[English Title : Treatment of membranous nephropathy]. / Comment je traite une glomérulonéphrite extra-membraneuse.

Membranous nephropathy (MN) is a frequent cause of nephrotic syndrome in adults. In recent years, many progresses have been made, both in terms of diagnosis and treatment. For diagnosis, the discovery of new antigens and diseases that may be associated with MN led to the establishment of a new classification of MNs. In terms of treatment, many progresses have also been made with increasingly effective management, particularly with the help of immunosuppressive drugs. However, there are still cases of MN refractory to conventional treatments. Numerous molecules are being developed to manage these refractory MNs. Among them, Obinutuzumab, a type II anti-CD20, allows a more profound depletion of B cells compared to Rituximab classically used in clinical routine. To illustrate this point, we present the case of a patient suffering from MN with anti-THSD7A antibodies in whom a clinical and biological improvement was observed with obinutuzumab, after failure of conventional therapies.

La glomérulonéphrite extra-membraneuse (GEM) est une cause fréquente de syndrome néphrotique de l'adulte. Au cours des dernières années, de nombreux progrès ont été réalisés, tant au niveau diagnostic que thérapeutique. D'un point de vue diagnostic, la découverte de nouveaux antigènes et de pathologies qui peuvent leur être associées a permis d'établir une nouvelle classification des GEM. Au niveau des traitements, de nombreux progrès ont également été réalisés, avec une prise en charge de plus en plus efficace, notamment à l'aide de traitements immunosuppresseurs. Cependant, il persiste des cas de GEM réfractaires aux traitements classiques. De nombreuses molécules sont en cours de développement pour permettre la prise en charge de ces GEM réfractaires. Parmi celle-ci, on retrouve l'obinutuzumab, un anti-CD20 de type II permettant une meilleure déplétion des cellules B que le rituximab déjà utilisé dans cette indication. Pour illustrer ce propos, nous présentons le cas d'un patient souffrant d'une GEM à anticorps anti-thrombospondine (THSD7A) chez lequel une amélioration clinique et biologique a été observée sous obinutuzumab, après échec des traitements conventionnels.

Management of immunosuppressive therapy after functional renal graft failure: results of a practice survey of French-speaking nephrologists / Gestion du traitement immunosuppresseur après arrêt fonctionnel du greffon rénal : résultats d'une enquête de pratique parmi les néphrologues francophones.

The management of patients with kidney transplant failure (KTF) remains a complex process involving multiple stakeholders. A working group of the Transplantation Commission of the French-speaking Society of Nephrology, Dialysis and Transplantation (SFNDT) conducted a survey on the management of immunosuppressants (IS) after KTF among nephrologists at transplant centres and general nephrologists in France, Switzerland and Belgium between March and June 2023. We analysed 232 replies from 58 nephrologists at transplant centres and 174 general nephrologists, aged 43.6 (+10.6) years. In the first three months following KTF, nephrologists reported discontinuing antimetabolite, calcineurin inhibitor (CNI) and corticosteroid treatment in 83%, 39.9% and 25.8% of cases respectively. Conversely, some nephrologists reported that they were continuing to use CNI (14%) and corticosteroids (19.1%) on a long-term basis. The patient's comorbidities associated with the discontinuation of IS treatment are cancer and opportunistic infections as KT's complications and presence of diabetes mellitus at KTF, whereas humoral rejection encourages the IS to be maintained. Transplantectomy is proposed by nephrologists most often for graft intolerance syndrome (86.5%), more rarely to discontinue IS (17.6%) or in the absence of plans of new transplantation (9.3%). In multivariate analyses, the presence of a protocol in the centre facilitated the management of IS by the general nephrologists. The management of IS after AFG by French-speaking nephrologists is heterogeneous. Specific prospective studies are needed to establish new best practice recommendations, based on more robust evidence, which could encourage better adherence by nephrologists.

