Effects of body weight variation in obese kidney recipients: a retrospective cohort study

Background. Obese kidney allograft recipients have worse results in kidney transplantation (KT). However, there is lack of information regarding the effect of body mass index (BMI) variation after KT. The objective of the study was to evaluate the effects of body weight changes in obese kidney transplant recipients. Methods. In this study we used data from the Catalan Renal Registry that included KT recipients from 1990 to 2011 (n ¼ 5607). The annual change in post-transplantation BMI was calculated. The main outcome variables were delayed graft function (DGF), estimated glomerular filtration rate (eGFR) and patient and graft survival. Results. Obesity was observed in 609 patients (10.9%) at the time of transplantation. The incidence of DGF was significantly higher in obese patients (40.4% versus 28.3%; P < 0.001). Baseline obesity was significantly associated with worse short- and long-term graft survival (P < 0.05) and worse graft function during the follow-up (P < 0.005). BMI variations in obese patients did not improve eGFR or graft or patient survival. Conclusions. Our conclusion is that in obese patients, decreasing body weight after KT does not improve either short-term graft outcomes or long-term renal function

Molecular Mechanisms of Kidney Injury and Repair

Chronic kidney disease (CKD) will become the fifth global cause of death by 2040, thus emphasizing the need to better understand the molecular mechanisms of damage and regeneration in the kidney. CKD predisposes to acute kidney injury (AKI) which, in turn, promotes CKD progression. This implies that CKD or the AKI-to-CKD transition are associated with dysfunctional kidney repair mechanisms. Current therapeutic options slow CKD progression but fail to treat or accelerate recovery from AKI and are unable to promote kidney regeneration. Unraveling the cellular and molecular mechanisms involved in kidney injury and repair, including the failure of this process, may provide novel biomarkers and therapeutic tools. We now review the contribution of different molecular and cellular events to the AKI-to-CKD transition, focusing on the role of macrophages in kidney injury, the different forms of regulated cell death and necroinflammation, cellular senescence and the senescence-associated secretory phenotype (SAPS), polyploidization, and podocyte injury and activation of parietal epithelial cells. Next, we discuss key contributors to repair of kidney injury and opportunities for their therapeutic manipulation, with a focus on resident renal progenitor cells, stem cells and their reparative secretome, certain macrophage subphenotypes within the M2 phenotype and senescent cell clearance

The effect of intracellular tacrolimus exposure on calcineurin inhibition in immediate- and extended-release tacrolimus formulations

Despite intensive monitoring of whole blood tacrolimus concentrations, acute rejection after kidney transplantation occurs during tacrolimus therapy. Intracellular tacrolimus concentrations could better reflect exposure at the site of action and its pharmacodynamics (PD). Intracellular pharmacokinetic (PK) profile following different tacrolimus formulations (immediate-release (TAC-IR) and extended-release (TAC-LCP)) remains unclear. Therefore, the aim was to study intracellular tacrolimus PK of TAC-IR and TAC-LCP and its correlation with whole blood (WhB) PK and PD. A post-hoc analysis of a prospective, open-label, crossover investigator-driven clinical trial (NCT02961608) was performed. Intracellular and WhB tacrolimus 24 h time-concentration curves were measured in 23 stable kidney transplant recipients. PD analysis was evaluated measuring calcineurin activity (CNA) and simultaneous intracellular PK/PD modelling analysis was conducted. Higher dose-adjusted pre-dose intracellular concentrations (C0 and C24) and total exposure (AUC0-24) values were found for TAC-LCP than TAC-IR. Lower intracellular peak concentration (Cmax) was found after TAC-LCP. Correlations between C0, C24 and AUC0-24 were observed within both formulations. Intracellular kinetics seems to be limited by WhB disposition, in turn, limited by tacrolimus release/absorption processes from both formulations. The faster intracellular elimination after TAC-IR was translated into a more rapid recovery of CNA. An Emax model relating % inhibition and intracellular concentrations, including both formulations, showed an IC50, a concentration to achieve 50% CNA inhibition, of 43.9 pg/million cells

Sustained inhibition of calcineurin activity with a Melt‐Dose Once‐daily Tacrolimus formulation in renal transplant recipients

