Enfermedad renal crónica asociada a la exposición a metales pesados y productos agroquímicos en Latinoamérica / Chronic kidney disease associated with heavy metal exposure and agrochemicals in Latin America

Introducción: La Organización Panamericana de la Salud reco-noce a la Enfermedad Renal Crónica de Causas No Tradiciona-les como una forma grave de insuficiencia renal de etiología incierta, la cual ha alcanzado proporciones epidémicas en las comunidades y saturación de los sistemas de salud. La enfer-medad se ha relacionado con infecciones, deshidratación, hi-peruricemia, exposición a agroquímicos o metales pesados y susceptibilidad genética. Objetivo: Realizar una revisión integradora sobre la relación entre la enfermedad renal de causa no tradicional con factores sociodemográficos, exposición agrícola y metales pesados en población latinoamericana. Metodología: Se realizó una revisión sistemática integradora bajo la guía PRISMA en las bases de datos Medigraphic, Bio-Med Central, Wiley Online Library, Web of Science, Science-Direct, PubMed y Scopus. Con las palabras claves: enfermedad renal, nefritis, metales pesados, agroquímicos, factor de riesgo. Se incluyeron 39 estudios después de evaluar la calidad meto-dológica de los mismos. Resultados: El 35,89% de los estudios incluídos tuvo una rigu-rosidad científica alta. Referente a las causas, se encontró que la exposición a agroquímicos fue la causa de mayor frecuencia en el padecimiento de esta enfermedad. Conclusión: Los metales pesados y agroquímicos han demos-trado influir en el desarrollo de la Enfermedad Renal Crónica de causas no tradicionales, no obstante, la mayoría de los re-sultados de los artículos incluidos no tienen resultados genera-lizables ni estadísticamente significativos. Los factores socio-demográficos han sido poco estudiados y se requiere de mayor investigación con rigurosidad científica sobre esta variable.(AU)

ntroduction: The Pan American Health Organization recognizes Chronic Kidney Disease of Nontraditional Causes as a serious form of kidney failure of uncertain etiology, which has reached devastating epidemic proportions in communities and saturation of health systems. Hypotheses related to infections, dehydration, global warming, hyperuricemia, exposure to agrochemicals or heavy metals and genetic susceptibility are mentioned, however, these hypotheses have not been conclusive. Objective: To carry out a systematic review on the relationship between non-traditional kidney disease and sociodemographic factors, agricultural exposure or heavy metals in the Latin American population. Methodology: An integrative systematic review was carried out under the PRISMA guide in the Medigraphic, BioMed Central, Wiley Online Library, Web of Science, ScienceDirect, PubMed and Scopus databases. With the keywords: kidney disease, nephritis, heavy metals, agrochemicals, risk factor. Of which 39 studies were included after evaluating their methodological quality. Results: it was found that 35.89% of the included studies had a high scientific rigor. Regarding the causes, it was found that exposure to agrochemicals was the most frequent cause of this disease. Conclusion: Heavy metals and agrochemicals have been shown to influence the development of Chronic Kidney Disease of Nontraditional Causes, however, most of the results are not generals and doesn ́t demonstrate a statistically significant relationship. Sociodemographic factors have been little studied and more rigorous scientific research on this variable is required.(AU)

Impact of locking solutions on conditioning biofilm formation in tunnelled haemodialysis catheters and inflammatory response activation.

INTRODUCTION: The surface of tunnelled cuffed catheters provides an optimal environment for the development of biofilms, which have recently been described as conditioning films because of the presence of adherent biological materials. These biofilms are associated with infection and thrombosis and potentially increase patients' inflammatory response. These complications could be reduced by the use of locking solutions. OBJECTIVE: To analyse biofilm formation, using confocal and electron microscopy, in tunnelled cuffed catheters locked with three different solutions and to determine the relationship between these solutions and inflammatory response. STUDY DESIGN: This prospective study included 35 haemodialysis patients with tunnelled cuffed catheter removal for non-infection-related reasons. The participants were divided into three groups according to the lock solution used: (1) heparin 1: 5000 IU; (2) citrate 4%; and (3) taurolidine 1.35%, citrate 4% and heparin 500 IU (taurolock); in the latter group, 25,000 IU taurolidine-urokinase was used in the last weekly session. All tunnelled cuffed catheters were cultured, and the inner surface was evaluated with confocal and electron microscopy. The inflammatory profile of included patients was determined at tunnelled cuffed catheter removal. RESULTS: There were no differences in clinical or demographic variables between the three subgroups. Biofilm thickness was lower in the taurolidine group than in the citrate 4% and heparin groups (28.85 ± 6.86 vs 49.99 ± 16.56 vs 56.2 ± 15.67 µm, respectively; p < 0.001), as was biofilm volume (1.01 ±1.18 vs 3.7 ± 2.15 vs 5.55 ±2.44, µm3, respectively; p < 0.001). The mean interleukin-6 value was 39%, which was 50% lower than in the citrate and heparin groups, but without significance differences. CONCLUSION: Our results show that biofilms were found in all tunnelled cuffed catheters, but the thickness and volume were significantly lower in tunnelled cuffed catheters locked with taurolidine solution. Therefore, the type of locking solution used in tunnelled cuffed catheters should maintain tunnelled cuffed catheter sterility and prevent catheter-related bloodstream infections. No significant difference was observed in the inflammatory profile according to the type of locking solution.