La prise en charge des patients avec un arrêt fonctionnel du greffon rénal (AFG) reste un processus complexe avec de multiples intervenants. Un groupe de travail de la Société francophone de néphrologie, dialyse et transplantation (SFNDT) a conduit une enquête sur la gestion des traitements immunosuppresseurs (IS) après AFG parmi les néphrologues de centres de transplantation et néphrologues généraux en France, Suisse et Belgique francophone entre mars et juin 2023. Nous avons pu analyser 232 réponses de néphrologues (centres de transplantation N = 58 et généraux N = 174) âgés de 43,6 (± 10,6) ans. Dans les 3 premiers mois suivant l'AFG, les néphrologues déclarent interrompre le traitement par antimétabolites (83 %), inhibiteurs de la calcineurine (ICN) (39,9 %) et corticoïdes (25,8 %). À l'inverse, certains déclarent maintenir les ICN (14 %) et les corticoïdes (19,1 %) au long cours en cas de projet de nouvelle transplantation rénale (TR). La survenue de cancer pendant la TR, d'infections opportunistes dans la dernière année de TR ou à l'initiation de la dialyse, et la présence d'un diabète lors de l'AFG sont associées avec l'arrêt du traitement IS alors que la perte du greffon par rejet humoral incite à le maintenir. En analyse multivariée, la présence d'un protocole dans le centre facilite la gestion des IS par les néphrologues généraux. Enfin, la transplantectomie est proposée par les néphrologues le plus souvent pour un syndrome d'intolérance du greffon (86,5 %), plus rarement pour interrompre les IS (17,6 %) ou en l'absence de projet de nouvelle TR (9,3 %). La gestion des IS après l'AFG par les néphrologues francophones est hétérogène. Des études prospectives spécifiques sont nécessaires afin de formuler de nouvelles recommandations de bonnes pratiques, reposant sur des données probantes plus robustes, qui pourraient encourager une meilleure adhésion par les néphrologues.

Insight into the potential of bone turnover biomarkers: integration in the management of osteoporosis and chronic kidney disease-associated osteoporosis.

PURPOSE OF REVIEW: Disturbances in mineral and bone metabolism occurring in osteoporosis and chronic kidney disease-associated osteoporosis place patients at high risk of fracture making these conditions a major public health concern. Due to the limited use of bone histomorphometry in clinical practice, the gold standard for assessing bone turnover, extensive efforts have been made to identify bone turnover markers (BTMs) as noninvasive surrogates. Since the identification of certain commonly used markers several decades ago, considerable experience has been acquired regarding their clinical utility in such bone disorders. RECENT FINDINGS: Mounting evidence suggested that BTMs represent a simple, low-risk, rapid and convenient way to obtain data on the skeletal health and that they may be useful in guiding therapeutic choices and monitoring the response to treatment. SUMMARY: BTMs could provide clinicians with useful information, independent from, and often complementary to bone mineral density (BMD) measurements. They have proven valuable for monitoring the effectiveness of osteoporosis therapy, as well as promising for discriminating low and high turnover states. Improved performance is observed when BTMs are combined, which may be useful for selecting treatments for chronic kidney disease-bone mineral disorders (CKD-MBD).

A Machine Learning-Driven Virtual Biopsy System For Kidney Transplant Patients.

In kidney transplantation, day-zero biopsies are used to assess organ quality and discriminate between donor-inherited lesions and those acquired post-transplantation. However, many centers do not perform such biopsies since they are invasive, costly and may delay the transplant procedure. We aim to generate a non-invasive virtual biopsy system using routinely collected donor parameters. Using 14,032 day-zero kidney biopsies from 17 international centers, we develop a virtual biopsy system. 11 basic donor parameters are used to predict four Banff kidney lesions: arteriosclerosis, arteriolar hyalinosis, interstitial fibrosis and tubular atrophy, and the percentage of renal sclerotic glomeruli. Six machine learning models are aggregated into an ensemble model. The virtual biopsy system shows good performance in the internal and external validation sets. We confirm the generalizability of the system in various scenarios. This system could assist physicians in assessing organ quality, optimizing allograft allocation together with discriminating between donor derived and acquired lesions post-transplantation.

Prognostic Biomarkers in Kidney Transplantation: A Systematic Review and Critical Appraisal.

