Intravenous iron for CAPD populations: proactive or reactive strategies?

Questions and answers on iron deficiency treatment selection and the use of intravenous iron in routine clinical practice

Iron deficiency is a common cause of morbidity and can arise as a consequence or complication from many diseases. The use of intravenous iron has increased significantly in the last decade, but concerns remain about indications and administration. Modern intravenous iron preparations can facilitate rapid iron repletion in one or two doses, both for absolute iron deficiency and, in the presence of inflammation, functional iron deficiency, where oral iron therapy is ineffective or has not worked. A multidisciplinary team of experts experienced in iron deficiency undertook a consensus review to support healthcare professionals with practical advice on managing iron deficiency in gastrointestinal, renal and cardiac disease, as well as; pregnancy, heavy menstrual bleeding, and surgery. We explain how intravenous iron may work where oral iron has not. We provide context on how and when intravenous iron should be administered, and informed opinion on potential benefits balanced with potential side-effects. We propose how intravenous iron side-effects can be anticipated in terms of what they may be and when they may occur. The aim of this consensus is to provide a practical basis for educating and preparing staff and patients on when and how iron infusions can be administered safely and efficiently. Key messages Iron deficiency treatment selection is driven by several factors, including the presence of inflammation, the time available for iron replenishment, and the anticipated risk of side-effects or intolerance. Intravenous iron preparations are indicated for the treatment of iron deficiency when oral preparations are ineffective or cannot be used, and therefore have applicability in a wide range of clinical contexts, including chronic inflammatory conditions, perioperative settings, and disorders associated with chronic blood loss. Adverse events occurring with intravenous iron can be anticipated according to when they typically occur, which provides a basis for educating and preparing staff and patients on how iron infusions can be administered safely and efficiently.

Oral versus Intravenous Iron Supplementation in Peritoneal Dialysis Patients

The vast majority of erythropoietin (EPO)–treated peritoneal dialysis (PD) patients require iron supplementation. Most authors and clinical practice guidelines recommend primary oral iron supplementation in PD patients because it is more practical and less expensive. However, numerous studies have clearly demonstrated that oral iron therapy is unable to maintain EPO-treated PD patients in positive iron balance. Once patients become iron-deficient, intravenous iron administration has been found to more effectively augment iron stores and hematologic response than does oral therapy.

We recently performed a prospective, cross-over trial in 28 iron-replete PD patients and showed that twice-monthly outpatient iron polymaltose infusions (200 mg) were a practical and safe alternative to oral iron. That treatment produced significant increases in hemoglobin concentration and body iron stores. The additional expense of intravenous iron therapy was completely offset by reductions in EPO dosage.

Careful monitoring of iron stores is important in patients receiving intravenous iron supplementation in view of epidemiologic links with infection and cardiovascular disease. Nevertheless, a growing body of evidence suggests that, as has been found for hemodialysis patients, intravenous iron therapy is superior to oral iron supplementation in EPO-treated PD patients.

Efficacy of a Low-Dose Intravenous Iron Sucrose Regimen in Peritoneal Dialysis Patients

Objective

Sufficient iron substitution leads to a decrease in the required recombinant human erythropoietin (rHuEPO) dose and/or an increased hematocrit in dialysis patients. Intravenous (IV) application of larger doses of iron sucrose may be associated with hyperferritinemia, appearance of catalytically free iron, and impaired phagocyte function. Therefore, we investigated the effectiveness of a low-dose IV iron regimen in peritoneal dialysis (PD) patients.

Patients and Interventions

Forty-five PD patients were followed over a period of 1 year. Serum ferritin, serum transferrin saturation, and hemoglobin were measured monthly. In cases of absolute iron deficiency (serum ferritin < 100 μg/L), 50 mg iron sucrose was given IV every second week. In cases of functional iron deficiency (ferritin ≥ 100 μg/L and transferrin saturation < 20%) and in iron repleted patients (ferritin ≥ 100 μg/L and transferrin saturation ≥ 20%), 50 mg IV iron sucrose was applied monthly. Iron therapy was stopped in cases of acute infection (until complete recovery) and when serum ferritin level was ≥ 600 μg/L.