Eight-Year Experience with Nocturnal, Every-Other-Day, Online Haemodiafiltration.

BACKGROUND: New haemodialysis therapeutic regimens are required to improve patient survival. Longer and more frequent dialysis sessions have produced excellent survival and clinical advantages, while online haemodiafiltration (OL-HDF) provides the most efficient form of dialysis treatment. METHODS: In this single-centre observational study, 57 patients on 4-5-hour thrice-weekly OL-HDF were switched to nocturnal every-other-day OL-HDF. Inclusion criteria consisted of stable patients with good prospects for improved occupational, psychological and social rehabilitation. The aim of this study was to report our 8-year experience with this schedule and to evaluate analytical and clinical outcomes. RESULTS: Nocturnal, every-other-day OL-HDF was well tolerated and 56% of patients were working. The convective volume increased from 26.7 ± 2 litres at baseline to 46.6 ± 6.5 litres at 24 months (p < 0.01). Increasing the dialysis dose significantly decreased bicarbonate, blood-urea-nitrogen and creatinine values. Predialysis phosphate levels fell markedly with complete suspension of phosphate binders from the second year of follow-up. Although haemoglobin was unchanged, there was a 50.4% reduction in darbepoetin dose at 24 months and a significant decrease in the erythropoietin resistance index. Blood pressure significantly decreased in a few months. Antihypertensive medication requirements were decreased by 60% after 3 months and by 73% after 1 year and this difference was maintained thereafter. CONCLUSIONS: Nocturnal, every-other-day OL-HDF could be an excellent therapeutic alternative since it is well tolerated and leads to clinical and social-occupational rehabilitation with satisfactory morbidity and mortality. These encouraging results strengthen us to continue and invite other clinicians to join this initiative.

Lesión renal aguda en la intoxicación por paracetamol / Acute kidney injury in paracetamol poisoning

No disponible

Optimización del flujo del líquido de diálisis en la hemodiafiltración on-line / Optimization of dialysate flow in on-line hemodiafiltration

Introducción: La hemodiafiltración on-line (HDF-OL) es actualmente la técnica más efectiva. Varios estudios aleatorizados y metaanálisis han observado una reducción de la mortalidad, con una asociación en relación directa con el volumen convectivo. En el momento presente no está bien establecido si el aumento del flujo del líquido de diálisis (Qd) puede suponer mejores resultados en términos de eficacia convectiva y depurativa. El objetivo del estudio fue valorar, en pacientes en tratamiento con HDF-OL, el efecto de la variación del Qd sobre el volumen convectivo y su capacidad depurativa. Material y métodos: Se incluyeron 59 pacientes, 45 varones y 14 mujeres que se encontraban en programa de HDF-OL con monitor 5008 Cordiax con autosustitución. Cada paciente fue analizado en 5 sesiones con HDF-OL posdilucional, con dializadores de helixona, en las que solo se varió el Qd (300, 400, 500, 600 y 700 ml/min). En cada sesión se determinaron concentración de urea (60 Da), creatinina (113 Da), 2-microglobulina (11.800 Da), mioglobina (17.200 Da) y 1-microglobulina (33.000 Da) en suero al inicio y al final de cada sesión, para calcular el porcentaje de reducción de estos solutos. Resultados: Se objetivó un aumento de litros de Qd por sesión, desde 117,9±6,4 L con Qd de 300 ml/min hasta 232,4±12 L conQd700 ml/min.Nose determinaron cambios en el volumen de sustitución ni en el volumen convectivo. En términos de difusión, el incremento del Qd mostró un aumento significativo de la dosis de diálisis, con un aumento de Kt de 68±6,9 L con Qd 300 ml/min hasta 75,5±7,3 L con Qd 700 ml/min (p < 0,001), y un aumento progresivo del porcentaje de reducción de urea con el incremento del Qd, que era significativamente inferior con Qd 300 ml/min. No se objetivaron cambios en el resto de moléculas estudiadas. Conclusión: La variación del Qd en HDF-OL no modifica el volumen convectivo. Un mayor Qd mostró un discreto incremento de la depuración de la urea, sin variaciones en las medianas ni en las grandes moléculas. Es recomendable optimizar el Qd al mínimo posible que garantice una adecuada dosis de diálisis y permita racionalizar el consumo de agua y concentrado de diálisis (AU)