SIGNIFICANCE STATEMENT: Why are there so few biomarkers accepted by health authorities and implemented in clinical practice, despite the high and growing number of biomaker studies in medical research ? In this meta-epidemiological study, including 804 studies that were critically appraised by expert reviewers, the authors have identified all prognostic kidney transplant biomarkers and showed overall suboptimal study designs, methods, results, interpretation, reproducible research standards, and transparency. The authors also demonstrated for the first time that the limited number of studies challenged the added value of their candidate biomarkers against standard-of-care routine patient monitoring parameters. Most biomarker studies tended to be single-center, retrospective studies with a small number of patients and clinical events. Less than 5% of the studies performed an external validation. The authors also showed the poor transparency reporting and identified a data beautification phenomenon. These findings suggest that there is much wasted research effort in transplant biomarker medical research and highlight the need to produce more rigorous studies so that more biomarkers may be validated and successfully implemented in clinical practice. BACKGROUND: Despite the increasing number of biomarker studies published in the transplant literature over the past 20 years, demonstrations of their clinical benefit and their implementation in routine clinical practice are lacking. We hypothesized that suboptimal design, data, methodology, and reporting might contribute to this phenomenon. METHODS: We formed a consortium of experts in systematic reviews, nephrologists, methodologists, and epidemiologists. A systematic literature search was performed in PubMed, Embase, Scopus, Web of Science, and Cochrane Library between January 1, 2005, and November 12, 2022 (PROSPERO ID: CRD42020154747). All English language, original studies investigating the association between a biomarker and kidney allograft outcome were included. The final set of publications was assessed by expert reviewers. After data collection, two independent reviewers randomly evaluated the inconsistencies for 30% of the references for each reviewer. If more than 5% of inconsistencies were observed for one given reviewer, a re-evaluation was conducted for all the references of the reviewer. The biomarkers were categorized according to their type and the biological milieu from which they were measured. The study characteristics related to the design, methods, results, and their interpretation were assessed, as well as reproducible research practices and transparency indicators. RESULTS: A total of 7372 publications were screened and 804 studies met the inclusion criteria. A total of 1143 biomarkers were assessed among the included studies from blood ( n =821, 71.8%), intragraft ( n =169, 14.8%), or urine ( n =81, 7.1%) compartments. The number of studies significantly increased, with a median, yearly number of 31.5 studies (interquartile range [IQR], 23.8-35.5) between 2005 and 2012 and 57.5 (IQR, 53.3-59.8) between 2013 and 2022 ( P < 0.001). A total of 655 studies (81.5%) were retrospective, while 595 (74.0%) used data from a single center. The median number of patients included was 232 (IQR, 96-629) with a median follow-up post-transplant of 4.8 years (IQR, 3.0-6.2). Only 4.7% of studies were externally validated. A total of 346 studies (43.0%) did not adjust their biomarker for key prognostic factors, while only 3.1% of studies adjusted the biomarker for standard-of-care patient monitoring factors. Data sharing, code sharing, and registration occurred in 8.8%, 1.1%, and 4.6% of studies, respectively. A total of 158 studies (20.0%) emphasized the clinical relevance of the biomarker, despite the reported nonsignificant association of the biomarker with the outcome measure. A total of 288 studies assessed rejection as an outcome. We showed that these rejection studies shared the same characteristics as other studies. CONCLUSIONS: Biomarker studies in kidney transplantation lack validation, rigorous design and methodology, accurate interpretation, and transparency. Higher standards are needed in biomarker research to prove the clinical utility and support clinical use.

Unveiling a new era with liquid chromatography coupled with mass spectrometry to enhance parathyroid hormone measurement in patients with chronic kidney disease.

Precise determination of circulating parathyroid hormone (PTH) concentration is crucial to diagnose and manage various disease conditions, including the chronic kidney disease-mineral and bone disorder. However, the lack of standardization in PTH assays is challenging for clinicians, potentially leading to medical errors because the different assays do not provide equivalent results and use different reference ranges. Here, we aimed to evaluate the impact of recalibrating PTH immunoassays by means of a recently developed LC-MS/MS method as the reference. Utilizing a large panel of pooled plasma samples with PTH concentrations determined by the LC-MS/MS method calibrated with the World Health Organization (WHO) 95/646 International Standard, five PTH immunoassays were recalibrated. The robustness of this standardization was evaluated over time using different sets of samples. The recalibration successfully reduced inter-assay variability with harmonization of PTH measurements across different assays. By recalibrating the assays based on the WHO 95/646 International Standard, we demonstrated the feasibility for standardizing PTH measurement results and adopting common reference ranges for PTH assays, facilitating a more consistent interpretation of PTH values. The recalibration process aligns PTH results obtained from various immunoassays with the LC-MS/MS method, providing more consistent and reliable measurements. Thus, establishing true standardization across all PTH assays is crucial to ensure consistent interpretation and clinical decision-making.