Results

To analyze the influence of iron substitution on erythropoiesis and rHuEPO requirements, the EPO resistance index (ERI; quotient of rHuEPO dose in units/kilogram/week and hemoglobin in grams per deciliter) was calculated every 3 months. The ERI decreased significantly during the course of the study in the whole patient group ( p = 0.009) as well as in the subgroup of 21 patients with absolute iron deficiency ( p = 0.01). A nonsignificant decrease in the ERI was observed within the group of 14 iron repleted patients ( p = 0.5). There was no significant change in the ERI in 10 patients with functional iron deficiency ( p = 0.6).

Conclusion

The low-dose IV iron regimen used in this study substantially decreased rHuEPO requirements in patients with absolute iron deficiency and was effective in maintaining iron stores in iron repleted patients. However, in the absence of significant hyperparathyroidism, aluminum toxicity, or inadequate dialysis, it did not improve the ERI in patients with functional iron deficiency.

Efficacy and safety of a low monthly dose of intravenous iron sucrose in peritoneal dialysis patients

PURPOSE

Scientific data regarding intravenous iron supplementation in peritoneal dialysis (PD) patients are scarce. In attempting to administer the minimum monthly IV iron dose that could improve erythropoiesis, we wanted to assess the safety and efficacy of monthly maintenance intravenous administration of 100 mg iron sucrose in PD patients.

METHODS

In a 9-month prospective study, all clinically stable PD patients received intravenously 200 mg of iron sucrose as a loading dose, followed by monthly doses of 100 mg for five consecutive months. Levels of hemoglobin (Hb), ferritin, transferrin saturation (TSAT), reticulocyte hemoglobin content (CHr) and C-reactive protein (CRP) were measured before each administration and 3 months after the last iron infusion. Also, doses of concurrent erythropoietin administration were recorded.

RESULTS

Eighteen patients were eligible for the study. Mean levels of Hb and ferritin increased significantly (from 10.0 to 10.9 mg/dL, p = 0.01 and from 143 to 260 ng/mL, p = 0.005), as well as the increase in TSAT levels approached borderline significance (from 26.2 to 33.1%, p = 0.07). During the 6 months of iron administration, the erythropoietin dose was reduced in five patients and discontinued in one. During the 3 months following the last iron infusion, three of them again raised the erythropoietin dose to previous levels. None of the patients experienced any side effects related to IV iron administration.

CONCLUSIONS

A monthly maintenance intravenous dose of 100 mg iron sucrose may be a practical, effective, and safe in the short term, treatment of anemia in PD patients resulting in improved hemoglobin levels, iron indices, and erythropoietin response.

Effectiveness and safety of ferric carboxymaltose therapy in peritoneal dialysis patients: an observational study

Background

The efficacy of intravenous (IV) ferric carboxymaltose (FCM) has been demonstrated in haemodialysis and non-dialysis studies, but evidence is lacking in patients undergoing peritoneal dialysis (PD).

Methods

This multicentre, retrospective study evaluated the effectiveness and safety of FCM in patients on PD over 12 months. We retrospectively reviewed the electronic medical records of PD patients who initiated FCM treatment between 2014 and 2017 across seven Spanish centres.

Results

Ninety-one patients were included in the safety population (mean ± SD age 57.7 ± 15.0 years) and 70 in the efficacy population (mean age 50.9 ± 14.5 years). No hypersensitivity reaction, FCM discontinuation or dose adjustment due to a serious adverse event (SAE) was registered in the safety population. The most common non-SAEs reported were headache (four events), mild hypotension (three events) and hypertension (two events), among others. In the efficacy population (n = 70), 68.6% of patients achieved ferritin levels of 200–800 ng/mL, 78.4% achieved transferrin saturation (TSAT) >20%, and 62.8% achieved TSAT >20% and ferritin >200 ng/mL after 12 months of FCM initiation (P < 0.01). Haemoglobin (Hb) levels were maintained at >11 g/dL with a lower dose of darbepoetin throughout the follow-up. The sub-analysis of patients naïve to IV iron and with absolute or relative iron deficiency (n = 51) showed that 76.5% reached ferritin >200 ng/mL, 80.4% TSAT >20% and Hb increased (1.2 g/dL) after 4 months of FCM treatment (P < 0.01).