Introduction: Currently, on-line hemodiafiltration (HDF-OL) is the most effective technique. Several randomized studies and meta-analyses have shown a reduced mortality and a direct association with convective volume has been reported. At present, it has not been established if an increased dialysate flow (Qd) results in improved results in terms of convective and depurative efficiency. We aim at assessing the effects of Qd variations on convective volume and its depurative capacity in patients on HDF-OL. Material and methods: A total of 59 patients (45 men and 14 women) from a HDF-OL programme in which a monitor 5008 Cordiax with self-replacement was used, were enrolled. Patients were assessed in 5 sessions with post-dilutional HDF-OL, using helixone-based dialyzers, with only Qd being changed (300, 400, 500, 600 and 700 ml/min). Serum levels of urea (60 Da), creatinine (113 Da), 2-microglobulin (11,800 Da), myoglobin (17,200 Da) and 1- microglobulin (33,000 Da) were measured at the beginning and at the end of each session, in order to estimate the percent reduction of such solutes. Results: An increased dialysate volume per session was observed, from 117.9±6.4 L with Qd 300 ml/min to 232.4±12 L with Qd 700 ml/min. No changes were found in replacement volume or convective volume. Regarding diffusion, Qd increase was associated to a significantly increased dialysis dose, with an increased Kt from 68±6.9 L with Qd 300 ml/min to 75.5±7.3 L with Qd 700 ml/min (p < 0,001), and a gradually increased percent reduction in urea associated to increased Qd with significantly lower levels being found with Qd 300 ml/min. No changes were found in other measured substances. Conclusion: Qd variations in HDF-OL do not change convective volume. A higher Qd was associated to a slightly increased urea clearance with no change being observed for medium and large molecules. Qd optimisation to the minimal level assuring an adequate dialysis dose and allowing water and dialysate use to be rationalised should be recommended (AU)

Optimization of dialysate flow in on-line hemodiafiltration.

INTRODUCTION: Currently, on-line hemodiafiltration (HDF-OL) is the most effective technique. Several randomized studies and meta-analyses have shown a reduced mortality and a direct association with convective volume has been reported. At present, it has not been established if an increased dialysate flow (Qd) results in improved results in terms of convective and depurative efficiency. We aim at assessing the effects of Qd variations on convective volume and its depurative capacity in patients on HDF-OL. MATERIAL AND METHODS: A total of 59 patients (45 men and 14 women) from a HDF-OL programme in which a monitor 5008 Cordiax with self-replacement was used, were enrolled. Patients were assessed in 5 sessions with post-dilutional HDF-OL, using helixone-based dialyzers, with only Qd being changed (300, 400, 500, 600 and 700ml/min). Serum levels of urea (60Da), creatinine (113 Da), ß2-microglobulin (11,800Da), myoglobin (17,200Da) and α1-microglobulin (33,000Da) were measured at the beginning and at the end of each session, in order to estimate the percent reduction of such solutes. RESULTS: An increased dialysate volume per session was observed, from 117.9±6.4 L with Qd 300ml/min to 232.4±12 L with Qd 700ml/min. No changes were found in replacement volume or convective volume. Regarding diffusion, Qd increase was associated to a significantly increased dialysis dose, with an increased Kt from 68±6.9 L with Qd 300ml/min to 75.5±7.3 L with Qd 700ml/min (p<0,001), and a gradually increased percent reduction in urea associated to increased Qd with significantly lower levels being found with Qd 300ml/min. No changes were found in other measured substances. CONCLUSION: Qd variations in HDF-OL do not change convective volume. A higher Qd was associated to a slightly increased urea clearance with no change being observed for medium and large molecules. Qd optimisation to the minimal level assuring an adequate dialysis dose and allowing water and dialysate use to be rationalised should be recommended.

Assessment of dialyzer surface in online hemodiafiltration; objective choice of dialyzer surface area.

