Reduction in erythropoietin doses by the use of chronic intravenous iron supplementation in iron-replete hemodialysis patients

BACKGROUND: Iron deficiency is the most common cause of suboptimal response to recombinant human erythropoietin (rHuEPO) in chronic hemodialysis (HD) patients. Iron supply can correct this situation, however, optimal dosage, route of administration, and monitoring of iron status during rHuEPO therapy in maintenance HD patients remains controversial. METHODS: We conducted a 12-month intravenous iron substitution trial in 149 iron-replete chronic HD patients receiving subcutaneous rHuEPO therapy. The available iron pool was maintained with 100 mg iron every 2 weeks or 1 month depending on serum ferritin and transferrin saturation levels, the rHuEPO dosage titrated depending on hematocrit (Hct) levels. RESULTS: After 12-month protocol, the Hct increased (28.7 +/- 4.1 vs 27.7 +/- 2.6, p = 0.003), rHuEPO requirement reduced 25% (46.1 +/- 28.9 vs 61.5 +/- 67.8 U/kg/week, p = 0.006), serum ferritin increased (1,383 +/- 727 vs 930 +/- 857 ng/ml, p < 0.001), so did the transferrin saturation (36.1 +/- 12.7 vs 27.5 +/- 12.8%, p < 0.001). The serum albumin decreased slightly but reached statistical significance (4.1 +/- 0.48 vs 4.2 +/- 0.36 g/dl, p = 0.006), so did the cholesterol levels (166 +/- 41 vs 173 +/- 38 mg/dl, p = 0.044) and pre-dialysis creatinine (11.3 +/- 2.3 vs 11.5 +/- 2.4 mg/dl, p = 0.015). Besides, the iPTH levels did not interfere with the rHuEPO dosage reduction and Hct increment in our patients. CONCLUSION: We conclude that maintaining high levels of serum ferritin and transferrin saturation could further reduce the requirement of rHuEPO in chronic HD patients, but the long-term effect of iron overloading to patients' nutritional status must be further evaluated in contrast to the economic saving.     

Longitudinal analysis of intermediate outcomes in adolescent hemodialysis patients

In 2000 and 2001, The Centers for Medicare & Medicaid Services (CMS) End-Stage Renal Disease (ESRD) Clinical Performance Measures (CPM) project collected data on all in-center hemodialysis (HD) patients in the United States aged >or=12 and <18 years. There were 433 of 486 (89%) patients and 435 of 516 (84%) patients who had the minimum required data submitted and were included in the 2000 and 2001 study years, respectively. There were 188 patients (43%) who had data submitted in both study years, providing longitudinal data on this cohort. A comparison of clinical parameters on these 188 patients in the 2000 and 2001 study years reveals significant improvement in mean calculated spKt/V (1.50+/-0.36 vs. 1.58+/-0.30, P<0.01), mean hemoglobin (11.0+/-1.6 g/dl vs. 11.5+/-1.3 g/dl, P<0.001), mean ferritin (286+/-278 ng/ml vs. 460+/-353 ng/ml, P<0.001), mean transferrin saturation (27.8+/-15.1% vs. 31.3+/-15.0%, P<0.05), mean serum albumin as measured by the bromocresol green method (3.83+/-0.54 g/dl vs. 3.95+/-0.42 g/dl, P<0.01), and mean height standard deviation score (-1.814+/-1.756 vs. -1.699+/-1.657, P<0.05). In addition, 20 of 29 (69%) patients who had a spKt/V <1.2 in the 2000 study year had a spKt/V >1.2 in the 2001 study year. Of 68 (44%) patients who had a catheter as their HD access in the 2000 study year, 30 had an arteriovenous fistula or graft in the 2001 study year and 49 of 80 (61%) patients who had a mean hemoglobin <11 g/dl in the 2000 study year had a hemoglobin >11 g/dl in the 2001 study year. In summary, these longitudinal data demonstrate significant improvements in nearly all clinical parameters studied in these adolescent HD patients.     

Intravenous ascorbic acid in hemodialysis patients with functional iron deficiency: a clinical trial

