Preface

United States Renal Data System 2006 Annual Data Report Abstract

In the last few years, intensive research has led to the widespread investigation of nanomaterials oriented toward the fabrication of solid-state gas sensors based mainly on metal oxide nanomaterials. SnO₂ and WO₃ have been widely explored in gas-sensor applications owing to their extraordinary physical and chemical properties. The development of these gas sensors has provided an efficient means of detecting volatile organic compounds (VOCs) in exhaled breath who remains critical for the early diagnosis of diseases. VOCs emanating from different bodily fluids have long been investigated as noninvasive indicators of the status of many health parameters. This concept gave rise to the biotechnology discipline where the determination of VOCs using multisensory systems is related to the presence of certain diseases. Herein, we developed an electronic nose (e-nose) which consists of six MQ sensors based on SnO₂ and six interdigitated sensors based on metal functionalized WO₃ nanowires. For emerging applications, this chapter aims to investigate whether the possibility of using an e-nose system will be able to monitor the exhaled VOCs as a noninvasive method to discriminate between patients with chronic kidney diseases, diabetes mellitus, and lung cancer. Advanced multivariate statistical approaches, such as principal components analysis, hierarchical cluster analysis, or support vector machines, were used for data processing. The application of these chemometrics on the database gathered from e-nose provided significant findings in terms of classification and identification of subjects depending on their health states. We can conclude, through these studies that the e-sensing performance of e-nose based on WO₃ can be enhanced by UV illumination and the selectivity of these sensors can be changed using different noble metals or by changing the operating temperature.

There are limited data on the degree of variability in practices surrounding prioritization of referrals for transplant evaluation and criteria for transplant candidacy and their association with transplantation rates. We surveyed transplant programs across the United States between January 2020 and May 2020 to determine current pre-transplantation practices. We examined the relation between these reported practices and the outcomes of waitlisted patients at responding programs between January 2015 and March 2021 using Scientific Registry of Transplant Recipients data. We used adjusted Cox models with random effects to accommodate clustering by program. Primary outcomes included living or deceased donor transplantation. Of 172 surveyed programs, 90 participated. Substantial variations were noted in when the candidacy evaluation began (13% reported when eGFR was <30 mL/min/1.73 m² and 17% reported no set policy) and the approach to pre-transplantation cardiac workup (multi-modality [58%], stress echocardiogram [20%]). Using adjusted models, a program policy of using other measures of body habitus to determine transplant candidacy rather than requiring patients to meet a body mass index (BMI) threshold of ≤35 kg/m² (reference group) for candidacy was associated with a higher hazard of living donor transplantation (HR 1.83 [95% CI 1.10–3.03]). Pre-transplant practices vary substantially across the United States, and select practices were associated with transplantation rates.

Alterations in the brain cortical structures of patients with chronic kidney disease (CKD) have been reported; however, the cause has not been determined yet. Herein, we used Mendelian randomization (MR) to reveal the causal effect of kidney damage on brain cortical structure.

Genome-wide association studies summary data of estimated glomerular filtration rate (eGFR) in 480,698 participants from the CKDGen Consortium were used to identify genetically predicted eGFR. Data from 567,460 individuals from the CKDGen Consortium were used to assess genetically determined CKD; 302,687 participants from the UK Biobank were used to evaluate genetically predicted albuminuria. Further, data from 51,665 patients from the ENIGMA Consortium were used to assess the relationship between genetic predisposition and reduced eGFR, CKD, and progressive albuminuria with alterations in cortical thickness (TH) or surficial area (SA) of the brain. Magnetic resonance imaging was used to measure the SA and TH globally and in 34 functional regions. Inverse-variance weighted was used as the primary estimate whereas MR Pleiotropy RESidual Sum and Outlier, MR-Egger and weighted median were used to detect heterogeneity and pleiotropy.

At the global level, albuminuria decreased TH (β = −0.07 mm, 95% CI: −0.12 mm to −0.02 mm, P = 0.004); at the functional level, albuminuria reduced TH of pars opercularis gyrus without global weighted (β = −0.11 mm, 95% CI: −0.16 mm to −0.07 mm, P = 3.74×10⁻⁶). No pleiotropy was detected.

Kidney damage causally influences the cortex structure which suggests the existence of a kidney-brain axis.

This study was supported by the Science and Technology Planning Project of Guangdong Province (Grant No. 2020A1515111119 and 2017B020227007), the National Key Research and Development Program of China (Grant No. 2018YFA0902803), the National Natural Science Foundation of China (Grant No. 81825016, 81961128027, 81772719, 81772728), the Key Areas Research and Development Program of Guangdong (Grant No. 2018B010109006), Guangdong Special Support Program (2017TX04R246), Grant KLB09001 from the Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, and Grants from the Guangdong Science and Technology Department (2020B1212060018).

Presepsin is a useful biomarker to diagnose sepsis. However, the correlation between plasma presepsin concentrations and kidney function in the elderly with chronic kidney disease (CKD) remains to be elucidated. We determined whether plasma presepsin concentrations were influenced by kidney function decline in the elderly.

