Iron deficiency anemia pathogenesis and lab diagnosis

from the dacie todd and wintrobe . i prepared this . there is lot of things in iron metabolism . but all can not be included

1. Iron deficiency anemia- pathophysiology and lab diagnosis Dr. Bahoran Singh

2. Introduction Anemia is functionally defined as an insufficient RBC mass to adequately deliver oxygen to peripheral tissues. Anemia is considered to be present if the hemoglobin ( Hb ) concentration or the hematocrit ( Hct ) is below the lower limit of the 95% reference interval for the individual’s age,sex , and geographic location . Anemia may be absolute, when red blood cell mass is decreased, or relative , when associated with a higher plasma volume . Causes of absolute anemia 1.impaired red cell production 2. increased erythrocyte destruction or loss in excess of the ability of the marrow to replace these losses .

3. Iron deficiency is the most common anaemia. 83-90% of all anemia constitute IDA Every day about 30 mg iron is used to make new hemoglobin. Daily iron loss is around 1 mg. In women menstruation and childbirth increase iron losses to about 1.5 mg/day.

4. The total content of iron in the body - about 4.2g. From them: - 75-80% belongs to the hemoglobin - 20 - 25% reserve - 5-10% part of the myoglobin -1% is part of the enzyme for the tissue respiration

5. DIETARY IRON There are 2 types of iron in the diet; heme iron and non- heme iron. Heme iron is present in Hb containing animal food like meat, liver & spleen. Non- heme iron is obtained from cereals, vegetables & beans.

6. Iron cycle

7. Most body iron is present in hemoglobin in circulating red cells The macrophages of the reticuloendotelial system store iron released from hemoglobin as ferritin and hemosiderin. In the plasma, total iron averages 110 µg/ dL Majority bound to the transferrin (capacity to bind 330 µg of iron per deciliter) So only one third of transferrin is saturated.

8. IRON METABOLISM Iron concentration (Fe) N : 50-150  g/dl Total Iron Binding Capacity N: 250-450  g/dl Transferrin saturation Transferrin receptor concentration Ferritin concentration N: 50-300 g/l

9. Overview of Iron Homeostasis erythroblast

10. IRON ABSORPTION Site- Proximal small intestine i.e. duodenum (first part- maximum absorption) and jejunum. 10% of dietary iron is absorbed it is determined by intraluminal factor i.e. pH and redox potential. Therapeutic ferrous iron is well absorbed on empty stomach. Haem iron is not affected by ingestion of other food items. Heme iron → Acid and gastric juices release it from apoprotein → Oxidised → hemin → directly absorb through mucosal cell intact.

11. INHIBITORS OF IRON ABSORPTION Food with polyphenol compounds Cereals like sorghum & oats V egetables such as spinach and spices Beverages like tea, coffee, cocoa and wine. A single cup of tea taken with meal reduces iron absorption by up to 11 %. Food containing phytic acid i.e. Bran Cow’s milk due to its high calcium & casein contents .

12. Promoters of Iron Absorption Foods containing ascorbic acid like citrus fruits, broccoli & other dark green vegetables Foods containing muscle protein Food fermentation aids iron absorption by reducing the phytate content of diet

13. Iron absorption at molecular level Iron is converted from Fe 3+ to Fe 2+ by ferrireductase (DCYTB). Fe 2+ transported across mucosal surface of enterocyte by DMT1 , stored as ferritin. Ferritin releases Fe 2+ which is transported across basolateral surface of enterocyte with help of ferroportin . Fe 2+ converted back to Fe 3+ by Hephaestin . Fe 3+ binds to transferrin in plasma.

14. Regulation of Iron Absorption R egulated at two stages Mucosal uptake At stage of transfer to blood 1. HIF-2 ά - a mediator of cellular adaptation to hypoxia, regulates DMT1 transcription and thus regulates mucosal uptake of iron because mucosal uptake depend on DMT 1. 2. Iron transfer to the plasma depends on the requirements of the erythron for iron and the level of iron stores. This regulation is mediated directly by hepcidin .

15. Cellular iron uptake & release

16. The reticuloendothelial macrophages play a major role in recycling iron resulting from the degradation of haemoglobin from senescent erythrocytes. They engulf red blood cells and release the iron within using haem oxygenase . The protein transporting iron to plasma is ferroportin .