INTRODUCTION: Online hemodiafiltration (OL-HDF) is currently the most effective technique. Several randomized studies and meta-analyses have observed a reduction in mortality as well as a direct association with convective volume. Currently, it has not been well established whether a larger dialyzer surface area could provide better results in terms of convective and depurative effectiveness. The aim of this study was to assess the effect of larger dialyzer surface areas on convective volume and filtration capacity. MATERIAL AND METHODS: A total of 37 patients were studied, including 31 men and 6 women, who were in the OL-HDF program using a 5008 Cordiax monitor with auto-substitution. Each patient was analyzed in 3 sessions in which only the dialyzer surface area varied (1.0, 1.4 or 1.8 m(2)). The concentrations of urea (60 Da), creatinine (113 Da), ß2-microglobulin (11800 Da), myoglobin (17200 Da) and α1-microglobulin (33000 Da) were determined in serum at the beginning and end of each session in order to calculate the percent reduction of these solutes. RESULTS: The convective volume reached was 29.8 ± 3.0 with 1.0 m(2), 32.7 ± 3.1 (an increase of 6%) with 1.4 m(2), and 34.7 ± 3.3 L (an increase of 16%) with 1.8 m(2) (p<.001). The increased surface of the dialyzer showed an increase in the dialysis dose as well as urea and creatinine filtration. The percentage of ß2m reduction increased from 80.0 ± 5.6 with 1.0 m(2) to 83.2 ± 4.2 with 1.4 m(2) and to 84.3 ± 4.0% with 1.8 m(2). As for myoglobin and a1-microglobulin, significant differences were observed between smaller surface area (1.0 m(2)) 65.6 ± 11 and 20.1 ± 9.3 and the other two surface areas, which were 70.0 ± 8.1 and 24.1 ± 7.1 (1.4 m(2)) and 72.3 ± 8.7 and 28.6 ± 12 (1.8 m(2)). CONCLUSION: The 40% and 80% increases in surface area led to increased convective volumes of 6 and 16% respectively, while showing minimal differences in both the convective volume as well as the filtration capacity when the CUF was higher than 45 ml/h/mmHg. It is recommended to optimize the performance of dialyzers with the minimal surface area possible when adjusting the treatment prescription.

Valoración de la superficie del dializador en la hemodiafiltración on-line. Elección objetiva de la superficie del dializador / Assessment of dialyzer surface in online hemodiafiltration; objective choice of dialyzer surface area

Introducción: La hemodiafiltración on-line (HDF-OL) es actualmente la técnica más efectiva. Varios estudios aleatorizados y metaanálisis han observado una reducción de la mortalidad, objetivándose una asociación en relación directa con el volumen convectivo. En el momento presente no está bien establecido si el aumento de superficie del dializador puede suponer mejores resultados en términos de eficacia convectiva y depurativa. El objetivo del estudio fue valorar el efecto del aumento de superficie del dializador sobre el volumen convectivo y la capacidad depurativa. Material y métodos: Se incluyeron 37 pacientes (31 varones y 6 mujeres) que se encontraban en programa de HDF-OL con monitor 5008Cordiax con autosustitución. Cada paciente fue analizado en 3 sesiones en las que solo se varió la superficie del dializador (1,0, 1,4 o 1,8m2). En cada sesión se determinaron la concentración de urea (60Da), creatinina (113Da), β2-microglobulina (11.800Da), mioglobina (17.200Da) y α1-microglobulina (33.000Da) en suero al inicio y al final de cada sesión, para calcular el porcentaje de reducción de estos solutos. Resultados: El volumen convectivo alcanzado fue de 29,8±3,0 con 1,0m2, de 32,7±3,1 (incremento del 6%) con 1,4m2 y de 34,7±3,3l (incremento del 16%) con 1,8m2 (p<0,001). El incremento de la superficie del dializador mostró un aumento de la dosis de diálisis y de la depuración de urea y creatinina. El porcentaje de reducción de β2-microglobulina se incrementó de 80,0±5,6 con 1,0m2, a 83,2±4,2 con 1,4m2 y a 84,3±4,0% con 1,8m2. Respecto a la mioglobina y la a1-microglobulina, se observaron diferencias significativas entre la menor superficie (1,0m2) 65,6±11 y 20,1±9,3; y las otras 2 superficies 70,0±8,1 y 24,1±7,1 (1,4m2) y 72,3±8,7 y 28,6±12 (1,8m2). Conclusión: El incremento del 40% y el 80% de la superficie conlleva un aumento del volumen convectivo de un 6 y un 16% respectivamente, aunque se evidenció una reducción en su máximo rendimiento, mostrando mínimas diferencias tanto en el volumen convectivo como en la capacidad depurativa cuando el CUF era superior a 45 ml/h/mmHg. Es recomendable optimizar el rendimiento de los dializadores a la mínima superficie posible adecuando la prescripción de tratamiento (AU)

