Emilio Sanchez-Casado

Assessment of Iron Status by Erythrocyte Ferritin in Uremic Patients With or Without Recombinant Human Erythropoietin Therapy

Erythrocyte ferritin may be a better estimator of iron bioavailability than the conventional markers of iron stores (serum ferritin and transferrin saturation). To investigate the accuracy of these conventional markers in uremic patients compared with erythrocyte ferritin, we studied 29 chronic hemodialysis patients on erythropoietin (EPO) therapy, 18 without EPO therapy, and 22 healthy control subjects. Apart from the red blood cell indices, serum ferritin, transferrin saturation, and erythrocyte ferritin, the analytical study included red blood cell protoporphyrin and plasma aluminum levels. The control group showed erythrocyte ferritin concentrations between 8.3 and 12.5 attograms/cell (95% confidence interval). In the EPO group, red blood cell protoporphyrin correlated negatively with erythrocyte ferritin, but not with serum ferritin or transferrin saturation. In the non-EPO group, serum ferritin, erythrocyte ferritin, and transferrin saturation did not correlate with red blood cell protoporphyrin. Even though erythrocyte ferritin correlated well with serum ferritin in the EPO group (r = 0.61, P = 0.0003), the sensitivity of normal serum ferritin levels (30 to 300 ng/mL) to discard a low erythrocyte ferritin concentration (erythrocyte ferritin less than 7 ag/cell) was 0.53, while the sensitivity of serum ferritin at levels less than 30 ng/mL to indicate an absolute iron deficiency expressed as a low erythrocyte ferritin concentration was 0.28. Only values of serum ferritin and transferrin saturation greater than 300 ng/mL and 35%, respectively, could rule out a relative iron deficiency expressed as a low erythrocyte ferritin and high red blood cell protoporphyrin concentration. Plasma aluminum levels did not correlate with red blood cell protoporphyrin or erythrocyte ferritin levels in either uremic group.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodialysis With Cuprophane or Polysulfone: Effects on Uremic Polyneuropathy

A longitudinal study was performed of 11 patients on hemodialysis (HD) who where changed from cuprophane (CU) to polysulfone (PSF) membranes. Delivered Kt/V was approximately 1.1 throughout the study period. Motor conduction velocities (MCV) and sensory conduction velocities (SCV) were measured predialysis and postdialysis while the patients were still on CU membranes, 1 month after changing to PSF, and 12 months after changing to PSF. There was no change in predialysis MCV or SCV. For example, predialysis MCV with CU (43.6 +/- 6.2) was still 43.6 +/- 4.8 m/s after 1 year of PSF dialysis (P = NS). Similarly, predialysis SCV with CU (45.1 +/- 4.6 m/s) was not increased after 1 year of PSF dialysis (42.0 +/- 3.6 m/s). However, the predialysis versus postdialysis comparisons did show a difference between CU and PSF for SCV. PSF dialysis increases SCV by 3.0 +/- 3.8, whereas with CU dialysis the increase in SCV (0.7 +/- 2.4) was not significant (delta SCV-CU v delta SCV-PSF, P < 0.05). Acutely, dialysis with both CU and PSF increased MCV by the same amount (CU, 1.5 +/- 2.1; PSF, 2.8 +/- 3.5; delta MCV-CU, P < 0.05; delta MCV-CU v delta MCV-PSF, P = NS). The results suggest that dialysis with PSF membranes acutely improved SCV more than dialysis with CU membranes. However, changing to PSF does not improve predialysis SCV values. Dialysis with both membranes improves MCV to the same extent.

