Development and Validation of an Inflammatory-Frailty Index for Kidney Transplantation

Increased Pretransplant Inflammatory Biomarkers Predict Death With Function After Kidney Transplantation

BACKGROUND

Chronic systemic inflammation is associated with mortality in patients with chronic kidney disease, cardiovascular disease, and diabetes. The goal of this study was to examine the relationship between pretransplant inflammatory biomarkers (growth differentiation factor-15 [GDF-15], interleukin-6 [IL-6], soluble tumor necrosis factor receptor-1, monokine induced by gamma interferon/chemokine [C-X-C motif] ligand 9 [MIG/CXCL9], monocyte chemoattractant protein-1, soluble FAS, tumor necrosis factor-α, interleukin-15, and interleukin-1β) and death with function (DWF) after kidney transplantation (KT).

METHODS

We retrospectively measured inflammatory biomarker levels in serum collected up to 1 y before KT (time from blood draw to KT was 130 ± 110 d) in recipients transplanted between January 2006 and December 2018. Kaplan-Meier estimation, Cox regression, and Gradient Boosting Machine modeling were used to examine the relationship between inflammatory biomarkers and DWF.

RESULTS

Our cohort consisted of 1595 KT recipients, of whom 62.9% were male and 83.2% were non-Hispanic White. Over a mean follow-up of 7.4 ± 3.9 y, 21.2% of patients (n = 338) experienced DWF. Patients with the highest quartile levels of GDF-15 (>4766 pg/mL), IL-6 (>6.11 pg/mL), and MIG/CXCL9 (> 5835 pg/mL) had increased rates of DWF, and each predicted mortality independently of the others. When adjusted for clinical factors (age, diabetes, etc), the highest quartile levels of GDF-15 and IL-6 remained independently associated with DWF. Adding inflammatory markers to a clinical Cox model improved the C-statistic for DWF from 0.727 to 0.762 using a Gradient Boosting Machine modeling approach.

CONCLUSIONS

These findings suggest that pre-KT serum concentrations of GDF-15, IL-6, and MIG/CXCL9 may help to risk stratify and manage patients undergoing KT and suggests that chronic inflammation may play a role in mortality in KT recipients.

Unmet Questions About Frailty in Kidney Transplant Candidates

Frailty occurs frequently among patients with advanced chronic kidney disease, especially among women. Assessing frailty in kidney transplant (KT) candidates is crucial for informing them about associated risks. However, there is poor agreement between frailty scales and research on their correlation with transplant outcomes. Being prefrail significantly impacts both graft and patient survival, often beginning with just 1 Fried criterion. Rather than viewing frailty as a categorical state, it should be regarded as a spectrum ranging from 1 to 5 criteria, with the risk of adverse outcomes escalating as frailty worsens. Frailty status fluctuates during the waiting period for KT; hence, a 1-time frailty evaluation is insufficient to determine risks and implement strategies for improving functional status. Further research should investigate the components of frailty that most frequently change during this waiting period and establish strategies to prevent or reverse frailty. Although careful evaluation of frail KT candidates is necessary to prevent early complications and mortality, exclusion based solely on a frailty score is unwarranted. Instead, efforts should focus on timely interventions to enhance their condition before transplantation. Although evidence is limited, exercise programs appear feasible and yield positive results. A pretransplant clinical framework encompassing multimodal prehabilitation-comprising physical therapy, nutritional measures, and psychological support-during the waiting list period may help alleviate the effects of frailty and poor fitness after KT, ultimately improving key outcomes. Despite logistical challenges, there is a pressing need for interventional trials in this area.

Electrocardiography-based Artificial Intelligence Algorithms Aid in Prediction of Long-term Mortality After Kidney Transplantation

BACKGROUND

Predicting long-term mortality postkidney transplantation (KT) using baseline clinical data presents significant challenges. This study aims to evaluate the predictive power of artificial intelligence (AI)-enabled analysis of preoperative electrocardiograms (ECGs) in forecasting long-term mortality following KT.

METHODS

We analyzed preoperative ECGs from KT recipients at three Mayo Clinic sites (Minnesota, Florida, and Arizona) between January 1, 2006, and July 30, 2021. The study involved 6 validated AI algorithms, each trained to predict future development of atrial fibrillation, aortic stenosis, low ejection fraction, hypertrophic cardiomyopathy, amyloid heart disease, and biological age. These algorithms' outputs based on a single preoperative ECG were correlated with patient mortality data.

