Advanced Level European Dialysis and Transplant Nurses Association/ European Renal Care Association Understanding Iron Deficiency Anaemia in Chronic Kidney Disease Information at Advanced Level. Karen Jenkins RN, PGDip HE, MSc Learning outcomes 1. Understand markers used to define iron deficiency anaemia in chronic kidney disease 2. Understand types of iron deficiency and when to treat 3. Gain knowledge and understanding of the medicines available to treat iron deficiency in chronic kidney disease 4. Understand how guidelines can be used in practice Introduction Iron deficiency is a public health problem and the most common and widespread nutritional disorder in the world 1. A deficiency of iron leads to a reduction of the normal physiological function of tissues in the blood, brain, and muscles. This can be detected by the symptoms of iron deficiency anaemia such as fatigue, breathlessness, deterioration in concentration and reduced exercise tolerance. The onset is often insidious and the symptoms can are similar to those experienced in chronic kidney disease (CKD) itself, diabetes and heart disease. Iron deficiency anaemia (IDA) is common in people with CKD, particularly those with stage 3B, 4 and 5 CKD 2 and in patients with both diabetes and CKD 3. Reduced iron levels in CKD can be caused by: Bleeding (Patients with CKD have a tendency to bleed due to platelet dysfunction) The inability to absorb iron from food The demand made on iron stores by the use of erythropoiesis stimulating agents. Haemodialysis blood loss The causes of IDA which apply to the general population can also apply to people with CKD and should not be excluded when investigating IDA. These include: Dietary iron deficiency Gastrointestinal disorders Infectious diseases e.g. malaria, tuberculosis Acquired immunodeficiency syndrome (HIV/AIDS) Haematological disorders e.g. thalassaemia Blood loss As iron has an essential role in the process of myoglobin and haemoglobin synthesis and lack of iron leads to a reduction in the function of tissue in the brain, muscles and blood 4. There are five stages of IDA Normal iron status (normal iron indices) Latent iron deficiency (reduction of iron stores) Iron depletion (no iron stores) Iron deficient erythropoiesis (reduced iron transportation) Iron deficiency anaemia (microcytic, hypochromic anaemia) Adequate iron stores are required to support the process of erythropoiesis. As red cell production increases, iron stores decrease and therefore need to be maintained. (150mg iron is required to raise haemoglobin by 1g/dl). 65% of iron stored in the body is used to form haemoglobin. If there are inadequate iron stores red cell survival is reduced. In people without CKD normal red cell survival is 120 days, in CKD it is ~ 90days. Markers used to define Iron deficiency in CKD There is ongoing debate as to the most accurate test to use to measure iron status. WHO 1 recognise that prevalence of iron deficiency has been derived from the prevalence of anaemia related to haemoglobin measurements. It is important to note that not all people with anaemia are iron deficient and that iron deficiency can occur without anaemia 5. A variety of tests can be used to diagnose IDA: Full blood count; red cell indices mean corpuscular volume (MCV) mean corpuscular Hb Concentration (MCHC) mean corpuscular haemoglobin (MCH) Serum ferritin Serum % transferrin saturation 1
Serum iron Total iron binding capacity (TIBC) Transferrin % Hypochromic red cells Nutritional status Gastrointestinal blood loss assessment The most common tests used or assessing iron status in CKD are Serum ferritin % Transferrin saturation (TSAT) levels %Hypochromic red cells These are explained in detail in the next section. Serum ferritin Serum ferritin is an indicator of iron storage but not of iron supply, it is an acute phase reactant and its levels are affected by inflammation. As cytokines are commonly increased in CKD, serum ferritin levels might not reflect true iron stores 6,7. If this is suspected, C reactive protein (CRP) levels should be measured at the same time to confirm the presence of infection or inflammation. Serum ferritin results should be treated with caution and repeated when the infection/inflammation subsides. Serum iron levels should also be noted. The units used to measure Serum ferritin are µg/l or ng/ml. The normal range can vary between laboratories. A reduced serum ferritin level <30ng/ml (30µg/L) is indicative of iron deficiency 8. Levels at which to maintain serum ferritin vary depending on which guideline is used in your area of practice. The section on guidelines will discuss the parameters which can be applied to people with CKD both with and without dialysis. %Transferrin