El líquido de diálisis con citrato no induce in vitro estrés oxidativo ni inflamación en comparación con el acetato / Citrate dialysate does not induce oxidative stress or inflammation in vitro as compared to acetate dialysate

El líquido de diálisis con citrato no induce in vitro estrés oxidativo ni inflamación en comparación con el acetato. El incremento de la acetatemia durante la sesión de hemodiálisis se ha asociado a una serie de alteraciones: aumento del estrés oxidativo, de las citocinas proinflamatorias y de la síntesis de óxido nítrico. El ácido cítrico puede jugar un papel alternativo al acetato como estabilizante del líquido de diálisis (LD). El citrato en comparación con el acetato tiene un patrón diferente en cuanto a la activación leucocitaria y del complemento. El objetivo de este estudio es comparar el acetato con el citrato en el LD respecto a su efecto inflamatorio en las células inmunocompetentes de la sangre. Material y métodos: El efecto del acetato o citrato fue investigado en sangre completa de pacientes urémicos y controles sanos in vitro, enfrentada a 4tipos de LD: el LD 1, con 1mmol/L de citrato y libre de acetato; LD 2, con 0,8mmol/L de citrato y 0,3mmol/L de acetato; LD 3, con 3mmol/L de acetato sin citrato y LD 4, con 4mmol/L de acetato sin citrato. Los tipos de células utilizados fueron: cultivo de monocitos humanos (THP-1); células mononucleares de sangre periférica (PBMC) de controles sanos y pacientes urémicos en HD. Se determinó ICAM-1, la cuantificación de los niveles de especies reactivas de oxígeno (ROS) y la cuantificación de microvesículas totales. Resultados: Los LD con acetato (L3 y L4) indujeron un incremento en la densidad de expresión de ICAM-1 en las células THP-1, no así los de citrato; con células inmunocompetentes de sujetos sanos los LD con acetato (L3 y L4) respecto a los con citrato (L1 y L2) observamos un incremento en la expresión de ICAM-1; con células de pacientes en hemodiálisis no existían diferencias significativas entre los diferentes LD. Tanto en las células de sujetos sanos como en las de los dializados, se incrementaron significativamente la expresión de especies reactivas de oxígeno y las microvesículas con los LD con acetato y no con citrato. Conclusiones: El acetato en el LD, en las concentraciones que se utilizan habitualmente en la práctica clínica, aumenta el estrés oxidativo y las microvesículas totales, y puede actuar como coadyuvante de los otros estímulos proinflamatorios a los que están sometidos los pacientes urémicos en hemodiálisis. Los LD con citrato no producen esta activación, por lo que podrían ser una alternativa en la clínica (AU)

Increased acetataemia during haemodialysis sessions has been associated with a number of abnormalities, including increased oxidative stress, pro-inflammatory cytokines and nitric oxide synthesis. However, citric acid may play an alternative role to acetate as a dialysate stabiliser given that the effect of citrate on complement and leukocyte activation is different to that of acetate. The purpose of this study was to compare the inflammatory effect in immunocompetent blood cells of acetate dialysate and citrate dialysate. Material and methods: The effect of acetate and/or citrate was investigated in the whole blood of uraemic patients and in healthy in vitro samples. Four types of dialysate were tested: dialysate 1, acetate-free with 1mmol/L of citrate; dialysate 2, with 0.8mmol/L of citrate and 0.3mmol/L of acetate; dialysate 3, citrate-free with 3mmol/L of acetate; and dialysate 4, citrate-free with 4mmol/L of acetate. The cell types used were: human monocyte culture (THP-1); and peripheral blood mononuclear cells (PBMCs) from healthy subjects and uraemic patients on haemodialysis. ICAM-1 was determined and levels of reactive oxygen species and total microvesicles were quantified. Results: Unlike the citrate dialysates, the dialysates with acetate (dialysate 3 and dialysate 4) induced increased ICAM-1 expression density in THP-1 cells; an increase in ICAM-1 expression was observed in the immunocompetent cells of healthy subjects with acetate dialysate (dialysate 3 and dialysate 4) but not with citrate dialysate (dialysate 1 and dialysate 2). No significant ICAM-1 differences were found between the different dialysates in the cells of haemodialysed patients. Reactive oxygen species expression and the number of microvesicles increased significantly with acetate dialysate but not with citrate dialysate in the cells of both healthy subjects and haemodialysed patients. Conclusions: At the concentrations in which it is generally used in clinical practice, acetate-based dialysate increases oxidative stress and the total number of microvesicles and may induce other pro-inflammatory stimuli typical of uraemic patients on haemodialysis. Citrate dialysates do not induce this activation, which could make them a suitable alternative in clinical practice (AU)

Influencia en la dosis de diálisis de diferentes flujos de líquido dializante en el paciente tratado con hemodiafiltración on-line o hemodiálisis convencional / Influence on the dialysis doses of different flow rates of dialysis fluid in patients treated with online haemodiafiltration or conventional haemodialysis