Complement-activating donor-specific anti-HLA antibodies in solid organ transplantation: systematic review, meta-analysis, and critical appraisal.

Introduction: Several studies have investigated the impact of circulating complement-activating anti-human leukocyte antigen donor-specific antibodies (anti-HLA DSAs) on organ transplant outcomes. However, a critical appraisal of these studies and a demonstration of the prognostic value of complement-activating status over anti-HLA DSA mean fluorescence intensity (MFI) level are lacking. Methods: We conducted a systematic review, meta-analysis and critical appraisal evaluating the role of complement-activating anti-HLA DSAs on allograft outcomes in different solid organ transplants. We included studies through Medline, Cochrane, Scopus, and Embase since inception of databases till May 05, 2023. We evaluated allograft loss as the primary outcome, and allograft rejection as the secondary outcome. We used the Newcastle-Ottawa Scale and funnel plots to assess risk of bias and used bias adjustment methods when appropriate. We performed multiple subgroup analyses to account for sources of heterogeneity and studied the added value of complement assays over anti-HLA DSA MFI level. Results: In total, 52 studies were included in the final meta-analysis (11,035 patients). Complement-activating anti-HLA DSAs were associated with an increased risk of allograft loss (HR 2.77; 95% CI 2.33-3.29, p<0.001; I²=46.2%), and allograft rejection (HR 4.98; 95% CI 2.96-8.36, p<0.01; I²=70.9%). These results remained significant after adjustment for potential sources of bias and across multiple subgroup analyses. After adjusting on pan-IgG anti-HLA DSA defined by the MFI levels, complement-activating anti-HLA DSAs were significantly and independently associated with an increased risk of allograft loss. Discussion: We demonstrated in this systematic review, meta-analysis and critical appraisal the significant deleterious impact and the independent prognostic value of circulating complement-activating anti-HLA DSAs on solid organ transplant risk of allograft loss and rejection.

A call for promoting living kidney donation in France in 2023 / Pourquoi développer la greffe de rein à partir de donneurs vivants en France en 2023 ?

Kidney transplantation from living donors is particularly under-developed in France in comparison with the US and most European countries. Among others, the lack of a proactive and evidence-based communication from French health providers is a potential cause that has been overlooked thus far. With this as a backdrop, the SFNDT Commission of transplantation has elaborated a 10 points-call for promoting living kidney transplantation in France in 2023 with the aims at (1) providing the entire nephrology community with a scientific rationale and (2) strenghtening the conviction of health providers, patients, and their relatives regarding the relevance of this modality of kidney transplantation.

La transplantation rénale à partir de donneur vivant est une activité qui reste insuffisamment développée en France. Ceci est particulièrement vrai en comparaison à la majorité des pays nord-américains et européens. Les raisons en sont multiples et incluent un défaut de communication proactive et argumentée par les acteurs de soins. La communication, l'information et finalement la promotion de la greffe à partir de donneurs vivants sont l'affaire de l'ensemble de la communauté néphrologique et, au premier rang, des néphrologues non spécifiquement impliqués en transplantation. C'est dans cet esprit que la Commission Transplantation de la Société francophone de néphrologie, dialyse et transplantation (SFNDT) a travaillé à l'élaboration d'un plaidoyer en tentant de répondre, en dix points, à la question « Pourquoi faut-il développer la transplantation rénale à partir de donneurs vivants en France en 2023 ? ¼. L'objectif est double : (1) fournir les principales bases d'une information scientifiquement argumentée et (2) renforcer la conviction de l'ensemble des acteurs de soins et des patients du bien-fondé de cette modalité de greffe.

[Delayed graft function : an ongoing clinical challenge]. / Reprise retardée de fonction du greffon après transplantation rénale : un challenge clinique toujours d'actualité.

