The Influence of Recombinant Human Erythropoietin on Tumor Necrosis Factor α and Interleukin-10 Production by Whole Blood Cell Cultures in Hemodialysis Patients

Abstract: Impaired immunological response in hemodialysis (HD) patients, which leads to inappropriate cytokine production, is partially caused by the hyperstimulation of both T lymphocytes and monocytes/macrophages. Recent data suggest that human recombinant erythropoietin (rhEPO) may have an immunological action. The goal of our study was to estimate the influence of rhEPO treatment on the production of the inflammatory cytokine tumor necrosis factor α (TNFα) and antiinflammatory cytokin interleukin-10 (IL-10) in 10 HD patients receiving rhEPO for 6 months. The levels of cytokines were measured in the in vitro cultures of whole blood. The level of IL-10 increased in all treated patients during the therapy, and it was accompanied by a transitory decrease of TNFα. The results of our studies suggest that rhEPO may reduce the inflammatory process by decreasing production of TNF α and increasing production of IL-10.     

Recombinant Human Erythropoietin Stimulates Production of Interleukin 2 by Whole Blood Cell Cultures of Hemodialysis Patients

Abstract: The impairment of function of human T lymphocytes, leading to an inappropriate cytokine production, is partially responsible for defective immunological response in hemodialysis patients (HD). Recent data suggest that recombinant human erythropoietin (rhEPO) may exert immunological effects. The aim of this study was to find out whether rhEPO treatment of the HD patients may have an effect on the interleukin 2 (IL-2) production by their whole blood cell cultures. The study was carried out in 10 HD patients receiving rhEPO for 6 months. Compared with the levels seen before the treatment, the concentration of IL-2 increased in the phytohemagglutinin-stimulated whole blood cell cultures of 7 of 10 patients under study. Addition of rhEPO in vitro to the whole blood cell cultures of the HD patients before implementation of erythropoietin confirmed that rhEPO is able to directly stimulate IL-2 production. Our studies show that the therapy with rhEPO affects IL-2 secretion.     

A parallel, comparative study of intravenous iron versus intravenous ascorbic acid for erythropoietin-hyporesponsive anaemia in haemodialysis patients with iron overload

Background: Functional iron deficiency may develop and cause erythropoietin resistance in haemodialysis patients with iron overload. Controversy remains as to whether intravenous iron medication can improve this hyporesponsiveness due to decreased iron availability, or whether iron therapy will aggravate haemosiderosis. Intravenous administration of ascorbic acid has been shown to effectively circumvent resistant anaemia associated with iron overload in a small preliminary study. To elucidate further the possible mechanisms of this resistance, a parallel, comparative study was conducted to compare the effects of intravenous iron and ascorbate therapies in iron-overloaded haemodialysis patients. Methods: Fifty haemodialysis patients with serum ferritin of >500 &mgr;g/l were randomly divided into two protocols. They were further stratified into controls (Control I, n=11) and intravenous iron group (IVFE, n=15) in protocol I; and into controls (Control II, n=12) and intravenous ascorbic acid group (IVAA, n=12) in protocol II. Controls had a haematocrit of >30% and did not receive any adjuvant therapy. IVFE and IVAA patients were hyporesponsive to erythropoietin and functionally iron deficient. Ferric saccharate (100 mg dose) was administered intravenously post-dialysis on five consecutive dialysis sessions in the first 2 weeks; and ascorbic acid (300 mg dose) thrice a week for 8 weeks. Red cell and iron metabolism indices were examined before and following therapy. Results: Mean values of haematocrit and transferrin saturation were significantly lower, and erythropoietin dose was higher in IVFE and IVAA patients compared to controls. Intravenous iron therapy neither improved erythropoiesis nor reduced erythropoietin dose during 12 weeks. Iron metabolism indices significantly increased at 2 and 6 weeks, but decreased at 12 weeks returning to the baselines. In contrast, mean haematocrit significantly increased from 25.8±0.5 to 30.6±0.6% with a concomitant reduction of 20% in erythropoietin dose after 8 weeks of ascorbate therapy. Serum ferritin modestly fell but with no statistical significance. The enhanced erythropoiesis paralleled a rise in transferrin saturation from 27±3 to 48±6% and serum iron from 70±11 to 107±19 &mgr;g/dl (P<0.05). Conclusions: Short term intravenous iron therapy cannot resolve the issue of functional iron deficiency in haemodialysis patients with iron overload. Intravenous administration of ascorbic acid not only facilitates iron release from storage sites, but also increases iron utilization in the erythron. Our study draws attention to a potential adjuvant therapy, intravenous ascorbic acid, to treat erythropoietin-hyporesponsive anaemia in iron-overloaded patients.     