La dosis de diálisis influye sobre la supervivencia del paciente en hemodiálisis, además de influir en la corrección de la anemia, en el estado nutricional y en el control de la tensión arterial, entre otros. Algunos autores han señalado el flujo del líquido dializante como un factor determinante de la dosis de diálisis del paciente en hemodiálisis de alto flujo y hemodiafiltración. El objetivo del presente estudio es evaluar el impacto en la eficacia de la diálisis de diferentes flujos de líquido dializante en pacientes tratados con hemodiafiltración on-line postdilucional y hemodiálisis convencional, mediante la medición del volumen convectivo final y del aclaramiento de pequeñas moléculas mediante el Kt. En todos los pacientes se realizan 9 sesiones de diálisis consecutivas variando el Qd: 3 sesiones con Qd 500 ml/min, 3 sesiones con Qd 800 ml/min y 3 sesiones con autoflujo . De los resultados obtenidos, el Kt se muestra significativamente mayor con Qd 800 ml/min (59,69 ± 6,07 litros) con respecto a Qd 500 ml/min (56,51 ± 6,33 litros, p<0,001) y autoflujo (58,02 ± 4,89 litros); así como el Kt del autoflujo mayor (p<0,001) que Qd 500 ml/min. El aumento del flujo de líquido dializante conlleva un incremento en la dosis de diálisis en pacientes tratados con hemodiafiltración on-line. El autoflujo consigue un incremento de dosis apreciable con respecto al Qd de 500 ml/min con un mínimo coste adicional, por lo que debería de considerarse como una medida en un esquema global de tratamiento, que permita la individualización en cada paciente (AU)

The dialysis dose affects survival of patients undergoing dialysis, as well as affecting the correction of anaemia, the nutritional state and the control of blood pressure, among others. Some authors have indicated the dialysis fluid flow rate as a determining factor in the dialysis dose for patients undergoing high-flow haemodialysis and haemodiafiltration. The aim of this study is to evaluate the impact on the dialysis efficacy of different flow rates of dialysis fluid in patients treated with on-line post-dilution haemodiafiltration and conventional haemodialysis, by measuring the final convective volume and rinse solution volume of small molecules using Kt. In all patients, 9 consecutive dialysis sessions were carried out varying the Qd: 3 sessions with Qd 500 ml/min, 3 sessions with Qd 800 ml/min and 2 sessions with autoflow. From the results obtained, Kt is shown to be significantly higher with Qd 800 ml/min (59.69 ± 6.07 litres) compared to Qd 500 ml/min (56.51 ± 6.33 litres, p<0.001) and autoflow (58.02 ± 4.89 litres); and Kt in autoflow was found to be higher (p<0.001) than Qd 500 ml/min. The increase in flow rate of dialysis fluid means an increase in the dialysis dose in patients treated with online haemodiafiltration. The autoflow achieves an appreciable increase in dose compared to Qd of 500 ml/min with a minimum additional cost, and should therefore be considered as a measure in an overall treatment framework, permitting individualization of treatment for each patient (AU)

How to avoid glucose degradation products in peritoneal dialysis fluids.

OBJECTIVE: The formation of glucose degradation products (GDPs) during sterilization of peritoneal dialysis fluids (PDFs) is one of the most important aspects of biocompatibility of glucose-containing PDFs. Producers of PDFs are thus trying to minimize the level of GDPs in their products. 3,4-Dideoxyglucosone-3-ene (3,4-DGE) has been identified as the most bioreactive GDP in PDFs. It exists in a temperature-dependent equilibrium with a pool of 3-deoxyglucosone (3-DG) and is a precursor in the irreversible formation of 5-hydroxymethyl furaldehyde (5-HMF). The aim of the present study was to investigate how to minimize GDPs in PDFs and how different manufacturers have succeeded in doing so. DESIGN: Glucose solutions at different pHs and concentrations were heat sterilized and 3-DG, 3,4-DGE, 5-HMF, formaldehyde, and acetaldehyde were analyzed. Conventional as well as biocompatible fluids from different manufacturers were analyzed in parallel for GDP concentrations. RESULTS: The concentrations of 3-DG and 3,4-DGE produced during heat sterilization decreased when pH was reduced to about 2. Concentration of 5-HMF decreased when pH was reduced to 2.6. After further decrease to a pH of 2.0, concentration of 5-HMF increased slightly, and below a pH of 2.0 it increased considerably, together with formaldehyde; 3-DG continued to drop and 3,4-DGE remained constant. Inhibition of cell growth was paralleled by 3,4-DGE concentration at pH 2.0 - 6.0. A high glucose concentration lowered concentrations of 3,4-DGE and 3-DG at pH 5.5 and of 5-HMF at pH 1. At pH 2.2 and 3.2, glucose concentration had a minor effect on the formation of GDPs. All conventional PDFs contained high levels of 3,4-DGE and 3-DG. Concentrations were considerably lower in the biocompatible fluids. However, the concentration of 5-H M F was slightly higher in all the biocompatible fluids. CONCLUSION: The best way to avoid reactive GDPs is to have a pH between 2.0 and 2.6 during sterilization. If pHs outside this range are used, it becomes more important to have high glucose concentration during the sterilization process. There are large variations in GDPs, both within and between biocompatible and conventionally manufactured PDFs.