Delayed Graft Function (DGF) is defined as the need for dialysis during the first week after transplantation. DGF is frequent and mostly derived from the ischemia/reperfusion cascade to which the graft is subjected throughout the transplantation process. A graft biopsy is recommended after 7 days of DGF to exclude an episode of acute rejection. Note that DGF per se is associated with an increased risk of acute graft rejection, as well as with a shorter long-term graft survival. Several strategies are being studied to mitigate the ischaemic damage, thereby improving graft quality. Among these, cellular therapy using mesenchymal stromal cells (MSC) is promising, in particular via the administration of MSC in the machine perfusion during the preservation of the graft. We will discuss here the different definitions of DGF and the main predictive factors of DGF, as well as the impact on the graft outcomes. The current strategies to prevent DGF will be briefly reviewed.

La reprise retardée de fonction du greffon rénal (DGF en anglais pour Delayed Graft Function), définie notamment par la nécessité de dialyse durant la 1ère semaine après transplantation, reste un événement fréquent. La DGF résulte principalement des phénomènes d'ischémie/reperfusion auxquels le greffon est soumis tout au long du processus de transplantation. Néanmoins, une biopsie du greffon est préconisée après 7 jours de DGF afin d'exclure une cause non ischémique telle qu'un rejet aigu. La DGF est per se associée à un risque accru de rejet du greffon, ainsi qu'à une moins bonne survie du greffon rénal au long cours. Plusieurs stratégies sont étudiées afin d'atténuer les dommages ischémiques et améliorer la qualité du greffon. Parmi celles-ci, la thérapie cellulaire par cellules stromales mésenchymateuses est prometteuse, notamment via l'administration de celles-ci dans la machine de perfusion lors de la préservation du greffon. Nous aborderons les différentes définitions de la DGF ainsi que ses principaux facteurs prédictifs, l'impact sur le devenir du greffon et, brièvement, les stratégies actuelles dans le cadre de la prévention de la DGF.

Monitoring 25-OH and 1,25-OH vitamin D levels in hemodialysis patients after starting therapy: Does it make sense?

BACKGROUND AND AIMS: In hemodialysis patients, monitoring 25-hydroxyvitamin D (25(OH)D) levels is recommended. It is however unclear if monitoring 1,25-dihydroxyvitamin D (1,25(OH)2D) levels is interesting. MATERIALS AND METHODS: We repeatedly measured 1,25(OH)2D (DiaSorin Liaison analyser) and 25(OH)D (LCMS/MS) concentrations in patients newly treated by active or native vitamin D to study the impact of such treatments on serum concentrations. RESULTS: Ten patients were included in the native and 12 in the active vitamin D group. In the native group, a significant increase was observed between the baseline and the last 25(OH)D concentrations available (21.65[17.39;25.26] versus 33.49[28.60;40.30] ng/mL, p = 0.0059). The baseline and last available 1,25(OH)2D concentrations were not different (12.15[4.25;15.40] versus 11.35[9.72;21.85] pg/mL, p = 0.5566). In the active group, no difference was observed between the baseline and the last 25(OH)D concentrations (51.70[42.97;63.95] versus 50.89[42.02;64.49] ng/mL, p = 0.5186). The same observation was made for 1,25 (OH)2D concentrations (25.65[17.05;41.85] versus 28.70[23.36;43.73] pg/mL, p = 0.6221). Using a linear mixed model, a significant change over time was only observed in 25(OH)D serum levels for patients treated by with native vitamin D. CONCLUSION: Measuring 1,25(OH)2D levels in patients newly treated by active vitamin D does not seem useful in monitoring active vitamin D therapy.

The prospective screening for SARS-CoV-2 S1/S2 antibodies delineates the factual incidence of COVID-19 and shows a sustained serological response post COVID-19 in kidney transplant recipients.

