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Examines whether standards for dialysate purity in hemodialysis is insufficiently strict. Ultrapure dialysis fluid and cytokine production in clinical dialysis; Ultrapure dialysis fluid and dialysis-related arnyloidosis; Response of ultrapure dialysis fluid to recombinant human erythroprotein.

Background. The CD14 molecule is a high-affinity receptor for the complex formed by lipopolysaccharide (LPS) and LPS-binding protein. Methods. We examined by flow cytometry the effect of in vitro and in vivo haemodialysis on cuprophane membrane and recombinant C5a on the expression of CD14 molecules at the surface of monocytes. Monocyte CD14 expression was also studied during in vitro and in vivo haemodialysis on polyacrylonitrile AN69 membrane. Results. In vitro haemodialysis of whole blood from healthy volunteers on cuprophane membrane resulted within 30 min in upregulation of monocyte CD14 expression. The reuse of the cuprophane membrane abolished both complement activation and CD14 upregulation. Moreover, incubation of whole blood with recombinant C5a led to an increased monocyte CD14 expression supporting a role for complement activation in the rapid cuprophane-induced CD14 upregulation. During AN69 dialysis which is not associated with complement activation in the blood phase, monocyte CD14 expression did not change during the first 60 min but was significantly increased after 3 h of in vitro haemodialysis. This late increase might be related to the presence of complement activation products adsorbed on the membrane. In vivo dialysis on cuprophane membrane also resulted in early monocyte CD14 upregulation as indicated by the higher CD14 expression found after 60 min on monocytes obtained from the efferent as compared to the afferent line of the dialyser, a phenomenon that was not observed during haemodialysis on AN69 membrane. Conclusions. Haemodialysis on the complement-activating cuprophane membrane induces the rapid upregulation of the CD14 LPS-receptor on monocytes. [ABSTRACT FROM PUBLISHER]

Enhanced levels of soluble TNF-receptors (sTNF-R) have been reported in patients with chronic renal failure. The aim of the present study was to evaluate the effects on sTNF-R levels in plasma of haemodialysis patients of the anticoagulation method and of the type of membrane used, as well as the variability of predialysis sTNF-R levels during time. All haemodialysis patients tested ( = 35) showed increased levels of both sTNF-R55 (72.4 ± 5.7 ng/ml, <0.001) and sTNF-R75 (18.2±2ng/ml, <0.00l) before dialysis, as compared with normal healthy controls (<2.5 ng7sol;ml for both sTNF-R), confirming previous observations. sTNF-R levels were determined before and during haemodialysis at different time intervals in patients receiving either heparin (2500 U, 5000 U, or 10000 U), low molecular weight heparin, or periodic saline flushing to prevent coagulation of the extracorporal circuit. A transient, small decrease in both sTNF-R levels occurred at the beginning of haemodialysis (=15 mm) with all anticoagulation methods used. At the end of haemodialysis, sTNF R55 and sTNF-R75 concentrations were only minimally affected (<0.05). Predialysis sTNF-R levels were similar in patients dialysed on either cellulose diacetate or polyacrylonitrile. Finally, there were only minimal variations in predialysis sTNF-R levels in individual patients during the 1 week observation period. Although the biological consequences of the increased TNF-binding ability of serum from haemodialysis patients is still unclear, it could play a role in the complex immunological perturbations of uraemic patients. [ABSTRACT FROM PUBLISHER]