BACKGROUND: Hemodialysis (HD) patients with functional iron deficiency (FID) often develop resistance to recombinant human erythropoietin (rHuEpo). In these patients, iron therapy may be a hazard, leading to iron overload and consequently to hemosiderosis. Recent studies suggest that intravenous ascorbic acid (IVAA) may circumvent rHuEpo resistance. The aim of our study was to show the effects of IVAA on FID and whether this results in a better correction of anemia in HD patients with stable hemoglobin (Hb) concentration and FID. METHODS: Twenty-seven HD patients with serum ferritin >300 microg/l, transferrin saturation (TS) <20% and hemoglobin (Hb) <10 g/dL were selected andrandomly divided into two groups to enter a cross-over trial with IVAA. In group I IV vitamin C 500 mg was administered three times a week for three months and discontinued in the next three months of the study. Vitamin C was not given the first three months in group II (control group, first three months of the study), who then received 500 mg IV three times a week for the next three months. RESULTS: Hb and TS% significantly increased (baselines vs 3 months, Hb 9.2 +/- 0.2 vs 10.0 +/- 0.3 g/dL, TS% 17.5 +/- 0.6 vs 25.7 +/- 1.7, respectively p < 0.01 and p <0.001) in group I after three months; ferritin fell significantly from 572 +/- 40 to 398 +/- 55 microg/L (p<0.004). Ten patients completed the study: mean Hb and TS% fell significantly (3 months vs final, Hb 9.9 +/- 0.3 vs 8.9 +/- 0.2 g/dL, TS% 25.1 +/- 1.2 vs 19.1 +/- 1.1, respectively p < 0.01 and p <0.001), while mean ferritin did not change. Mean Hb, ferritin and TS% remained unchanged in group II after three months. Hb and TS% mean values rose significantly (3 months vs final, Hb 9.0 +/- 0.2 vs 9.9 +/- 0.2 g/dl, TS% 18.4 +/- 1.0 vs 27.0 +/- 1.0, respectively p < 0.005 and p <0.001), and ferritin markedly decreased from 450 +/- 50 to 206 +/- 24 microg/L (p < 0.001) at the end of the study. The rHuEpo dose was kept unchanged throughout the study. Differences were analyzed after three months. Mean Hb rose (0.8 +/- 0.2 g/dL) in group I but dropped (-0.1 +/- 0.1 g/dL) (p< 0.009) in group II. Ferritin dropped in both groups (group I vs group II, -173 + /-48 vs - 33 +/- 21 microg/L) (p < 0.01) while TS% increased (group I vs group II, 8.2 +/- 1.5 vs 0.4 +/- 0.7) (p < 0.001). CONCLUSION: IVAA may partially correct FID and consequently help rHuEpo hyporesponsive anemia.     

Pruritus in haemodialysis patients: International results from the Dialysis Outcomes and Practice Patterns Study (DOPPS).

BACKGROUND: Pruritus affects many haemodialysis (HD) patients. In this study, pruritus and its relationship to morbidity, mortality, quality of life (QoL), sleep quality and patient laboratory measures were analysed in >300 dialysis units in 12 countries. METHODS: Pruritus data were collected from 18 801 HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) (1996-2004). Analyses were adjusted for age, gender, black race, Kt/V, haemoglobin, serum albumin, albumin-corrected serum calcium, serum phosphorus, 13 comorbidities, depression, years on dialysis, country and facility clustering effects. RESULTS: Moderate to extreme pruritus was experienced by 42% of prevalent HD patients in DOPPS during 2002/2003. Many patient characteristics were significantly associated with pruritus, but this did not explain the large differences in pruritus between countries (ranging from 36% in France to 50% in the UK) and between facilities (5-75%). Pruritus was slightly less common in patients starting HD than in patients on dialysis >3 months. Pruritus in new end-stage renal disease (ESRD) patients likely results from pre-existing conditions and not haemodialysis per se, indicating the need to understand development of pruritus before ESRD. Patients with moderate to extreme pruritus were more likely to feel drained [adjusted odds ratio (AOR) = 2.3-5.2, P < 0.0001] and to have poor sleep quality (AOR = 1.9-4.1, P < or = 0.0002), physician-diagnosed depression (AOR = 1.3-1.7, P < or = 0.004), and QoL mental and physical composite scores 3.1-8.6 points lower (P < 0.0001) than patients with no/mild pruritus. Pruritus in HD patients was associated with a 17% higher mortality risk (P < 0.0001), which was no longer significant after adjusting for sleep quality measures. CONCLUSIONS: The pruritus/mortality relationship may be substantially attributed to poor sleep quality. The many poor outcomes associated with pruritus underscore the need for better therapeutic agents to provide relief for the 40-50% of HD patients affected by pruritus.     

Serum levels of folate and cobalamin are lower in depressed than in nondepressed hemodialysis subjects.

