Catalytically active iron and bacterial growth in serum of haemodialysis patients after i.v. iron-saccharate administration.

BACKGROUND: I.v. iron is commonly administered to haemodialysis patients suffering from anaemia to improve their response to erythropoietin therapy. It has been unclear whether routinely used doses of i.v. iron preparations could result in iron release into plasma in amounts exceeding the iron binding capacity of transferrin. Here, we have studied the effect of 100 mg of iron saccharate given as an i.v. injection on transferrin saturation and the appearance of potentially harmful catalytically active iron. METHODS: We followed serum iron, transferrin and transferrin-saturation before and 5-210 min after administration of iron saccharate in 12 patients on chronic haemodialysis due to end-stage renal disease. We measured catalytically active iron by the bleomycin-detectable iron (BDI) assay and transferrin iron forms by urea gel electrophoresis, and studied iron-dependent growth of Staphylococcus epidermidis inoculated into the serum samples in vitro. RESULTS: The iron saccharate injection resulted in full transferrin saturation and appearance of BDI in the serum in seven out of the 12 patients. BDI appeared more often in patients with a low serum transferrin concentration, but it was not possible to identify patients at risk based on serum transferrin or ferritin level before i.v. iron. The average transferrin saturation and BDI level increased until the end of the follow-up time of 3.5 h. The appearance of BDI resulted in loss of the ability of patient serum to resist the growth of S. epidermidis, which was restored by adding iron-free apotransferrin to the serum. Iron saccharate, added to serum in vitro, released only little iron and promoted only slow bacterial growth, but caused falsely high transferrin saturation by one routinely used serum iron assay. CONCLUSIONS: The results indicate that 100 mg of iron saccharate often leads to transferrin oversaturation and the presence of catalytically active iron within 3.5 h after i.v. injection. As catalytically active iron is potentially toxic and may promote bacterial growth, it may be recommendable to use dosage regimens for i.v. iron that would not cause transferrin oversaturation.     

Importance of iron supply for erythropoietin therapy

BACKGROUND.: rHuEpo and iron therapy corrects renal anaemia. However, dosage,route of administration, and monitoring of iron and rHuEpo therapyin uraemic patients remains controversial. METHODS.: Therefore a 22-month i.v. iron substitution trial, subdividedinto four study periods, was initiated in 64 iron-depleted chronichaemodialysis (HD) patients receiving i.v. rHuEpo therapy. Withinthe first period (6 months) patients were treated with high-doseiron (100mg at the end of HD treatment, mean cumulative i.v.iron saccharate dosage was 2538±810 mg per patient) inorder to replete the iron stores. During the 2nd period (6 months)the available iron pool was maintained with low-dose iron byadministration of 10, 20, or 40 mg iron at each HD, dependingon haemoglobin, serum ferritin and transferrin saturation levels.During the 3rd period (4 months), the iron-replete patientswere randomized to i.v. or s.c. route of rHuEpo administration.During the 4th period (3 months) iron substitution was omittedto exclude severe iron overload. RESULTS.: In the first study period, high-dose iron therapy dramaticallyreduced the weekly rHuEpo requirement by 70% of the initialdose (from 217±179 to 62.6±70.2 U/kg/week). Inthe 2nd period iron storage pools were easily maintained. Serumferritin and transferrin saturation levels remained stable duringthis study period. Randomization for thrice-weekly i.v. or s.c.administration of rHuEpo in the 3rd study period revealed comparableefficacy for both administration routes in iron-replete patients.In well-nourished patients (serum albumin >40 g/1) withouthyperparathyroidism (parathyroid hormone levels < 100 pg/ml),50–60 U/kg/week rHuEpo were required in contrast to >100 U/kg/week in patients with hyperparathyroidism. In the 4thstudy period, withdrawal of iron administration led to a rapiddecrease of serum ferritin and transferrin saturation levels,indicating the absence of severe iron overload. CONCLUSIONS.: Long-term thrice-weekly i.v. low-dose iron therapy (10–20mg per HD treatment) proved to be a very effective, economicaland safe treatment schedule for iron-replete HD patients. Intravenousand s.c. rHuEpo therapy was equally efficacious in iron-replete,well-nourished patients. HD patients with increased parathyroidhormone levels require significantly more rHuEpo than HD patientswith parathyroid hormone levels values <100 pg/ml).     

