Cumulative iron dose and resistance to erythropoietin.

INTRODUCTION: Optimizing anemia treatment in hemodialysis (HD) patients remains a priority worldwide as it has significant health and financial implications. Our aim was to evaluate in a large cohort of chronic HD patients in Fresenius Medical Care centers in Spain the value of cumulative iron (Fe) dose monitoring for the management of iron therapy in erythropoiesis-stimulating agent (ESA)-treated patients, and the relationship between cumulative iron dose and risk of hospitalization. METHODS: Demographic, clinical and laboratory parameters from EuCliD(®) (European Clinical Dialysis Database) on 3,591 patients were recorded including ESA dose (UI/kg/week), erythropoietin resistance index (ERI) [U.I weekly/kg/gr hemoglobin (Hb)] and hospitalizations. Moreover the cumulative Fe dose (mg/kg of bodyweight) administered over the last 2 years was calculated. Univariate and multivariate analyses were performed to identify the main predictors of ESA resistance and risk of hospitalization. Patients belonging to the 4th quartile of ERI were defined as hypo-responders. RESULTS: The 2-year iron cumulative dose was significantly higher in the 4th quartile of ERI. In hypo-responders, 2-year cumulative iron dose was the only iron marker associated with ESA resistance. At case-mix adjusted multivariate analysis, 2-year iron cumulative dose was an independent predictor of hospitalization risk. DISCUSSION: In ESA-treated patients cumulative Fe dose could be a useful tool to monitor the appropriateness of Fe therapy and to prevent iron overload. To establish whether the associations between cumulative iron dose, ERI and hospitalization risk are causal or attributable to selection bias by indication, clinical trials are necessary.

[Resistance index to epoetin alpha and to darbepoetin-alpha in chronic hemodialysis patients: a cohort study]. / Estudio de dos cohortes de pacientes para evaluar el índice de resistencia a epoetina alfa y a darbepoetin alfa en pacientes en hemodiálisis crónica.

The effectiveness of the erythropoietic response can be evaluated using the resistance index (RI) to erythropoietic agents (EA) that measures the relationship between the dose administered and the hemoglobin levels attained. In a hemodialysis population, the RI is associated with several clinical and biochemical parameters, such as albumin levels, C-reactive protein (CRP), body mass index (BMI) and Kt/V. This index therefore reflects an important group of parameters that indicate comorbidities and measures the effectiveness of the treatment received. A substantial proportion of chronic hemodialysis patients show a relative resistance to human recombinant erythropoietin (rHuEPO) and require high doses to reach hemoglobin levels above 11 g/dl. Darbepoetin alpha is a new erythropoietic agent with a longer half-life than rHuEPO and greater biological activity in vivo. Furthermore, it remains at clinically effective plasma levels for much longer than rHuEPO. This study evaluated the effect on RI of switching from epoetin alpha to darbepoetin alpha in hemodialysis patients requiring i.v. rHuEPO at either high ( >10,000 UI/w) or low ( <4,000 UI/w) doses, compared to a control group receiving epoetin alpha. Unlike the control group, both groups of patients who switched to darbepoetin alpha showed a reduction in RI and a progressive reduction in the dose required of darbepoetin alpha with respect to the equivalent dose at treatment conversion. In the group requiring high doses, darbepoetin alpha RI (DRI) at week 24 was a significant 23.9% lower than epoetin alpha RI (ERI) at conversion (week 0) (p <0.01). In the group requiring low doses, DRI at week 24 was 13.4% lower than the ERI at conversion (p = NS). In both control groups, ERI at week 24 was higher than ERI at week 0. All groups showed stable hemoglobin levels across the study, with mean levels between 11.5 and 13.3 g/dl. CRP at week 24 was significantly related to albumin levels (p <0.001). In conclusion, switching hemodialysis patients from epoetin alpha to darbepoetin alpha was associated with a significant improvement in RI in the group of patients with high doses of EA, which we consider to be an important indicator of the effectiveness and quality of the treatment administered.

[Guidelines for quality management of dialysis solutions]. / Guías de gestión de calidad del líquido de diálisis (LD).

A Best Practice Guideline about Dialysis fluid purity has been developed under the leadership of the Spanish Society of Nephrology. The Guideline has established recommendations for standards for preparing dialysate: water, concentrates and hemodialysis proportioning systems. The Guideline was based on the European pharmacopoeia, the Real Farmacopea Española, the AAMI Standards and Recommended Practices, European Best Practice Guidelines for Haemodialysis (Section IV), literature reviews, according to their level of evidence, and the opinion of the expert spanish group. Two levels of quality of water were defined: purified water and high purified water (Ultra pure) and for dialysate: standard dialysate and ultra pure dialysate. Regular use of ultra pure dialysate is necessary for hemofiltration and hemodiafiltration on-line and desirable for high-flux hemodialysis to prevent and delay the occurrence of complications: inflammation, malnutrition, anemia and amyloidosis. Water, concentrates and dialysate quality requirements are defined as maximum allowable contaminant levels: chemicals (1.1.2), microbial and endotoxins: [table: see text] Monitoring frequency, maintenance and corrective actions were specified. Methods of sampling and analysis were described in appendix (Anexos). For microbiological monitoring, TSA or R2A medium are recommended, incubated during 5 days at a temperature of 30-35 degrees C. The dialysate quality assurance process involves all dialysis staff members and requires strict protocols. The physician in charge of hemodialysis has the ultimate responsibility for dialysate quality. All suggestions and questions about this Guideline are wellcome to www.senefro.org