Saturation %Transferrin saturation (% TSAT) refers to the transport system of iron. Transferrin fluctuates due to the diurnal variation of serum iron and is affected by nutritional status, leading to a lack of sensitivity and specificity in assessing iron s availability 9. Although commonly used it is not a very reliable marker as it constantly changes. Therefore more than one measurement is needed to ascertain an average reading. % Hypochromic Red cells The measurement of Hypochromic Red cells and reticulocyte haemoglobin content is a direct assessment of the incorporation of iron into erythrocyte haemoglobin, giving an estimate of the recent functional availability of iron into the erythron. This test can be a more accurate marker than serum ferritin or transferrin saturation 10. Hypochromic red blood cells (HRC) tend to have less colour than normal red blood cells and increase in number when iron stores are insufficient and/or mobilization of iron is inadequate. 2.5% of red cells are normally hypochromic. Red blood cells are hypochromic if they have a haemoglobin concentration of < 280 g/l. A HRC level greater than 10% is an indication of iron deficiency 11. N.B. This test is not available in all laboratories. Types of Iron Deficiency There are two types of iron deficiency Absolute iron deficiency Functional iron deficiency Absolute Iron deficiency This is when there are inadequate iron stores available to support the erythropoietic needs of the bone marrow, i.e. not enough iron stores to make the required amount of haemoglobin. It can be caused by: insufficient dietary intake, poor absorption in the gut or blood loss. It can be defined as a serum ferritin, level < 100µg/L, and/ or %Transferrin Saturation level <20% or Hypochromic red cells >6% 12. Functional Iron Deficiency This is when there are sufficient iron stores but the iron is not readily available to meet the demands of erythropoiesis i.e. it doesn t reach the bone marrow fast enough. The most common test used to define functional iron deficiency is transferrin saturation (TSAT). A normal TSAT is 20-40%. Functional iron deficiency is defined by normal (30-200µg/ L) or raised serum ferritin levels (>800 µg/l), % Transferrin saturation < 20% or % hypochromic red cells >6%. Table 1 is a summary of Absolute and Functional IDA Table 1: Types of iron deficiency Absolute Iron Deficiency Iron stores inadequate to support the erythropoietic needs of the bone marrow Defined as serum ferritin <100µg/l % Transferrin saturation<20% %Hypochromic red cells>10%. Functional Iron deficiency Iron stores adequate but cannot supply marrow quickly enough with the iron required to support demands of erythropoiesis when stimulated acutely (e.g. with ESA therapy) Defined by normal (30-200µg/L)or raised serum ferritin levels (>800 µg/l) % Transferrin saturation < 20% % hypochromic red cells >10%. 2
Medicines used to treat iron deficiency anaemia Choosing Iron supplementation KDIGO 12 suggest the route of administration of iron supplementation for adults with CKD, not receiving Haemodialysis (HD) be based on: Severity of IDA Availability of venous access Response to previous use of oral iron Side effects of previous oral or IV iron therapy Patient adherence Cost Whether or not receiving ESA therapy Patient s overall clinical status iron content of three commonly used oral iron supplements and related therapeutic doses 17. The side following side effects of oral iron often affect adherence to treatment Gastric irritation Nausea Constipation, (more common in the elderly population) Diarrhoea, more likely in patients with inflammatory bowel disease. Dark colouring of stool It is also important to remember that oral iron can interact with some medicines commonly used in CKD. See Table 3 Table 3 Interaction with other medicines If a trial of oral iron is unsuccessful intravenous (IV) iron can be considered based upon iron status tests (Ferritin, %TSAT, %HRC) to achieve the optimum Hb level to be attained. UK guidelines (NICE) 13 recommend people receiving ESA maintenance therapy should be given iron supplementation to maintain: Serum ferritin levels 200-500µg/L in both HD and non HD patients and either %TSATS >20% or %HRC < 6% unless ferritin >800µg/L NICE 12 opinion is that in practice this is likely to require the use of IV iron supplementation. Studies carried out in patients with CKD not receiving dialysis 14,15 suggest a small efficacy advantage of IV, compared with oral administration of iron with a mean Haemoglobin difference of 0.31g/dl (3.1g/L) However, while these studies indicated IV iron significantly increased serum levels of ferritin and TSAT, haemoglobin levels were not consistently raised. The choice of iron