17. Ferroportin and Hepcidin Hepcidin - its synthesis is controlled at molecular level. Interaction of diferric transferrin,bone morphogenetic proteins (BMPs), interleukin (IL)- 6 and other inflammatory cytokines with cell surface receptors TfR1, TfR2, hemojuvelin (HJV) and IL-6 receptor lead to upregulation of the hepcidin gene. Mechanism of action- it binds to both TfR1 and TfR2, decreasing the affinity of each for transferrin. Stabilization and endocytosis of TfR2 stimulates hepcidin production D iferric transferrin displaces the protein HFE from TfR1, leaving it free to interact with TfR2, thus stimulating hepcidin production in response to plasma iron levels .

18. Increased erythropoiesis causes decreased hepcidin . Hepcidine function Blocks ferroportin Prevents absorption of iron from enterocytes. Prevents iron exportation from macrophages. Increased in inflammation. Leads to reduced serum iron, microcytic anemia, and incomplete response to iron therapy. Ferroportin Transporter protein of iron in enterocytes and macrophages. Blocked by hepcidin .

19. Newborn Iron Stores Endowed with 75 mg/kg of iron at birth Dependent on hemoglobin concentration at birth (majority of iron in circulating RBCs) Depleted by 3 months in low birth weight infants without supplementation Depleted by age 5-6 months in term infants Delayed cord clamping (by 2 minutes) leads to higher ferritin and iron stores at 6 months of age

20. Iron storage Iron stored in two forms Soluble ferritin Insoluble hemosiderin- denatured form of ferritin in which the protein shells have partly degraded, allowing the iron cores to aggregate. Hemosiderin deposits are seen on Prussian-blue positivity after staining of tissue sections with potassium ferrocyanide in acid.

21. Regulation of Iron Metabolism I ron metabolism is regulated post transcriptionally by iron regulatory proteins- IRP 1 and IRP 2. The conformation of IRP1 required for binding to mRNA iron-responsive elements (IREs ). IRP2 are directly affected by the amount of iron within a cell. When the labile iron pool is deficient of iron, IRP1 has an available binding site for IRE . When the labile iron pool is saturated with iron, the iron binds to IRP1 to produce a 4Fe-4S cluster which blocks the IRE binding site and prevents IRP1 binding to the IRE. In the presence of iron, IRP2 is degraded. Regulation of iron proteins by IRP on basis of location of IRE on mRNA at 3’UTR- Stabiles translocation of TfR & DMT 1 5’UTR- inhibit translation of mRNA

22. IRON TRANSPORT Transferrin is the major protein responsible for transporting iron in the body Transferrin receptors, located in almost all cells of the body, can bind two molecules of transferrin. One molecule of transferrin binds two molecules of iron. Both transferrin saturation & transferrin receptors are important in assessing iron status

23. Transferrin, when incompletely saturated with iron , exists in four forms : Apotranferrin Monoferrric transferrin A Monoferrric transferrin B Diferric Transferrin There distribution may be determined by urea-polyacrylamide electrophoresis . The plasma iron pool (transferrin-bound iron) is about 3 mg .

24. Other iron transporter proteins 1. Haptoglobin - S erum glycoprotein It binds with Hemoglobin ά ẞ dimer released into the bloodstream by hemolysis. H emoglobin– haptoglobin complex is removed from plasma by macrophages having receptor CD 163 . 2. Hemopexin - P lasma glycoprotein that binds heme and transports the haem to cells by a process that involves receptor-mediated endocytosis

25. 3. Ferritin- present in low conc in plasma. Mostly appears as glycosylated and has low content of iron. It is also released into the circulation as a result of tissue damage. 4. Non-transferrin-bound iron- I ron that is not bound to transferrin. Have low molecular mass and can be bound by specific iron chelators . Chemical form is not known but rapidly removed from circulation by liver. This removal involve zinc transporter ZIP14 .

