Hemodiafiltración con reinfusión endógena del ultrafiltrado (HFR): hacia una diálisis convectiva, difusiva y adsortiva / Hemodiafiltration with endogenous reinfusion of the regenerated ultrafiltrate (HFR): Towards a convective, diffusive, and adsorptive dialysis

La hemodiafiltración con reinfusión endógena del ultrafiltrado (HFR) es una técnica de diálisis caracterizada por un cartucho de resina con poder adsorbente que combina los mecanismos difusión, convección y adsorción en un solo esquema terapéutico. Después de cerca de 20 años de experiencia clínica con HFR, el presente artículo revisa la evidencia acumulada con esta técnica, planteando si la adición de la adsorción, como tercer mecanismo depurativo, debería ser el siguiente paso en el tratamiento de los pacientes en hemodiálisis. La HFR, a pesar de producir una extensa eliminación de toxinas urémicas, ha demostrado reducir la pérdida de nutrientes y componentes fisiológicos durante la sesión de diálisis frente a la hemodiafiltración on-line, mitigando el estado inflamatorio y el estrés oxidativo en esta población. Además de su facilidad de uso, la técnica también es altamente biocompatible y puede utilizarse en situaciones de un acceso vascular comprometido. En base a estas observaciones, la HFR parece ser una técnica especialmente útil para pacientes con elevada comorbilidad, incluyendo aquellos con fragilidad, desnutrición o enfermedad cardiovascular. En esta revisión, como panel de consenso de nefrólogos con experiencia clínica en HFR, examinamos la literatura existente y resumimos nuestros puntos de vista sobre cómo usar esta técnica, qué perfil de paciente puede ser más adecuado para la HFR, y cómo prescribir y monitorizar de manera práctica esta modalidad de diálisis (AU)

Hemodiafiltration with endogenous reinfusion of the ultrafiltrate (HFR) is a dialysis technique characterized by a resin cartridge with adsorptive properties that combines the mechanisms of diffusion, convection, and adsorption in a single therapeutic regimen. After nearly 20 years of clinical experience with HFR, this article reviews the accumulated evidence with this technique, considering whether adsorption reduction, as a third purification mechanism, should be the next step in the treatment of hemodialysis patients. HFR, beyond producing an extensive removal of uremic toxins, has demonstrated to reduce the loss of nutrients and other physiological components during the dialysis session as compared to online hemodiafiltration, ameliorating the inflammatory state and oxidative stress in this population. In addition to its ease of use, the technique is also highly biocompatible and can be used in patients with a compromised vascular access. Based on these observations, HFR appears to be an especially useful therapy for high-comorbidity patients, including those with frailty, malnutrition, or cardiovascular disease. In this review, we, as a consensus panel of nephrologists experienced with HFR, survey existing literature and summarize our views on when to use this technique, which patients may be best suited for HFR, and how to effectively prescribe and monitor this modality of dialysis in daily clinical practice (AU)

Hemodiafiltration with endogenous reinfusion of the regenerated ultrafiltrate (HFR): towards a convective, diffusive, and adsorptive dialysis.

Hemodiafiltration with endogenous reinfusion of the ultrafiltrate (HFR) is a dialysis technique characterized by a resin cartridge with adsorptive properties that combines the mechanisms of diffusion, convection, and adsorption in a single therapeutic regimen. After nearly 20 years of clinical experience with HFR, this article reviews the accumulated evidence with this technique, considering whether adsorption reduction, as a third purification mechanism, should be the next step in the treatment of hemodialysis patients. HFR, beyond producing an extensive removal of uremic toxins, has demonstrated to reduce the loss of nutrients and other physiological components during the dialysis session as compared to online hemodiafiltration, ameliorating the inflammatory state and oxidative stress in this population. In addition to its ease of use, the technique is also highly biocompatible and can be used in patients with a compromised vascular access. Based on these observations, HFR appears to be an especially useful therapy for high-comorbidity patients, including those with frailty, malnutrition, or cardiovascular disease. In this review, we, as a consensus panel of nephrologists experienced with HFR, survey existing literature and summarize our views on when to use this technique, which patients may be best suited for HFR, and how to effectively prescribe and monitor this modality of dialysis in daily clinical practice.

Experiencia en hemodiálisis domiciliaria en España / Spanish home hemodialysis experience

Resumen Antecedentes: existe actualmente un interés creciente, a nivel mundial, por las posibilidades que ofrece la hemodiálisis domiciliaria, la cual se encuentra más extendida en países del norte de Europa, Canadá, Reino Unido, Estados Unidos, Australia y Nueva Zelanda. En España, ha crecido de manera muy lenta, excepto en determinadas regiones como la provincia de Castellón, donde hemos puesto especial interés en la expansión de las técnicas dialíticas domiciliarias. Objetivo: describir la experiencia en el programa de hemodiálisis domiciliaria del Hospital General de Castellón. Metodología: estudio descriptivo de los pacientes incluidos en el programa de hemodiálisis domiciliaria del Hospital General de Castellón, desde su inicio en enero del 2008 hasta diciembre del 2017. Resultados: en su conjunto, entrenamos a 41 pacientes, de los que 36 llegaron a hemodializarse en casa (régimen corto-diario). La edad de los pacientes era 58,3±13,4 años; y el índice de Charlson, 4,1±1,6. 62 % de los pacientes eran hombres, 25,6 % padecían diabetes mellitus; 15,4 % tenían diagnóstico de insuficiencia cardíaca y 32 % eran portadores de fístula de hemodiálisis. El 38,5 % de los pacientes en edad laboral estaba activo. Obtuvimos una supervivencia técnica considerando el evento muerte+fallo técnico, censurando el trasplante, del 79,4 % al año, 75,2 % a los 2 años y 42,1 % a los 5 años. En el análisis univariante, resultaron determinantes la edad, la presencia de diabetes mellitus y la presencia de insuficiencia cardíaca. En el análisis multivariante, solo se mantuvo la insuficiencia cardíaca. Las reducciones semanales de fósforo y beta-2-microglobulina fueron significativamente mayores con hemodiálisis corta diaria, en comparación con la hemodiafiltración on-line. La hemodiafiltración on-line fue superior en la reducción semanal a partir de los 17 800 daltons para la mioglobina. Conclusiones: la hemodiálisis domiciliaria es una técnica posible que ofrece al paciente una adecuada reinserción sociolaboral, buenos niveles de reducción semanal de toxinas urémicas y una aceptable supervivencia técnica en el tiempo.