Influence of first and long-term dialysis on uraemia-associated increased basal production of interleukin-1 and tumour necrosis factor alpha by circulating monocytes

In a previous study we demonstrated the presence of circulating interleukin-1 (IL-1) in long-term haemodialysis patients and of tumour necrosis factor alpha (TNF alpha) in both long-term haemodialysis and not-yet-dialysed uraemic patients. The present report investigates the spontaneous capacity of monocytes to produce and secrete these two cytokines in 35 long-term haemodialysis patients and 36 uraemic patients undergoing their first dialysis session. Predialytic cell-associated IL-1 concentrations in freshly isolated monocytes were significantly increased both in long-term haemodialysis and first-dialysis uraemic patients compared to normal individuals. In both groups in comparison to normal individuals, although intracellular TNF alpha could not be detected in freshly isolated monocytes, both extracellular IL-1 and TNF alpha concentrations were greatly increased after 20 h of in vitro culture of monocytes in the absence of exogenous stimulation and in serum-free conditions. However, long-term haemodialysis patients showed higher values of secreted IL-1 than not-yet dialysed uraemic patients. During a single dialysis session a significant increase in both cell-associated and secreted IL-1 but not TNF alpha was observed in long-term haemodialysis patients. In contrast, no change in the concentration of either cytokine could be detected at the end of the first dialysis session in uraemic patients. Our findings strongly suggest that factors related to uraemia could be a sufficient signal to initiate intracellular IL-1 protein synthesis and TNF alpha release by monocytes, but that greater IL-1 release could be stimulated during the periodic haemodialysis procedure.     

Influence of some immune factors on the IL-6 and soluble IL-2 receptors in haemodialysed patients

In respect to the immune deficiency state of long-term haemodialysed patients, both cytokines and their receptor disturbances have been taken into consideration. The purpose of our study was to evaluate the effect of uraemic and haemodialysis factors on the interleukin-6 and interleukin-2 soluble receptor levels and the reactivity after influenza vaccination. We have found that IL-6 and IL-2 receptor levels were statistically significantly elevated (98.8±39 pg/ml and 1557±544 U/ml, respectively) in serum of haemodialysed patients. The fact that increased immune complexes statistically correlated with soluble IL-2 receptor levels (p<0.01) was very interesting for us. In order to study the immunological response after vaccination, 10 patients have been investigated after influenza vaccination. Plasma samples were collected before, as well as 1 and 4 weeks after vaccine administration. Antibody titres measured by haemagglutinin inhibition showed decreased antibody levels in haemodialysed patients. We conclude that the interleukin disturbance and the elevated interleukin-2 receptor levels together with the presence of circulating immune complexes can influence in some way the immune response of haemodialysed patients.     