Experience of iron saccharate supplementation in haemodialysis patients treated with erythropoietin

We assessed the efficacy of intravenous (i.v.) iron saccharate (VENOFER) vs oral iron supplementation in haemodialysis patients treated with low-dose erythropoietin (EPO). Twenty haemodialysis patients with serum ferritin >200 ng/mL and transferrin saturation >30% were assigned to one of the two groups. In Group 1, 10 were given i.v. iron saccharate (100 mg i.v. twice weekly) post dialysis. In Group 2, oral ferrous sulphate 200 mg was given thrice daily. In both groups, subcutaneous EPO 25 units/kg body weight (BW) was started simultaneously, twice weekly. After 3 months (study completion) the mean haemoglobin and haematocrit was significantly increased in Group 1 than in Group 2 (Hb 11.60±0.64 G/dL vs 10.5 G/dL±1.14 P <0.01). The final mean EPO dose was 25% lower in Group 1 than in Group 2 (3400±1356 U/week vs 4600±1356 U/week P =0.10) and the mean serum ferritin was higher in the i.v. iron group than the oral group (671 ng/mL±388 vs 367 ng/mL±238 P =NS). The same was also observed with transferrin saturation (44.6%±19.8 in Group 1 vs. 29%±11.0 in Group 2 P =NS). No adverse effects were seen during the study. In conclusion, we observed that regular use of i.v. iron had a significantly enhanced haemoglobin response, better maintained serum ferritin and lower EPO dosage requirement than the oral iron group.     

Experience of iron saccharate supplementation in haemodialysis patients treated with erythropoietin

SUMMARY: We assessed the efficacy of intravenous (i.v.) iron saccharate (VENOFER) vs oral iron supplementation in haemodialysis patients treated with low-dose erythropoietin (EPO). Twenty haemodialysis patients with serum ferritin >200 ng/mL and transferrin saturation >30% were assigned to one of the two groups. In Group 1, 10 were given i.v. iron saccharate (100 mg i.v. twice weekly) post dialysis. In Group 2, oral ferrous sulphate 200 mg was given thrice daily. In both groups, subcutaneous EPO 25 units/kg body weight (BW) was started simultaneously, twice weekly. After 3 months (study completion) the mean haemoglobin and haematocrit was significantly increased in Group 1 than in Group 2 (Hb 11.60 ± 0.64 G/ dL vs 10.5 G/dL ± 1.14 P <0.01). the final mean EPO dose was 25% lower in Group 1 than in Group 2 (3400 ± 1356 U/week vs 4600 ± 1356 U/week P =0.10) and the mean serum ferritin was higher in the i.v. iron group than the oral group (671 ng/mL ± 388 vs 367 ng/mL ± 238 P =NS). the same was also observed with transferrin saturation (44.6%± 19.8 in Group 1 vs. 29%± 11.0 in Group 2 P =NS). No adverse effects were seen during the study. In conclusion, we observed that regular use of i.v. iron had a significantly enhanced haemoglobin response, better maintained serum ferritin and lower EPO dosage requirement than the oral iron group.     

'Oversaturation' of transferrin after intravenous ferric gluconate (FerrlecitR) in haemodialysis patients

BACKGROUND: Chronic haemodialysis causes blood loss and iron-deficiency.This can be corrected with intravenous preparations, e.g. sodiumferric-gluconate (FeGl). In two patients complaints of hypotensionand malaise during FeGl infusion coincided with high levelsof serum iron and a calculated transferrin iron saturation above100%. Iron toxicity could be the cause of these complaints.Free iron is known to aggravate the toxicity of free radicalsand other reactive oxygen products that are constantly formedin the body. We compared four rates of FeGl infusion with regardto iron parameters. METHODS: 20 dialysis patients received a total of 36 infusions of FeGl.A rapid infusion of 125 mg (Protocol A (n=10)) or 62.5 mg (ProtocolB (n=7)) of FeGl was given during the last 30 min of dialysis.A slow infusion of 125 mg (Protocol C (n=9)) or 62.5 mg (ProtocolD (n=10)) was given during 4 or 4.5 h of dialysis. Blood wastaken at regular intervals before, during, and after dialysisfor determination of serum iron, transferrin, ferritin, haematocrit,total protein, albumin, and lactate dehydrogenase (LDH). Transferrinsaturation was calculated from transferrin and serum iron. RESULTS: With rapid infusion A (125mg) the highest levels of serum iron(median 120 (range 40–159) micromol/l) and transferrinsaturation (207 (84–331)%) were seen at the end of theinfusion. These were significantly higher than the peak levelswith B, C, and D (P0.03). With rapid infusion B (62.5 mg), peaklevels were intermediately high (serum iron 61 (50–96)µmol/l; transferrin saturation 118 (91–174)%). Withslow infusion C (125 mg) similar peak levels were seen (serumiron 83 (43–106) µmol/l; transferrin saturation141 (88–172)%). With slow infusion D (62.5 mg), the lowestpeak levels were seen (serum iron 38 (31–55) µmol/l;transferrin saturation 78 (43–92)%). These levels weresignificantly lower than those with A, B and C (p0.002). Onlywith D all patients showed a transferrin saturation lower than100%. Ferritin was increased before the next dialysis in allpatients. LDH was not significantly elevated during any infusion. CONCLUSIONS: The commonly used rapid infusion rate (A) of FeGl causes ‘oversaturation’of transferrin. This is compatible with iron toxicity due tofree iron which may explain our patients' complaints. Free ironcannot be measured directly. LDH as a crude measure of celldamage was not elevated. Better measurements to prove free irontoxicity, like lipid peroxides, are not yet readily available.Infusion during a longer period at a lower dose (D) is effectiveand eliminates ‘oversaturation’ of transferrin andprobably the danger of iron toxicity.     