OBJECTIVE: The purpose of this study was to evaluate if there was a significant difference in serum and RBC folate or serum cobalamin levels in depressed and nondepressed subjects on hemodialysis (HD). DESIGN: A cross-sectional design was used in this study. Each subject's serum folate and cobalamin, and red blood cell (RBC) folate were measured. The Beck Depression Index II (BDI-II) was used to assess for depression. Subjects with scores of 10 or greater were considered depressed. Other laboratory, anthropometric, and demographic data were obtained from the subjects' medical records. To assess for significant differences (P < 0.05) in the laboratory values of the outcome variables between depressed and nondepressed subjects, t tests were performed on the groups' mean values. SETTING: The study was conducted with patients in two dialysis centers in Texas. PATIENTS OR OTHER PARTICIPANTS: Seventy-three individuals undergoing HD for at least six months who met study inclusion criteria were solicited to participate in the study after the study was approved by the respective institutional review board. INTERVENTION: Depression and mental status of each subject were assessed using the BDI-II and the Folstein Mini-Mental State Exam, respectively. MAIN OUTCOME MEASURE: Serum folate, cobalamin, total homocysteine, and RBC folate were measured and mean values were evaluated for significant differences in the depressed and nondepressed groups. RESULTS: Of the subjects in this study, 43.8% had BDI-II scores > 10 indicating depression. The nondepressed subjects had significantly higher mean serum folate (281 +/- 649 vs. 52 +/- 137 ng/mL), serum cobalamin (1162 +/- 1014 vs. 757 +/- 463 pg/mL), and RBC folate (1433 +/- 1757 vs. 810 +/- 654 ng/mL) levels than did depressed subjects. In the nondepressed group, 39% of subjects were taking a supplement containing 35-42 mg folacin and 7 mg cobalamin per week while only 9.1% of depressed subjects were taking a vitamin containing these levels of B vitamins. The group means were not significantly different for age, months on HD, body mass index, erythropoietin/kg body weight, total homocysteine, hemoglobin, albumin, or ferritin. CONCLUSION: As with the general population, lower serum folate, RBC folate, and serum cobalamin levels were found in depressed as compared to nondepressed subjects on HD. Plasma levels of these vitamins may be one of many factors related to depression, but larger studies with stronger designs are needed to confirm the results of this study.     

Calcium carbonate is an effective phosphate binder when dialysate calcium concentration is adjusted to control hypercalcemia

The efficacy of calcium carbonate (CaCO3) as a phosphate binder has been limited by its tendency to cause hypercalcemia. Since standard dialysate calcium concentrations (3.0-3.5 mEq/l) increase the risk of developing hypercalcemia with large doses of CaCO3 by inducing positive calcium balance during hemodialysis (HD), we compared control of hyperphosphatemia in 41 HD patients during 4 months each of aluminum hydroxide (Al(OH)3) and CaCO3 when the dialysate calcium concentration was lowered, as required, to maintain the predialysis serum calcium concentration within the normal range. Mean predialysis serum phosphorus and calcium concentrations were 5.0 +/- 0.2 mg/dl and 9.3 +/- 0.1 mg/dl, respectively, during 4 months CaCO3 (9.2 +/- 0.3 g/day) and 4.9 +/- 0.2 g/dl and 9.1 +/- 0.1 mg/dl during the previous 4 months Al(OH)3 therapy (2.9 +/- 0.2 g/day). Reducing the dialysate calcium concentration to below 3.0 mEq/l (mean 2.1 +/- 0.04) in the 11 patients who developed hypercalcemia on CaCO3 decreased serum calcium (-1.1 +/- 0.15 mg/dl) and ionized calcium (-0.3 +/- 0.04 mEq/l) during HD, enabled CaCO3 (8.8 +/- 0.4 g/day) to be continued, and maintained predialysis serum calcium and phosphorus at 10.4 +/- 0.1 mg/dl and 5.2 +/- 0.3 mg/dl, respectively. No improvement in acidosis or biochemical hyperparathyroidism was observed during CaCO3 therapy but serum aluminum was significantly decreased after CaCO3 (p less than 0.005). We conclude that CaCO3 prevents interdialytic hyperphosphatemia as effectively as Al(OH)3 without increasing the predialysis serum calcium x phosphorus product, provided serum calcium is maintained within the normal range by adjusting the dialysate calcium concentration.     

Clinical outcomes of systemic lupus erythematosus patients undergoing continuous ambulatory peritoneal dialysis.

