Comparison of first use and reuse of cuprophan membranes on interleukin-1 receptor antagonist and interleukin-1 beta production by blood mononuclear cells

Production of interleukin 1 receptor antagonist and interleukin 1 during haemodialysis with cellulose membranes

An in vivo cross-over study has investigated plasma and cellular levels of IL-1 (IL-1α IL-1β and IL-1Ra) when using Cuprophan (C) and cellulose triacetate (CTA) membranes to assess the roles of complement activation and dialysate endotoxin content in the induction of cytokines during the dialysis procedure. The mean C5a level during Cuprophan dialysis was 29.9 ± 0.63 ng/ml (Mean ± SEM), while for the cellulose triacetate dialysis was 3.09 ± 0.7 ng/ml. The endotoxin content of the dialysate was 0.31 ± 0.34 EU/ml and 0.68 ± 1.39 EU/ml. These two factors failed to produce measurable changes in plasma or cellular IL-1α and IL-1β levels during treatment. The plasma IL-1Ra levels pre-dialysis were similar to those for normal controls (CTA 769 ± 156 ng/ml, C739 ± 93, normal controls 635 ± 33) with a considerable day to day variation. A membrane independent fall in plasma IL-1Ra at 15 minutes was noted (CTA 420 ± 92 ng/ml, C 503 ± 139) with a return to pre-dialysis levels by the end of treament. Cellular IL-1Ra levels pre-dialysis were similar to the normal group - (CTA 1904 ± 291 ng/ml, C 1564 ± 292 and normal control 1971 ± 368). However, on average, the values when using cellulose triacetate were 655 ± 623 pg/ml higher than for Cuprophan (p=0.03). These findings indicate that the measurement of plasma cytokine levels is of limited use in the study of cytokine induction by the haemodialysis procedure and that IL-1Ra may be a better indicator of the host response to cytokine stimuli during treatment. However, a considerable inter-patient and intra-treatment variation is present and further studies are required to elucidate the factors involved.

Review: membranes for haemodialysis

Haemodialysis, by design, uses a semipermeable membrane to separate blood from dialysate. The qualities of this membrane determine the nature of the 'traffic' between the blood and dialysate. In this sense, the qualities of the membrane determine what size molecules move from one compartment to the other, the amount and rate at which they might move and the amount and rate of water movement across the membrane. In addition, the nature of the membrane influences the biological response of the patient both in terms of what is or is not removed by the dialysis process and by way of the reaction to the biocompatibility of the membrane. This brief review will explore aspects of dialysis membrane characteristics.

Oxidative stress in hemodialyzed patients and the long-term effects of dialyzer reuse practice

OBJECTIVES

To investigate the existence of an altered oxidant/ antioxidant balance in patients on regular hemodialysis treatment (RHT) and whether there is any effect of dialyzer reuse on oxidative damage and antioxidative mechanism.

DESIGN AND METHODS

Malondialdehyde (MDA) levels and glutathione peroxidase (GPx) activities in both plasma and erythrocytes, plasma selenium (Se) levels, and erythrocyte superoxide dismutase (SOD) activities of RHT patients were determined at the beginning and end of 4-month reuse period.

RESULTS

When compared to healthy controls, both plasma and erythrocyte MDA levels were found to be significantly higher in RHT patients before the dialyzer reuse practice; whereas both plasma and erythrocyte GPx activities, erythrocyte SOD activity, and also plasma Se levels were lower in the same patient group than those of controls. When statistical comparison was made on RHT patients between before and after the reuse period, the decreases in MDA levels but increases in the enzyme activities and also an increase in plasma Se levels were observed after the reuse period. However, erythrocyte SOD activities and plasma Se levels measured after the reuse period were not found to be statistically different from the control values; MDA levels still remained elevated above the control values, and GPx activities were not attained to those of controls, after the reuse practice. In addition, positive correlations were found between activities of erythrocyte SOD and GPx enzymes, between GPx and Se levels and negative correlations between the activities of both enzymes and MDA levels in erythrocytes of patients on RHT.

CONCLUSION

These findings may indicate that dialyzer reuse may provide, at least partly, an improvement on oxidative stress in patients on RHT.

Influence of dialysis membranes on interleukin-1 beta and interleukin-1 receptor antagonist production by peripheral blood mononuclear cells