Introduction: Online hemodiafiltration (OL-HDF) is currently the most effective technique. Several randomized studies and meta-analyses have observed a reduction in mortality as well as a direct association with convective volume. Currently, it has not been well established whether a larger dialyzer surface area could provide better results in terms of convective and depurative effectiveness. The aim of this study was to assess the effect of larger dialyzer surface areas on convective volume and filtration capacity. Material and methods: A total of 37 patients were studied, including 31 men and 6 women, who were in the OL-HDF program using a 5008 Cordiax monitor with auto-substitution. Each patient was analyzed in 3 sessions in which only the dialyzer surface area varied (1.0, 1.4 or 1.8 m2). The concentrations of urea (60 Da), creatinine (113 Da), β2-microglobulin (11800 Da), myoglobin (17200 Da) and α1-microglobulin (33000 Da) were determined in serum at the beginning and end of each session in order to calculate the percent reduction of these solutes. Results: The convective volume reached was 29.8 ± 3.0 with 1.0 m2, 32.7 ± 3.1 (an increase of 6%) with 1.4 m2, and 34.7 ± 3.3 L (an increase of 16%) with 1.8 m2 (p<.001). The increased surface of the dialyzer showed an increase in the dialysis dose as well as urea and creatinine filtration. The percentage of β2m reduction increased from 80.0 ± 5.6 with 1.0 m2 to 83.2 ± 4.2 with 1.4 m2 and to 84.3 ± 4.0% with 1.8 m2. As for myoglobin and a1-microglobulin, significant differences were observed between smaller surface area (1.0 m2) 65.6 ± 11 and 20.1 ± 9.3 and the other two surface areas, which were 70.0 ± 8.1 and 24.1 ± 7.1 (1.4 m2) and 72.3 ± 8.7 and 28.6 ± 12 (1.8 m2). Conclusion: The 40% and 80% increases in surface area led to increased convective volumes of 6 and 16% respectively, while showing minimal differences in both the convective volume as well as the filtration capacity when the CUF was higher than 45 ml/h/mmHg. It is recommended to optimize the performance of dialyzers with the minimal surface area possible when adjusting the treatment prescription (AU)

Hemodiafiltración on-line con autosustitución: valoración de los cambios del flujo de sangre sobre el volumen convectivo y eficacia / On-line haemodiafiltration with auto-substitution: assessment of blood flow changes on convective volume and efficiency

Introducción: La hemodiafiltración on-line (HDF-OL) es actualmente la técnica más efectiva y varios estudios aleatorizados y metaanálisis han visto una reducción de la mortalidad, observándose una asociación en relación directa con el volumen convectivo. El flujo de sangre (Qb) limita el flujo de infusión al 25-33 % y constituye el principal factor limitante para alcanzar un volumen de sustitución óptimo. Con la reciente incorporación de monitores con sistema de autosustitución, el objetivo del estudio fue valorar el efecto de las variaciones del Qb sobre el volumen convectivo y la capacidad depurativa. Material y métodos: Se incluyeron 23 pacientes, 17 varones y 6 mujeres, con una edad media de 65,5 ± 10 años, tiempo de diálisis 292,2 ± 15 min, que se encontraban en programa de HDF-OL con monitor 5008 Cordiax con autosustitución. Cada paciente fue analizado en cinco sesiones en las que solo se varió el Qb (250, 300, 350, 400 y 450 ml/min). En cada sesión se determinaron el volumen de sustitución, el volumen convectivo total y los parámetros de diálisis. Se determinó la concentración de urea (60 Da), creatinina (113 Da), β2-microglobulina (11 800 Da), mioglobina (17 200 Da), prolactina (23 000 Da), α1-microglobulina (33 000 Da) y α1-glicoproteína ácida (40 000 Da) en plasma al inicio y al final de cada sesión para calcular el porcentaje de reducción de estos solutos. Resultados: La presión transmembrana fue inferior con Qb 250 ml/min. Se observó un aumento significativo del volumen convectivo con el incremento del Qb, 23,7, 26,9, 30,2, 32,8 y 35,2 l/sesión a 250, 300, 350, 400 y 450 ml/min, respectivamente (P < 0,001), representando un porcentaje de la sangre total depurada del 33,2, 31,2, 30,2, 28,7 y 27,3 %, respectivamente. Los porcentajes de reducción de urea y creatinina aumentaron progresivamente con el Qb, se observaron ligeras diferencias con la β2-microglobulina y la mioglobina, y no se observaron cambios en las grandes moléculas. Conclusión: Por cada 50 ml/min de aumento del Qb el volumen convectivo aumenta entre 8 y 12 ml/min. El sistema de autosustitución potencia los Qb más bajos en el porcentaje del volumen convectivo respecto a la sangre total depurada. El Qb aumenta la capacidad depurativa de las moléculas pequeñas, favorece la de la β2-microglobulina y la mioglobina, y no influye en moléculas de superior peso molecular (AU)