A randomized, controlled parallel-group trial on efficacy and safety of iron sucrose (Venofer) vs iron gluconate (Ferrlecit) in haemodialysis patients treated with rHuEpo.

BACKGROUND: The objectives of the present trial were to compare the efficacy and safety of two i.v. iron preparations with respect to haemoglobin levels, iron status and recombinant human erythropoetin (rHuEpo) dosage requirements in stable, rHuEpo-treated haemodialysis patients (maintenance phase of iron treatment) over 6 months. METHODS: A total of 59 patients were randomized and assigned to one of two treatment groups and 55 patients were analysed (iron sucrose n=27; iron gluconate n=28). Iron sucrose was administered in a dose of 250 mg iron diluted in 100 ml normal saline given over 60 min once per month, while 62.5 mg iron as iron gluconate was given once per week in a slow push injection (5 min). RESULTS: --Efficacy parameters: Haemoglobin levels could be maintained from baseline to endpoint in both groups. There were, however, more patients in the iron sucrose group than in the iron gluconate group for whom treatment was discontinued because their haemoglobin values exceeded 12.5 g/dl or ferritin values exceeded 1000 ng/ml (five vs two and three vs one patient, respectively). Transferrin saturation and serum ferritin increased significantly in both groups (+255.7 ng/ml with iron sucrose and +278.5 ng/ml with iron gluconate), while rHuEpo dosage did not change significantly throughout the study. --Safety parameters: There were a total of 174 infusions of iron sucrose and 720 injections of iron gluconate during the trial; all of them were well tolerated. In particular, we did not observe anaphylactoid reactions or any events suggestive of iron toxicity such as hypotension, dizziness, or nausea. CONCLUSIONS: High doses of iron sucrose (Venofer((R)) at a dose of 250 mg/month) was equally effective in maintaining haemoglobin and equally well tolerated as low doses of iron gluconate (Ferrlecit((R)) at a dose of 62.5 mg once per week) in stable, rHuEpo treated haemodialysis patients.     

Regular low-dose intravenous iron therapy improves response to erythropoietin in haemodialysis patients

BACKGROUND.: Erythropoietin (Epo) is an effective but expensive treatmentfor anaemia in patients with chronic renal failure. Hyporesponsivenessto Epo, particularly in haemodialysis patients, is most commonlydue to a functional iron deficiency, which is difficult to monitorreliably. METHODS.: Forty-six stable haemodialysis patients, receiving Epo therapy,were commenced on regular low-dose intravenous iron (sodiumferric gluconate complex) at a dose of 62.5 mg/5 ml given asa slow injection post-dialysis twice weekly, weekly, or fort-nightly,according to their serum ferritin levels. Haemoglobin, serumferritin, Epo dose, and iron dose were measured at 6-weeklyintervals over a 6-month period. RESULTS: At the beginning of the study, 12 patients in the group hadferritin levels of less than 100 µg/l, and were thus consideredto potentially have an absolute iron deficiency. The study groupwas therefore split into two subgroups for the purpose of analysis,i.e. the 12 patients with ferritin levels of less than 100 µg/lat the start of the study or ‘low ferritin group’,and the remaining 34 patients with ferritin levels of greaterthan 100 µg/l at the start of the study or ‘normalferritin group’. In the low ferritin group (n=12), intravenous iron therapy increasedserum ferritin levels, and produced a significant rise in haemoglobin,and a significant reduction in Epo dose. (Ferritin pre-iron,median (range) 68 (20–96)µg/l; post-iron, 210.5(91–447)µg/l, P<0.003, Wilcoxon. Haemoglobinpre-iron, 10.05 (8.2–11.9)g/dl; post-iron, 11.0 (9.9–11.9)g/dl,P<0.03. Epo dose pre-iron, 9000 (4000–30000) i.u./week;post-iron, 6000 (2000–10000)i.u./week, P<0.05.) Similar results were obtained in the normal ferritin group (n=34)following intravenous iron therapy, with significant increasesin serum ferntin levels and haemoglobin concentrations, anda significant reduction in Epo dose. (Ferritin pre-iron, 176(103–519) µg/l; post-iron, 304.5 (121–792)µg/l,P<0.0001. Haemoglobin pre-iron, 9.85 (6.5–12.8)g/dl;post-iron: 11.25 (9.9–13.3)g/dl, P<0.0001. Epo dosepre-iron, 6000 (2000–15 000)i.u./week; post-iron, 4000(0–15000)i.u./week, P<0.005.) CONCLUSION.: Regular intravenous iron supplementation in haemodialysis patientsimproves the response to Epo therapy.     