OBJECTIVES: The purpose of this study was to evaluate the outcome of systemic lupus erythematosus (SLE) patients on continuous ambulatory peritoneal dialysis (CAPD). METHODS: Eighteen SLE patients who had been undergoing CAPD for at least 3 months in our unit were compared with 36 other age- and gender-matched non-diabetic CAPD patients with an underlying primary chronic glomerulonephritis (CGn). The clinical outcome, infective complications, lupus activities, biochemical parameters, haemoglobin level and the use of erythropoietin were reviewed. RESULTS: The duration of dialysis of the two studied groups was not different, with a mean of 35.4 months for the SLE group and 36.7 months for the CGn group. Before dialysis, SLE patients had a significantly lower albumin level (30.4+/-6.6 vs 35.4+/-5.59 g/dl, P<0.01), while the mean haemoglobin levels of the two groups were similar (8.5+/-1.8 g/dl for SLE vs 9.0+/-1.9 g/dl for the control group). However, the weekly dose of erythropoietin (EPO) used was significantly higher in the SLE group (6000 vs 3818 U/week, P<0.01) to maintain a similar haemoglobin level during dialysis. Regarding the infective complications, the SLE group had a higher peritonitis rate (5.7 episodes/100 patient-months vs 2.4 episodes/100 patient-months, P<0.05), and an increase in the non catheter related infection rate (6.67 episodes/100 patient-months vs 1.1 episodes/100 patient-months, P<0.001). However, no significant difference could be demonstrated in the Tenckhoff catheter exit site infection rate (2 episodes/100 vs 1.7 episode/100 patient-months). The number of patients who received a kidney transplant or required a change of mode to haemodialysis was similar among the two groups. Seven patients died during the follow-up period, and the overall mortality rate was much higher in the SLE group than in the control group (0.83/100 vs 0.15/100 patient-months, P<0.05). CONCLUSIONS: SLE patients on CAPD have a significantly lower pre-dialysis serum albumin level and use a higher dose of Epo to achieve a comparable haemoglobin level than other non-diabetic CGn CAPD patients. They also have a poorer prognosis in terms of infective complications and mortality rate.     

The haemodynamic response to submaximal exercise during isovolaemic haemodialysis.

INTRODUCTION: Exercise during haemodialysis has potential benefits but may compromise cardiovascular stability. We studied its acute effects on relative blood volume (RBV) and other haemodynamic parameters. METHODS: Two groups of 10 patients were exercised submaximally using a stationary cycle during isovolaemic dialysis whilst RBV was monitored continuously. In study 1, patients exercised for two 10 min periods separated by 10 min rest. Cardiac output (CO), peripheral vascular resistance (PVR), central blood volume (CBV) and stroke volume were measured using ultrasound dilution immediately before and after each exercise session. In study 2, haemoglobin, serum total protein and albumin levels were measured before and immediately after the exercise session and at the nadir of the RBV trace. RESULTS: RBV fell immediately on exercise initiation, the maximum reduction being 2.0+/-1.1% (after 5.9+/-1.4 min of exercise 1: P<0.001) and 2.0+/-1.2% (after 4.7+/-2.3 min of exercise 2: P<0.001). CO increased significantly after both periods of exercise (4.5+/-0.96 and 5.1+/-1.1 to 7.2+/-2.1 and 7.9+/-2.4 l/min, P<0.001 in both). Stroke volume increased significantly and PVR fell significantly during exercise. CBV increased in absolute terms but fell as a proportion of CO. Mean haemoglobin level at the RBV nadir was significantly higher than baseline (12.3+/-1.8 vs 11.8+/-1.7 g/dl: P<0.05: mean change 4.4+/-2.3%), as was mean total protein concentration (66.0+/-6.9 vs 62.0+/-8.1 g/l: P = 0.001: mean change 6.8+/-5.9%) and mean serum albumin concentration (36.0+/-3.9 vs 34.1+/-3.9 g/l: P<0.001: mean change 5.8+/-3.5%). CONCLUSION: The haemodynamic response to exercise during haemodialysis is comparable with that in normal individuals. The rapid reduction in RBV on exercise occurs in spite of a significant increase in CO, mainly as a consequence of fluid shifts from the microvasculature to the interstitium.     

Soluble transferrin receptor is correlated with erythropoietin sensitivity in dialysis patients.

BACKGROUND: Iron deficiency is the most common cause of erythropoietin (EPO) resistance in dialyzed patients with renal anemia. Subclinical or functional iron deficiency is difficult to diagnose in these patients. The soluble transferrin receptor (sTf-R) is considered as a sensitive and specific indicator of bone marrow iron availability. PATIENTS AND METHODS: To evaluate the clinical usefulness of this novel marker, we investigated relationships between EPO requirements and various hematological and biochemical parameters of erythropoiesis in 27 pediatric end-stage renal failure patients treated by hemodialysis (HD, n = 11) or chronic peritoneal dialysis (PD, n = 16). Iron was substituted intravenously once or twice per week in HD, and by daily oral administration to PD patients. Serum sTf-R concentrations were measured by an enzyme-linked immunosorbent assay. Serum ferritin and transferrin concentrations were determined using nephelometric assays. Hemoglobin and iron levels were estimated by automated procedures. RESULTS: While neither transferrin saturation nor serum ferritin concentrations were indicative of EPO requirements, a highly significant correlation between the EPO efficacy index (EPO dose divided by hemoglobin concentration) and sTf-R was observed (r = 0.65, p = 0.001). The intravenous iron substitution in HD patients was associated with higher ferritin concentrations compared to the orally substituted PD patients (280+/-100 ng/ml vs. 124+/-83 ng/ml, p<0.002). In contrast, sTf-R concentrations were similar in both treatment groups (25.7+/-7.7 nM vs. 27+/-10.8 nM, n.s.), as were hemoglobin concentrations and EPO requirements. CONCLUSION: Our results suggest that sTf-R is a more sensitive indicator of functional iron deficiency and impaired EPO responsiveness than serum ferritin or transferrin saturation in dialyzed patients. Intensified iron substitution to patients with elevated sTf-R concentrations may considerably improve the cost efficacy of EPO treatment.     