Introduction: On-line haemodiafiltration (OL-HDF) is currently the most effective technique and several randomised studies and meta-analyses have seen a reduction in mortality and an association directly related with convective volume is observed. Blood flow (Qb) limits the infusion rate to 25-33 % and is the main limiting factor for reaching an optimum substitution volume. With the recent incorporation of monitors with auto-substitution systems, the aim of the study was to assess the effect of Qb variations on convective volume and purifying capacity. Material and Methods: 23 patients, 17 men and 6 women, were included, with an average age of 65.5 ±10 years, time on dialysis 292.2 ± 15 minutes, which were in the OL-HDF programme with the 5008 Cordiax monitor with auto-substitution. Each patient was analysed over 5 sessions in which only the Qb was changed (250, 300, 350, 400 and 450 ml/min). In each session the substitution volume, total convective volume and parameters of dialysis were measured. The concentration of urea (60 Da), creatinine (113 Da), β2-microglobulin (11,800 Da), myoglobin (17,200 Da), prolactin (23,000 Da), α1-microglobulin (33,000 Da) and α1-acid glycoprotein (40,000 Da) in plasma was measured at the start and end of each session in order to calculate the percentage of reduction of these solutes. Results: The trans-membrane pressure was less, with Qb 250 ml/min. A significant increase in convective volume was observed with the increase in Qb, 23.7, 26.9, 30.2, 32.8 and 35.2 l/session to 250, 300, 350, 400 and 450 ml/min, respectively (P < 0.001), representing a percentage of total purified blood of 33.2, 31.2, 30.2, 28.7 and 27.3 % respectively. The percentages of reduction of urea and creatine progressively increased with Qb, slight differences were observed with β2-microglobulin and myoglobin, and no changes were observed in the larger molecules. Conclusion: For each 50 ml/min increase in Qb, the convective volume increased by between 8 and 12 ml/min. The auto-substitution system strengthens the lowest Qbs in the percentage of convective volume with regards to total purified blood. Qb increases the purifying capacity of small molecules, favouring that of β2-microglobulin and myoglobin, and does not influence molecules of a greater molecular weight (AU)

On-line haemodiafiltration with auto-substitution: assessment of blood flow changes on convective volume and efficiency.

INTRODUCTION: On-line haemodiafiltration (OL-HDF) is currently the most effective technique and several randomised studies and meta-analyses have seen a reduction in mortality and an association directly related with convective volume is observed. Blood flow (Qb) limits the infusion rate to 25-33 % and is the main limiting factor for reaching an optimum substitution volume. With the recent incorporation of monitors with auto-substitution systems, the aim of the study was to assess the effect of Qb variations on convective volume and purifying capacity. MATERIAL AND METHODS: 23 patients, 17 men and 6 women, were included, with an average age of 65.5 ±10 years, time on dialysis 292.2 ± 15 minutes, which were in the OL-HDF programme with the 5008 Cordiax monitor with auto-substitution. Each patient was analysed over 5 sessions in which only the Qb was changed (250, 300, 350, 400 and 450 ml/min). In each session the substitution volume, total convective volume and parameters of dialysis were measured. The concentration of urea (60 Da), creatinine (113 Da), β2-microglobulin (11,800 Da), myoglobin (17,200 Da), prolactin (23,000 Da), α1-microglobulin (33,000 Da) and α1-acid glycoprotein (40,000 Da) in plasma was measured at the start and end of each session in order to calculate the percentage of reduction of these solutes. RESULTS: The trans-membrane pressure was less, with Qb 250 ml/min. A significant increase in convective volume was observed with the increase in Qb, 23.7, 26.9, 30.2, 32.8 and 35.2 l/session to 250, 300, 350, 400 and 450 ml/min, respectively (P < 0.001), representing a percentage of total purified blood of 33.2, 31.2, 30.2, 28.7 and 27.3 % respectively. The percentages of reduction of urea and creatine progressively increased with Qb, slight differences were observed with β2-microglobulin and myoglobin, and no changes were observed in the larger molecules. CONCLUSION: For each 50 ml/min increase in Qb, the convective volume increased by between 8 and 12 ml/min. The auto-substitution system strengthens the lowest Qbs in the percentage of convective volume with regards to total purified blood. Qb increases the purifying capacity of small molecules, favouring that of β2-microglobulin and myoglobin, and does not influence molecules of a greater molecular weight. 