Sodium ferric gluconate complex in sucrose is safe and effective in hemodialysis patients: North American Clinical Trial.

A new intravenous (i.v.) iron compound, sodium ferric gluconate complex in sucrose (Ferrlecit, R&D Laboratories, Inc, Marina Del Rey, CA), was administered over 8 consecutive dialysis days in equally divided doses to a total of either 0.5 or 1.0 g in a controlled, open, multicenter, randomized clinical study of anemic, iron-deficient hemodialysis patients receiving recombinant human erythropoietin (rHuEPO). Effectiveness was assessed by increase in hemoglobin and hematocrit and changes of iron parameters. Results were compared with historically matched controls on oral iron. High-dose i.v. treatment with 1.0 g sodium ferric gluconate complex in sucrose resulted in significantly greater improvement in hemoglobin, hematocrit, iron saturation, and serum ferritin at all time points, as compared with low-dose i.v. (0.5 g) or oral iron treatment. Despite an initial improvement in mean serum ferritin and transferrin saturation, 500 mg i.v. therapy did not result in a significant improvement in hemoglobin at any time. Eighty-three of 88 patients completed treatment with sodium ferric gluconate complex in sucrose: 44 in the high-dose and 39 in the low-dose group. Two patients discontinued for personal reasons. The other three discontinued because of a rash, nausea and rash, and chest pain with pruritus, respectively. In comparison with 25 matched control patients, adverse events could not be linked to drug therapy, nor was there a dose effect. In conclusion, sodium ferric gluconate complex in sucrose is safe and effective in the management of iron-deficiency anemia in severely iron-deficient and anemic hemodialysis patients receiving rHuEPO. This study confirms the concepts regarding iron therapy expressed in the National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF-DOQI) that hemodialysis patients with serum ferritin below 100 ng/mL or transferrin saturations below 18% need supplementation with parenteral iron in excess of 1.0 g to achieve optimal response in hemoglobin and hematocrit levels.     

Hypochromic red cells and reticulocyte haemglobin content as markers of iron-deficient erythropoiesis in patients undergoing chronic haemodialysis.

BACKGROUND: In patients on chronic haemodialysis, because of a non-specific increase in serum ferritin, iron deficiency may be overlooked leading to failure of erythropoietin treatment. A reticulocyte haemglobin content < 26 pg and a percentage of hypochromic red cells > 2.5 have been proposed as markers of iron-deficient erythropoiesis in such subjects, but it is unclear which parameter is superior. METHODS: We measured haematocrit, reticulocyte haemglobin content, ferritin and the percentage of hypochromic red cells over 10-150 days in 36 chronic haemodialysis patients in a university hospital. Transferrin saturation was also measured in a subset of 25 patients; iron deficiency was defined as a transferrin saturation < 15%. RESULTS: The diagnostic sensitivity and specificity of a reticulocyte haemoglobin content < 26 pg in detecting iron deficiency were 100% and 73% respectively, compared with 91% and 54% for a percentage of hypochromic red cells > 2.5. Paradoxical reticulocyte haemglobin concentrations occurred on follow-up in five patients receiving 4000 U erythropoietin per haemodialysis (HD). In three patients, reticulocyte haemglobin content exceeded 26 pg despite a persistent lack of iron. In a fourth, iron gluconate (62.5 mg i.v./HD) increased transferrin saturation to 27% and reduced the percentage of hypochromic red cells from 12 to 4, while reticulocyte haemglobin remained > 30 pg. In the final patient, iron gluconate increased transferrin saturation from 8 to 30% and reduced the percentage of hypochromic red cells from 40 to below 5, but reticulocyte haemglobin content remained < or = 26 pg throughout. CONCLUSIONS: The reticulocyte haemglobin content is superior to the percentage of hypochromic red cells in detecting iron deficiency in haemodialysis patients.     