supplementation will ultimately depend on clinical need and fulfilling the aim to manage and treat IDA effectively. Oral Iron As there are several preparations of oral iron available, the decision which to use is usually based on by the tolerability of side effects, frequency of administration and patient choice. The daily amount needed to treat IDA is approximately 200mg of elemental iron per day 16. Table 2 illustrates the elemental Medicine Antacids or medicines containing sodium bicarbonate, aluminium, magnesium, zinc Bisphosphonates Calcium Levodopa Levothyroxine Methyldopa Penicillamine Tetracyclines Zinc Type of Interaction and action required Reduced oral absorption of iron. Ensure medicine taken 2-3 hrs apart. medicines. Ensure medicine taken at least 30 minutes to 1 hr apart medicines. Ensure medicine taken 2-3 hrs apart. Chelation, reduced oral absorption of both medicines. Ensure medicines taken at least 2-3 hrs apart Reduced oral absorption of levothyroxine. Ensure medicines taken at least 2-3 hours apart. Reduced oral absorption and decreased antihypertensive effect. Ensure medicines taken at least 2 hours apart, *may require an increase in methyldopa dose. Reduced oral absorption of penicillamine. Ensure iron is taken at least 2 hours after penicillamine dose. medicines. Ensure medicines taken at least 3 hours apart.. medicines. Ensure medicines taken at least 2-3 hours apart. Table 2 Therapeutic Dosing of Oral Iron Iron Salt Amount Content of Elemental iron Therapeutic Dose Ferrous fumerate syrup* 140mg/5ml 45mg 10-20 mls x 2 per day Ferrous Gluconate 300mg 35mg 300mg 4-6 x per day Ferrous Sulphate 200mg 65mg 200mg 2-3 x per day * Ferrous Fumerate is often used for patients with swallowing difficulties 3
Patients not receiving haemodialysis may receive oral iron either as a prophylactic or as a continuation of maintenance therapy after initial correction with intravenous iron an example of prophylactic dosing of oral iron can be seen in Table 4. Table 4 Prophylactic Dosing of Oral Iron Oral Preparation Ferrous Sulphate Ferrous Gluconate Intravenous Iron Dose/Frequency 200mg once daily 300mg x 2 daily The use of IV iron supplementation for patients receiving haemodialysis has been common practice for many years. Although a meta-analysis by Rozen et al 18 demonstrated that 60% of people with CKD not having haemodialysis can achieve their aspirational Hb target and maintain it by IV iron repletion alone, i.e. without additional use of ESA therapy, the use of IV iron in practice varies. This may be due to several factors: Practicalities of administration Access to resources Availability of preparation (e.g. on hospital formulary) Cost of preparation Availability of Venous Access Patient choice A review by The European medicines Agency (EMA) in June 2013 19 highlighted the risk of serious allergic reactions following the administration of IV iron containing medicines, especially in pregnant women. Recommendations from the review have implications for the administration of IV iron for renal patients, in particular those who have home haemodialysis. The EMA (2013) state that iron preparations should only be given in an environment where resuscitation facilities are available, by staff who have been trained to evaluate and manage anaphylactic and anaphylactoid reactions. This is to ensure that patients who develop an allergic reaction can be treated immediately. This ruling means that patients are no longer able to give IV iron themselves at home. This has been common practice in the UK for some time. This change means patients will now have to go to their nearest renal unit to receive IV iron therapy. The EMA also commented on the use of test doses. They no longer advocate the administration of a test dose due to data indicating that allergic reactions may still occur in patients who have not reacted to a test dose. Product SPC s may need to be amended if this recommendation is made permanent. There are several preparations of IV iron with different methods of administration e.g. divided bolus doses or single dose infusion. See Table 5. This list is not exhaustive and other preparations may be available worldwide. The following side effects are common with the administration of IV iron 16 Taste disturbances Nausea Vomiting Abdominal pain Diarrhoea Chest pain Headache Dizziness Flushing Fever Myalgia Arthralgia Hypotension Bradycardia Tachycardia Hypersensitivity reactions Injection site reactions Table 5 IV Iron Preparations Name of Drug Cosmofer (Iron (III) Hydroxide dextran complex) Ferinject (Ferric Carboxymaltose) Monofer (Iron Isomaltoside) Max dose Bolus Frequency of bolus Maximum Single Dose Infusion Rate of Infusion 200mg Max 3 per week 20mg/kg 4-6 hrs Yes 1000mg 1-2 per week 1000mg 15 mins No 200mg 3 per week 20mg/Kg Up to 1 hour No Test Dose required Rienso (Ferumoxytol) 510mg 2-8 days apart 510mg N/A No Venofer (Iron Sucrose) 200mg 3 per week 200mg 30 mins Yes Ferrlicit (Sodium Ferric Gluconate complex) HD Only 125mg Daily in HD 125mg Up to 1 hour Yes 4