RESULTS

Among 6504 KT recipients included in the study, 1764 (27.1%) died within a median follow-up of 5.7 y (interquartile range: 3.00-9.29 y). All AI-ECG algorithms were independently associated with long-term all-cause mortality (P < 0.001). Notably, few patients had a clinical cardiac diagnosis at the time of transplant, indicating that AI-ECG scores were predictive even in asymptomatic patients. When adjusted for multiple clinical factors such as recipient age, diabetes, and pretransplant dialysis, AI algorithms for atrial fibrillation and aortic stenosis remained independently associated with long-term mortality. These algorithms also improved the C-statistic for predicting overall (C = 0.74) and cardiac-related deaths (C = 0.751).

CONCLUSIONS

The findings suggest that AI-enabled preoperative ECG analysis can be a valuable tool in predicting long-term mortality following KT and could aid in identifying patients who may benefit from enhanced cardiac monitoring because of increased risk.

Abdominal computed tomography measurements of body composition and waitlist mortality in kidney transplant candidates

Body mass index is often used to determine kidney transplant (KT) candidacy. However, this measure of body composition (BC) has several limitations, including the inability to accurately capture dry weight. Objective computed tomography (CT)-based measures may improve pre-KT risk stratification and capture physiological aging more accurately. We quantified the association between CT-based BC measurements and waitlist mortality in a retrospective study of 828 KT candidates (2010-2022) with clinically obtained CT scans using adjusted competing risk regression. In total, 42.5% of candidates had myopenia, 11.4% had myopenic obesity (MO), 68.8% had myosteatosis, 24.8% had sarcopenia (probable = 11.2%, confirmed = 10.5%, and severe = 3.1%), and 8.6% had sarcopenic obesity. Myopenia, MO, and sarcopenic obesity were not associated with mortality. Patients with myosteatosis (adjusted subhazard ratio [aSHR] = 1.62, 95% confidence interval [CI]: 1.07-2.45; after confounder adjustment) or sarcopenia (probable: aSHR = 1.78, 95% CI: 1.10-2.88; confirmed: aSHR = 1.68, 95% CI: 1.01-2.82; and severe: aSHR = 2.51, 95% CI: 1.12-5.66; after full adjustment) were at increased risk of mortality. When stratified by age, MO (aSHR = 2.21, 95% CI: 1.28-3.83; P interaction = .005) and myosteatosis (aSHR = 1.95, 95% CI: 1.18-3.21; P interaction = .038) were associated with elevated risk only among candidates <65 years. MO was only associated with waitlist mortality among frail candidates (adjusted hazard ratio = 2.54, 95% CI: 1.28-5.05; P interaction = .021). Transplant centers should consider using BC metrics in addition to body mass index when a CT scan is available to improve pre-KT risk stratification at KT evaluation.

The Development and Evaluation of a Prediction Model for Kidney Transplant-Based Pneumocystis carinii Pneumonia Patients Based on Hematological Indicators

BACKGROUND

This study aimed to develop a simple predictive model for early identification of the risk of adverse outcomes in kidney transplant-associated Pneumocystis carinii pneumonia (PCP) patients.

METHODS

This study encompassed 103 patients diagnosed with PCP, who received treatment at our hospital between 2018 and 2023. Among these participants, 20 were categorized as suffering from severe PCP, and, regrettably, 13 among them succumbed. Through the application of machine learning techniques and multivariate logistic regression analysis, two pivotal variables were discerned and subsequently integrated into a nomogram. The efficacy of the model was assessed via receiver operating characteristic (ROC) curves and calibration curves. Additionally, decision curve analysis (DCA) and a clinical impact curve (CIC) were employed to evaluate the clinical utility of the model. The Kaplan-Meier (KM) survival curves were utilized to ascertain the model's aptitude for risk stratification.

RESULTS

Hematological markers, namely Procalcitonin (PCT) and C-reactive protein (CRP)-to-albumin ratio (CAR), were identified through machine learning and multivariate logistic regression. These variables were subsequently utilized to formulate a predictive model, presented in the form of a nomogram. The ROC curve exhibited commendable predictive accuracy in both internal validation (AUC = 0.861) and external validation (AUC = 0.896). Within a specific threshold probability range, both DCA and CIC demonstrated notable performance. Moreover, the KM survival curve further substantiated the nomogram's efficacy in risk stratification.