26. AT RISK GROUPS 1. Infants 2. Under 5 children 3. Children of school age 4. Women of child bearing age 5. Geriatric age group

27. Causes of iron deficiency Chronic blood loss Increased demand Malabsorbtion of iron Inadequate iron intake Intravascular hemolysis and hemoglobinuria-hemosiderinuria Combinations

28. Increased demands Pregnancy Lactation Growing infants and children Menstruating women Multiparity Parturition

29. Decreased intake Decreased iron in the diet Vegetarian diet Low socioeconomic status Lack of balanced diet or poor intake Alcoholism Decreased absorbtion Gastric surgery Achlorhydria Duodenal pathology Chronic renal failure patients Coeliac Sprue Pica

30. Increased iron loss Menorrhagia G astrointestinal hemorrhag e P.Ulcer Oesophagitis Varices Hiatal hernia Malignancy Angiodysplasia Diverticulosis Meckel diverticula Colitis or im perforated b o w el disease Hemorrhoids NSAID use Parasites

31. Increased iron loss Bleeding disorder Pulmonary lesions with bleeding Hemoglobinuria – hemosiderinuria (chronic intravascular hemolysis) Hemodialysis Hematuria (chronic) Frequent donation 250 mg iron /unit-blood

32. Pathogenesis of iron deficiency anemia T here are three pathogenic factors Impaired Hb synthesis d/t reduced iron supply Generalized defect in cellular proliferation Survival of erythroid precursor and erythrocytes is reduced W hen transferrin saturation ‹15%, marrow supply of iron reduced and is inadequate to meet basal requirement for Hb production. erythrocyte protoporphyrin raised each RBC contain less Hb so microcytic and hypochromic

33. Clinical features of iron deficiency anemia Fatigue and Other Nonspecific Symptoms irritability, palpitations, dizziness, breathlessness , headache, and fatigue Neuromuscular System impair muscular performance, a bnormalities in muscle metabolism , behavioral disturbances, Neurologic development in infants and scholastic performance in older children may be impaired . Sometimes neuralgia pains, vasomotor disturbances, or numbness and tingling.

34. Epithelial tissues Site findings Nails Flattening Koilonychia Tongue Soreness Mild papillary atrophy Absence of filiform papillae Mouth Angular stomatitis Hypopharynx Dysphagia Esophageal webs Stomach Achlorhydria Gastritis

35. Plummer-Vinson syndrome The most common anatomic lesion is a “web” of mucosa at the juncture between the hypopharynx and the esophagus

36. Immunity and Infection Defective lymphocyte-mediated immunity and impaired bacterial killing by phagocytes. Pica “craving to eat earth ” Pagophagia is, defined as the purposeful eating of at least one tray of ice daily for 2 months , F ood pica- compulsively eating one food, often something that is brittle and makes a crunching sound when chewed. Genitourinary System - Disturbances in menstruation, Skeletal System diploic spaces may be widened, and the outer tables thinned

37. Developmental Stages of Iron Deficiency Anemia ( WHO) Pre-latent – reduction in iron stores without reduced serum iron levels Hb , MCV, Transferrin saturation- Normal, Iron absorption -increase, Serum ferritin and marrow iron reduced no clinical manifestation Latent- iron stores are exhausted, but the blood hemoglobin level remains normal index of the blood within the standard clinical picture is caused by the sideropenic syndrome Iron Deficiency Anemia blood hemoglobin concentration falls below the lower limit of normal the clinical manifestations in the form of sideropenic syndrome and general anemic symptoms

38. Stages in the Development of Iron Deficiency   Stage 1 ( Prelatent ) Stage 2 (Latent) Stage 3 (Anemia) Bone marrow iron Reduced Absent Absent Serum ferritin Reduced <12 μ g/L <12 μ g/L Transferrin saturation Normal <16% <16% Free erythrocyte protoporphyrin , zinc protoporphyrin Normal increased increased Serum transferrin receptor Normal increased increased Reticulocyte hemoglobin content Normal reduced reduced Hemoglobin Normal Normal Reduced Mean corpuscular volume Normal Normal Reduced Symptoms Fatigue, malaise   Pallor, pica, in some patients

39. Laboratory diagnosis Complete blood count Bone marrow Serum parameter ferrokinetic Studies

40. BLOOD AND BONE MARROW FINDINGS BLOOD : peripheral smear findings microcytosis, h y pochromia, anisocytosis , poikilocytosis ( eliptocytes and pencil cells

41. AUTOMATED ANALYSER FINDINGS

42. IRON DEFICIENCY ANEMIA M CV - Reduced ( N : 80-100 fl ) M CH - Reduced ( N : 27-32 pg ) MCH C– Normal to reduced (N: 30-34 mg/dl) Iron- Reduced (N: 4 gm ) TIBC - I ncreased (N: 47-70 µ mol /l) T ransferin Saturation - Reduced (N :16-50%) Ferritin - R educed (N:15–300 µg/l ) RDW: High ( N : 11.5- 14 %) Retic ulocytes : Normal/Low (N: 0.5- 2.5%) Pl a t elates : Normal/Low/High WBC: Normal/Low Smear: Hypochromia,anisocytosis, microcytosis , poikilocytosis