Tacrolimus (Tac) is the cornerstone calcineurin inhibitor in transplantation. Extended-release Meltdose formulation (Tac-LCP) offers better bioavailability compared with immediate-release formulation (Tac-IR). We postulated that the less fluctuating pharmacokinetic (PK) profile of Tac-LCP might maintain a sustained inhibition of calcineurin activity (CNA) between dose intervals. Higher concentrations (peak plasma concentration (Cmax )) after Tac-IR may not result in a more potent CNA inhibition due to a capacity-limited effect. This study was aimed at evaluating the pharmacodynamic (PD)/PK profiles of Tac-IR compared with Tac-LCP. An open-label, prospective, nonrandomized, investigator-driven study was conducted. Twenty-five kidney transplant recipients receiving Tac-IR were switched to Tac-LCP. Before and 28 days after conversion, intensive CNA-PD and PK sampling were conducted using ultra-high-performance liquid chromatography-tandem accurate mass spectrometry. PD nonlinear mixed effects model was performed in Phoenix-WinNonlin. Statistically significant higher Cmax (P < 0.001) after Tac-IR did not result in lower CNA as compared with after Tac-LCP (P = 0.860). Tac-LCP showed a statistically more maintained CNA inhibition between dose intervals (area under the effect-time curve from 0 to 24 hours (AUE0-24h )) compared with Tac-IR, in which CNA returned to predose levels after 4 hours of drug intake (373.8 vs. 290.5 pmol RII·h/min·mg prot, Tac-LCP vs. Tac-IR; P = 0.039). No correlation was achieved between any PD and PK parameters in any formulations. Moreover, Tac concentration to elicit a 50% of the maximum response (half-maximal inhibitory concentration) was 9.24 ng/mL. The higher Cmax after Tac-IR does not result in an additional CNA inhibition compared with Tac-LCP attributable to a capacity-limited effect. Tac-LCP may represent an improvement of the PD of Tac due to the more sustained CNA inhibition during dose intervals

Editorial:Protecting Olympic Participants from COVID-19 — The Trialled and Tested Process

The COVID-19 pandemic has created many challenges to ensure a safe environment for competitive sport. While modern medicine has already developed effective protocols for the treatment and prevention of the disease, there are serious concerns about hosting a sporting event of the scale of the Olympic Games, where more than 11¿000 athletes from over 200 nations are expected to participate. Accordingly, there have been many calls to cancel the Tokyo Olympic Games, also known as Tokyo 2020, in both the international press and the scientific literature. A recent perspective published in the New England Journal of Medicine (NEJM) highlights the complexity and risks of convening the Tokyo Olympic Games during the COVID-19 pandemic. Despite the many uncertainties, much has been learnt over the past 18 months and many policies trialled and tested to protect athletes during sports participation..

Research ethics review system state in Argentina and the adaptation in response to the COVID-19 pandemic