Percentage hypochromic red cells and the response to intravenous iron therapy in anaemic haemodialysis

Introduction: Iron deficiency is commonly encountered in haemodialysis (HD) patients and may be overcome by i.v. therapy. We have examined the percentage hypochromic red cells (%HRC) for predicting response to i.v. iron in subjects with a low serum ferritin. Methods: Prospective study of i.v. iron saccharate (trivalent iron 200 mg/week for 8 weeks) in anaemic (Hb <10 g/dl) HD patients with serum ferritin <100 &mgr;g/l despite oral iron therapy. Response to i.v. iron was assessed by comparing Hb at 0 and 8 weeks according to %HRC at baseline (0-3%, 4-9%, ⩾10%). Results are mean±1 SD. Results: For all subjects (n=82), Hb and ferritin increased between 0 and 8 weeks (8.9±1.0 to 10.1±1.4, P<0.0001; 55±24 to 288±126, P<0.0001). Patients were stratified into three groups according to %HRC at baseline (0-3%, 4-9%, ⩾10%). Hb increased significantly in all three groups. The mean increase in Hb was greater (0-3%, 0.6±1.2; 4-9%, 1.2±1.0; ⩾10%, 1.6±1.4; P=0.02) and the proportion of patients showing a ⩾1 g/dl increase in Hb was greater (0-3%, 27%; 4-9%, 47%; ⩾10%, 67%; P=0.02) in those with the largest %HRC pre-treatment. Conclusion: Intravenous iron therapy is effective in improving Hb in anaemic HD patients with a low ferritin. However, the magnitude of this response and the proportion of patients responding is related to the percentage hypochromic red cells prior to treatment.     

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.     

Low-dose continuous iron therapy leads to a positive iron balance and decreased serum transferrin levels in chronic haemodialysis patients

Background. Iron balance is critical for adequate erythropoiesis,but its optimal therapeutic regimen remains to be defined. Continuousmaintenance therapy with iron has been proposed for dialysispatients on recombinant human erythropoietin (rHuEpo) in thehope that the regimen is adequate and safe. Methods. We determined serum ferritin, transferrin, transferrinsaturation (TSAT), serum transferrin receptors, albumin andC-reactive protein (CRP) in a 3-year prospective study in 30chronic haemodialysis patients on dialysis treatment for 132±111months (18 males, 12 females; mean age 56±14 years).Beginning in the year 2000, they regularly received low-dosemaintenance iron supplementation (i.v. iron gluconate 31.25mg/week) for 12 months (Period 1 or first treatment phase),followed by a 6-month withdrawal (Period 2 or stop phase) andthen by continuous maintenance iron therapy (i.v. iron gluconate31.25 mg/week) for another 9 months (Period 3 or re-challengephase). Results. A significant increase in serum ferritin and TSAT wasobserved, with values exceeding 500 ng/ml and 50% in 10/30 (33%)and 7/30 (23%) of subjects, respectively, in Period 1, and in11 and 5% in Period 3. A significant decrease in serum transferrinwas documented during Period 1, followed by an increase in Period2 and a decrease in Period 3. Serum albumin remained stable.Serum transferrin was always negatively correlated with ferritin(r = –0.41, P<0.001) and weakly correlated with serumtransferrin receptors (r = 0.178, P<0.05), but was not correlatedwith serum albumin or CRP. Regression equations based on pre-treatmentserum ferritin values were developed for predicting the valueof serum ferritin at any time following the beginning of continuousiron supplementation. They fitted a linear relationship formales (y = 81 + 21.5 x time) and for females (y = 65 + 22 xtime). Percentile charts for quantitative tracking of serumferritin increases and decreases in patients have also beendeveloped from values measured at different times. These chartsshow box-plot distributions of expected ferritin against time. Conclusions. Even continuous low-dose maintenance iron therapy,with only 31.25 mg weekly over 1 year, cannot prevent the riskof iron overload in patients with moderate anaemia. Furthermore,this treatment is responsible for decreases in serum transferrin,unrelated to changes in serum albumin, possibly of concern forhypo-transferrinaemia as an independent risk factor for irontoxicity.     