Conclusion

In this multicentre, retrospective, real-world study conducted in the PD population, FCM was effective, safe and easy to administer during routine clinical visits.

Utility of erythrocyte indices in identifying iron depletion in pregnancy

Background

Iron deficiency anaemia in pregnancy is common and is a major cause of maternal and neonatal morbidity worldwide. Serum ferritin is the current gold standard test for identifying iron depletion, with a cut-off value of 30 µg/L. Recent studies in low- and middle-income countries have identified mean cell haemoglobin concentration as a surrogate marker for the prediction of iron depletion.

Methods

We studied values from 786 antenatal blood results from 2018 in Oxford, UK, and correlated the red cell indices with serum ferritin measurements.

Results

Haemoglobin, mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration have low specificity and sensitivity for the identification of iron depletion.

Conclusions

We found that haemoglobin, mean cell volume, mean cell haemoglobin and mean cell haemoglobin concentration do not have sufficient predictive value in this population to be used as a screening test for non-anaemic iron depletion.

What do we learn about the “Anemia Module” of the French language Peritoneal Dialysis ? Interest and Results

Background: Anemia is commonly observed in patients with chronic kidney disease (CKD) as soon as the glomerular filtration rate falls below than 30 ml/min. CKD patients frequently have iron deficiency. The use of both erythropoiesis-stimulating agents (ESA) and iron therapy is the backbone of anemia management in CKD. For this reason, an adequate iron supply is mandatory to achieve the optimal therapeutic benefit of erythropoiesis stimulating agents (ESAs). Many groups agree that anemia in peritoneal dialysis (PD) patients is less severe than in hemodialysis (HD) patients and that there are important differences in treatment practices for anemia between PD and HD patients. Methods: Analysis of the Anemia module of the French Language Peritoneal Dialysis Registry (RDPLF) register from the database set up in 2005 with a study of the period 2010-2017. Results: Data from 568 patients who participated in the Anemia module were analysed during the 2010-2017 follow-up period. Their median age were 71 years, 42% were female, median dialysis vintage was 13 months, 40,5% of patients had diabetes mellitus, 74% of patients were treated with ESA, 23% were on oral iron and only 11% have received intravenous iron. In terms of biological assessment, the average hemoglobin level was close to 12 g/dl and median CRP was close to 5 mg/l. For the iron balance, ferritin reached an average level of 270 µg/l in 2013 and stabilized in 2017 at 200 µg/l. The transferrin saturation coefficient always fluctuated between 23 % and 25 % from year 2010 to year 2017. Conclusion: The results of the Anemia module of RDPLF register appear to be in line with the target values of the ERA-EDTA latest European guideline on anemia (ERBP 2013) and show the low use of intravenous iron in PD (usually as second line therapy).

Iron deficiency in pregnancy

Iron deficiency (ID) and related anaemia (IDA) during pregnancy are highly prevalent worldwide in both developed and developing nations although the causes are often different. At conception, many women lack sufficient iron stores to meet the increased requirements of pregnancy, which are calculated at approximately 1200 mg. Appraisal of iron status in pregnant women is problematic, however the most reliable available diagnostic test is a serum ferritin < 20 µg/L. ID is often associated with other nutritional disorders, and there is frequently a secondary cause or association. A greater oral intake is usually insufficient to meet the increased demands of pregnancy, however regular oral supplements (given either daily or intermittently) can often meet maternal needs and avoid associated neonatal complications of IDA. Over-treatment with iron should be avoided, but intravenous administration is useful when deficiency is discovered late, is severe, or if the woman is intolerant of oral formulations. This paper reviews the current literature, and addresses differences in the prevalence and causes of ID betwen developed and developing nations. It examines gestational iron requirements, distinguishes between ID and IDA, and highlights difficulties in diagnostic testing. Finally, it appraises the evidence for and against different treatment regimens, ranging from food fortification to intravenous iron infusions, according to availability and to need.