Anthropometric measures, cytokines and survival in haemodialysis patients.

BACKGROUND: Lower serum albumin concentration (sAlb) and higher levels of pro-inflammatory cytokines have been reported to predict death in patients treated with haemodialysis (HD). SAlb, along with anthropometric measures, has been used as a surrogate marker for nutritional status in patients with chronic disease. Though adequate nutrition has been considered an important factor for patients treated with HD, it has not been established if any nutritional markers other than lower serum albumin and lower body mass index (BMI) predict death. Furthermore, it has not been shown whether anthropometric measures other than BMI are associated with predictors of mortality. METHODS: At the outset of the study, patients were assessed using demographic and anthropometric indices including arm fat area (AFA), arm muscle area (AMA), BMI, per cent ideal weight (PIW), pre-dialysis sAlb, and circulating levels of tumour necrosis factor-alpha (TNF-alpha), IL-1 and IL-6. A severity index, previously demonstrated to be a mortality marker, was used to grade medical co-morbidity. RESULTS: Two-hundred and forty patients entered the study. The mean age was 55.1+/-14.3 years, mean sAlb 3.76+/-0.60 mg/dl, mean AFA 1742+/-1225 mm(2), mean AMA 5464+/-1817 mm(2), mean PIW 101.0+/-21.3% and mean BMI 24.9+/-5.6 kg/m(2). PIW, BMI, AFA and AMA were, as expected, all highly correlated with one another. SAlb correlated with serum transferrin; however, neither sAlb nor serum transferrin concentration correlated with circulating cytokine levels. Circulating cytokines and sAlb did not correlate with PIW, BMI, AFA or AMA. In Cox regression analyses using multiple control variables, IL-6 predicted survival, while the anthropometric measures did not. CONCLUSIONS: Pro-inflammatory cytokines and sAlb are robust predictors of death in patients treated with HD. PIW and BMI correlate well with other anthropometric measures in patients treated with HD, but these measures do not correlate with markers of inflammation. Anthropometric measures are poor predictors of survival compared with measures linked to the acute-phase response.     

Efficacy of hepatic computed tomography to detect iron overload in chronic hemodialysis

The diagnostic efficacy of hepatic computed tomography density (HCTD) in comparison with serum ferritin for the detection of iron overload was investigated in uremic patients on maintenance hemodialysis (HD) and in patients with idiopathic hemochromatosis (IHC). Ten IHC patients, 38 HD patients and 40 healthy subjects underwent the CT scanning of the liver and determination of percent saturation of transferrin, serum ferritin concentration and HLA typing. Liver iron content was determined by histochemical grading and direct measurement of liver iron concentration either in IHC patients or in HD patients. Nineteen HD patients were considered to have iron overload on the basis of liver iron concentration exceeding 3.6 mumol/100 mg dry weight. The mean +/- SD values of HCTD in healthy subjects, IHC patients, HD patients with iron overload and without iron overload were 60.2 +/- 5.6, 79 +/- 5.6, 71.4 +/- 3.6, 58 +/- 3.8 Hounsfield units, respectively. HCTD showed positive correlations with liver iron concentration and serum ferritin either in IHC patients or in HD patients. The analysis of the diagnostic efficacy of HCTD in comparison with serum ferritin for the detection of excessive hepatic iron in HD patients demonstrated that HCTD had higher sensitivity, specificity, positive and negative predictive values. Cut-off points were arbitrarily fixed to 66 Hounsfield units for HCTD, 400 micrograms/liter for serum ferritin and 3.6 mumol/100 mg dry weight for liver iron concentration. Seventeen HD patients who possessed the histocompatibility antigens associated with IHC, namely HLA-A3 and/or HLA-B7 and/or HLA-B14, had liver iron concentration, serum ferritin and HCTD values higher than those of the HD patients without these "hemochromatosis alleles".(ABSTRACT TRUNCATED AT 250 WORDS)     

Switching from subcutaneous to intravenous erythropoietin alpha in haemodialysis patients requires a major dose increase.