Erythropoietin and oxidative stress in haemodialysis: beneficial effects of vitamin E supplementation

Oxidative stress can produce profound alterations to cellular membrane lipids, impairing cell metabolism and viability. This phenomenon, previously observed in haemodialysis patients, had been proposed as a significant factor in regard to haemodialysis-related shortened red blood cells (RBC) survival. In the present study, several parameters associated with oxidative stress were evaluated in a group of haemodialysis patients either receiving erythropoietin therapy (n=12, mean erythropoietin dose 88±24 U/kg/week) or not receiving such therapy (n=20), and in 38 controls. Malonyldialdehyde (MDA, nmol/ml), an end-product of lipid peroxidation, and RBC anti-oxidant systems were measured, including RBC &agr;-tocopherol (RBC vitamin E, mg/l), RBC glutathione (GSH, nmol/mgHb), and RBC superoxide dismutase activity (SOD, U/mgHb). Plasma vitamin E concentrations were also evaluated. Finally, oral vitamin E supplementation (500 mg daily), an exogenous antioxidant, was administered for 6 months to seven patients from the dialysis group receiving erythropoietin while oxidative parameters were repeatedly evaluated and erythropoietin requirements monitored, in order to appreciate the therapeutic relevance of an antioxidant supplementation. An elevation of serum MDA was observed in all haemodialysis patients and a significant decrease in RBC vitamin E, despite normal serum vitamin E levels. Furthermore, the reduction in RBC vitamin E was more important in patients treated with erythropoietin. Vitamin E supplementation resulted in a significant increase in RBC vitamin E (from 0.3±0.1 to 1.2±0.2 mg/l of pellet) and a reduction in erythropoietin dose (from 93±24 to 74±26 U/kg/week) while maintaining stable haemoglobin concentrations. These results suggest that the oxidative stress could be one of the resistance factors to erythropoietin response in haemodialysis and that vitamin E supplementation could have a sparing effect on erythropoietin dosage requirement. Key words: antioxidant; erythropoietin; haemodiafiltration; lipid peroxidation; oxidative stress; vitamin E      

IL-6 and IL-8 response to erythropoietin therapy in radical hysterectomy

BACKGROUND: The use of recombinant human erythropoietin (rHuEPO) improves autologous blood donation before elective surgery. However, there are other studies indicating that rHuEPO may suppress postoperative endogenous production of erythropoietin and stimulate inflammatory mediator release. Weekly donations generate only a moderate increase in endogenous erythropoietin production. We scheduled patients with cancer to predeposit three units of blood in 2 weeks, with or without rHuEPO therapy. The aim was to determine whether rHuEPO therapy and/or an aggressive donation schedule alter perioperative erythropoietin concentrations and whether rHuEPO therapy leads to the release of the pro-inflammatory cytokines IL-6 and IL-8. METHODS: Thirty women scheduled for radical hysterectomy and pelvic lymphadenectomy were randomly assigned to either a control group with no rHuEPO therapy or to receive rHuEPO. Three units of whole blood were collected from each patient before the operation. Concentrations of haemoglobin, erythropoietin (s-EPO) and cytokines (IL-6 and IL-8) were repeatedly analyzed before and after the operation. RESULTS: During the preoperative donation period, median s-EPO levels in the control group increased from 7 to 14 IU l(-1). There was a great increase in s-EPO concentrations 1 h postoperatively in the rHuEPO group compared with the control group (P < 0.001). IL-6 and IL-8 were not significantly changed after intravenous administration of rHuEPO. CONCLUSION: The use of rHuEPO therapy to optimise autologous blood donation does not influence IL-6 and IL-8 release. 1 h postoperatively rHuEPO therapy resulted in elevated s-EPO concentrations. There was, however, no difference in s-EPO between the groups from day 1 postoperatively and until the end of the study.     