[Efficacy of bolus intravenous iron treatment in peritoneal dialysis patients]

INTRODUCTION

Normocytic, normochromic anemia is one of the first signs of chronic renal failure and it is common in patients on chronic dialysis treatment. It causes decrease in oxygen supply to tissues, increases cardiac minute volume, causes left ventricular hyperthrophy, cardiac insufficiency, disorders related to cognitive functions and immune response, and increases morbidity and mortality rates. The leading cause of anemia in patients on chronic peritoneal dialysis (PD) is iron depletion and most patients on PD need oral or parenteral iron supplementation. The aim of this study was to evaluate our first experience with bolus intravenous ferrogluconate therapy in patients on chronic peritoneal dalysis at the Nephrology Clinic of the Clinical Center of Serbia (CCS).

MATERIAL AND METHODS

We examined 11 patients, 7 males and 4 females, mean-age 49 years (range 31 to 68 years) on chronic PD. All patients received blood transfusions, oral or intramuscular iron supplementation before 465 to 665 mg ferrogluconate therapy was given in 500 ml. saline intravenous infusion: 5 of them were on erythropoietin therapy and 2 of them started with EPO therapy after the ferrogluconate therapy.

RESULTS

The blood count improved during the first 3 months after application of bolus intravenous iron therapy (ferrogluconate); erytrhopoietin dose was not increased during the follow-up. Some patients suffered from side effects during infusion and 6 patients received the complete treatment.

DISCUSSION

Blood count improves in a number of patients affected by endstage renal desease during the first months on continuous ambulatory peritoneal dialysis (CAPD) treatment. But a large number of patients on chronic CAPD treatment are iron-depleted and they require oral or parenteral substitution. Side effects and complications of intravenous iron therapy were not severe and only one patient suffered from allergic manifestations. Ferremia and blood count improved in patients who did not receive erythropoietin during the follow-up, and patients on erythropoietin therapy required lower doses after receiving the intraveonous iron therapy.

CONCLUSION

Blood count improvement and the lack of severe side effects speak in favor of further iron supplementation with bolus intravenous iron replacement.

Intravenous iron treatment in paediatric chronic kidney disease patients not on erythropoietin

Intravenous (i.v.) iron treatment reduces erythropoietin (EPO) dose in paediatric haemodialysis patients. The efficacy in paediatric nonhaemodialysis patients is less well established. i.v. iron is routinely given in our institution to these patients, including some who have not started EPO. The effect of this strategy was examined. Patients with chronic kidney disease (CKD) or peritoneal dialysis (PD) not on EPO were identified. Case notes were reviewed for haemoglobin (Hb), red cell and iron indices for 6 months before and at least 3 months after i.v. iron. Five patients were identified. Mean age was 13.3 years and mean i.v. iron (Venofer) dose = 3.1 mg/kg. Median number of doses = 7 (range 3-10). Hb increased significantly after i.v. iron from 11.4 +/- 0.7 to 12.8 +/- 1.3 g/dl (p = 0.02). Mean cell volume increased from 87.7+/-3.4 to 90.1 +/- 3.7 fl (p = 0.01), and mean cell Hb remained unchanged: 29.2 +/- 1.2 to 29.7 +/- 1.0 pg (p = 0.12). Absolute and percentage reticulocyte count remained unchanged. There was no change in iron indices: ferritin 55.1 +/- 31.3 to 97.3 +/- 46.5 ng/ml (p = 0.3), iron 18.9 +/- 6.9 to 18.1 +/- 4.2 micromol/l (p = 0.7), transferrin 1.9 +/- 1.6 to 2.0 +/- 0.1 g/l (p = 1.0), transferrin saturation 35.7 +/- 8.1 to 40.3 +/- 18.0% (p = 0.5). i.v. iron slightly improved Hb levels in five paediatric CKD and PD patients not receiving EPO. This strategy may delay the need for EPO treatment and deserves further evaluation.