Systemic hypertension as assessed by casual blood pressure measurements is a frequently reported side-effect of recombinant human erythropoietin (rHuEpo) treatment. We investigated the effect of rHuEpo treatment on the 24-h ambulatory blood pressure and heart rate profiles of 13 chronic haemodialysis patients. After 3–4 months of rHuEpo therapy it was found that the mean haematocrit had increased from 24.5± 1.0% to 32.0± 1.1% (<0.005), while body-weight and control of uraemia as assessed by routine laboratory data remained unchanged. Despite gradual and incomplete correction of anaemia by use of low doses of rHuEpo, increases in the ambulatory systolic and diastolic blood pressure were found. The greatest increases affected day-time systolic blood pressure and night-time diastolic blood pressure, and these increases were significant (<0.05). As a result, pulse pressure increased during day-time (<0.05) while the nighttime decline in diastolic blood pressure disappeared. An increase in peripheral resistance after partial correction of renal anaemia might explain these observations. rHuEpo therapy increased the percentage of abnormal ambulatory blood pressure measurements (defined as systolic blood pressure>140 mmHg and/or diastolic blood pressure >90 mmHg) from 33% to 52% (P<0.05) while in contrast, mean casual prehaemodialytic and posthaemodialytic blood pressure values remained unchanged. We conclude that changes in 24-h blood pressure profiles should be carefully assessed by ambulatory blood pressure monitoring in haemodialysis patients treated with rHuEpo, since these changes are likely to be missed when only causal blood pressures are measured. [ABSTRACT FROM PUBLISHER]

Iron overload, which is a common complication in haemodialysis patients, is known to enhance bacterial growth and virulence, and to alter phagocytosis. We reviewed the data of 61 haemodialysed patients to clarify the clinical relevance of iron status to the risk of bacterial infection. Increased concentrations of serum ferritin were associated with a greater infection rate (<0.0025), which was already true for ferritin values between 500 and l000μ/l (.<0.025). Furthermore, in 21 iron-overloaded patients treated with an iron-chelator (desferrioxamine), the infection rate decreased from 1/19 patient-months to 1/112 (<0.005), and returned to previous values when desferrioxamine was stopped. Our results demonstrate the importance of haemosiderosis in the increased susceptibility of haemodialysed patients to infections; this susceptibility is decreased by desferrioxamine therapy, which probably acts by restoring phagocytosis and reducing the bioavailability of iron for pathogens. [ABSTRACT FROM PUBLISHER]

We compared plasma beta-2-microglobulin βM at a 1-year interval in 25 CAPD patients and 25 patients haemodialysed with cuprophane membranes and matched for residual renal function and duration of renal replacement therapy. Plasma βM remained lower in CAPD patients throughout the study, and increased significantly with time both in CAPD and haemodialysis patients, as renal function decreased. In both groups, plasma βM was negatively correlated with residual creatinine clearance, the influence of the latter being much greater in haemodialysis, as demonstrated by comparison of the regression lines. In haemodialysis, but not in CAPD. plasma βM also correlated with time on dialysis. In CAPD patients. the daily peritoneal output averaged 38 mg (range 16–59 mg), and was directly correlated with plasma βM CAPD thus allows a significant peritoneal removal of βM which progressively takes over from the declining renal function, resulting in lower plasma βM than in matched haemodialysis patients. However, the peritoneal removal of βM remains insufficient and values increase with time as renal function declines. Thus, if βM amyloidosis is related to raised plasma levels, the risk of βM amyloidosis in CAPD should simply be delayed as compared to haemodialysis. [ABSTRACT FROM PUBLISHER]

Key words: acute renal failure; anuria; percutaneous angioplasty; renal artery stenosis; renovascular hypertension; transplantation, renal [ABSTRACT FROM PUBLISHER]

Three patients on chronic maintenance haemodialysis have progressively increased their haematocrit to reach values between 40 and 45%, a situation associated with an increased risk of thrombosis of their arteriovenous fistulae. Two of them had been submitted to repeated phebotomies, which remained unsuccessful despite the induction of a profound iron deficiency in one of them. Hence, a trial with oral theophylline was performed in the three patients, resulting in a sustained decrease of the haematocrit (from 43.6 to 33%) and endogenous erythropoietin (from 46 to 15 mU/ml) levels. In two patients, theophylline therapy was stopped transiently due to gastrointestinal side-effects, which resulted in a rapid return to previous haematocrit levels; rechallenge with a better tolerated preparation, however, was efficient again. We conclude that oral theophylline appears to be an efficient treatment to control too high haematocrit levels in dialysis patients. [ABSTRACT FROM PUBLISHER]