CONCLUSIONS

Based on hematological parameters, especially CAR and PCT, a simple nomogram was established to stratify prognostic risk in patients with renal transplant-related PCP.

Frailty and prognosis of patients with kidney transplantation: a meta-analysis

BACKGROUND

The prevalence of frailty among candidates and recipients of kidney transplantation (KT) is well-established, yet the impact of frailty on clinical outcomes following KT remains uncertain. To address this knowledge gap, we conducted a systematic meta-analysis to comprehensively assess the aforementioned relationship.

METHODS

The present study conducted a comprehensive search of PubMed, Embase, and Cochrane Library databases to identify relevant observational studies that compared mortality risk and other clinical outcomes of KT recipients with and without frailty. Two authors independently conducted data collection, literature searching, and statistical analysis. The results were synthesized using a heterogeneity-incorporating random-effects model.

RESULTS

In this meta-analysis, 6279 patients from 13 cohort studies were included, and 1435 patients (22.9%) were with frailty before KT. There were higher mortality rates among frail patients at admission, compared to those without frailty (risk ratio [RR]: 1.97, 95% confidence interval [CI]: 1.57 to 2.47, p < 0.001; I2 = 19%). Subgroup analysis suggested the association between frailty and high mortality risk after KT was consistent in studies of frailty assessed via Physical Frailty Phenotype or other methods, and in studies of follow-up duration < or ≥ 5 years. In addition, frailty was associated with higher incidence of delayed graft function (RR: 1.78, 95% CI: 1.21 to 2.61, p = 0.003; I2 = 0%), postoperative complications (RR: 1.88, 95% CI: 1.15 to 3.08, p = 0.01; I2 = 0%), and longer hospitalization (RR: 1.55, 95% CI: 1.22 to 1.97, p < 0.001; I2 = 0%).

CONCLUSION

Following KT, frail patients are at higher risks for all-cause mortality, delayed graft function, postoperative complications, and longer hospital stays.

Creating the nursing care map in the evaluation of kidney transplant candidates: A scoping review and narrative synthesis

AIMS

To analyse the aspects involved in the care of individuals assessed as kidney transplant candidates and to identify the role of nurses in providing specialised care for this population.

DESIGN

Scoping review. The results were summarised using a narrative synthesis technique.

DATA SOURCES

A review of the literature published between 2001 and 2021 was conducted between October and November 2021 using PubMed, CINAHL and SciELO.

REVIEW METHODS

The research team agreed on a search strategy based on clinical practice guidelines for assessing kidney transplantation candidates. Quantitative, qualitative and mixed methods studies published in peer-reviewed journals in English, Spanish, French and Portuguese were included.

RESULTS

A total of 377 studies were identified, and 49 articles were included after the inclusion and exclusion criteria were applied. The narrative synthesis was structured into four themes: Physical needs; Psychological and quality of life needs; Education and adherence needs; and Nurses' role.

CONCLUSION

Nursing assessment of kidney transplantation candidates should encompass physical, psychosocial and adherence aspects. A variety of methodologies and resources are available for this assessment. Nurses contribute to coordinating access to kidney transplantation, aiming to improve adherence to an appropriate lifestyle to prevent patients from being excluded from kidney transplantation or suffering from kidney transplantation-related complications.

IMPACT

Based on our findings, we managed to design a nursing care map for kidney transplantation candidates combining the main elements of nursing care that should be incorporated into this process. Advanced practice nursing professionals play a crucial role in accessing renal transplant care.

Nutritional Risk of Candidates for Simultaneous Pancreatic-Kidney Transplantation-A Narrative Review

INTRODUCTION

Not much is known about the significance of nutritional status and support in transplant surgery, least of all in simultaneous pancreatic and kidney transplantation. Malnutrition in the context of simultaneous pancreatic-kidney transplantation seems to be complex and a still poorly investigated problem. Since SPKTX is highly qualified and also has a small volume procedure, it is difficult to obtain data from large cohorts of patients. The aim of this article is to gather existing evidence and information about the subject, as well as to elicit some questions and goals for the future.