Sympathetic skin response in peritoneal dialysis patients

To determine if there is any difference in nerve conduction studies or sympathetic skin response (SSR) between patients on peritoneal dialysis and those on regular hemodialysis, we did a cross-sectional observational study. The study group consisted of 24 patients on peritoneal dialysis (PD) (12 men, aged 45 ± 17 years) and 20 patients on hemodialysis (HD) (11 men, aged 50 ± 22 years). All of these patients were in stable clinical condition, they were receiving adequate dialysis, and none of them had systemic diseases. Motor and sensory nerve conduction studies of the common and medial peroneal nerve and SSR were performed in all patients. There were no differences in motor and sensory nerve conduction velocities between PD and HD patients. All PD patients had detectable SSR. However, six patients on HD (30%) failed to show SSR (p < 0.05). Mean SSR amplitude was higher in PD patients than in HD patients (1233 ± 843 vs. 605 ± 771 &mgr;v, p < 0.05). There were no differences in mean SSR latency between PD and HD patients. PD modality (continuous ambulatory PD vs. automated PD) or the presence of residual renal function did not influence nerve conduction studies or SSR. In conclusion, using standard nerve conduction studies, no differences could be found between HD and PD. However, a higher proportion of patients on HD showed an impaired SSR, suggesting that subclinical neuropathy may be more common in HD than PD patients.

Angiotensin-converting enzyme inhibitors versus angiotensin receptor blockers for diabetic nephropathy: a retrospective comparison.

Introduction. There are no adequate head-to-head comparisons of angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB) in type 2 diabetic patients in spite of some interesting attempts. Furthermore, there are no adequate studies about the effects of ACE inhibitors in type 2 diabetic patients, who are the great majority of diabetic individuals. This study has retrospectively compared the effects of ACE inhibitors and ARBs used to treat diabetic nephropathy in a group of type 2 diabetic subjects. Design and methods. Patients (n=154) were treated with ACE inhibitors (mean age 59.5±13.3 years, 52.6% were male). Eighty-five patients had been treated with ARBs from 1999 until now (mean age 62.6±10.9 years, 56.0% were male, differences not significant). Kaplan-Meier survival analysis was used to calculate survival before reaching end-stage renal disease (ESRD) (glomerular filtration < 15 ml/min, stage V of renal disease as defined by KDOQI clinical guidelines) or starting renal replacement therapy. Only patients treated for more than six months were included in the survival analysis. Comparison of survival was made at three, five and seven years after starting treatment. Results. Pre-ESRD survival was 91.9% at three years, 81.6% at five years and 61.9% at seven years of follow-up for patients treated with ACE inhibitors. For patients treated with ARBs, pre-ESRD survival was 95.3% at three years, 82.1% at five years and 78.2% at seven years of follow-up (p=0.02, log-rank test). At 36 months, the comparative odds ratio for having started renal replacement therapy or reaching end-stage renal failure was 0.246 (95% confidence interval 0.114—0.531, p<0.001 for chi-square and likelihood ratio tests). The risk for the ARB cohort was 0.682 (95% confidence interval 0.578—0.804), meanwhile for ACE inhibitor patients it was 2.768 (95% confidence interval 1.481—5.172). Conclusions. The effects of ACE inhibitors and ARBs seem to be different, favouring the use of ARBs. These results may have been influenced by the different circumstances when each kind of drug was indicated, since ARBs were used with the specific recommendations for control of blood pressure in diabetic patients. An earlier referral of these patients may also have had some effect on these results. The need for a well-designed prospective study on type 2 diabetic patients with heavy proteinuria is warranted.

Estudio prospectivo controlado aleatorizado sobre el uso precoz de espironolactona o losartán en la regresión de la HVI postrasplante renal