BACKGROUND: The impact of immunosuppression on the occurrence of Coronavirus Disease 2019 (COVID-19) remains unclear. METHODS: We conducted a prospective screening of anti-S1/S2 IgGs against SARS-CoV-2 Spike protein from March, 1 2020 to May, 15 2021 (prior to the vaccination campaign) in a cohort of 713 kidney transplant recipients (KTRs). In a first phase, the factual incidence and seroprevalence of COVID-19 was established in this cohort: cases diagnosed by serology were added to RT-PCR-based diagnoses to obtain the overall incidence of COVID-19 in both symptomatic and asymptomatic KTRs. In the second phase, the kinetics of the post-COVID-19 humoral response were studied, taking into account the severity of the disease defined by the need for oxygen therapy (group S, "severe") or not (group nS, "not severe"). RESULTS: The combined diagnostic approaches identified 138 COVID-19 cases (19.2%), with 37 diagnoses by serology (26.8%). The rate of asymptomatic KTRs reached 20.3% (28/138). Thirteen patients (9.4%) died from COVID-19. The seroconversion rate was 91.7% (99/108). The peak anti-S1/S2 IgG level was 85 [30-150] AU/ml and was similar between the S and nS groups (117 [38; 186] AU/ml versus 73 [23; 140] AU/ml). A high probability of persistence of anti-S1/S2 IgG post-COVID-19 was observed, with only 10.1% (7/69) of the patients having negated their serology during the 9-month follow-up. CONCLUSION: Our pragmatic serological screening combined with RT-PCR tests provides a better estimation of the real incidence of COVID-19 in KTRs. A significant proportion of KTRs develop humoral immunity post COVID-19, which most often persists beyond 9 months.

The uptake of [18F]-fluorodeoxyglucose by the renal allograft correlates with the acute Banff scores of cortex inflammation but not with the 1-year graft outcomes.

Introduction: [18F]FDG PET/CT noninvasively disproves acute kidney allograft rejection (AR) in kidney transplant recipients (KTRs) with suspected AR. However, the correlation of biopsy-based Banff vs. PET/CT-based scores of acute inflammation remains unknown, as does the prognostic performance of [18F]FDG PET/CT at one year post suspected AR. Methods: From 2012 to 2019, 114 [18F]FDG-PET/CTs were prospectively performed in 105 adult KTRs who underwent per cause transplant biopsies. Ordinal logistic regression assessed the correlation between the extent of histological inflammation and the mean standardized [18F]FDG uptake values (mSUVmean). Functional outcomes of kidney allografts were evaluated at one year post per cause biopsy and correlated to mSUVmean. Results: A significant correlation between mSUVmean and acute Banff score was found, with an adjusted R 2 of 0.25. The mSUVmean was significantly different between subgroups of "total i", with 2.30 ± 0.71 in score 3 vs. 1.68 ± 0.24 in score 0. Neither the function nor the survival of the graft at one year was statistically related to mSUVmean. Discussion: [18F]FDG-PET/CT may help noninvasively assess the severity of kidney allograft inflammation in KTRs with suspected AR, but it does not predict graft outcomes at one year.

[Diagnostic trap: Lithium neurotoxicity with normal lithemia]. / Piège diagnostique : neurotoxicité au lithium avec lithémie normale.

We describe here the case of a 54-year-old bipolar woman, followed in psychiatry and treated with lithium and a selective serotonin reuptake inhibitor (escitalopram) and lamotrigine, presenting a lithium poisoning with an altered state of consciousness caused by a supposed mismanagement of her treatment. Lithium poisoning was suggested based on neurological clinical features, but the blood test brought out a lithium concentration within the therapeutic values at 1,2 mmol/L (N: 0,6-1,2 mmol/L). The classic biological complications related to lithium poisoning (hypercalcemia, diabetes insipidus) confirmed the diagnosis. The patient has been transferred to our nephrology department where she got two hemodialysis sessions conducting to clinical and biological improvement, confirming the diagnosis of lithium poisoning despite the normal blood levels. Later, she was transferred to the psychiatry department for follow-up and for treatment adjustment.

Estimation of glomerular filtration rate for drug dosing in patients with very high or low body mass index.