METHODS

We searched through the Pub-Med database using the keywords "pancreas and kidney transplantation" combined with "nutritional risk", "nutritional status", "malnutrition", "nutritional intervention", and "frailty", finding a total of 4103 matching results. We then narrowed it down to articles written in English with the full text available. We also researched through the references of articles most accurately matching our researched terms.

RESULTS

There are numerous tools that have been investigated for the screening of malnutrition, such as the NRI index, PNI index, NLR, SGA scale, and NRS-2002 scale, each of which proved to be of some use in predicting patient outcomes in different surgical settings. Since all of them differed in components and assessed parameters and, in the absence of more sensitive or infallible indicators, the most reasonable approach seems to evaluate them jointly.

CONCLUSION

It is important to underline the necessity of nutritional screening and the subsequent introduction of adequate therapy while awaiting transplantation in an attempt to improve results. Considering the complexity of surgical procedures and the severity of underlying diseases with their intense metabolic components, the patient's nutritional status seems to significantly influence results. Consequently, nutritional risk assessments should be a part of the routine care of patients qualified for transplantation.

Use of frailty assessment instruments in nephrology populations: a scoping review

BACKGROUND

Frailty is a clinical syndrome of accelerated aging associated with adverse outcomes. Frailty is prevalent among patients with chronic kidney disease but is infrequently assessed in clinical settings, due to lack of consensus regarding frailty definitions and diagnostic tools. This study aimed to review the practice of frailty assessment in nephrology populations and evaluate the context and timing of frailty assessment.

METHODS

The search included published reports of frailty assessment in patients with chronic kidney disease, undergoing dialysis or in receipt of a kidney transplant, published between January 2000 and November 2021. Medline, CINAHL, Embase, PsychINFO, PubMed and Cochrane Library databases were examined. A total of 164 articles were included for review.

RESULTS

We found that studies were most frequently set within developed nations. Overall, 161 studies were frailty assessments conducted as part of an observational study design, and 3 within an interventional study. Studies favoured assessment of participants with chronic kidney disease (CKD) and transplant candidates. A total of 40 different frailty metrics were used. The most frequently utilised tool was the Fried frailty phenotype. Frailty prevalence varied across populations and research settings from 2.8% among participants with CKD to 82% among patients undergoing haemodialysis. Studies of frailty in conservatively managed populations were infrequent (N = 4). We verified that frailty predicts higher rates of adverse patient outcomes. There is sufficient literature to justify future meta-analyses.

CONCLUSIONS

There is increasing recognition of frailty in nephrology populations and the value of assessment in informing prognostication and decision-making during transitions in care. The Fried frailty phenotype is the most frequently utilised assessment, reflecting the feasibility of incorporating objective measures of frailty and vulnerability into nephrology clinical assessment. Further research examining frailty in low and middle income countries as well as first nations people is required. Future work should focus on interventional strategies exploring frailty rehabilitation.

Cellular Senescence and Frailty in Transplantation

Purpose of review

To summarizes the literature on cellular senescence and frailty in solid-organ transplantation and highlight the emerging role of senotherapeutics as a treatment for cellular senescence.

Recent findings

Solid-organ transplant patients are aging. Many factors contribute to aging acceleration in this population, including cellular senescence. Senescent cells accumulate in tissues and secrete proinflammatory and profibrotic proteins which result in tissue damage. Cellular senescence contributes to age-related diseases and frailty. Our understanding of the role cellular senescence plays in transplant-specific complications such as allograft immunogenicity and infections is expanding. Promising treatments, including senolytics, senomorphics, cell-based regenerative therapies, and behavioral interventions, may reduce cellular senescence abundance and frailty in patients with solid-organ transplants.

Summary

Cellular senescence and frailty contribute to adverse outcomes in solid-organ transplantation. Continued pursuit of understanding the role cellular senescence plays in transplantation may lead to improved senotherapeutic approaches and better graft and patient outcomes.

Frailty assessment as part of transplant listing: yes, no or maybe?