[Mitomycin C in open angle glaucoma surgery with previous failed glaucoma surgery]. / Mitomicina C en la cirugía del glaucoma de ángulo abierto con fracaso quirúrgico previo.

PURPOSE: This study investigates the results of trabeculectomy with peroperative topical application of mitomycin-C performed on eyes with previous failed glaucoma filtering surgery. METHODS: The study includes 34 eyes of 26 patients operated on open angle glaucoma between March 1992 and October 1996, with a minimum of 6 months follow-up (mean 28.1 months). All the eyes had undergone prior one (27) o two (7) filtering surgeries. We evaluated intraocular pressure (IOP) and treatment reduction after surgery. Success was defined as IOP <20 mmHg, without deterioration of the visual field and/or papilla and without oral carbonic anhydrase inhibitors (OCAI) treatment. RESULTS: Average IOP decrease (p<0,001) from 21.06+/-3.70 mmHg to 13.88+/-2.42 mmHg after surgery and the number of medications dropped from 2.44+/-0.69 to 0.68+/-1.02 (p<0.01). The success rate was 88.2%. The major complication was hypotony maculopathy in 3 eyes (8.8%). CONCLUSIONS: Trabeculectomy with mitomycin-C decreases IOP and postoperative medications in eyes with previous unsuccessful filtering surgery.

[The Ahmed valve implant in complicated glaucoma]. / El implante valvular de Ahmed en el glaucoma complicado.

PURPOSE: Prospective study initiated in September of 1994 in patients with complicated glaucoma who had had the Ahmed valve implanted. METHODS: 12 eyes from 12 patients were studied until February of 1996, with a median follow-up of 9.3+/-5.1 months (range 3-18 months). The most common diagnostic was pseudophakic glaucoma (8 ojos). 3 eyes had aphakic glaucoma and 1 eye had traumatic glaucoma. The success is defined as intraocular pressure (IOP)

[Determination of the degree of renal functioning and cardiovascular risk factors in an aged population seen at a health center]. / Determinación del grado de funcionamiento renal y factores de riesgo cardiovascular en la problación anciana adscrita a un centro de salud.

We report the results of a study to assess the glomerular filtration rate in the elderly population seen at the center and to investigate the prevalence of cardiovascular risk factors and use of drugs in this age group. The glomerular filtration rate could be measured in 64.6% of the elderly population. In 94 (17.6%) of the 825 evaluated individuals the clearance values were 50 ml/min or lower. Only 6 of them had previously known chronic renal failure. A high prevalence of concomitant cardiovascular risk factors was found (48.7% were hypertensive, 25.1% diabetic, 19% smokers, 24.1% had hyperlipidemia and 38.8% were obese). The rate of drug use was also high (69.6% took two or more drugs sustainedly). These findings indicate the need to evaluate the renal function in elderly people before prescribing drug therapy.

[IgA mesangial glomerulonephritis (author's transl)]. / La glomerulonefritis mesangial IgA.

Glomerulonephritis with mesangial deposition of IgA was diagnosed in 31 patients. In Spain this disease is the second more frequent primary glomerulonephritis, representing 27% of them. One out of every four patients with IgA mesangial glomerulonephritis ends the clinical course in renal failure. Such bad evolution might be predicted by the existence of arterial hypertension, severe proteinuria, degree of glomerular sclerosis, presence of HLA Bw35, and increased polymeric IgA in serum. The present pathogenetic concepts are reviewed.

[Surgical treatment of carcinoma of the esophagogastric junction]. / Tratamiento quirúrgico del carcinoma de la unión esofagogástrica.

The results obtained from diagnosis and treatment of six patients with cardioesophagic junction cancer, diagnosed by histopathologic study during surgery, are presented. Three patients presented with diaphragmatic hernia as well. Esophagogastroduodenal roentgenological study was interpreted as neoplasia in three patients only; it was supposed that the other three patients had a benign esophageal stricture. Endoscopy oriented the malignity diagnosis in four patients, and for benign lesion in the other two. Biopsy showed malignant lesion in three patients and it was negative in the other three. Exfoliative cytology was positive in four patients and negative in two. Esophagogastric resection was done in four patients. One of them died post-operatively. The other have survived 36, 22 and 16 months.