Fil: Palmero, Ana. Ministerio de Salud de la Nación; Argentina.Fil: Torales, Santiago. Ministerio de Salud de la Nación; Argentina.Fil: Garau, Laura. Ministerio de Salud de la Ciudad Autónoma de Buenos Aires; Argentina.Fil: Álvarez, Jorgelina. Ministerio de Salud, Desarrollo Social y Deportes de Mendoza; Argentina.Fil: Martinelli, Beatriz. Ministerio de Salud de Santa Fe; Argentina.Fil: Vukotich, Claudia. Ministerio de Salud de la Ciudad Autónoma de Buenos Aires; Argentina.Fil: Sanchez, Silvina. Ministerio de Salud de la Provincia de Buenos Aires; Argentina.Fil: Burger, Carlos. Ministerio de Salud de la Provincia de Buenos Aires; Argentina.Fil: Mercado, Daniel. Ministerio de Salud de Córdoba; Argentina.Fil: Lencina, Verónica. Ministerio de Salud de Salta; Argentina.Fil: Oliva, Valeria. Ministerio de Salud de Salta; Argentina.Fil: Anze, Ismael. Ministerio de Salud de Salta; Argentina.Fil: Apaza, Gladis. Ministerio de Salud de Jujuy; Argentina.Fil: Bazán de Casella, María Cristina. Ministerio de Salud de Tucumán; Argentina.Fil: Burgos, Graciela. Ministerio de Salud de Santiago del Estero; Argentina.Fil: Martín, María Cristina. Ministerio de Salud de Misiones; Argentina.Fil: Margaria, Laura. Ministerio de Salud de Río Negro; Argentina.Fil: Manonelles, Gabriela. Ministerio de Salud de Santa Cruz; Argentina.Fil: Benzi, Patricia. Ministerio de Salud de Entre Ríos; Argentina.Fil: Pérez Pazo, Andrea. Ministerio de Salud Pública de San Juan; Argentina.INTRODUCCIÓN: un sistema de evaluación ética de las investigaciones en seres humanos es esencial para proteger los derechos de los participantes. Los desafíos impuestos por la pandemia de la COVID-19 para conducir investigaciones éticas que produzcan resultados con rapidez demuestran la necesidad de fortalecerlo. El objetivo de este estudio fue describir el estado de situación de los sistemas de evaluación ética de las provincias de Argentina y las adaptaciones realizadas por la pandemia. MÉTODOS: se realizó una encuesta a los comités provinciales de ética en investigación o áreas similares de los ministerios de Salud que ejercen la vigilancia sobre la evaluación ética de las investigaciones de su jurisdicción. RESULTADOS: respondieron 16 de las 17 provincias encuestadas. El 93,7% de los comités provinciales evalúa investigaciones en seres humanos y tiene procedimientos operativos estandarizados (POE). El 68,7% lleva un registro de los comités de ética en investigación (CEI) de su jurisdicción. Un 75% acredita a los CEI y un 68,7% los supervisa. El 100% tiene un registro de las investigaciones en salud; en 56,2% de los casos este registro es público. Del total, 81,2% realizan actividades de capacitación. El 100% adaptó los POE para evaluar estudios sobre la COVID-19. DISCUSIÓN: los resultados muestran sistemas provinciales consolidados. Se requiere fortalecer la transparencia en la investigación mediante el registro público de las investigaciones. Se identificaron posibilidades de mejora para proponer acciones a futuro

Research ethics review system state in Argentina and the adaptation in response to the COVID-19 pandemic

Fil: Palmero, Ana. Ministerio de Salud de la Nación; Argentina.Fil: Torales, Santiago. Ministerio de Salud de la Nación; Argentina.Fil: Garau, Laura. Ministerio de Salud de la Ciudad Autónoma de Buenos Aires; Argentina.Fil: Álvarez, Jorgelina. Ministerio de Salud, Desarrollo Social y Deportes de Mendoza; Argentina.Fil: Martinelli, Beatriz. Ministerio de Salud de Santa Fe; Argentina.Fil: Vukotich, Claudia. Ministerio de Salud de la Ciudad Autónoma de Buenos Aires; Argentina.Fil: Sanchez, Silvina. Ministerio de Salud de la Provincia de Buenos Aires; Argentina.Fil: Burger, Carlos. Ministerio de Salud de la Provincia de Buenos Aires; Argentina.Fil: Mercado, Daniel. Ministerio de Salud de Córdoba; Argentina.Fil: Lencina, Verónica. Ministerio de Salud de Salta; Argentina.Fil: Oliva, Valeria. Ministerio de Salud de Salta; Argentina.Fil: Anze, Ismael. Ministerio de Salud de Salta; Argentina.Fil: Apaza, Gladis. Ministerio de Salud de Jujuy; Argentina.Fil: Bazán de Casella, María Cristina. Ministerio de Salud de Tucumán; Argentina.Fil: Burgos, Graciela. Ministerio de Salud de Santiago del Estero; Argentina.Fil: Martín, María Cristina. Ministerio de Salud de Misiones; Argentina.Fil: Margaria, Laura. Ministerio de Salud de Río Negro; Argentina.Fil: Manonelles, Gabriela. Ministerio de Salud de Santa Cruz; Argentina.Fil: Benzi, Patricia. Ministerio de Salud de Entre Ríos; Argentina.Fil: Pérez Pazo, Andrea. Ministerio de Salud Pública de San Juan; Argentina.INTRODUCCIÓN: un sistema de evaluación ética de las investigaciones en seres humanos es esencial para proteger los derechos de los participantes. Los desafíos impuestos por la pandemia de la COVID-19 para conducir investigaciones éticas que produzcan resultados con rapidez demuestran la necesidad de fortalecerlo. El objetivo de este estudio fue describir el estado de situación de los sistemas de evaluación ética de las provincias de Argentina y las adaptaciones realizadas por la pandemia. MÉTODOS: se realizó una encuesta a los comités provinciales de ética en investigación o áreas similares de los ministerios de Salud que ejercen la vigilancia sobre la evaluación ética de las investigaciones de su jurisdicción. RESULTADOS: respondieron 16 de las 17 provincias encuestadas. El 93,7% de los comités provinciales evalúa investigaciones en seres humanos y tiene procedimientos operativos estandarizados (POE). El 68,7% lleva un registro de los comités de ética en investigación (CEI) de su jurisdicción. Un 75% acredita a los CEI y un 68,7% los supervisa. El 100% tiene un registro de las investigaciones en salud; en 56,2% de los casos este registro es público. Del total, 81,2% realizan actividades de capacitación. El 100% adaptó los POE para evaluar estudios sobre la COVID-19. DISCUSIÓN: los resultados muestran sistemas provinciales consolidados. Se requiere fortalecer la transparencia en la investigación mediante el registro público de las investigaciones. Se identificaron posibilidades de mejora para proponer acciones a futuro