43. Bone marrow findings BONE MARROW Early stage - Normoblastic hyperplasia Normoblasts - smaller than normal deficient in hemoglobin Irregular shaped with frayed margins polychromatic and pyknotic cytoplasm of erythroblasts is vacuolated and irregular in outline ( micronormoblastic erythropoiesis ) absence of stainable iron WBCs- Giant neutrophil bands or metamyelocytes Storage iron is absent

44. Marrow film- Iron deficiency anemia

45. M arrow film- prussian blue stain

46. Lab tests of iron deficiency of increased severity NORMAL Fe deficiency Without anemia ( prelatent ) Fe deficiency With mild anemia (latent) Fe deficiency With severe anemia (IDA) Serum Iron 60-150 60-150 <60 <40 Iron Binding Capacity 300-360 300-390 350-400 >410 Saturation 25-55 30 <15 <10 Hemoglobin Normal Normal 9-12 6-7 Serum Ferritin 40-200 <20 <10 0-10

47. Methods for assessing iron status Measurements Reference range Diagnostic Value Confounding factors Hemoglobin concentration Male: 13–17 g/dl Female: 12–15 g/dl Defining anemia and assessing its severity. Response to a therapeutic trial of iron confirms iron deficiency anaemia (IDA). Other causes of anemia besides iron deficiency 2. Red cell indices Mean cell volume Mean cell haemoglobin (MCH) 83–101 fl 27–32 pg Low values indicate iron deficient erythropoiesis. May be reduced in disorders of haemoglobin synthesis, other than iron deficiency ( thalassaemia , sideroblastic anaemias , anaemia of chronic disease) 3. Tissue iron supply Serum iron 10–30 µ mol /l Low values in iron deficiency, high values in iron overload Reduced in acute and chronic disease; labile, use of fasting morning sample reduces variability

48. MEASUREMENT REFERENCE RANGE (ADULTS) DIAGNOSTIC USE CONFOUNDING FACTORS Total iron binding capacity (TIBC) 47–70 µ mol /l High values -tissue iron deficiency Low value- iron overload Rarely used on its own. Reliable reference ranges not available Transferrin saturation (TS) (iron/TIBC × 100) 16–50% Low- iron deficiency anemia Reduced in acute and chronic disease Iron supply to the bone marrow Serum transferrin receptor ( sTfR ) Red cell zinc protoporphyrin (ZPP) 2.8–8.5 mg/l <80 µ mol / mol Hb Reduced red cell ferritin or increased ZPP, sTfR and % hypochromic red cells indicate impaired iron supply to the bone marrow. Identifying early iron deficiency and, with a measure of iron stores. Distinguishing this from anemia of chronic disease. sTfR concentration is related to extent of erythroid activity as well as iron supply to cells. ZPP may be increased by other causes of impaired iron incorporation into haem ( sideroblastic anaemias , lead poisoning, inflammation)

49. MEASUREMENT REFERENCE RANGE (ADULTS) DIAGNOSTIC USE CONFOUNDING FACTORS Iron stores Serum ferritin Male 15–300 µg/l Female 15–200 µg/l Correlated with body iron stores from deficiency to overload Increased : as acute-phase protein By release of tissue ferritin after organ damage. Decreased : vitamin C deficiency Bone marrow Grade Graded as absent, present or increased Used to d/b ACD and IDA. Adequate sample required

50. Serum Iron R eference interval is 50–160 µg/ dL Determination of iron status requires- E stimate of the amount of haemoglobin iron (usually by measuring the haemoglobin concentration ( Hb ) in the blood). L evel of storage iron (measuring serum ferritin concentration ). Assay of serum iron - It is modification of method recommended by the International Council for Standardization in Haematology (ICSH) and is based on the development of a coloured complex when ferrous iron released by serum protein denaturation in the presence of reducing agent is treated with a chromogen solution. Alternate methods- 1. Microtitre plate method 2. Automated Methods for Serum Iron- non-precipitation method , available from Randox Ltd . INTERPRETATION Level reduced in - Iron deficiency anemia Anemia of chronic diseases Infections