Frailty, characterized by a decreased physiological reserve and an increased vulnerability to stressors, is common among kidney transplant (KT) candidates and recipients. In this review, we present and summarize the key arguments for and against the assessment of frailty as part of KT evaluation. The key arguments for including frailty were: (i) sheer prevalence and far-reaching consequences of frailty on KT, and (ii) the ability to conduct a more holistic and objective evaluation of candidates, removing the inaccuracy associated with 'eye-ball' assessments of transplant fitness. The key argument against were: (i) lack of agreement on the definition of frailty and which tools should be used in renal populations, (ii) a lack of clarity on how, by whom and how often frailty assessments should be performed, and (iii) a poor understanding of how acute stressors affect frailty. However, it is the overwhelming opinion that the time has come for frailty assessments to be incorporated into KT listing. Although ongoing areas of uncertainty exist and further evidence development is needed, the well-established impact of frailty on clinical and experiential outcomes, the invaluable information obtained from frailty assessments, and the potential for intervention outweigh these limitations. Proactive and early identification of frailty allows for individualized and improved risk assessment, communication and optimization of candidates.

Frailty and Age-Associated Assessments Associated with Chronic Kidney Disease and Transplantation Outcomes

Background. Frailty is often defined as a decrease in physiological reserve and has been shown to be correlated with adverse health outcomes and mortality in the general population. This condition is highly prevalent in the chronic kidney disease (CKD) patient population as well as in kidney transplant (KT) recipients. Other age-associated changes include sarcopenia, nutrition, cognition, and depression. In assessing the contributions of these components to patient outcomes and their prevalence in the CKD and KT patient population, it can be determined how such variables may be associated with frailty and the extent to which they may impact the adverse outcomes an individual may experience. Objectives. We sought to perform a systematic literature review to review published data on frailty and associated age-associated syndromes in CKD and KT patients. Results. Over 80 references pertinent to frailty, sarcopenia, nutrition, cognition, or depression in patients with CKD or KT were identified. Systematic review was performed to evaluate the data supporting the use of the following approaches: Fried Frailty, Short Physical Performance Battery, Frailty Index, Sarcopenia Index, CT scan quantification of muscle mass, health-related quality of life, and assessment tools for nutrition, cognition, and depression. Conclusion. This report represents a comprehensive review of previously published research articles on this topic. The intersectionality between all these components in contributing to the patient’s clinical status suggests a need for a multifaceted approach to developing comprehensive care and treatment for the CKD and KT population to improve outcomes before and after transplantation.

Frailty and solid-organ transplant candidates: a scoping review

Background

There is currently no consensus as to a standardized tool for frailty measurement in any patient population. In the solid-organ transplantation population, routinely identifying and quantifying frailty in potential transplant candidates would support patients and the multidisciplinary team to make well-informed, individualized, management decisions. The aim of this scoping review was to synthesise the literature regarding frailty measurement in solid-organ transplant (SOT) candidates.

Methods

A search of four databases (Cochrane, Pubmed, EMBASE and CINAHL) yielded 3124 studies. 101 studies (including heart, kidney, liver, and lung transplant candidate populations) met the inclusion criteria.

Results

We found that studies used a wide range of frailty tools (N = 22), including four ‘established’ frailty tools. The most commonly used tools were the Fried Frailty Phenotype and the Liver Frailty Index. Frailty prevalence estimates for this middle-aged, predominantly male, population varied between 2.7% and 100%. In the SOT candidate population, frailty was found to be associated with a range of adverse outcomes, with most evidence for increased mortality (including post-transplant and wait-list mortality), post-operative complications and prolonged hospitalisation. There is currently insufficient data to compare the predictive validity of frailty tools in the SOT population.

Conclusion

Overall, there is great variability in the approach to frailty measurement in this population. Preferably, a validated frailty measurement tool would be incorporated into SOT eligibility assessments internationally with a view to facilitating comparisons between patient sub-groups and national and international transplant services with the ultimate goal of improved patient care.

The clinical application of frailty in nephrology and transplantation

PURPOSE OF REVIEW

Clinicians treating end-stage kidney disease (ESKD) and kidney transplant patients face unique challenges in their care because of the high burden of frailty in these patients. Frailty has gained significant attention by medical and surgical specialties for risk stratification in the past decades. This review highlights the importance of measuring frailty in kidney transplant candidates and recipients.

RECENT FINDINGS

Emerging data support that frailty is present even at younger ages among patients undergoing dialysis, transplant evaluation, or transplantation. It is estimated that 18.8% of younger (18-64 years) candidates, 25.2% of older (≥65 years) candidates, 14.3% of younger recipients, and 20.8% of older recipients are frail. Additionally, frailty is dynamic and subject to change pretransplantation and posttransplantation. Although many patients and clinicians are aware of the importance of measuring frailty, further studies addressing the need for interventions to reduce frailty burden are needed.