Abstract Background: There is currently a growing interest, worldwide, for the possibilities offered by home hemodialysis, which is more widespread in northern European countries, Canada, the United Kingdom, the United States, Australia and New Zealand. In Spain, it has grown very slowly, except in certain regions such as the province of Castellón, where we have placed special interest in the expansion of home dialysis techniques. Objective: To describe the experience in the Home Hemodialysis program of the Hospital General de Castellón. Methodology: Descriptive study of the patients included in the home hemodialysis program of the Hospital General de Castellón, from its beginning in January 2008 to December 2017. Results: As a whole, we trained 41 patients, of whom 36 came to hemodialysis at home (short-day regimen). Age 58,3±13,4 years, Charlson index 4,1±1,6, 62 % men, 25,6 % with diabetes mellitus, 15,4 % with diagnosis of heart failure, 32 % with hemodialysis fistula, 38,5 % of working-age patients were active. We obtained a technical survival considering the event death+technical failure, censoring transplant of 79,4 % a year, 75,2 % at 2 years and 42,1 % at 5 years, resulting determinants of the event in the univariate analysis: age, presence of diabetes mellitus and presence of heart failure, and only heart failure in the multivariate. The weekly reductions of phosphorus and beta-2-microglobulin were significantly greater with daily short hemodialysis with respect to on-line haemodiafiltration. Being the on-line hemodiafiltration superior in the weekly reduction from the 17800 daltons of myoglobin. Conclusions: Home hemodialysis is a possible technique that offers the patient an adequate social-labor reintegration with good levels of weekly reduction of uraemic toxins and an acceptable technical survival over time.

Contribution of uraemic toxins to the vascular fibrosis associated with chronic kidney disease. / Contribución de las toxinas urémicas a la fibrosis vascular asociada a la enfermedad renal crónica.

BACKGROUND: Patients with chronic kidney disease present with an accumulation of uraemic toxins, which have been identified as pathogenic agents associated with cardiovascular mortality, which is very high is this patient group. A phenomenon common to the progressive renal dysfunction and associated vascular damage, is the abnormal accumulation of extracellular matrix (ECM) proteins in the renal or vascular structures. OBJECTIVE: To determine the contribution of uraemia or the uraemic toxins to the production of cytokinins and ECM in aortas of uraemic animals or human aortic smooth muscle cells (HASMCs). MATERIALS AND METHODS: Mice were used with uraemia induced by a diet rich in adenine (0.2%) for 2, 4 or 6 weeks. Kidney function was evaluated by means of urine volume, plasma levels of creatinine, urea, fractional excretion of sodium, and vascular damage using histology, as well as protein expression using RT-qPCR. The HASMCs were incubated in vitro with uraemic toxins: p-cresol 10-100 (µg/ml) and indoxyl-sulphate25-100 (µg/ml) alone or simultaneously. The protein expression was evaluated using Western blot and confocal microscopy. RESULTS: The administration of adenine produced progressive kidney damage in the mice, thickening of the aortic wall, and increasing the expression of TGF-ß1 and ECM proteins. The toxins at high doses and combined also induced the expression of TGF-ß1 and ECM proteins by the HASMCs. CONCLUSIONS: The uraemia produced by an adenine rich diet or high doses of uraemic toxins induced the abnormal deposit of ECM proteins in the vascular wall or its production by HASMCs. The understanding of the mechanisms that underlie this pathophysiological process may be useful in the prevention of cardiovascular damage associated with the progress of chronic kidney disease, a disease, at the moment that is irreversible and occasional silent until its diagnosis in advanced stages.

Gut microbiota in chronic kidney disease. / Microbiota intestinal en la enfermedad renal crónica.

The intestinal microflora maintains a symbiotic relationship with the host under normal conditions, but its imbalance has recently been associated with several diseases. In chronic kidney disease (CKD), dysbiotic intestinal microflora has been reported with an increase in pathogenic flora compared to symbiotic flora. An enhanced permeability of the intestinal barrier, allowing the passage of endotoxins and other bacterial products to the blood, has also been shown in CKD. By fermenting undigested products that reach the colon, the intestinal microflora produce indoles, phenols and amines, among others, that are absorbed by the host, accumulate in CKD and have harmful effects on the body. These gut-derived uraemic toxins and the increased permeability of the intestinal barrier in CKD have been associated with increased inflammation and oxidative stress and have been involved in various CKD-related complications, including cardiovascular disease, anaemia, mineral metabolism disorders or the progression of CKD. The use of prebiotics, probiotics or synbiotics, among other approaches, could improve the dysbiosis and/or the increased permeability of the intestinal barrier in CKD. This article describes the situation of the intestinal microflora in CKD, the alteration of the intestinal barrier and its clinical consequences, the harmful effects of intestinal flora-derived uraemic toxins, and possible therapeutic options to improve this dysbiosis and reduce CKD-related complications.