Iron supplementation in haemodialysis - practical clinical guidelines

Background. The aim of this prospective study was to test a new protocol for iron supplementation in haemodialysis patients, as well as to assess the utility of different iron metabolism markers in common use and their 'target' values for the correction of iron deficiency. Methods. Thirty-three of 56 chronic haemodialysis patients were selected for long-term (6 months) i.v. iron therapy at 20 mg three times per week post-dialysis based on the presence of at least one of the following iron metabolism markers: percentage of transferrin saturation (%TSAT) <20%; percentage of hypochromic erythrocytes (%HypoE) >10% and serum ferritin (SF) <400 &mgr;g/l. Reasons for patient exclusion were active inflammatory or infectious diseases, haematological diseases, psychosis, probable iron overload (SF ⩾400 &mgr;g/l) and/or acute need of blood transfusion mostly due to haemorrhage and change in renal replacement treatment. Results. More than half (51.8%) of the patients of our dialysis centre proved to have some degree of iron deficiency in spite of their regular oral iron supplementation. At the start of the study the mean haemoglobin was 10.8 g/dl and increased after the 6 months of iron treatment to 12.8 g/dl (P<0.0001). The use of erythropoietin decreased from 188 units/kg/week to 84 units/kg/week. The criterion for iron supplementation with the best sensitivity/specificity relationship (100/87.9%) was ferritin <400 &mgr;g/l. Patients with ferritin <100 &mgr;g/l and those with ferritin between 100 &mgr;g/l and 400 &mgr;g/l had the same increase in haemoglobin but other parameters of iron metabolism were different between the two groups. Conclusions. Routine supplementation of iron in haemodialysis patients should be performed intravenously. Target ferritin values should be considered individually and the best mean haemoglobin values were achieved at 6 months with a mean ferritin of 456 &mgr;g/l (variation from to 919 &mgr;g/l). The percentage of transferrin saturation, percentage of hypochromic erythrocytes and ferritin <100 &mgr;/l, were not considered useful parameters to monitor routine iron supplementation in haemodialysis patients. No significant adverse reactions to iron therapy were observed. Keywords: erythropoietin; ferritin; haemodialysis; iron; intravenous      

Economic appraisal of maintenance parenteral iron administration in treatment of anaemia in chronic haemodialysis patients

BACKGROUND.: Iron deficiency is common in haemodialysis patients and adequatesupplementation by the oral or parenteral route has been limitedby drug side-effects, absorption, and cost. Intermittent doses of intravenous iron dextran complex are recommendedin patients with inadequate iron stores despite maximal toleratedoral dose. We conducted a prospective study with economic analysisof a regular maintenance intravenous iron regimen in this groupof patients. METHODS.: Fifty patients comprising one-half of our haemodialysis populationrequired intravenous iron treatment, i.e. they failed to achievean arbitrary goal serum ferritin 100 µg/l despite maximaltolerated oral iron dose. After a loading dose of intravenousiron dextran complex (IV-FeD) based on Van Wyck's nomogram (400±300mg) they received a maintenance dose of 100 mg IV-FeD once every2 weeks. Initial goal serum ferritin was set at 100–200µg/l. If no increase in haemoglobin was achieved at thislevel, transferrin saturation was measured to assess bioavailableiron, and when less than 20%, goal serum ferritin was increasedto 200–300 µg/l. Recombinant human erythropoietin(rHuEpo) was used where needed to maintain haemoglobin in the9.5–10.5 g/l range only if ferritin requirements weremet. RESULTS.: Mean haemoglobin rose from 87.7±12.1 to 100.3±13.1g/l (P<0.001, Cl 7.7–17.9) at mean follow-up of 6 months(range 3–15 months). In patients on rHuEpo, dose per patientwas reduced from 96±59 u/kg per week to 63±41u/kg per week, repres enting a 35% dose reduction (P<0.05,Cl 1–65). An annual cost reduction of $3166 CDN was projected;however, in the first year this is offset by the cost of theloading dose of IV-FeD required at the beginning of treatment.No adverse reactions were encountered. CONCLUSIONS.: Iron deficiency is very common in our haemodialysis population,especially in those patients receiving rHuEpo. A carefully monitoredregimen of maintenance parenteral iron is a safe, effective,and economically favourable means of iron supplementation inpatients with insufficient iron stores on maximum toleratedoral supplements.     

