Long-term treatment with CL-EE efficiently improves the oxidative stress associated with hemodialysis and potentially reduces dialysis complications due to oxidative stress.

This study was designed to determine whether bisphenol A (BPA) is eluted from hemodialyzers in which polycarbonate and polysulfone based on BPA are used as materials. Four types of polysulfone hemodialyzer (PS hemodialyzer: PS-A, PS-B, PS-C and PS-D) and an ethylene-vinyl alcohol copolymer dialyzer (EVAL hemodialyzer) were used in this study. In the PS-C, PS-D and EVAL hemodialyzers, polycarbonate was used in the case headers at both ends of the hemodialyzer. In in vitro experiments, the hemodialyzers were filled with reverse osmotic water, and BPA concentrations were measured. Saline solution (200 ml) was then circulated through a blood circuit tube connected to the hemodialyzer, and BPA concentrations in the saline solution were measured. In in vivo experiments, BPA concentrations in whole blood samples from hemodialysis patients treated with PS-C (n = 3) and PS-D (n = 3) hemodialyzers were measured. In in vitro experiments, BPA was detected in the effluents of the PS-C, PS-D and EVAL hemodialyzers. In in vivo experiments, BPA was detected in whole blood samples from hemodialysis patients treated with the PS-D hemodialyzer (mean value, 0.77 ppb). This is the first report of BPA elution from hemodialyzers in which polycarbonate and polysulfone are used, and also the first report of detection of BPA in whole blood samples from patients on hemodialysis.

During hemodialysis, platelets are activated across a dialyzer. Soluble P-selectin (sP-selectin) is a form of P-selectin which is a glycoprotein relocated from secretory granules to the surfaces of platelets and endothelial cells after these cells have been physiologically activated. To investigate whether sP-selectin is useful as a marker of platelet activation during hemodialysis, we measured the plasma concentration of sP-selectin by enzyme-linked immunosorbent assay in 6 patients hemodialyzed in our institute using regenerated cellulose (RC) membranes and thereafter polysulfone membranes. Concomitantly, we also measured the plasma concentration of platelet factor 4 and β-thromboglobulin which are released from α-granules of activated platelets. During hemodialysis with RC membranes, the β-thromboglobulin level was significantly increased 15 min (p < 0.05) and the sP-selectin level 15 (p < 0.05) and 180 min (p < 0.05) after initiation of dialysis on the venous side as compared with the arterial side of the hemodialyzer. During hemodialysis with polysulfone membranes, no significant variation in plasma β-thromboglobulin and sP-selectin levels was detected. The platelet factor 4 level increased more significantly across a dialyzer 180 min after initiation of dialysis with RC than with polysulfone membranes (p < 0.01). The changes in plasma platelet factor 4 and β-thromboglobulin levels demonstrated that platelets are more activated during hemodialysis with RC than with polysulfone membranes. The changes in plasma sP-selectin levels during hemodialysis with RC confirm that the release of P-selectin purely from activated platelets was detected by enzyme-linked immunosorbent assay. sP-selectin may be a marker of platelet activation during hemodialysis.

The aim of this study was to determine the significance of 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is known as a marker of oxidative stress in vivo, in patients with chronic renal failure (CRF). Fifty-one non-dialysed CRF patients (29 men and 22 women; mean +/- SD age, 57.8 +/- 12.8 years) who were under dietary therapy for at least 6 months were enrolled in the study. Both serum and urinary 8-OHdG levels were measured by using high-sensitive enzyme-linked immunosorbent assay (ELISA) kits. We examined the relationship between 8-OHdG levels and clinical indices in patients with CRF. As a result, the serum 8-OHdG level was strongly correlated with serum levels of urea nitrogen (UN; r = 0.58; P < 0.0001), creatinine (Cr; r = 0.53; P < 0.0001), and beta2-microglobulin (beta2-MG; r = 0.54; P < 0.0001). Furthermore, the serum 8-OHdG level was inversely correlated with creatinine clearance (Ccr; r = -0.54; P < 0.0001). In contrast, urinary 8-OHdG level was not correlated with any of the clinical parameters. This is the first report of 8-OHdG level determination in patients with CRF. It is suggested that serum 8-OHdG level is not sufficient as a marker of oxidative damage in patients with CRF, and it should be corrected according to the residual renal function to estimate the accurate degree of oxidative stress.

The demethylation pathway in methionine metabolism in the liver, which is linked directly to the creatinine generation system, may be disturbed in diabetic patients on HD. This may be the reason why serum tHcy and creatinine in diabetic patients on HD are lower than in non-diabetic patients on HD. Therefore, it is necessary to consider the possibility of an altered relation between serum tHcy and vessel disease when evaluating the atherogenic risk in diabetic patients on HD.