Change in haemoglobin concentration,haematocrit and vasoactive hormones in haemodialysis patients with erythropoietin-associated hypertension

The changes in haemoglobin concentration, haematocrit, plasma renin, activity (PRA) and atrial natriuretic peptide (ANP) were studied in 10 haemodialysis patients with erythropoietin-associated hypertension. All patients received intravenously 1500 IU of recombinant human erythropoietin (rHuEPO) thrice weekly for 24 weeks. Treatment with rHuEPO induced significant rises in haemoglobin concentration (p<0.001) and haematocrit (p<0.01)., However, the difference between post- and pretreatment levels of haemoglobin (ΔHb) was not correlated with that between post-and pre-treatment mean blood pressure (ΔMBP). No correlation was found between ΔHt (difference between post- and pre-treatment values of haematocrit) and ΔMBP. These results indicate that elevation of the haematocrit and haemoglobin concentration of haemodialysis patients does not necessarily lead to an increase in blood pressure. In these patients, no significant differences were observed in PRA and ANP, comparing pre-treatment values with those measured 4, 8, 12 or 24 weeks after commencing rHuEPO. This suggests that neither PRA nor ANP play a central role in the pathogenesis of rHuEPO-induced hypertension.     

Hyporesponsiveness to Erythropoietin Therapy in Hemodialyzed Patients: Potential Role of Prohepcidin,Hepcidin, and Inflammation

Hepcidin is the key regulator of iron metabolism. Iron supplementation is often introduced in dialyzed patients to replete or to maintain iron stores, particularly in patients treated with erythropoietic-stimulating agents. The present study was aimed to assess possible relation between hepcidin and erythropoietin therapy, with particular attention being paid to erythropoietin-hyporesponsiveness in hemodialyzed patients. Prohepcidin and hepcidin were studied using commercially available kits from DRG Instruments GmbH, Germany (ELISA method) and Bachem, UK (RIA method). TNFα and IL-6 were studied using kits from and R&D (Abington, UK), and hsCRP was studied using kits from American Diagnostica, USA. Hyporesponsive patients to erythropoietin therapy had significantly lower serum albumin, cholesterol, LDL, hemoglobin, hematocrit, and residual renal function, and significantly higher serum ferritin, hsCRP, IL-6, TNFα, and erythropoietin dose. The difference in serum prohepcidin and hepcidin did not reach statistical significance; however, there was a tendency toward higher values of both prohepcidin and hepcidin in hyporesponsive patients. In conclusion, though hyporesponsiveness to erythropoietin therapy occur in dialyzed patients, it is mainly associated with subclinical inflammation than with hepcidin excess. Further studies are needed to develop a reliable and reproducible assay to elucidate the potential contribution of hepcidin to hyporesponsiveness during erythropoietin therapy.     

Effect of recombinant human erythropoietin on synthesis of methylguanidine in uraemic patients on haemodialysis or continuous ambulatory peritoneal dialysis

The effect of recombinant human erythropoietin (rHuEPO) on synthesis of methylguanidine was studied in 6 uraemic patients on haemodialysis and 5 uraemic patients on continuous ambulatory peritoneal dialysis (CAPD). The Two groups of patients were started on a 24-week course of thrice weekly 1500 IU of rHuEPO by the intravenous route. Serum methylguanidine level and methylguanidine/creatinine ratio were comparable in these groups. In the two groups no significant differences were observed in these measurements comparing the pretreatment values with those 4, 8, 12 or 24 weeks after starting rHuEPO administration. During rHuEPO therapy, serum methylguanidine levels and methylguanidine/creatinine ratio showed no considerable difference between the two groups. These findings suggest that administration of rHuEPO does not alter methylguanidine synthesis in uraemic patients on haemodialysis and CAPD.     

Early postoperative compensatory anti-inflammatory response syndrome is associated with septic complications after major surgical trauma in patients with cancer