Predictors of the response to treatment in anemic hemodialysis patients with high serum ferritin and low transferrin saturation

Treating hemodialysis patients to combat anemia corrects hemoglobin but exacerbates iron deficiency by utilizing iron stores. Patients needing iron should receive this by intravenous (i.v.) means. The Dialysis patients' Response to IV iron with Elevated ferritin (DRIVE) trial investigated the role of i.v. iron in anemic patients with high ferritin, low transferrin saturation, and adequate epoetin doses. We examined whether baseline iron and inflammation markers predict the response of hemoglobin to treatment. Patients (134) were randomized to no added iron or to i.v. ferric gluconate for eight consecutive hemodialysis sessions spanning 6 weeks with epoetin increased by 25% in both groups. The patients started with hemoglobin less than or equal to 11 g/dl, ferritin between 500 and 1200 ng/ml, and transferrin saturation of less than 25%. Significantly, patients with a reticulocyte hemoglobin content greater than or equal to 31.2 pg were over five times more likely to achieve a clinically significant increase in hemoglobin of greater than 2 g/dl. Lower reticulocyte hemoglobin contents did not preclude a response to i.v. iron. Significantly higher transferrin saturation or lower C-reactive protein but not ferritin or soluble transferrin receptor levels predicted a greater response; however their influence was not clinically significant in either group. We conclude that none of the studied markers is a good predictor of response to anemia treatment in this patient sub-population.     

Effect of intravenous iron on haemodialysis catheter microbial colonization and blood-borne infection

BACKGROUND: Intravenous (i.v.) iron is employed to treat absolute and relative iron deficiency in end-stage renal disease patients. However, there exists the possibility that i.v. iron increases infection risk. This pilot study examines whether i.v. iron gluconate acutely increases tunnelled haemodialysis catheter colonization, microbial growth, or blood-borne infection. METHODS: Nineteen patients with haemodialysis catheters who met criteria to receive an i.v. iron load entered the study. Six matched patients with catheters who did not receive iron were controls. Blood aspirated from the catheter prior to initiation of haemodialysis was sent for qualitative/quantitative cultures. The study consisted of three baseline cultures, five cultures during iron (125 mg of ferric gluconate per treatment), and three cultures following iron administration. Patients were monitored for infection for 30 days following iron. RESULTS: Fifteen iron-treated patients and six controls completed the study. Thirty-three per cent of treated patients were colonized at baseline; 66% were colonized following iron. Thirty-three per cent of controls (2/6) were colonized at baseline; no new colonization developed during follow up. Neither treated patients nor controls had significant microbial growth within catheters; one patient in the iron-treated group developed candidaemia. CONCLUSION: Intravenous iron is not associated with acute microbial growth in catheters or clinical infection. However, a trend towards increased catheter colonization following iron administration exists.     

Is zinc protoporphyrin an indicator of iron-deficient erythropoiesis in maintenance haemodialysis patients?

BACKGROUND.: Zinc protoporphyrin (ZPP), a metabolic intermediate generatedin the red blood cell by incorporation of zinc instead of iron,has been suggested to be a sensitive and specific parameterof absolute iron deficiency in haemodialysis (HD) patients. METHODS.: We studied 62 HD patients, 29–86 years old, with ZPP levels>50 µmol/mol haeme (normal value of ZPP <40 µmol/molhaeme) assessing the value of ZPP as a marker of functionaliron deficiency at different cut-off points of ZPP. None ofthe patients had apparent inflammatory disease, infectious disease,or malignancy. ZPP, haemoglobin, iron and ferritin levels weredetermined before, and after a 24-week period of once-weeklyi.v. administration of 40 mg iron, to determine whether ZPPlevels return to normal during adequate iron supplementation(960 mg iron/patient). RESULTS.: There was no significant change in ZPP levels after iron supplementationin patients with a ZPP >50 µmol/mol haeme (96.7±49.8versus 88.4±43.5 µmol/mol haeme before and afteriron administration respectively, P=n.s.). However, in patientswith a ZPP >90 µmol/mol haeme, there was a significantreduction in ZPP levels (141.2±54.5 versus 108.0±48.8µmol/mol haeme, P<0.001). Serum ferritin increasedsignificantly in both groups. There was no correlation betweenZPP and serum ferritin at any time during the study. There wasalso no correlation between serum aluminium levels and ZPP andno significant difference in changes in ZPP in patients receivingdesferrioxamine therapy compared to those not receiving desferrioxaminetherapy. We did find a significant correlation between moderatelyelevated total blood lead concentrations and ZPP levels at theend of the study. The ZPP levels were not significantly differentin the range from 50–110 µmol/mol haeme before andafter i.v. iron supplementation in the responders (10% increaseof haemoglobin or 20% decrease of the recombinant human erythropoietindose) compared with the non-responders. CONCLUSIONS.: Our data indicate that ZPP cannot be used to predict the erythropoieticresponse to iron supplementation. However, ZPP levels may bean indicator of functional iron deficiency due to blockade ofthe reticuloendothelial iron release in haemodialysis patients.     

