The effects of 1-year treatment with a haemodiafiltration with on-line regeneration of ultrafiltrate (HFR) dialysis on biomarkers of oxidative stress in patients with chronic renal failure.

In the last few years haemodiafiltration with on-line regeneration of ultrafiltrate (HFR) has been shown to have a positive impact on inflammation and oxidative stress biomarkers, but its effect on antioxidant levels and on oxidative damage to biomolecules in the long-term is still unknown. This is a randomised clinical study over 12 months involving 40 patients on haemodialysis, comparing the effect of HFR (n=25) dialysis with haemodialysis with polysulfone (HD-PS, n=15) on oxidative stress. Total antioxidant capacity, enzymatic antioxidant [superoxide dismutase (SOD), catalase and glutathione peroxidase], non-enzymatic (GSH) and biomarkers of oxidative stress (TBARs, carbonyl groups and 8-OH-dG) were evaluated. The antioxidant activity decreased in the lymphocytes of patients dialysed with HFR, with a significant decrease in the enzyme SOD. In the oxidative stress biomarkers, an increase was seen in the levels of 8-OH-dG in patients on HD-PS dialysis but not in those treated with HFR. Throughout the year the changes in antioxidant levels and biomarkers of oxidative damage in patients dialysed with HFR were generally more modest and fluctuated less than those dialysed with HD-PS. Our study indicates that, in general, long-term dialysis with HFR does not modified antioxidant parameters or increases the oxidative damage to biomolecules. The HFR showed to be a biocompatible technique for long-term dialysis.

Fracaso agudode injerto renal poramiloidosis AA de novo en una paciente afectada de pioderma gangrenoso / No disponible

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Effect of a hemodiafiltration session with on-line regeneration of the ultrafiltrate on oxidative stress. Comparative study with conventional hemodialysis with polysulfone.

BACKGROUND: The influence of a dialysis session using hemodiafiltration with on-line regeneration of the ultrafiltrate (HFR) is compared with that of a conventional hemodialysis session with polysulfone (HD-PS) and with a group of healthy individuals. METHODS: Total antioxidant capacity (TAC), antioxidants, i.e., superoxide dismutase (SOD) glutathione peroxidase (GPX), reduced glutathione (GSH) and catalase, and biomarkers of oxidative stress were evaluated in plasma, whole blood and lymphocytes. RESULTS: The study showed decreased plasma TAC, decreased activities of antioxidant enzymes and decreased GSH levels along with increased thiobarbituric-acid-reactive substances and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels in lymphocytes. The antioxidants and biomarkers of lipid and protein damage after dialysis sessions with HFR were similar or better than following HD-PS. Thus, the blood GPX activity was comparable to that of healthy controls and significantly better than following HD-PS. An increase in 8-OHdG levels was observed in the HD-PS group after dialysis but not in the HFR group. CONCLUSIONS: These results show that HFR induces less oxidative stress than HD-PS.

Different functional characteristics of residual nephrons in infantile vs adult diffuse cortical necrosis.

In this report we study the functional characteristics of residual nephrons in a 37 year-old woman, 7 months after diffuse bilateral cortical necrosis (CN) of unknown etiology, and in two infants, aged 13 and 15 months, who suffered CN in early infancy after surgical shock and acute dehydration, respectively. In the three cases CN was proven histologically by renal biopsy but undamaged nephrons were only present in the juxtamedullary area in the adult patient whereas in the two infants they were located in the outer part of the cortex. At the time of the study all patients presented a similar degree of renal insufficiency (creatinine clearance: 17-23 ml/min/1.37 m2). The adult patient showed a partly conserved ability to concentrate the urine, a marked free water formation in relation to the degree of distal sodium delivery and an unimpaired capacity to acidify the urine after an acid load. Both infants, by the contrary, were unable to concentrate the urine, had lower free water formation at similar rates of distal sodium delivery and presented a clear incapacity to acidify the urine. These results confirm previous finding indicating the sparing of juxtamedullary nephrons after CN in the adult subject but favor the existence of a surviving population of superficial nephron when CN occurs in early infancy. These differences are probably in relation with associated damage of deep cortex and medulla infancy due to the specific characteristics of blood flow distribution present at that age.