Peripheral oedema Paraesthesia Fatigue Anaphylactoid reactions Contraindications for the use of IV iron include: History of allergic disorders such as asthma and eczema Infection Active rheumatoid arthritis Previous allergic reaction to iron therapy Cost Implications of Treating IDA Oral Iron This is by far the cheapest option. It can be self administered at home, does not require an additional clinic or hospital appointment, is easily accessible and can be prescribed by the patients GP. IV Iron The cost of and availability of the drug can influence how an IV iron service is run. Economic factors will play an important part in service development particularly in regard to any reimbursements made for the administration of the drug 20. A comparative cost analysis of three types of IV iron preparations, including drug cost, nursing time, equipment and patient transportation examined the comparative cost to the health economy of IV iron supplementation options including blood transfusion 21. A blood transfusion cost the most followed by multiple small doses of IV iron. A single does infusion of IV iron proved to be the most cost effective overall. Drug costs will vary from country to country, and although oral iron will be the cheapest available treatment it is not necessarily the most effective for people with CKD 21. Guidelines - application to practice A plethora of guidelines exist to guide healthcare professionals in the management of IDA in CKD: European Best Practice Guidelines 22 (2004) KDOQI 15 (2006) UK NICE Guideline 39 23 (2006) UK Renal Association 24 (2010) UK NICE Guideline 114 13 (2011) Kidney Disease Improving Global Outcomes 12 - KDIGO (2012) Deciding which guidance to apply to practice can be a challenge whilst striving to provide the best level of care based on the highest level of available evidence. The majority of renal units will have protocols for anaemia management which will include the treatment of IDA in both the dialysis and non-dialysis population. What does the evidence say? KDIGO 12 recommend iron supplementation be used when an increase in Hb concentration without starting ESA treatment is desired, based on patient symptoms, overall clinical goals, including transfusion avoidance, improvement of anaemia related symptoms and exclusion of active infection. The iron markers and parameters utilised by KDIGO 11 are Serum Ferritin <500µg/L, %TSATS <30%. KDIGO 12 suggests a 1-3 month trial of oral iron therapy for adults not receiving haemodialysis if an increase in Hb is required without the use of ESA therapy and Serum ferritin <500µg/L, %TSATS <30%. UK NICE Guidance13 recommend Investigating and managing anaemia in people with CKD Hb level <11 g/dl (111g/L) or <10.5 g/dl in those under 2 years) and or/symptoms attributable to anaemia (such as tiredness, shortness of breath, lethargy and palpitations are present Those receiving ESA therapy maintain serum ferritin levels between 200 and 500 μg/l in both haemodialysis and non-haemodialysis patients, %TSATS >20% (unless ferritin is >800 μg/l) or %HRC< 6% Those requiring correction of IDA maintain Serum ferritin > 200 μg/l %TSAT > 20% (unless ferritin > 800 μg/l) %HRC < 6% (unless ferritin > 800 μg/l) Review iron doses if serum ferritin rises above 500µg/L. Whether to use oral or intravenous iron supplementation in those with CKD not receiving haemodialysis is a continuing debate and the evidence to date, does not support a clear preference or advantage for either. A trial of oral iron may be more practical for those with mild IDA and who need to avoid excess venepuncture. The main aim of treatment should be based on patient symptoms, and severity of IDA. Studies such as the FIND Study 26 are currently in progress to further investigate a direct comparison between oral and IV iron. It is hoped that the results of such studies will provide clear evidence to guide us in the optimal treatment and management of IDA. CARI 25 (2012) 5