51. Serum ferritin Normal value - 15–300 µg/L (Men>women) W ater-soluble complex of iron hydroxide with the protein apoferritin . It is located in cells of the liver, spleen, bone marrow . Ferritin assay - Immunoradiometric assay ( 1 st method) MOA - Excess radiolabelled antibody react with ferritin and antibody not bound to ferritin was removed with an immunoadsorbent . Interpretation – Ferritin is the basic protein which deposits iron. Serum ferritin concentration reflects iron reserve of individual. Reduced in iron deficiency anemia. It is acute phase reactant so raised in some hepatocellular diseases, malignancies, and inflammatory diseases , so may give disproportionately high estimate of storage iron . Age between 6 months- 15 yrs reference value is low.

52. Transferrin T ransferrin has a very high affinity for iron at neutral pH and iron release takes place through a specific membrane receptor LIMITATION The concentration of transferrin is subjected to the daily variations Acute inflammation contributes to lowering the transferrin level CLINICAL SIGNIFICANCE Basic clinical index for the differentiation between the iron-deficiency ([TF]↑) and hemolytic anemia ([TF]↓) More precise index than total iron binding capacity After the liberation of iron from the complex, TF ion of Fe3+ must be restored into Fe2+

53. Serum (Total) Iron-Binding Capacity (TIBC) Iron in plasma binds to transferrin and TIBC is the measure of this protein. The additional iron-binding capacity of transferrin is known as the unsaturated iron-binding capacity (UIBC ). TIBC = UIBC + serum iron concentration . TIBC(µ mol /l) = Transferrin conc ( gm /l) × 25 Estimation of TIBC - By adding an excess of iron to a solution and measuring the iron retained in solution after the addition of a suitable reagent such as ‘ light’ magnesium carbonate or an ion-exchange resin that removes excess iron. Principle Excess iron as ferric chloride is added to serum. Any iron that does not bind to transferrin is removed with excess magnesium carbonate. The iron concentration of the iron-saturated serum is then measured . Raised in iron deficiency anemia

54. UIBC DETERMINATION The UIBC may be determined by methods that detect iron remaining and able to bind to chromogen , after adding a standard and excess amount of iron to the serum . The UIBC is the difference between the amount added and the amount binding to the chromogen . METHODS- Chromogen solution Microtitre tray UIBC is being evaluated as a screening test for iron overload in genetic haemochromatosis .

55. Serum Transferrin ( Beta-globulin) Main function - transport of absorbed iron in the depot (liver, spleen), into the medullary erythroid predecessors and into the reticulocytes. Basic place of synthesis - liver. Reference interval for adults is 200–300 µg/ dL (2.0–3.0 g/l ) 1 mg of transferrin binds 1.4 µg of iron. ESTIMATION OF SERUM TRANSFERRIN- by an immunological assay-Rate immunonephelometric methods INTERPRETATION An increase in the content of transferrin with lowering in the level of iron of serum is characteristic for the iron-deficiency state. A decrease in the level of transferrin can be with the damage of the liver (different genesis) and with the loss of protein (for example, in nephrotic syndrome). The level of transferrin is increased in the last term of pregnancy .

56. Transferrin saturation The transferrin saturation is the ratio of the serum iron concentration and the TIBC expressed as a percentage Normally, this is 20%–55 %. A transferrin saturation of <16% is usually considered to indicate an inadequate iron supply for erythropoiesis. Used for detection of genetic haemochromatosis . Normal diurnal variation serum iron is as much as 30 % with highest values in the morning and lowest values late in the day . fasting morning blood specimens are preferred for the diagnosis of iron deficiency. Transferrin Index It is serum iron concentration ( µ mol /l ) divided by the transferrin concentration (determined immunologically and expressed as µ mol /l)

57. SERUM TRANSFERRIN RECEPTOR There are two types of transferrin receptors TfR1 and TfR2 . TfR1 is essential for tissue iron delivery Transferrin binds to TfR1 , the complex is internalized and iron is released when the pH of the internal vesicles is reduced to about 5.5 .