We investigated the production of interleukin (IL)-1 beta and IL-1 receptor antagonist (Ra) by peripheral blood mononuclear cell (PBMC) in vitro during hemodialysis of 7 dialysis patients using 4 differential dialysis membranes (regenerated cellulose [RC], polyamide [PA], polysulfone [PS] and AN-69). Blood sampling was performed before dialysis (0 min), 15 min after starting dialysis, and after dialysis (240 min) during the last session of each treatment. The cellular content of fresh cells and the production of IL-1 beta and IL-1Ra with and without lipopolysaccharide (LPS) stimulation of the cells were evaluated and measured by enzyme-linked immunosorbent assay (ELISA). The level of IL-1 beta with LPS stimulation using RC, PA, and PS membranes was significantly reduced at 15 min and was not changed at 240 min as compared with the level at 0 min. On the other hand, the level of IL-1 beta with LPS stimulation using an AN-69 membrane at 15 and 240 min was not significantly different from that at 0 min. Neither initial cellular content nor spontaneous production of IL-1 beta were detected at 0, 15, or 240 min in any of the membranes. The spontaneous production of IL-1Ra at 15 and 240 min was not significantly different from that at 0 min in any of the membranes. The cellular content of IL-1Ra using the RC membrane was significantly lower at 15 min and did not differ at 240 min from the level at 0 min. The cellular content of IL-1Ra using PA, PS, and AN-69 membranes was not significantly different at 15 and 240 min from that at 0 min. However, the IL-1Ra level with LPS stimulation using RC and PA membranes was significantly reduced from that at 0 min, but the level using PS and AN-69 membranes was not different from that at 0 min. Because IL-1 beta and IL-1Ra levels 15 min after starting dialysis using bioincompatible dialysis membranes were reduced from the levels at 0 min, the findings suggest that measurement of cytokines' during dialysis treatment at an early stage is a useful marker for evaluating the biocompatibility of a dialysis membrane.

Regional hemodialysis anticoagulation: hypertonic tri-sodium citrate or anticoagulant citrate dextrose-A

Regional citrate anticoagulation should be a simple process of substituting hypertonic (1.6 mol/L) citrate for heparin and adjusting the infusion to obtain an arterial activated clotting time of 150 to 200 seconds. Serious, documented complications of citrate anticoagulation involve citrate intoxication during isolated ultrafiltration; hyperaluminemia, hyperammonemia, and hypernatremia during sorbent dialysis; and profound alkalosis, paresthesias, arrhythmia, and cardiac arrest during bicarbonate dialysis. We suspected that some of these complications could be avoided by using anticoagulant citrate dextrose-A (ACD) rather than hypertonic tri-sodium citrate (TSC) as the anticoagulant. In a cross-over study with random assignment order eight adults underwent mid-week dialyses with ACD (0.113 mol/L citrate) and TSC (1.6 mol/L citrate) regional citrate anticoagulation. Predialysis to postdialysis changes in Na (mEq/L), Ca (mg/dL), ionized Ca (mg/dL), pH, and HCO3 (mEq/L) are listed below. [Table in journal] Using continuous blood flow and avoiding isolated ultrafiltration and sorbent dialysis should prevent the delivery system complications of regional citrate anticoagulation. During this evaluation isotonic and hypertonic citrate resulted in similar serum sodium changes, and standard dialysate effectively reversed the citrate/calcium interaction of both hypertonic and isotonic citrate infusions to restore homeostasis without a separate calcium infusion. The combination of TSC and bicarbonate dialysate does produce a profound metabolic alkalosis, which is lessened by using ACD. In general, regional citrate anticoagulation is simplified by using standard dialysate with a hypertonic rather than an isotonic citrate infusion, and dangerous complications are further evaded by adjusting the dialysate bicarbonate to 25 to 30 mmol/L or substituting a mixture of citric acid and TSC (ACD) for TSC.

Plasma levels of IL-1 beta, TNF alpha and their specific inhibitors in undialyzed chronic renal failure, CAPD and hemodialysis patients

The presence of naturally occurring inhibitors of interleukin-1 (IL-1) and tumor necrosis factor (TNF) in a variety of diseases has been demonstrated. The IL-1 receptor antagonist (IL-1Ra) binds to IL-1 receptors and blocks the activity of IL-1, and a soluble form of the p55 TNF receptor (TNFsRp55) binds and neutralizes TNF. In the present study, plasma levels of IL-1 beta, IL-1Ra, TNF alpha and TNFsRp55 were measured in 29 undialyzed patients with chronic renal failure (CRF), 13 patients on continuous ambulatory peritoneal dialysis (CAPD), 42 patients on chronic hemodialysis (HD) and in 15 healthy controls. Of the 29 patients with CRF, 13 had end-stage renal disease (ESRD, estimated GFR < 10 ml/min). Among health controls, plasma levels of IL-1 beta, IL-1Ra and TNF alpha were at or below the limit of detection of the assay. In undialyzed patients with ESRD, or in patients on CAPD or HD, plasma levels of IL-1 beta were 428 +/- 134 pg/ml, 378 +/- 83 and 352 +/- 43 pg/ml, respectively. Although plasma levels of IL-1 beta in each group of patients were higher than those in healthy controls (< 160 pg/ml), these differences were not statistically significant. In contrast, plasma levels of IL-1Ra in undialyzed patients with ESRD (629 +/- 125 pg/ml, P = 0.03), CAPD (902 +/- 164 pg/ml, P < 0.0001) and HD patients (642 +/- 73 pg/ml, P = 0.004) were significantly higher than those in healthy controls (103 +/- 15).(ABSTRACT TRUNCATED AT 250 WORDS)