Questions 1. What investigations are required to diagnose IDA? 2. What factors influence the tests used to identify IDA? 3. Which tests are used to diagnose IDA in CKD? 4. Which medicines are most effective in the treatment of IDA? 5. How can guidelines be used in practice to ensure all patients with CKD have access to treatment of IDA? References 1. World Health Organization, (2007). Assessing the iron status of populations: report of a joint World Health Organization/ Centers for Disease Control and Prevention technical consultation on the assessment of iron status at the population level, 2nd ed., Geneva,Available at http://www.who.int/nutrition/publications/micronutrients/anaemia_iron_deficiency/9789241596107.pdf 2. Stevens PE, O Donoghue DJ, De Lusignan S, Van Vllymen J, Klebe B, Middleton R,Hague N, New J, Farmer CK; (2007); Chronic kidney disease management in the United Kingdom: NEOERICA project results. Kidney International Jul;72(1):92-9. 3. New JP, Aung T, Baker PG, Yongsheng G, Pylpczuk R,Houghton J, Rudenski A, New RP, Hegarty J, Gibson JM, O Donoghue DJ, Buchan IE; (200)8;The high prevalence of unrecognized anaemia in patients with diabetes and chronic kidney disease: a population-based study Diabetes Medicine May;25(5):564-9. 4. Gregory J. Anderson, David M. Frazer and Gordon D. McLaren: Iron absorption and metabolism; Current opinions in Gastroenterology,(2009), 25; 129 135 5. Jenkins K (2011); Back to Basics Anaemia; Journal of Renal Nursing, Vol. 3, Iss. 1, 25 Jan 2011, pp 28-31 6. Mast, A. (2001(. The clinical utility of peripheral blood tests in the diagnosis of iron deficiency anemia. Bloodline 1, 7-9. 7. Coyne, D. (2006). Iron indices: what do they really mean? Kidney International Supp 101, S4-8. 8. World Health Organization (001; Iron deficiency anaemia: assessment, prevention and control, a guide for programme managers. Geneva 9. Fishbane, S., Imbriano, L.J., Kowalski, E.A., & Maesaka, J.K. (1996). The evaluation of ironstatus in patients receiving recombinant human erythropoietin. Journal of the American Society of Nephrology 7, 654-657 10. Goodnough, L.T., Nemeth, E., & Ganz, T. (2010) Detection, evaluation and management of iron-restricted erythropoiesis. Blood 116, 4754-4761 11. Eloísa Urrechaga, Luís Borque and Jesús F. Escanero 2012. Assessing Iron Status in CKD Patients: New Laboratory Parameters, Chronic Kidney Disease, Prof. Monika Göőz (Ed.), ISBN: 978-953-51-0171-0, InTech, DOI: 10.5772/25645. Available from: http://www.intechopen.com/books/chronic-kidney-disease/assessing-iron-status-in-ckd- patients-newlaboratory-parameters 12. Kidney Disease Improving Global Outcomes (KDIGO) Anemia Work Group. (2012). KDIGO Clinical Practice guideline for anemia in CKD. Kidney International 2 (Suppl 279-335) 13. NationaI Collaborating Centre for Chronic Conditions (2011) Clinical Guideline 114: Anaemia Management in people with chronic kidney disease www.nice.org accessed 10th August 2013 14. Van Wyck DB, Roppolo M, Martinez CO et al (2005). A randomized, controlled trial comparing IV iron sucrose to oral iron in anemic patients with nondialysis-dependent CKD. Kidney Int ; 68: 2846 2856. 15. Agarwal R, Rizkala AR, Bastani B et al. A randomized controlled trial of oral versus intravenous iron in chronic kidney disease. (2006) American Journal of Nephrology ; 26: 445 45 16. KDOQI Clinical Practice Guidelines and Clinical Practice Recommendations for Anemia in Chronic Kidney Disease; (2006) American Journal of Kidney Diseases, Vol 47, No 5, Suppl 3 (May),: pp S1-S3 17. British National Formulary (65) March Sept 2013 www.bnf.org 18. Rozen-Zvi B, Gafter-Gvili A, Paul M et al. (2008) Intravenous versus oral iron supplementation for the treatment of anemia in CKD: systematic review and meta-analysis. American Journal of Kidney Disease 52; 897 90 19. Anaemia Nurse Specialist Association & British Renal Society CKD Forum (2012); A guide to community administration of intravenous iron for people with anaemia of chronic kidney disease www.anaemianurse.org www.britishrenal.org/ ckdforum 20. Bhandari S (2011) Update of comparative analysis of cost minimization following introduction of newly available intravenous iron therapies in hospital practice. Therapeutics and Clinical Risk Management 7 501-509 21. Jenkins K; (2013) Journal of Renal Nursing, Vol. 5, Iss. 4, 24 Jul 2013, pp 170-177 6
22. Revised European Best Practice Guidelines for the Management of Anaemia in Patients with Chronic Renal Failure Nephrology Dialysis Transplant (2004) Volume 19 suppl 2 May 2004 23. http://www.nice.org.uk/cg39 Accessed 19th August 2013 24. http://www.renal.org/clinical/guidelinessection/anaemiainckd.aspx Accessed 19th August 2013 25. McMahon LP, MacGinley R. KHA-CARI guideline: biochemical and haematological targets: haemoglobin concentrations in patients using erythropoietin-stimulating agents. Nephrology (2012); 17(1):17-9. 26. FIND Study: An Open-label, Multicentre, Randomised, 3-arm Study to Investigate the Comparative Efficacy and Safety of IV Ferric Carboxymaltose Versus Oral Iron for Treatment of Iron Deficiency Anaemia in Subjects With Non-dialysisdependent CKD. www.clinicaltrials.gov accessed 22.06.13 7