Serologic features of primary Sjögren's syndrome: clinical and prognostic correlation.

Sjögren's syndrome (SS) is a chronic inflammatory systemic autoimmune disease. The disease spectrum extends from sicca syndrome to systemic involvement and extraglandular manifestations, and SS may be associated with malignancies, especially non-Hodgkin's lymphoma. Patients with SS present a broad spectrum of serologic features. Certain serological findings are highly correlated with specific clinical features, and can be used as prognostic markers.

Influence of prevalent vertebral fractures on the quality of life of patients with systemic lupus erythematosus.

BACKGROUND: The prevalence of vertebral fractures in systemic lupus erythematosus (SLE) ranges between 20% and 21.4%, and patients with these fractures have impaired walking and activities of daily living. Moreover, clinical and radiological vertebral fractures have been associated with increased mortality. OBJECTIVES: To compare the quality of life of patients with SLE with and without vertebral fractures. METHODS: The study group comprised 140 women with SLE undergoing screening for vertebral fractures using a standardized method. SLE disease activity and organ damage were measured by the Mexican Systemic Lupus Erythematosus Disease Activity Index (MEX-SLEDAI) and the Systemic International Collaborating Clinics/American College of Rheumatology damage index (SLICC), respectively. The QUALEFFO and Center for Epidemiologic Studies Depression Scale were used to measure health-related quality of life and depression, respectively. RESULTS: The median age of the 140 patients was 43 years (range 18-76); disease duration was 72 months (range 6-432); 49.7% were menopausal. Thirty-four patients (24.8%) had vertebral fractures (> or = 1), mostly in the thoracic spine. Patients with vertebral fractures had a higher mean age (49.5 +/- 13.4 vs. 41 - 13.2 years, P= 0.001) and disease damage (57.1% vs. 34.4%, P = 0.001). The global QUALEFFO score was not different between the vertebral fractures group and the non-vertebral group. The only significant difference in the QUALEFFO items was in physical function (P = 0.04). A significant correlation was found between the severity of vertebral fractures and the QUALEFFO pain (r = 0.27, P = 0.001) and physical function (r = 0.37, P = 0.02) scores. The number of vertebral fractures correlated only with physical function (r = 0.01). CONCLUSIONS: The HRQOL of women with SLE is low, regardless of whether they have vertebral fractures or not, but patients with vertebral fractures have worse physical function compared to those without. Strategies to improve the HRQOL of patients with SLE with or without vertebral fractures are necessary.

Susac's syndrome: an update.

Susac's syndrome is an infrequent neurological disorder characterized by the clinical triad of encephalopathy, hearing loss, and branch retinal artery occlusions. Its pathophysiology is not entirely clear, although it is now thought that it is most probably an immune-mediated endotheliopathy that affects the microvasculature of the brain, retina, and inner ear. An early diagnosis is important as treatment can halt disease progression and prevent permanent disability.

Immunopathogenesis of vitiligo.

Vitiligo is a common depigmenting disorder which may have devastating psychological and social consequences and is characterized by the presence of circumscribed white macules in the skin due to the destruction of melanocytes in the epidermis. Various hypotheses have been proposed to explain the pathomechanisms involved in this disease, and studies have shown the participation of autoimmune processes in the pathogenesis of vitiligo. Cellular and humoral immunities have been implicated in the development of vitiligo and their role continues to be investigated. Peripheral blood and skin biopsies of patients with vitiligo show that T-cells, mononuclear cells, various pro-inflammatory cytokines, and auto-antibodies can damage melanocytes. Further research is required to determine whether autoimmunity is the main mechanism of vitiligo or only a consequence.

Transradial percutaneous coronary intervention without on-site cardiac surgery for stable coronary disease and myocardial infarction: preliminary report and initial experience in 174 patients.