Intravenous versus Oral Iron Supplementation in Peritoneal Dialysis Patients

Iron supplementation is required in a preponderance of peritoneal dialysis (PD) patients treated with erythropoietic stimulatory agents (ESAs). Although many authors and clinical practice guidelines recommend primary oral iron supplementation in ESA-treated PD patients, numerous studies have clearly demonstrated that, because of a combination of poor bioavailability of oral iron, gastrointestinal intolerance, and noncompliance, oral iron supplementation is insufficient for maintaining a positive iron balance in these patients over time. Controlled trials have demonstrated that, in iron-deficient and iron-replete PD patients alike, intravenous (IV) iron supplementation results in superior iron stores and hemoglobin levels with fewer side effects than oral iron produces. Careful monitoring of iron stores in patients receiving IV iron supplementation is important in view of conflicting epidemiologic links between IV iron loading and infection and cardiovascular disease. Emerging new iron therapies such as heme iron polypeptide and ferumoxytol may further enhance the tolerability, efficacy, and ease of administration of iron in PD patients.

[Anemia in peritoneal dialysis patients]

A normocytic normochromic anemia is one of the first signs of renal failure. Since anemia increases morbidity and mortality, its elimination is one of the essential objectives of the treatment. Human recombinant erythropoietin (rHuEPO) has changed the therapeutical approach to anemia. The aim of the present study was to compare efficacy of anemia correction in peritoneal dialysis patients depending on treatment and dialysis modality. The study is the retrospective analysis of 64 patients who presented to our Clinic in 2003. Eighteen (28.13%) patients were treated with rHuEPO, 14 (28%) underwent continuous ambulatory peritoneal dialysis (CAPD), 2 (100%)--automated peritoneal dialysis (APD) and 2 (33.3%)--intermittent peritoneal dialysis (IPD). Mean hemoglobin level was 98.6 +/- 17.82 g/l in patients treated with rHuEPO versus 98.81 +/- 15.14 g/l in patients without rHuEPO treatment. Erythropoietin requirements were 3392.85 +/- 1211.77 IU/week All patients received iron supplementation during rHuEPO therapy. Mean serum ferritin levels were 463.41 +/- 360 ug/l. Transferrin saturation (TSAT) was 0.35 +/- 0.16%. No difference of serum iron and TSAT levels was found between CAPD and IPD patients. The degree of anemia significantly differed between CAPD and IPD patients. A total of 17.11% of PD patients were given blood transfusions, most frequently during the first three months after the onset of dialysis. Our conclusion is that the number of patients receiving rHuEPO should be increased, as 50% of our patients should be substituted, while only 28% are being treated. As 50% of patients receiving rHuEPO failed to reach target Hgb levels, higher EPO doses should be considered. Iron stores should be continuously monitored, particularly in patients receiving rHuEPO, since iron deficiency is an important problem for patients undergoing peritoneal dialysis, especially during erythropoietin therapy. Oral iron supplementation is satisfactory in the majority of patients, and iron-gluconate is absorbed better than iron-sulphate. If required, intra-venous iron bolus is safe and efficient. Continuous peritoneal dialysis treatment improves blood count more effectively compared to intermittent procedures, as hemoglobin levels are significantly higher in patients with comparable iron stores. Peritoneal dialysis is particularly efficient in improving the blood count in diabetics, since no significant difference of anemia between patients affected by diabetes mellitus and the others could be found in our study.

Effect of intravenous iron sucrose in peritoneal dialysis patients who receive erythropoiesis-stimulating agents for anemia: a randomized, controlled trial

Although iron therapy is essential to optimize use of erythropoiesis-stimulating agents (ESA), randomized, controlled trials have heretofore been unavailable to evaluate reliably the efficacy of intravenous iron as an adjuvant to ESA treatment in peritoneal dialysis (PD) patients. In a multicenter trial, patients who had anemia, PD-dependent chronic kidney disease, stable ESA therapy, and a broad range of iron status (ferritin < or = 500 ng/ml, transferrin saturation < or = 25%) were randomly assigned to receive either 1 g of iron sucrose intravenously in three divided doses (300 mg over 1.5 h on days 1 and 15, 400 mg over 2.5 h on day 29) or no supplemental iron. No serious adverse drug events occurred after intravenous iron administration. The primary end point, peak hemoglobin increase, was higher (1.3 +/- 1.1 versus 0.7 +/- 1.1, mean +/- SD; P = 0.0028), and anemia intervention (transfusion, increase in ESA dose, or intravenous iron therapy not called for in protocol) occurred later (P = 0.0137) and less often in intravenous iron-treated patients compared with untreated control subjects (one of 66 [1.3%] versus five of 30 [16.7%]). Among patients who did not require intervention, iron-treated patients showed a calculated net ESA dose decrease compared with untreated control subjects. Baseline iron status did not predict responsiveness to intravenous iron therapy. Intravenous iron sucrose is an effective adjunct to ESA therapy in anemic patients with PD-dependent chronic kidney disease and is administered safely as 300 mg over 1.5 h or 400 mg over 2.5 h. Evidence of iron deficiency at baseline is not required to demonstrate intravenous iron efficacy.