Tools for a personalized tacrolimus dose adjustment in the follow-up of renal transplant recipients. Metabolizing phenotype according to CYP3A genetic polymorphisms versus concentration-dose ratio

Background and justification: The strategy of the concentration-dose (C/D) approach and the different profiles of tacrolimus (Tac) according to the cytochrome P450 polymorphisms (CYPs) focus on the metabolism of Tac and are proposed as tools for the follow-up of transplant patients. The objective of this study is to analyse both strategies to confirm whether the stratification of patients according to the pharmacokinetic behaviour of C/D corresponds to the classification according to their CYP3A4/5 cluster metabolizer profile. Materials and methods: 425 kidney transplant patients who received Tac as immunosuppressive treatment have been included. The concentration/dose ratio (C/D) was used to divide patients in terciles and classify them according to their Tac metabolism rate (fast, intermediate, and slow). Based on CYP3A4 and A5 polymorphisms, patients were classified into 3 metabolizer groups: fast (CYP3A5*1 carriers and CYP34A*1/*1), intermediate (CYP3A5*3/3 and CYP3A4*1/*1) and slow (CYP3A5*3/*3 and CYP3A4*22 carriers). Results: When comparing patients included in each metabolizer group according to C/D ratio, 47% (65/139) of the fast metabolizers, 85% (125/146) of the intermediate and only 12% (17/140) of the slow also fitted in the homonym genotype group. Statistically lower Tac concentrations were observed in the fast metabolizers group and higher Tac concentrations in the slow metabolizers when compared with the intermediate group both in C/D ratio and polymorphisms criteria. High metabolizers required approximately 60% more Tac doses than intermediates throughout follow-up, while poor metabolizers required approximately 20% fewer doses than intermediates. Fast metabolizers classified by both criteria presented a higher percentage of times with sub-therapeutic blood Tac concentration values. Conclusion: Determination of the metabolizer phenotype according to CYP polymorphisms or the C/D ratio allows patients to be distinguished according to their exposure to Tac. Probably the combination of both classification criteria would be a good tool for managing Tac dosage for transplant patients. Resumen: Antecedentes y justificación: La estrategia de la aproximación concentración-dosis (C/D) y los distintos perfiles del tacrolimus (Tac) según los polimorfismos del citocromo P450 (CYPs) se centran en el metabolismo de Tac y se plantean como herramientas para el seguimiento de los pacientes trasplantados. El objetivo de este estudio es comparar la exposición al Tac analizado según ambas estrategias. Materiales y métodos: Se han incluido 425 pacientes trasplantados renales. El cálculo del cociente concentración Tac/dosis (C/D) permitió dividir la población en terciles y clasificar los pacientes según su tasa de metabolismo del Tac en 3 grupos (rápida, intermedia y lenta). En base los polimorfismos del CYP3A4 y A5, los pacientes se agruparon en metabolizadores rápidos (portadores del CYP3A5*1 y CYP34A *1/*1), intermedios (CYP3A5*3/3 y CYP3A4*1/*1) y lentos (CYP3A5 *3/*3 y portadores del CYP3A4*22). Resultados: Al comparar los pacientes de cada grupo metabolizador según los dos criterios coincidieron el 47% (65/139) de los metabolizadores rápidos, el 85% (125/146) de los intermedios y solo el 12% (17/140) de los lentos. Se observaron concentraciones de Tac estadísticamente menores en los metabolizadores rápidos y concentraciones mayores en los lentos, comparándolos con el grupo intermedio según el cociente C/D o según polimorfismos. Los metabolizadores rápidos requirieron alrededor del 60% más de dosis de Tac que los intermedios a lo largo del seguimiento, mientras que los lentos aproximadamente un 20% menos de dosis que los intermedios. Los metabolizadores rápidos clasificados por ambos criterios presentan un porcentaje mayor de veces con valores de concentración de Tac en sangre infra-terapéuticos. Conclusión: La determinación del fenotipo metabolizador según los polimorfismos del CYP o bien cociente C/D permite distinguir los pacientes según su exposición al Tac. Probablemente la combinación de ambos criterios de clasificación sería una buena herramienta en el manejo de la dosificación de Tac para los pacientes trasplantados