BACKGROUND: Patients who undergo major surgery for cancer are at high risk of postoperative infection. Postoperative immunosuppression may be due to dysregulation of cytokine production. The aim of this study was to investigate the association between changes in serum proinflammatory and anti-inflammatory cytokine concentrations and postoperative septic complications after major surgery. METHODS: Serial blood samples were collected from 30 consecutive patients for determination of serum cytokine levels. Healthy volunteers were used as the control group. RESULTS: Eleven patients developed no complications (group 1), 14 developed sepsis or severe sepsis (group 2), and five developed septic shock (group 3). On day 1 the patients in groups 2 and 3 had significantly higher levels of interleukin (IL) 6 than those in group 1. IL-6 levels remained high until day 5. Tumour necrosis factor (TNF), IL-1, interferon (IFN) gamma and IL-12 levels were not affected by surgical trauma or by the occurrence of septic complications. After operation the circulating IL-1 receptor antagonist (IL-1ra) concentration was increased in all groups, but patients in group 3 had significantly higher levels of IL-1ra than those in group 1. IL-1ra levels correlated with IL-6 levels. The pattern of IL-10 levels was similar to that of IL-1ra levels. CONCLUSION: Serum concentrations of proinflammatory cytokines (TNF, IL-1, IFN-gamma and IL-12) were not affected by operation or the occurrence of septic complications. The postoperative increase in IL-6 concentration was associated with septic morbidity, while raised IL-1ra concentration was associated with postoperative septic shock.     

Responses of interleukin-6 and tumor necrosis factor during and after cardiac surgery undergoing cardiopulmonary bypass and pancreatoduodenectomy

To evaluate the effect of cardiopulmonary bypass on immunological function, we measured interleukin-6 (IL-6) and tumor necrosis factor (TNF) in 12 patients undergoing cardiac surgery during and after cardiopulmonary bypass, and in 10 patients with pancreatoduodenectomy. Plasma IL-6 levels were determined using the Human Interleukin 6 ELISA Kit, and TNF levels were determined using a highly sensitive sandwich enzyme immunoassay. In patients with cardiac surgery, plasma levels of IL-6 and TNF increased during cardiopulmonary bypass, and in patients with pancreatoduodenectomy, IL-6 and TNF levels significantly increased at the end of intraabdominal manipulation. These results suggest that endotoxin may have activated the immune system and stimulated cytokine production after pancreatoduodenectomy and during bypass.     

Blood transfusion and cytokines’ changes in total knee replacement

Introduction

The aim of this prospective comparative study was to evaluate the serum levels of different cytokines and the frequency of adverse reactions and wound infections in patients who underwent total knee replacement (TKR) and were not transfused or received either allogeneic blood transfusion or postoperative auto-transfusion (PAT) with unwashed shed blood.

Materials and methods

A total of 248 patients were categorized into three groups; in Group 0 (n 85) patients received no blood transfusion, in Group 1 (n 92) patients received PAT and in Group 2 (n 71) patients received allogeneic blood transfusion. Patient’s demographic and clinical data including age, gender, body mass index, preoperative haemoglobin value, adverse reactions and complications were documented. The serum levels of IL-1b, IL-6, IL-8, IL-10 and TNF were measured preoperatively, and on the first, third and fifth postoperative day. A statistical analysis of the results was performed.

Results

A significant elevation of cytokine values were observed during the first five postoperative days in patients who received blood transfusion after TKR. Adverse reactions (chills and pyrexia) were also more common in patients who received blood transfusion, whereas superficial infections were more common in patients who received allogeneic blood transfusion.

Conclusion

The immunological status—as expressed by the measured cytokine levels—is altered in patients receiving blood transfusion compared to patients receiving no blood transfusion during the first five postoperative days. PAT is preferable to allogeneic blood transfusion in terms of the rate of adverse reactions and superficial wound infections.     

Tumour necrosis factor levels during acute rejection and acute tubular necrosis in renal transplant recipients

Plasma tumour necrosis factor levels were measured serially in 16 patients following renal transplantation, and in 10 patients on haemodialysis and in 12 patients on peritoneal dialysis. The patients on peritoneal dialysis had lower plasma TNF levels than the patients on haemodialysis. There was a decrease in TNF levels immediately following renal transplantation; this is probably related to the bolus doses of methylprednisolone administered intra-operatively. Patients with acute rejection had higher levels of TNF than non-rejecting patients. The increase in TNF levels in rejecting patients was observed 2 days before the clinical manifestation of acute rejection. There was a marked decrease in TNF levels in rejecting patients in response to treatment with steroids. Patients with delayed graft function had higher levels of TNF on the first post-operative day compared to patients with immediate function. These changes in plasma TNF levels following renal transplantation have important clinical and therapeutic implications.     