An accurate estimated glomerular filtration rate (eGFR) is essential in drug dosing. This study demonstrates the limitations of indexed (ml/min/1.73 m2 ) and de-indexed (ml/min) eGFR based drug dosing in patients with obesity or underweight. This systematic study aimed to determine the most appropriate approach to estimate the GFR for standardized eGFR based drug dosing in these patients. (Raw) data of 12 studies were selected to investigate the accuracy and bias of both the indexed and de-indexed estimations of the Modification of Diet in Renal Disease (MDRD) study equation and the Chronic Kidney Disease Epidemiology Collaboration equation (CKD-EPI), and of the Cockcroft-Gault (CG) in patients with obesity or underweight. Accuracy was calculated as the proportion of eGFR values within 30% of the measured GFR (P30) using an inert tracer (e.g., iohexol, inulin, 51 Cr-EDTA, or iothalamate clearance). An accuracy of at least 80% was considered acceptable. GFR values estimated with the CG, MDRD, and CKD-EPI differ significantly within a patient with obesity or underweight regardless of whether it is indexed or de-indexed. All studies, with two exceptions, show that all three equations are inaccurate for patients with underweight or class II obesity (P30: 55%-94%). De-indexing eGFR improves not or modestly the accuracy, and mostly remains below the 80% (P30: 62%-100%). CG was highly inaccurate in obese and underweight patients (P30: 7%-82%). Although these results show that CG is obsolete, the accuracy of MDRD and CKD-EPI is low in patients with obesity or underweight and de-indexing is not the solution. Better education and more accurate methods for appropriate drug dosing (e.g., measured GFR with inert tracer, therapeutic drug monitoring, or 24-h creatinine clearance) are recommended.

Age-adapted percentiles of measured glomerular filtration in healthy individuals: extrapolation to living kidney donors over 65 years.

OBJECTIVES: Most data on glomerular filtration rate (GFR) originate from subjects <65 years old, complicating decision-making in elderly living kidney donors. In this retrospective multi-center study, we calculated percentiles of measured GFR (mGFR) in donors <65 years old and extrapolated these to donors ≥65 years old. METHODS: mGFR percentiles were calculated from a development cohort of French/Belgian living kidney donors <65 years (n=1,983), using quantiles modeled as cubic splines (two linear parts joining at 40 years). Percentiles were extrapolated and validated in an internal cohort of donors ≥65 years (n=147, France) and external cohort of donors and healthy subjects ≥65 years (n=329, Germany, Sweden, Norway, France, The Netherlands) by calculating percentages within the extrapolated 5th-95th percentile (P5-P95). RESULTS: Individuals in the development cohort had a higher mGFR (99.9 ± 16.4 vs. 86.4 ± 14 and 82.7 ± 15.5 mL/min/1.73 m2) compared to the individuals in the validation cohorts. In the internal validation cohort, none (0%) had mGFR below the extrapolated P5, 12 (8.2%) above P95 and 135 (91.8%) between P5-P95. In the external validation cohort, five subjects had mGFR below the extrapolated P5 (1.5%), 25 above P95 (7.6%) and 299 (90.9%) between P5-P95. CONCLUSIONS: We demonstrate that extrapolation of mGFR from younger donors is possible and might aid with decision-making in elderly donors.

Long-term clinical follow-up of patients suffering from moderate-to-severe COVID-19 infection: a monocentric prospective observational cohort study.

OBJECTIVES: Various symptoms and considerable organ dysfunction persist following infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Uncertainty remains about the potential mid- and long-term health sequelae. This prospective study of patients hospitalized with coronavirus disease 2019 (COVID-19) in Liège University Hospital, Belgium aimed to determine the persistent consequences of COVID-19. METHODS: Patients admitted to the University Hospital of Liège with moderate-to-severe confirmed COVID-19, discharged between 2 March and 1 October 2020, were recruited prospectively. Follow-up at 3 and 6 months after hospital discharge included demographic and clinical data, biological data, pulmonary function tests (PFTs) and high-resolution computed tomography (CT) scans of the chest. RESULTS: In total, 199 individuals were included in the analysis. Most patients received oxygen supplementation (80.4%). Six months after discharge, 47% and 32% of patients still had exertional dyspnoea and fatigue. PFTs at 3-month follow-up revealed a reduced diffusion capacity of carbon monoxide (mean 71.6 ± 18.6%), and this increased significantly at 6-month follow-up (P<0.0001). Chest CT scans showed a high prevalence (68.9% of the cohort) of persistent abnormalities, mainly ground glass opacities. Duration of hospitalization, intensive care unit admission and mechanical ventilation were not associated with the persistence of symptoms 3 months after discharge. CONCLUSION: The prevalence of persistent symptoms following hospitalization with COVID-19 is high and stable for up to 6 months after discharge. However, biological, functional and iconographic abnormalities improved significantly over time.