SUMMARY

Frailty is independently associated with many adverse outcomes in ESKD and kidney transplant populations. Given the growing number of ESKD and kidney transplant patients, it is pivotal to expand the utility of frailty measurement in clinical practice, recognize the burden of frailty, and identify appropriate interventions to mitigate the adverse effects of frailty.

Pre-Kidney Transplant Unintentional Weight Loss Leads to Worse Post-Kidney Transplant Outcomes

BACKGROUND

Weight loss before kidney transplant (KT) is a known risk factor for weight gain and mortality; however, whereas unintentional weight loss is a marker of vulnerability, intentional weight loss might improve health. We tested whether pre-KT unintentional and intentional weight loss have differing associations with post-KT weight gain, graft loss, and mortality.

METHODS

Among 919 KT recipients from a prospective cohort study, we used adjusted mixed effects models to estimate post-KT BMI trajectories, and Cox models to estimate death-uncensored graft loss, death-censored graft loss, and all-cause mortality by one-year pre-KT weight change category [stable weight (change≤5%), intentional weight loss (loss>5%), unintentional weight loss (loss>5%), and weight gain (gain>5%)].

RESULTS

Mean age was 53 years, 38% were Black, and 40% were female. In the pre-KT year, 62% of recipients had stable weight, 15% had weight gain, 14% had unintentional weight loss, and 10% had intentional weight loss. In the first three years post-KT, BMI increases were similar among those with pre-KT weight gain and intentional weight loss, and lower compared to those with unintentional weight loss (difference +0.79 kg/m2/year, 95% CI: 0.50-1.08 kg/m2/year, p < 0.001). Only unintentional weight loss was independently associated with higher death-uncensored graft loss (adjusted Hazard Ratio [aHR]=1.80, 95% CI:1.23-2.62), death-censored graft loss (aHR=1.91, 95% CI:1.12-3.26) and mortality (aHR=1.72, 95% CI:1.06-2.79) relative to stable pre-KT weight.

CONCLUSIONS

This study suggests that unintentional, but not intentional, pre-KT weight loss is an independent risk factor for adverse post-KT outcomes.

Adding high-sensitivity C-reactive protein to frailty assessment to predict mortality and cardiovascular events in elderly inpatients with cardiovascular disease

OBJECTIVE

Chronic inflammation is associated with major adverse cardiovascular events (MACEs), mortality, and frailty. Our aim was to add high-sensitivity C-reactive protein (hsCRP) to the frailty assessment to predict its association with prognosis of older adults with cardiovascular disease (CVD).

METHODS

A comprehensive geriatric assessment was conducted at baseline in 720 in-patients aged ≥65 years with CVD. We divided the population into frailty and non-frailty groups according to the Fried phenotype, and hsCRP was further combined with frailty to stratify all patients into c-frailty and non-c-frailty groups. Predictive validity was tested using Cox proportional hazards regression model analysis and the discriminative ability was evaluated by receiver operating characteristic (ROC) curves.

RESULTS

Of all the subjects enrolled, 51.0% were male and the mean age was 75.32 ± 6.52 years. The all-cause death and MACE rate was 6.4% at the 1-year follow-up. Frailty and c-frailty were independent predictors of all-cause death and MACE (hazard ratio [HR]: 2.55, 95% confidence interval [CI]: 1.35-4.83, p = 0.004; HR: 3.67, 95% CI: 1.83-7.39, p < 0.001). Adding hsCRP to the frailty model resulted in a significant increase in the area under the ROC curve from 0.74 (95% CI: 0.70-0.77) to 0.77 (95% CI: 0.71-0.84) (p = 0.0132) and a net reclassification index of 7.9% (95% CI: 1.96%-12.56%, p = 0.012).

CONCLUSION

Adding hsCRP to the frailty assessment is helpful to identify a subgroup of older CVD patients with a higher risk of death and MACE over a period of 1 year.

TRIAL REGISTRATION

ChiCTR1800017204; date of registration: 07/18/2018. URL: http://www.chictr.org.cn/showproj.aspx?proj=28931.