A prospective crossover trial comparing intermittent intravenous and continuous oral iron supplements in peritoneal dialysis patients.

BACKGROUND: Concomitant iron supplementation is required in the great majority of erythropoietin (Epo)-treated patients with end-stage renal failure. Intravenous (i.v.) iron supplementation has been demonstrated to be superior to oral iron therapy in Epo-treated haemodialysis patients, but comparative data in iron-replete peritoneal dialysis (PD) patients are lacking. METHODS: A 12-month, prospective, crossover trial comparing oral and i.v. iron supplementation was conducted in all Princess Alexandra Hospital PD patients who were on a stable dose of Epo, had no identifiable cause of impaired haemopoiesis other than uraemia, and had normal iron stores (transferrin saturation >20% and serum ferritin 100-500 mg/l). Patients received daily oral iron supplements (210 mg elemental iron per day) for 4 months followed by intermittent, outpatient i.v. iron infusions (200 mg every 2 months) for 4 months, followed by a further 4 months of oral iron. Haemoglobin levels and body iron stores were measured monthly. RESULTS: Twenty-eight individuals were entered into the study and 16 patients completed 12 months of follow-up. Using repeated-measures analysis of variance, haemoglobin concentrations increased significantly during the i.v. phase (108+/-3 to 114+/-3 g/l) compared with each of the oral phases (109+/-3 to 108+/-3 g/l and 114+/-3 to 107+/-4 g/l, P<0.05). Similar patterns were seen for both percentage transferrin saturation (23.8+/-2.3 to 30.8+/-3.0%, 24.8+/-2.1 to 23.8+/-2.3%, and 30.8+/-3.0 to 26.8+/-2.1%, respectively, P<0.05) and ferritin (385+/-47 to 544+/-103 mg/l, 317+/-46 to 385+/-47 mg/l, 544+/-103 to 463+/-50 mg/l, respectively, P=0.10). No significant changes in Epo dosages were observed throughout the study. I.v. iron supplementation was associated with a much lower incidence of gastrointestinal disturbances (11 vs 46%, P<0.05), but exceeded the cost of oral iron treatment by 6.5-fold. CONCLUSIONS: Two-monthly i.v. iron infusions represent a practical alternative to oral iron and can be safely administered to PD patients in an outpatient setting. Compared with daily oral therapy, 2-monthly i.v. iron supplementation in PD patients was better tolerated and resulted in superior haemoglobin levels and body iron stores.     

Efficacy of low‐dose i.v. iron therapy in haemodialysis patients

Aim: i.v. iron therapy is more effective in maintaining adequate iron status in haemodialysis (HD) patients than oral iron therapy (OIT). However, data on lower doses of i.v. iron therapy are insufficient. Methods: A non‐randomized, open‐label study was performed to compare the efficacy of low‐dose (≤50 mg/week of iron sucrose) i.v. iron therapy (LD‐IVIT) with OIT in HD patients with 100–800 µg/L serum ferritin levels over 4 months. Results: Eighty‐nine patients in the LD‐IVIT group (40 men, 49 women; aged 61 ± 13 years) and 30 patients in the oral iron therapy group (17 men, 13 women; aged 59 ± 7 years) were evaluated. After 4 months of each treatment, serum ferritin levels increased from 398 ± 137 to 529 ± 234 µg/L in the LD‐IVIT group (P < 0.01) but decreased from 351 ± 190 to 294 ± 175 µg/L in the OIT group (P < 0.01). In the LD‐IVIT group, transferrin saturation (from 28% ± 11% to 30% ± 14%, P = 0.49), weekly doses of recombinant human erythropoietin (from 5822 ± 2354 to 5636 ± 2306 IU/week, P = 0.48) and haemoglobin (from 101 ± 9 to 103 ± 9 g/L, P = 0.15) levels remained stable. Conclusion: LD‐IVIT may be one of the regimens that may be considered for maintaining iron status in HD patients. However, efficacy of LD‐IVIT should be verified by further randomized study.