The effects of aprotinin and steroids on generation of cytokines during coronary artery surgery.

OBJECTIVE: To compare the efficacy of aprotinin and methylprednisolone in reducing cardiopulmonary bypass (CPB)-induced cytokine release, to evaluate the effect of myocardial cytokine release on systemic cytokine levels, and to determine the influence of cytokine release on perioperative and postoperative hemodynamics. DESIGN: Prospective, randomized clinical trial. SETTING: University teaching hospital and clinics. PARTICIPANTS: Thirty patients undergoing elective coronary artery bypass graft surgery. INTERVENTION: Patients were randomly allocated into groups treated with aprotinin (n = 10) or methylprednisolone (n = 10) or into an untreated control group (n = 10). Aprotinin-treated patients received aprotinin as a high-dose regimen (6 x 10(6) KIU), and methylprednisolone-treated patients received methylprednisolone (30 mg/kg intravenously) before CPB. MEASUREMENTS AND MAIN RESULTS: Patients were analyzed for hemodynamic changes and alveolar-arterial PO2 difference (AaDO2) until the first postoperative day. Plasma levels of proinflammatory cytokines (tumor necrosis factor [TNF]-alpha, interleukin [IL]-1beta, IL-6, and IL-8) were measured in peripheral arterial blood immediately before the induction of anesthesia, 5 minutes before CPB, 3 minutes after the start of CPB, 2 minutes after the release of the aortic cross-clamp, 1 hour after CPB, 6 hours after CPB, and 24 hours after CPB; and in coronary sinus blood immediately before CPB and 2 minutes after the release of the aortic cross-clamp. The hemodynamic parameters did not differ among the groups throughout the study. After CPB, AaDO2 significantly increased (p < 0.05) in all groups. A significant decrease in AaDO2 was observed in aprotinin-treated patients at 24 hours after CPB compared with the other groups (p < 0.05). TNF-alpha level from peripheral arterial blood significantly increased in control patients 1 hour after CPB (p < 0.01) and did not significantly increase in methylprednisolone-treated patients throughout the study. In all groups, IL-6 levels increased after the release of the aortic cross-clamp and reached peak values 6 hours after CPB. At 6 hours after CPB, the increase in IL-6 levels in methylprednisolone-treated patients was significantly less compared with levels measured in control patients and aprotinin-treated patients (p < 0.001). In control patients, IL-8 levels significantly increased 2 minutes after the release of the aortic cross-clamp (p < 0.05), and peak values were observed 1 hour after CPB (p < 0.01). IL-8 levels in control patients were significantly higher compared with patients treated with aprotinin and patients treated with methylprednisolone 1 hour after CPB (p < 0.05). CONCLUSION: This study showed that methylprednisolone suppresses TNF-alpha, IL-6, and IL-8 release; however, aprotinin attenuates IL-8 release alone. Methylprednisolone does not produce any additional positive hemodynamic and pulmonary effects. An improved postoperative AaDO2 was observed with the use of aprotinin.     

Fluctuations in haemoglobin levels in haemodialysis, pre-dialysis and peritoneal dialysis patients receiving epoetin alpha or darbepoetin alpha