BACKGROUND: A change in the licensing arrangements for the use of erythropoietin alpha in haemodialysis patients has required a switch in the route of administration from subcutaneous (SC) to intravenous (IV). Previous work suggested that the IV route was less efficacious but studies since the enforced switch have not confirmed this. METHODS: We studied haemoglobin levels and the mean weekly dose of erythropoietin alpha in 86 haemodialysis patients at monthly intervals over the 6 month period before and after a change in the route of administration of erythropoietin alpha from SC to IV. Changes in other parameters known to be associated with erythropoietin response were also monitored. RESULTS: Mean haemoglobin level fell following the switch from 11.9 g/dl+/-1.4 at baseline to 11.3 g/dl+/-1.4 at 1 month (P = 0.001) and to a trough of 11.0 g/dl+/-1.3 at 2 months (P<0.001) before partial recovery to 11.4 g/dl+/-1.2 (P = 0.007) at 6 months. Mean weekly dose of erythropoietin after 2 months was significantly higher than baseline (8791 IU+/-5314 vs 8035 IU+/-4893). The dose continued to increase and by 6 months was 10605 IU (P<0.001), 32% higher than baseline. There was a small reduction in residual renal function, which was an independent predictor of change in dose requirement. There was a small increase in parathyroid hormone levels, but no change in serum ferritin, dosing frequency, total Kt/V, serum albumin, normalised protein catabolic rate, C-reactive protein, hospitalization rate and dialyser reuse rate. CONCLUSIONS: Switching from SC to IV erythropoietin alpha caused a significant fall in haemoglobin levels in the first 2 months. This was partially reversed by 6 months at the expense of a 32% dose increase in the dose of erythropoietin alpha by 6 months. The economic impact may be considerable.     

Intravenous ascorbic acid as an adjuvant therapy for recombinant erythropoietin in hemodialysis patients with hyperferritinemia.

BACKGROUND: Inadequate iron mobilization and defective iron utilization may cause recombinant erythropoietin (rEPO) hyporesponsiveness in hemodialysis (HD) patients with iron overload. We have demonstrated that intravenous ascorbic acid (IVAA), but not intravenous iron medication, can effectively circumvent the functional iron-deficient erythropoiesis associated with iron overload in HD patients. However, it is uncertain whether all HD patients with hyperferritinemia will consistently respond to IVAA and which index may indicate functional iron deficiency in the special entity. Therefore, a prospective study was conducted to establish the guidelines for IVAA adjuvant therapy. METHODS: Sixty-five HD patients with serum ferritin levels of more than 500 microgram/liter were recruited and divided into the control (N = 19) and IVAA (N = 46) groups. IVAA patients with a hematocrit (Hct) of less than 30% received 300 mg of ascorbic acid three times per week for eight weeks. Controls had a Hct of more than 30% and did not receive the adjuvant therapy. Red blood cell and reticulocyte counts, iron metabolism indices, erythrocyte zinc protoporphyrin (E-ZPP), and the concentrations of plasma ascorbate and oxalate were examined before and following the therapy. RESULTS: Thirteen patients (four controls and nine IVAA patients) withdrew by the end of the study. Eighteen patients had a dramatic response to IVAA with a significant increase in their hemoglobin and reticulocyte index and a concomitant 24% reduction in rEPO dose after eight weeks. This paralleled a significant rise in serum iron and transferrin saturation (TS) and a fall in E-ZPP and serum ferritin (baselines vs. 8 weeks, serum iron 68 +/- 37 vs. 124 +/- 64 microgram/dl, TS 27 +/- 10 vs. 48 +/- 19%, E-ZPP 123 +/- 44 vs. 70 +/- 13 micromol/mol heme, and serum ferritin 816 +/- 435 vs. 587 +/- 323 microgram/liter, P < 0. 05). Compared with responders, mean values of hemoglobin, rEPO dose, iron metabolism parameters, and E-ZPP showed no significant changes in controls (N = 15) and in non-responders (N = 19). Thirty-seven patients (18 responders and 19 non-responders) were further analyzed by receiver operating characteristic curves to seek the criteria for prediction of a response to IVAA treatment. The results showed that E-ZPP at a cut-off level of more than 105 micromol/mol heme and TS at a level of less than 25% were more specific to confirm the status of functional iron deficiency in iron-overloaded patients. The two criterion values had the highest accuracy to predict a response to treatment. CONCLUSIONS: Functional iron-deficient erythropoiesis plays a role in rEPO-hyporesponsive anemia in HD patients with hyperferritinemia. IVAA may be an adjuvant therapy for rEPO in these patients, and E-ZPP of more than 105 micromol/mol heme and TS of less than 25% should be used to guide the IVAA treatment.     