Resorption and tolerance of the high doses of ferrous sulfate and ferrous gluconate in the patients on peritoneal dialysis

Background/Aim. Iron supplementation plays a crucial role in peritoneal dialysis (PD) patients. Oral iron substitution is more convenient than intravenous therapy in PD patients, but impaired absorption and adverse effects may be limiting factors for oral treatment. The aim of this study was to compare the absorption and side effects of high doses ferrous sulphate and ferrous gluconate in PD patients. Methods. Blood samples were taken from 29 PD patients at baseline, as well as 2, 4 and 8 hours after oral intake of 4 ferrous sulphate tablets (containing 105 mg elemental iron per tablet). The test was repeated using 8 ferrous gluconate drinkable ampoules (containing 50 mg elemental iron per ampoule). Results. The maximal increase in serum iron level during the test with iron sulphate was 113.51?103.37% versus the initial values of 183.87?37.38% during the ferrous gluconate test. The maximal values of serum iron after the intake of ferrous sulphate were 26.23?9.95 ?mol/l versus 30.97?8.65 ?mol/l after the intake of ferrous gluconate. There was a statistically significant difference between these two groups. Six patients showed an increase in serum iron of more than 300% after a high ferrous gluconate dose, while in 15 of the patients serum iron increased between 100% and 300%, and in 8 of the patients serum iron levels increased by less than 100%. Side effects occurred more frequently after the intake of ferrous sulphate than ferrous gluconate. Conclusion. High doses of oral iron were well absorbed and tolerated in PD patients. Ferrous gluconate was better absorbed and tolerated than ferrous sulphate, thus we recommend it for oral iron supplementation in PD patients.

A randomized, controlled study of the consequences of hemodialysis membrane composition on erythropoietic response

BACKGROUND

Membrane biocompatibility has long been thought to be relevant to hemodialysis outcomes and, possibly, renal anemia.

METHODS

We performed a randomized, controlled, single-center study comparing the consequences on renal anemia of 2 dialyzers of equivalent performance, but different composition, during 7 months. Two hundred eleven patients of an unselected dialysis population of 235 patients gave informed consent to undergo random assignment to either group A (SF170E; modified cellulose triacetate/midflux membrane; Nipro, Osaka, Japan) or group B (HF80LS; polysulfone/high-flux membrane; Fresenius, Bad Homburg, Germany). Anemia management was identical in both treatment groups and followed strict clinical protocols managed by computer algorithms. Dialysis adequacy, hemoglobin (Hb) level, ferritin level, percentage of red blood cell hypochromicity, C-reactive protein (CRP) level, and intravenous iron and epoetin doses were monitored monthly.

RESULTS

One hundred seventy-seven patients completed the 7-month study. Equilibrated Kt/V increased in both groups. Hb outcome improved overall, but did not differ between the 2 study groups. Epoetin dose was not significantly different after 7 months compared with baseline in either group. Hb level, epoetin dose, iron status, CRP level, dialysis Kt/V, and residual renal function did not differ between the 2 groups. A slight but significant negative correlation was identified between dialysis Kt/V and Hb level in the population as a whole (Spearman's correlation, -0.16; P = 0.04).

CONCLUSION

No significant epoetin-sparing effect was identified through the use of the high-flux polysulfone HF80LS membrane over the modified cellulose triacetate SF170E membrane. Although not a primary outcome for this study, there was a suggestion of benefit of improved Hb level, without increased need for epoetin, through increasing delivered dialysis dose.