58. Estimation of transferrin receptors ( TfR ) Transferrin receptors have been purified from placenta and from serum. Three enzymes immunoassay kits F ully automated, diagnostic, immunoassay systems . Four different units ( nmol /l, µg/ml , mg/l and ku /l) INTERPRETATION sTfR concentrations are high in neonates and decline until adult concentrations are reached at 17 years . Increased during pregnancy

59. sTfR CONCENTRATION CONDITION Increased Increased erythroid proliferation : Autoimmune haemolytic anaemia Hereditary spherocytosis ẞ Thalassaemia intermedia or major ẞ Thalassaemia / HbE Haemoglobin H disease Sickle cell anaemia Polycythaemia vera Decreased tissue iron stores: Iron deficiency anaemia Normal to increased Idiopathic myelofibrosis Myelodysplastic syndrome Chronic lymphocytic leukaemia Normal Haemochromatosis Acute and chronic myeloid leukaemia Most lymphoid malignancies Solid tumours Anaemia of chronic disease Decreased Chronic renal failure Aplastic anaemia After bone marrow transplantation

60. Erythrocyte Porphyrins Protoporphyrin IX is the immediate precursor to haem . The enzyme ferrochelatase is able to insert ferrous iron to produce haem or zinc cation to form zinc protoporphyrin (ZPP). When iron supply to ferrochelatase is limiting, ZPP increases. When ferrochelatase is limiting, free protoporphyrin accumulates . Normal reference value is adults is less than 70 µ mol / mol haem . ANALYSIS - Two dedicated analysers are available: the Proto Fluor Z from Helena Laboratories, Beaumont, Texas ( www.helena.com ) and the ZPP 206D from Aviv Biomedical Inc The measurement of EP levels as an indicator of iron deficiency has particular advantages in pediatric hematology. Mean ZPP values Female > Male Level of porphyrins in Iron def anemia according to WHO C hildren younger than age 5 years- >61 µ mol / mol haem all other subjects, levels should be >70 µ mol / mol haem . Erythrocyte porphyrins became elevated before the development of anemia O ne of the earliest indicators of iron defiiency

61. Serum Transferrin Receptor–to–Serum Ferritin Ratio ( TfR /F) N ew approach to estimate total body iron stores . H ave limited value in identifying anemia of chronic disease (ACD ) B etter utilized in identifying iron defiiency anemia coexisting with ACD

62. Differential diagnosis of Microcytic anaemia Iron deficiency anemia Anemia of chronic disease Thalassaemia Sideroblastic anemia MCV Reduced Low normal or normal Low Low in inherited but normal in acquired Serum iron Reduced Reduced Normal Raised Serum TIBC Raised Reduced Normal Normal Serum Ferritin Reduced Normal or raised Normal Raised Iron in BM Absent Present Present Present

63. Iron Deficiency in Infancy and Childhood INFANTS- There are rapid changes in iron status in the first year of life as fetal Hb is replaced by adult hemoglobin. The serum ferritin concentration is a less useful because of rapid decline in concentration in the first 6 months and the low concentrations generally found in children older than 6 months of age .

64. Children- reason for detecting iron deficiency is to identify those who will respond to iron therapy. B est predictor of response was the initial Hb , Serum ferritin, transferrin saturation and erythrocyte protoporphyrin (EP) had lower efficiencies. ZPP provides a useful indicator of iron deficient erythropoiesis

65. Iron Balance in Pregnancy Iron Fate Mean Amount (mg) Range (mg) Lost to fetus 270 200–370 Lost in placenta, cord 90 30–170 Lost with bleeding at delivery 150 90–310 Normal body iron loss 170 150–200 Added to expanded red blood cell mass 450 200–600  Total 1,130 670–1,650 Returned to stores when 450 200–600 Net loss (over 9 mo) 680 470–1,050

66. Iron deficiency in Pregnancy In early pregnancy serum ferritin concentrations usually provide a reliable indication of iron deficiency Haemodilution in the 2nd and 3rd trimesters of pregnancy reduces the concentrations of all measures of iron status. determination of values as ratios (ZPP µ mol / mol haem , transferrin saturation and sTfR /ferritin ) should be more reliable.

67. In healthy women who were not anaemic and who were supplemented with iron, serum iron, transferrin saturation and serum ferritin fell from the 1 st to the 3rd trimester and increased after delivery; TIBC increased during pregnancy and fell after delivery . sTfR concentrations increased (approximately two-fold) during pregnancy and this probably reflects increased erythropoiesis .

68. CONCLUSION Body iron status can usually be assessed by considering the Hb , red cell indices and serum ferritin concentration, along with evidence of inflammation, infection and liver disease.