One hundred seventy outpatients with CKD aged ≥65 y were enrolled. Plasma presepsin concentrations were measured using immunoassay analysis. The relationship between plasma presepsin concentration and kidney function was assessed.

The median age of patients of this cohort was 778 (72–85) y and the mean estimated glomerular filtration rate was 51.8 ± 28.1 ml/min/1.73 m². Plasma presepsin concentrations in those with CKD G4-G5 (362 pg/ml [273–553]) were significantly higher than in those with CKD G1-G2 (111 pg/ml [91–113]) and CKD G3 (145 pg/ml [124–205]) (p < 0.001, p < 0.001, respectively). A high correlation between plasma presepsin concentrations and kidney function was observed (R² = 0.733, p < 0.001). Even after adjusting for confounders, plasma presepsin concentrations were independently associated with kidney function.

Increases in plasma presepsin concentrations were exponentially correlated to kidney function decline in the elderly with CKD.

L’épuration extrarénale ou la greffe rénale ne peuvent être considérées comme le seul traitement pour les sujets atteints d’une insuffisance rénale chronique terminale. Le traitement conservateur est devenu une alternative thérapeutique légitime et doit être exposé de façon objective aux patients atteints d’une maladie rénale chronique. Cette étude avait pour objectif de réaliser un état des lieux des pratiques médicales concernant le traitement conservateur par les équipes de néphrologie d’une région française.

Il s’agissait d’une enquête de pratique transversale réalisée en 2015 à l’aide d’un questionnaire envoyé à 66 néphrologues de la région Normandie de 14 centres de traitement de l’insuffisance rénale.

Parmi les 48/66 néphrologues ayant répondu aux questionnaires, 38 (79,2 %) n’utilisaient pas d’outils d’aide à la décision pour la mise en place d’un traitement conservateur. De plus, 42/48 (87,5 %) néphrologues ne proposaient pas de réflexion collective autour de la prise en charge de ces patients. Dans la totalité des centres, il n’existait pas de réunion dédiée à la décision de traitement conservateur. En cas de décision d’un tel traitement, 34/48 néphrologues (70,8 %) abordaient le pronostic vital avec le patient, 31/48 néphrologues (64,6 %) utilisaient les termes « mort » ou « décès » pour préciser le devenir sous traitement conservateur.

Les résultats de cette étude montrent que le parcours des patients dans le traitement conservateur est hétérogène et n’est pas formalisé dans notre région. Des améliorations sont nécessaires afin d’intégrer le traitement conservateur dans l’offre de soins du patient atteint d’une maladie rénale chronique.

Renal replacement therapy and renal transplantation can’t be considered as the only way to treat old end-stage renal disease patients. Nowadays conservative management has to be considered and proposed as a treatment option to patients with a chronic kidney disease. The aim of this study was to describe nephrologists’ practices concerning conservative management care in a French department.

A cross-sectional practices survey has been conducted in 2015. A survey was sent to 66 nephrologists in 14 treatment centers in the Normandy region.

49 of the 66 nephrologists responded to the questionnaire. Among the 48 nephrologists who responded to the questionnaire, 38 out of 48 (79.2%) did not use decision support tools to implement conservative treatment. In all, 42/48 (87.5%) nephrologists did not discuss with their colleagues before providing conservative treatment. Meeting dedicated to the decision of conservative treatment did not exist in any center surveyed in this study. When conservative management was chosen, 34/48 nephrologists (70.8%) discussed end-of-life. And 31/48 nephrologists (64.6%) used the term “death”.

The results of this study show that the course of the patients in conservative treatment is heterogeneous and is not formalized. Improvements are needed to integrate conservative treatment for patients with chronic kidney disease.

Patients receiving hemodialysis (HD) have a higher risk of cognitive impairment and dementia than the general population. The accumulation of uremic toxins in the brain causes uremic encephalopathy, however, limited data exists to elucidate the effect of protein-bound uremic toxins on cognitive function. Here we investigate the effect of indole-3 acetic acid (IAA) and hippuric acid (HA), two different protein-bound uremic toxins from amino acid derivatives, on cognitive function by Silico and in a clinical study. Prevalent HD patients were enrolled in two independent hospitals. Serum IAA and HA were measured using mass spectrometry. Cognitive performance was measured using Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Cognitive Abilities Screening Instrument (CASI) by trained psychologists. Using silico data to predict the effect of blood-brain barrier penetration was performed. The silico data demonstrated that IAA and HA had positive blood-brain barrier penetration ability. Amongst the 230 HD patients, serum IAA was associated with poor MMSE score (β= -0.90, 95% CI -1.61 to -0.19) and poor CASI score (β= -3.29, 95% CI -5.69 to -0.88) in stepwise multiple linear regression analysis. In logistic regression model, Serum IAA was also associated with cognitive impairment based on MMSE definition (OR, 1.96, 95% CI 1.10, 3.5) and CASI definition (OR, 2.09, 95% CI 1.21, 3.61). There was no correlation between Serum HA levels and cognitive function status. In conclusion, IAA, not HA, was associated with cognitive impairment in HD patients. Further large scale and prospective studies are needed to confirm our findings.