Intravenous iron supplementation for the treatment of anaemia in pre-dialyzed chronic renal failure patients.

BACKGROUND: Intravenous iron is a recognized therapy of anaemia in chronic haemodialyzed patients, especially in those receiving erythropoietin (Epo), while its role in the anaemia of pre-dialyzed chronic renal failure (CRF) patients is much less clear. This study attempted to evaluate the effects of intravenous iron in anaemic pre-dialyzed patients. METHODS: Sixty anaemic (haemoglobin<11 g/dl) non-diabetic patients with moderate CRF [32 males, 28 females; mean age 52.2+/-12.5 years; mean glomerular filtration rate 36.2+/-5.2 ml/min], without iron deficiency, iron overload or inflammation, without concomitant erythropoietin treatment and without any previous iron therapy were enrolled. Intravenous iron was administered as iron sucrose, 200 mg elemental iron per month for 12 months, with 1 month pre-study survey and 1 month follow-up after the last iron dose. RESULTS: Intravenous iron supplementation was associated with a significant increase in haemoglobin (from 9.7+/-1.1 at the baseline to 11.3+/-2.5 g/dl after 12 months, a mean increase of 1.6 g/dl), a further 36% of patients reaching the target haemoglobin of 10 g/dl. There was a significant increase in serum iron from 73.9+/-17.2 to 101.8+/-12.2 microg/dl, in serum ferritin from 98.0 (24.8-139.0) to 442.5 (86.0-496.0) microg/l and in transferrin saturation from 21.6+/-2.6 to 33.6+/-3.2%. No worsening of renal function, no increase in blood pressure and no other side effects were noted. CONCLUSIONS: Intravenous iron therapy in pre-dialysis patients with no Epo seems often to ameliorate the anaemia, avoiding the necessity of Epo or blood transfusions in one-third of pre-dialyzed non-diabetic patients. Intravenous iron supplementation appears to be an effective and safe treatment for anaemia in pre-dialysis CRF patients.     

Nutritional anaemia in 11-year-old schoolchildren in the western Cape

A nutritional anaemia survey was carried out on 610 11-year-old coloured, black and white schoolchildren in urban and rural communities in the western Cape. The mean (+/- 1 SD) haemoglobin concentration was 13.0 +/- 1.2 g/dl. The coloured and black subgroups considered together had a significantly lower mean haemoglobin concentration than the white subgroup (12.8 +/- 1.2 g/dl v. 13.4 +/- 1.0 g/dl) (F = 37.47; P less than 0.0001). The urban population as a whole had a significantly lower geometric mean (1 SD range) serum ferritin concentration than the rural population (25.6 (13.5-48.6) micrograms/l v. 34.1 (21.3-54.6) micrograms/l) (F = 42.94; P less than 0.0001). The lowest geometric mean serum ferritin values were found in the urban coloured (23.1 (11.5-46.4) micrograms/l) and urban black schoolchildren (23.7 (13.2-42.6) micrograms/l), with figures of less than 12 micrograms/l in 11.7% and 12.5% respectively. Although 28% of the children had red cell folate values below the recommended lower limit of normal (175 ng/ml), probability plot analysis of the data suggested that folate deficiency was not a major problem in the study population. The calculated daily iron and folate intakes were below the age-related recommended dietary allowance (RDA) in all the subgroups, yet anaemia was relatively uncommon. These findings suggest that the RDA values are too high. Overall the prevalence of nutritional anaemia was low and only the urban coloured subgroup showed significant second populations with low haemoglobin and serum ferritin measurements.     

A randomized trial of iron deficiency testing strategies in hemodialysis patients.

BACKGROUND: Diagnosis of iron deficiency in hemodialysis patients is limited by the inaccuracy of commonly used tests. Reticulocyte hemoglobin content (CHr) is a test that has shown promise for improved diagnosis in preliminary studies. The purpose of this study was to compare iron management guided by serum ferritin and transferrin saturation to management guided by CHr. METHODS: A total of 157 hemodialysis patients from three centers were randomized to iron management based on (group 1) serum ferritin and transferrin saturation, or (group 2) CHr. Patients were followed for six months. Treatment with intravenous iron dextran, 100 mg for 10 consecutive treatments was initiated if (group 1) serum ferritin <100 ng/mL or transferrin saturation <20%, or (group 2) CHr <29 pg. RESULTS: There was no significant difference between groups in the final mean hematocrit or epoetin dose. The mean weekly dose of iron dextran was 47.7 +/- 35.5 mg in group 1 compared to 22.9 +/- 20.5 mg in group 2 (P = 0.02). The final mean serum ferritin was 399.5 +/- 247.6 ng/mL in group 1 compared to 304.7 +/- 290.6 ng/mL in group 2 (P < 0.05). There was no significant difference in final TSAT or CHr. Coefficient of variation was significantly lower for CHr than serum ferritin and transferrin saturation (3.4% vs. 43.6% and 39.5%, respectively). CONCLUSIONS: CHr is a markedly more stable analyte than serum ferritin or transferrin saturation, and iron management based on CHr results in similar hematocrit and epoetin dosing while significantly reducing IV iron exposure.     