Effectiveness and safety of the conversion to MeltDose ®

Tacrolimus is the cornerstone of immunosuppressive therapy after kidney transplantation. Its narrow therapeutic window mandates serum level strict monitoring and dose adjustments to ensure the optimal risk-benefit balance. This observational retrospective study analyzed the effectiveness and safety of conversion from twice-daily immediate-release tacrolimus (IR-Tac) or once-daily prolonged-release tacrolimus (PR-Tac) to the recent formulation once-daily MeltDose((R)) extended-release tacrolimus (LCP-Tac) in 365 stable kidney transplant recipients. We compared kidney function three months before and three months after the conversion. Three months after conversion, the total daily dose was reduced ~35% (P < .0001), and improved bioavailability and stable serum LCP-Tac concentrations were observed. There was no increase in the number of patients requiring tacrolimus dose adjustments after conversion. Renal function was unaltered, and no cases of BPAR were reported. Reports of tremors, as collected in the clinical histories for each patient, decreased from pre-conversion (20.8%) to post-conversion (11.8%, P < .0001). LCP-Tac generated a cost reduction of 63% compared with PR-Tac. In conclusion, the conversion strategy to LCP-Tac from other tacrolimus formulations in stable kidney transplant patients showed safety and effectiveness in a real-world setting, confirming the data from RCTs. The specific pharmacokinetic properties of LCP-Tac could be potentially advantageous in patients with tacrolimus-related adverse events

Colony stimulating factor-1 receptor drives glomerular parietal epithelial cell activation in focal segmental glomerulosclerosis

Parietal epithelial cells (PECs) are kidney progenitor cells with similarities to a bone marrow stem cell niche. In focal segmental glomerulosclerosis (FSGS) PECs become activated and contribute to extracellular matrix deposition. Colony stimulating factor-1 (CSF-1), a hematopoietic growth factor, acts via its specific receptor, CSF-1R, and has been implicated in several glomerular diseases, although its role on PEC activation is unknown. Here, we found that CSF-1R was upregulated in PECs and podocytes in biopsies from patients with FSGS. Through in vitro studies, PECs were found to constitutively express CSF-1R. Incubation with CSF-1 induced CSF-1R upregulation and significant transcriptional regulation of genes involved in pathways associated with PEC activation. Specifically, CSF-1/CSF-1R activated the ERK1/2 signaling pathway and upregulated CD44 in PECs, while both ERK and CSF-1R inhibitors reduced CD44 expression. Functional studies showed that CSF-1 induced PEC proliferation and migration, while reducing the differentiation of PECs into podocytes. These results were validated in the Adriamycin-induced FSGS experimental mouse model. Importantly, treatment with either the CSF-1R-specific inhibitor GW2580 or Ki20227 provided a robust therapeutic effect. Thus, we provide evidence of the role of the CSF-1/CSF-1R pathway in PEC activation in FSGS, paving the way for future clinical studies investigating the therapeutic effect of CSF-1R inhibitors on patients with FSGS