Aim: To characterize the haemoglobin variability of haemodialysis, peritoneal dialysis and pre‐dialysis patients treated with either epoetin alpha or darbepoetin alpha in a clinical setting where treatment was administered according to current standard Australian practice. Methods: Data on haemodialysis, pre‐dialysis and peritoneal dialysis patients were extracted from the Renal Anaemia Management database (RAM) from 1 January 2001 to 31 December 2004. The variance in haemoglobin was calculated from patient records with more than five haemoglobin observations over a period of at least 4 weeks following 9 weeks of therapy. A mixed‐model was fitted to the within‐patient variances and weighting was based on the number of observations minus 1 for each record. Results: The mean within‐patient variance in haemoglobin levels for i.v. administered erythropoietin‐stimulating agents (IV) haemodialysis, s.c. administered erythropoietin‐stimulating agents (SC) haemodialysis, predialysis_SC and peritoneal dialysis_SC patients receiving epoetin alpha were 9% (95% CI: 13% to 5%, P < 0.0001), 17% (95% CI: 32% to 0.2%, P = 0.047), 19% (95% CI: 27% to 11%, P < 0.0001) and 26% (95% CI: 33% to 18%, P < 0.0001) lower than that for patients receiving darbepoetin alpha. The mean haemoglobin levels for haemodialysis_IV, haemodialysis_sc predialysis_SC and peritoneal dialysis_SC patients receiving darbepoetin alpha were 11.6 g/dL, 11.2 g/dL, 11.5 g/dL and 11.5 g/dL compared with 11.5 g/dL, 11.6 g/dL, 11.7 g/dL and 11.5 g/dL for patients receiving epoetin alpha. Conclusion: There was 9–26% greater within‐patient fluctuation in haemoglobin levels in patients receiving darbepoetin alpha compared with epoetin alpha. The causes of haemoglobin fluctuations and the implications for patient outcomes and resource use require further study.     

Cytokines in stored red blood cell concentrates: promoters of systemic inflammation and simulators of acute transfusion reactions?

Background: The cytokine network has important implications for the systemic inflammatory and metabolic response in trauma and infection. Cytokines exogenously administered to traumatized and infected patients may have implications for the trauma response in these patients. The main objective of this study was to characterize red blood cell concentrates (RBCs) with regard to cytokine content.
Methods: We investigated the concentrations of tumor necrosis factor α (TNF), interleukin-1 β (IL-1), interleukin-6 (IL-6) and interleukin-8 (IL-8) in sixteen units of RBCs stored at +4° C during 40 days. Samples from RBCs were taken every tenth day. Healthy volunteers were used as controls.
Results: IL-1 and IL-8 in RBCs were increased compared to controls, P< 0.01 - P < 0.001 and TNF in RBCs were increased on days 1 and 40 compared to controls, P < 0.05. During storage TNF was highest on day 1, 69 (< 3 - 1060) pg/ml, median (range). IL-1 concentrations increased during the period of storage from 5 (< 2 - 205) pg/ml to 174 (< 2 - 2180) pg/ml, P < 0.01. IL-6 was 6 (< 2 - 210) pg/ml on day 1 and did not change over the period of storage. IL-8 was highest on day 40,164 (15 - 790) pg/ml and compared to day 1 the concentrations were increased on day 10 and day 40, P < 0.05 for both comparisons.
Conclusions: The results indicate the presence of TNF, IL-1, IL-6 and IL-8 in stored RBCs, though there was a great variability over the period of storage and between units of RBCs. In some samples of RBCs the content of cytokines reached levels that may be anticipated to contribute to systemic inflammation and the symptomatology of acute transfusion reactions.     

Nutritional vitamin D supplementation in haemodialysis: A potential vascular benefit?