Oxidative stress and ferritin levels in haemodialysis patients.

BACKGROUND: Increased oxidative stress (OS) and inflammation are associated with atherosclerotic coronary artery disease in haemodialysis (HD) patients. Ferritin may have other effects in addition to its role in storing intracellular iron. This study was performed to determine any relationships between markers of OS, nutrition and inflammation in HD patients with normal and high ferritin levels. METHODS: Our cohort comprised 34 maintenance dialysis patients on erythropoietin therapy and 22 healthy controls. HD patients were divided into two groups: 17 with normal (<800 ng/ml) and 17 with high (>800 ng/ml) ferritin levels, and we measured lipid profile, albumin, highly sensitive C-reactive protein (hsCRP), anti-oxidant enzymes [whole blood glutathione peroxidase (Gpx), serum superoxide dismutase (SOD), paraoxonase, arylestherase (AE) and total anti-oxidant status (TAOC)], anti-oxidants (vitamin C) and lipid peroxidation products [red blood cell malondialdehyde (RBC MDA)]. RESULTS: Compared with controls, the HD patients had higher serum urea, blood pressure, triglyceride, hsCRP, RBC MDA, SOD and TAOC values and lower albumin, low-density lipoprotein cholesterol, apolipoprotein AI, paraoxonase, AE and whole blood Gpx activities. Serum vitamin C, uric acid, apolipoprotein B, total- and high-density lipoprotein cholesterol, apolipoprotein B MDA, and lymphocyte levels in the HD patients with normal and high ferritin levels were similar. The OS markers of HD patients did not differ, whether or not they received intravenous iron supplementation or had transferrin saturations < 50% or > or = 50%. CONCLUSION: HD patients are in a higher oxidative state, which results in the reduction of total anti-oxidant capacity and also have an increased inflammation status. We could not find a relationship between ferritin level and OS markers in HD patients receiving erythropoietin.     

Determinants of circulating soluble transferrin receptor level in chronic haemodialysis patients.

BACKGROUND: The aim of this study was to identify the factors determining the circulating soluble transferrin receptor (sTfR) concentrations in haemodialysis (HD) patients on maintenance recombinant human erythropoietin (rHuEpo) treatment. METHODS: In a prospective cross-sectional study, 91 chronic HD patients and 18 anaemic controls with normal renal function were recruited. For each subject, blood samples were measured for complete blood count, reticulocyte count, percentage of hypochromic red cells (% HRC), serum ferritin, serum iron, transferrin saturation (TS), serum erythropoietin (sEpo), C-reactive protein (CRP), and sTfR. HD patients received constant rHuEpo doses and basal sEpo was measured > or = 86 h after the last injection. The age, gender, dialysis vintage, and the above-mentioned parameters were used as independent variables and logarithmic sTfR (log(10)sTfR) as a dependent variable in the forward stepwise multiple regression model. RESULTS: HD patients were similar to controls regarding haematocrit, serum ferritin, TS, and % HRC, but had significantly lower sTfR, sEpo, and reticulocyte index. Univariate analyses showed that the sTfR level strongly correlated with sEpo (r=0.60, P<0.001) and % HRC (r=0.60, P<0.001), and significantly with serum ferritin (r=-0.29, P<0.01), TS (r=-0.27, P<0.05), and dose of rHuEpo administered (r=0.27, P<0.05) in HD patients. sTfR also had a positive correlation with haematocrit (r=0.26, P<0.05), red blood cell (RBC) count (r=0.23, P<0.05), and reticulocyte count (r=0.24, P<0.05), but not with CRP (r=0.16, P>0.05). Multivariate regression analysis disclosed that sEpo, HRC, and serum ferritin were the independent predictors of sTfR level. Overall, the model explained 58.8% of the variability in sTfR (R(2)=0.588, P<0.001). CONCLUSIONS: Circulating sTfR is a good index of marrow erythropoietic activity in HD patients during rHuEpo treatment. Its level is also independently up-regulated by functional iron deficiency in the process of enhanced erythropoiesis. Our study showed that sTfR levels quantitatively reflect the integrated effects of iron availability, iron reserves, and erythropoietic stimulation.