BACKGROUND: On-site cardiac surgery is not widely available in developing countries despite a high prevalence of coronary artery disease. OBJECTIVES: To analyze the safety, feasibility and cost-effectiveness of transradial percutaneous coronary intervention without on-site cardiac surgery in a community hospital in a developing country. METHODS: Of the 174 patients who underwent PCI for the first time in our center, we analyzed two groups: stable coronary disease and acute myocardial infarction. The primary endpoint was the rate of complications during the first 24 hours after PCI. We also analyzed the length of hospital stay and the rate of hospital readmission in the first week after PCI, and compared costs between the radial and femoral approaches. RESULTS: The study group comprised 131 patients with stable coronary disease and 43 with acute MI. Among the patients with stable coronary disease 8 (6.1%) had pulse loss, 12 (9.16%) had on-site hematoma, and 3 (2.29%) had bleeding at the site of the puncture. Among the patients with acute MI, 3 (6.98) had pulse loss and 5 (11.63%) had bleeding at the site of the puncture. There were no cases of atriovenous fistula or nerve damage. In the stable coronary disease group, 130 patients (99%) were discharged on the same day (2.4 +/- 2 hours). In the acute MI group, the length of stay was 6.6 +/- 2.5 days with at least 24 hours in the intensive care unit. There were no hospital readmissions in the first week after the procedure. The total cost, which includes equipment related to the specific approach and recovery room stay, was significantly lower with the radial approach compared to the femoral approach (US$ 500 saving per intervention). CONCLUSIONS: The transradial approach was safe and feasible in a community hospital in a developing country without on-site cardiac surgery backup. The radial artery approach is clearly more cost-effective than the femoral approach.

Etiopathogenesis of Behcet's disease.

Bechet's disease (BD) is an inflammatory, multi systemic disease with spontaneous remissions and relapses similar to various autoimmune diseases. BD leads to organ damage, including the eyes, skin, joints, etc., which produces various clinical manifestations. The central histopathologic characteristic is systemic vasculitis with perivascular inflammatory infiltrates. The etiopathogenesis is unknown, although immunological abnormalities, possibly induced by susceptible microbiological pathogens, have been postulated.

Osteoporosis in patients with systemic lupus erythematosus.

In recent years the survival of patients with systemic lupus erythematosus has increased markedly. Consequently, long-term complications, such as osteoporosis, are currently of paramount importance. SLE is known to increase the risk of bone fractures, and numerous studies have found that SLE patients have osteoporosis. Of the various risk factors associated with osteoporosis in SLE, disease duration, the use of corticosteroids and chronic disease-related damage are consistently reported, with differences between studies probably due to the different populations studied. The role of chronic inflammation in osteoporosis is also important. On the other hand, little attention has been paid to osteoporotic fractures, especially of the vertebra, which are associated with reduced quality of life, increased mortality rates and increased risk of new vertebral and non-vertebral fractures in the general population.

Risk factors of vertebral fractures in women with systemic lupus erythematosus.

The aim of the current study was to analyze the role of traditional and systemic lupus erythematosus (SLE)-related risk factors in the development of vertebral fractures. A cross-sectional study was performed in women with SLE attending a single center. A vertebral fracture was defined as a reduction of at least 20% of vertebral body height. Two hundred ten patients were studied, with median age of 43 years and median disease duration of 72 months. Osteopenia was present in 50.3% of patients and osteoporosis in 17.4%. At least one vertebral fracture was detected in 26.1%. Patients with vertebral fractures had a higher mean age (50 +/- 14 vs. 41 +/- 13.2 years, p = 0.001), disease damage (57.1% vs. 34.4%, p = 0.001), lower bone mineral density (BMD) at the total hip (0.902 +/- 0.160 vs. 982 +/- 0.137 g/cm(2), p = 0.002), and postmenopausal status (61.9% vs. 45.3%, p = 0.048). Stepwise logistic regression analysis revealed that only age (p = 0.001) and low BMD at the total hip (p = 0.007) remained as significant factors for the presence of vertebral fracture. The high prevalence of vertebral fractures in the relatively young population implies that more attention must be paid to detect and treat vertebral fractures.

Use of rituximab in patients with systemic lupus erythematosus: an update.

Systemic lupus erythematosus (SLE) is a chronic, occasionally life threatening, multisystem disorder. Patients suffer from a wide group of symptoms and have a variable prognosis that depends of the severity and type of organ involvement. The clinical manifestations include fever, skin lesions, arthritis, neurologic, renal, cardiac, and pulmonary disease. The pathogenesis of this serious multisystem autoimmune disease is based on polyclonal B cell immunity, which involves connective tissue and blood vessels. The novel biologic therapies have raised hope for more effective and safer treatment for SLE. Although definitive studies are still under development, the impressive preliminary results of therapies specifically targeting B cells and the signaling pathways involved in B-T-cell interactions suggest that the depletion of memory cells accounts, at least in part, for the clinical efficacy of rituximab therapy in patients whose disease is resistant to other immunosuppressive therapies. However these findings, although provocative, require further investigation in larger cohorts.