Evaluation of the Impact of a New Synthetic Vitamin E-Bonded Membrane on the Hypo-Responsiveness to the Erythropoietin Therapy in Hemodialysis Patients: A Multicenter Study

BACKGROUND

Oxidative stress has been related to hypo-response to erythropoiesis-stimulating agents (ESAs) in hemodialysis (HD) patients. The aim of this study was to verify whether vitamin E (ViE) on a synthetic polysulfone dialyzer can improve ESA responsiveness.

METHODS

This controlled, multicenter study involved 93 HD patients on stable ESA therapy, who were randomized to either ViE-coated polysulfone dialyzer or to a low-flux synthetic dialyzer. The primary outcome measure was the change in ESA resistance index (ERI) from baseline.

RESULTS

Mean ERI decreased in the ViE group by 1.45 IU/kg*g/dl and increased in the control group by 0.53 IU/kg*g/dl, with a mean difference of 1.98 IU/kg*g/dl (p = 0.001 after adjusting for baseline ERI, as foreseen by the study protocol). Baseline ERI was inversely related to its changes during follow-up only in the control group (R2 = 0.29).

CONCLUSIONS

The ViE dialyzer can improve ESA response in HD patients. Changes in ERI during follow-up are independent from baseline ERI only in the ViE group. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=453442.

Effects of a vitamin E-bonded membrane and of glutathione on anemia and erythropoietin requirements in hemodialysis patients

BACKGROUND

The oxidative damage of RBC membranes in hemodialysis (HD) patients increases red blood cell (RBC) susceptibility to hemolysis and impairs cell survival. Reduction of the oxidative stress might lead to better control of anemia and reduction of the erythropoietin (rhEPO) dose.

METHODS

We studied 38 stable HD patients, given a mean dose of rhEPO of 104+/-65 U/kg BW/week, at baseline and during antioxidant treatment with either a full or a 50% dose of EPO. Antioxidant treatment involved the combined use of glutathione, GSH (1200 mg i.v. at the end of each dialysis session) and a vitamin E-bonded HD membrane, CL-E. RBC and reticulocyte counts were done monthly. RBC survival (51Cr T/2) was assayed in 18 patients before and after the end of the study. Oxidative status was determined in 10 patients by measuring plasma concentrations of malondyhaldeide-4-hydroxynonenal (MDA-4HNE), reactive oxygen molecular species (ROMs), and oxydized-LDL (oxLDL) as indices of oxidative stress, alpha-tocopherol and total thiols as single antioxidants, and TAS as a marker of total antioxidant plasma activity.

RESULTS

Antioxidant treatment significantly reduced the high basal plasma concentrations of MDA4HNE and oxLDL, and significantly increased those of alpha-tocopherol, whereas TAS and thiols were unmodified. These changes lasted after the reduction of EPO. Anemia significantly improved with treatment, due to a significant increase in RBC survival. A close direct linear relationship was detected between plasma levels of vitamin E and hemoglobin.

CONCLUSIONS

Adequate control of oxidative stress achieves better control of anemia in HD patients. Since several antioxidant systems are impaired in uremia, the combined use of the CL-E membrane and GSH seems to be the best antioxidant therapy so far, with significant saving of the rhEPO dose.

Clinical manifestations in patients on chronic dialysis with high titres of ANCA

Eight untreated patients with an apparent renal-limited disease continued to maintain high titres of ANCA long after the onset of the disease and the start of dialysis. In spite of the high ANCA titres, three of them remained for a long time free of symptoms related to the disease. Three pts developed, at various times from the beginning of the disease, fatal pulmonary hemorrhages.

Prospective controlled trial of a Y-connector and disinfectant to prevent peritonitis in continuous ambulatory peritoneal dialysis

A controlled study in two centres compared the efficacy of the standard continuous ambulatory peritoneal dialysis (CAPD) system with that of a new method consisting of a Y-shaped set filled with sodium hypochlorite during the dwelling time. 62 new CAPD patients were randomly allocated to the standard method (group A: 30 patients; age 55.5 +/- 17.5 years) or to the Y-system (group B: 32 patients; age 55.1 +/- 14.3 years). In group A, there were 31 peritonitis episodes in 17 patients (57%) during a cumulative period of 351 months--1 episode every 11.3 patient-months. In group B, there were 11 peritonitis episodes in 10 patients (31%) during 363 months--1 episode every 33 patient-months. Life-table analysis showed a significant difference between the incidence of peritonitis in the two groups. The Y-system method is simple and economical and the frequency and the severity of side-effects appears to be acceptable.