La hipertrofia ventricular izquierda (HVI) es una afeccion prevalente en dialisis. Existen evidencias contradictorias sobre la remision de HVI tras el trasplante que influyen en la morbilidad cardiovascular y muerte subita postrasplante. Los trasplantados tienen un incremento de actividad del eje RAA y TGF beta 1 que podria evitar la remision de HVI en el postrasplante. El uso precoz de espironolactona o losartan podria favorecer una paulatina remision de la misma. Material y metodos: Estudio controlado con 44 pacientes (11 por rama) sobre el efecto de espironolactona, losartan o la combinacion en un uso antes de los 2 primeros meses sobre la remision de HVI. Seguimiento de 2 anos con ecocardiografia inicial, al ano y a los 2 anos tras la intervencion. Medicion de niveles TFG beta 1. Resultados: No hubo diferencias en variables demograficas, parametros ecocardiograficos funcion renal ni tension arterial en los 4 grupos previamente a la intervencion. Al 1.er ano se encontraron diferencias en el volumen de la auricula izquierda (VAI) y en el indice de masa ventricular izquierda (IMVI) siendo estas diferencias mayores en el grupo de espironolactona. Al 2.° ano se objetivaron cambios en el grosor de pared posterior (8,6 vs. 11,5 mm; p = 0,001), tabique interventricular (9,8 vs. 12,7 mm; p = 0,001), VAI ajustada a superficie corporal (22,5 vs. 32,5 ml/m2; p = 0,017), masa ventricular izquierda ajustada a superficie corporal (73 vs. 102 g/m2; p = 0,001), IMVI (36 vs. 48,5; p = 0,001), en el grupo de espironolactona respecto al grupo control, pero no en contrastes de los otros grupos. Estos cambios fueron independientes de los niveles de TGF beta 1. Existe correlacion estrecha de la dosis de espironolactona con espesores ventriculares, IMVI y VAI. El uso de espironolactona no se relaciono con hipercaliemia toxica. Conclusiones: El uso de espironolactona se asocia a remision de HVI postrasplante y VAI de forma independiente del control tensional, funcion renal y niveles TGf beta 1.

Influye el monitor en el volumen de infusión de la hemodiafiltración online

Introduccion y objetivo: Recientes estudios muestran asociacion entre mortalidad y volumen convectivo total (VCT) en la HDF online-post. El sistema Ultracontrol (EvosysUC) de Gambro o el sistema de autosustitucion de la 5008 CorDiax de Fresenius (5008-C) incorporan avances tecnologicos que intentan maximizar el volumen de infusion (VI). El objetivo del presente trabajo es comparar en un grupo de pacientes que realiza habitualmente HDF online-post el VI conseguido con ambos monitores y con 2 filtros diferentes, manteniendo constantes el resto de parametros de la dialisis. Material y metodo: Hemos realizado a 11 pacientes 6 sesiones con monitor 5008-C y 6 sesiones con Evosys UC, utilizando 2 filtros diferentes Fx-80 y Evodial 2,2 a lo largo de 4 semanas consecutivas. Se ha mantenido constante el tiempo de 4 h, Qb 350-400 ml/m y Qd 500 ml/m. Un total de 6 pacientes tenian FAV y 5 cateter. Los parametros de dialisis recogidos en cada sesion han sido: VI, peso, Kt medido por dialisancia ionica, PA, PV y PTM inicial y final, TAS y TAD horaria, ultrafiltracion total, volumen de sangre tratada, numero de alarmas del monitor y tolerancia por parte del paciente. Analiticamente se determino cada semana hematocrito, proteinas totales y albumina. Resultados: Analizamos 128 sesiones, 63 con 5008-C y 62 con Evosys- UC. El VI medio fue de 24,18 L, 22,99 ± 3,21 con 5008-COR frente a 25,34 ± 3,33 con Evosys-UC. En el analisis multivariante, ajustando todas las demas variables, cambiar del monitor 5008-Cordiax al monitor Evosys-UC supone un aumento de 1,64 L (0,90-2,38 l) en el VI, p < 0,001. El filtro, el volumen de sangre tratada y las proteinas totales son otros de los factores influyentes de forma significativa. Conclusiones: En pacientes que no consiguen un VI optimo con 5008-C, una opcion puede ser cambiar al sistema Ultracontrol de Gambro ya que otros factores pueden no ser modificables.