Aim: Vitamin D deficiency is highly prevalent in end‐stage renal disease and has been associated with atherosclerosis, endothelial dysfunction and left ventricular hypertrophy. Although activated vitamin D has shown to be cardioprotective, the cardiovascular benefits of nutritional vitamin D (i.e. ergocalciferol or cholecalciferol) have not been explored in the dialysis population. The aim of this investigation was to evaluate the effect of ergocalciferol therapy on vascular adhesion molecules, markers of inflammation and atherosclerosis among haemodialysis patients. Methods: This was a pilot study of matched haemodialysis patients. For every patient enrolled taking ergocalciferol, an age and race matched control was recruited. Predialysis blood samples were collected and assayed for adhesion molecules (soluble vascular cell adhesion molecule‐1 (sVCAM‐1), soluble intercellular adhesion molecule‐1 (sICAM‐1), E‐selectin and P‐selectin), inflammatory cytokines (interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α)), oxLDL‐β₂GPI and IgG anticardiolipin. Results: A total of 40 haemodialysis patients were studied (20 on ergocalciferol therapy, 20 not receiving ergocalciferol therapy). Patients taking ergocalciferol had higher 25‐hydroxyvitamin D levels compared with those not taking ergocalciferol. Even though doxercalciferol usage and dosing was similar between groups, plasma sVCAM‐1, sICAM‐1 and P‐selectin concentrations were lower among ergocalciferol treated patients. No significant differences in E‐selectin, IL‐6, TNF‐α, oxLDL‐β₂GPI or anticardiolipin antibody levels were observed. Conclusion: Patients receiving ergocalciferol had lower plasma levels of vascular adhesion molecules despite equivalent use of activated vitamin D therapy. Future investigations should confirm the role of nutritional vitamin D therapy, in addition to activated D therapy, in haemodialysis patients and the potential vascular benefits of these agents.     

Lipid and apolipoprotein patterns during erythropoietin therapy: roles of erythropoietin, route of administration, and diet

Background. Long term effects of rHuEpo on the blood lipid profile have not been well documented. The aim of this paper is to prospectively evaluate whether rHuEpo therapy affects lipid metabolism, and whether these effects are influenced by changes in dietary habits and by route of rHuEpo administration. Methods. The study was performed in 33 maintenance haemodialysis patients (MHP) treated for one year with rHuEpo either intravenously (n = 15) or subcutaneously (n = 18), three times per week at the end of each dialysis session. The doses were 50 IU/kg intravenously or 35 IU/kg subcutaneously during the first 6 months and 20 IU/kg during the following months. The control group consisted of 17 MHP not treated with rHuEpo. Total cholesterol, LDL-cholesterol and HDL-cholesterol, triglycerides, apolipoproteins A1 and B, haemoglobin, serum albumin, blood urea nitrogen, serum creatinine, Kt/V, protein catabolic rate, and plasma erythropoietin were assessed at months 0, 2, 4, 6, 9, 12 and 2 weeks after rHuEpo discontinuation. Changes in food intake were evaluated on the basis of weekly dietary diaries before, and 3 and 9 months after treatment. Patients were divided into two groups: group A consisted of 19 patients who showed an increase in their energy intake (10% or more of basal value), and group B was formed by 14 patients without or with slight changes in their food intake. After the 6th month, dialysis schedules were adapted to new protein catabolic rate values in patients who increased their food intake. Results. During follow-up, there were no significant changes in any of the parameters in the control group. In group A, blood urea nitrogen, serum creatinine, protein catabolic rate, cholesterol, LDL cholesterol, triglycerides and apolipoprotein B increased significantly since the first months of rHuEpo treatment, and changes in cholesterol and apolipoprotein B correlated significantly with changes in protein catabolic rate. In group B, cholesterol, LDL cholesterol, and apolipoprotein B decreased significantly after the 6th month of treatment, without changes in blood urea nitrogen, serum creatinine and protein catabolic rate values. In both groups A and B, HDL cholesterol decreased significantly until the 6th month and returned to basal values in the following months and apolipoprotein A1 decreased until the 4th month and rose to levels higher than basal values in the following months. First rHuEpo administration and rHuEpo suspension at end of follow-up did not show any acute effect on lipid profile, despite significant changes in plasma erythropoietin values. Changes in lipid profile were similar with intravenous and subcutaneous administration of rHuEpo. Conclusions: We infer that long-term rHuEpo treatment positively affects the lipid profile, but in some patients who show exaggerated increase in their food intake these effects may be balanced and overcome by increment in some atherogenic blood lipid fractions. The changes in lipid and apolipoprotein patterns during rHuEpo therapy are not influenced by route of rHuEpo administration.