applied to imaging procedures for all patients with special focus on those performed on children and adolescents.