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Hypochromic Microcytic Anaemias in Children

Mariane de Montalembert, MDService de Pédiatrie

Hospital NeckerParis, France

Adlette C. Inati, MDHead

Division of Pediatric Hematology-OncologyMedical Director

Children's Center for Cancer and Blood DiseasesRafik Hariri University Hospital

Beirut, Lebanon 

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Diagnosis and Causes of Hypochromic Microcytic

Anaemias in Children

Mariane de Montalembert, MDService de Pédiatrie

Hospital NeckerParis, France

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Hypochromic Microcytic Anaemias

• The most common forms of anaemia in children and adolescents

• Constitute a very heterogeneous group of diseases that may be acquired or inherited

• Nutritional iron deficiency and β-thalassaemia trait are the primary causes in paediatrics, while bleeding disorders and anaemia of chronic disease are quite common in adulthood

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Causes of Hypochromic Microcytic Anaemias

EnterocyteErythroid precursor

Malabsorption Defects in heme synthesis or iron acquisition

• Breastfeeding with inadequate supplementary food• Preterm, low birth weight• Growth spurt• Inadequate calorie intake• Vegetarian diet

• Celiac disease• Helicobacter pylori gastritis• Autoimmune atrophic gastritis• IRIDA (TMPRSS6 mutation)• Chronic inflammation

• Haemoglobinopathies• Sideroblastic anaemia• Erythropoietic porphyria• DMT1 mutations• Ferroportin disease• Hereditary atransferrinaemia• Hereditary aceruloplasminaemia

• Polymenorrhea• Parasitic infestations• Peptic ulcer• Inflammatory bowel disease• Meckel diverticulum

Graphic courtesy of Dr. Mariane de Montalembert.

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Diagnostic Tree

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Tests for Assessing Iron Status• Serum iron• Total iron binding capacity (TIBC)• Transferrin saturation = serum iron/TIBC x 100• Serum ferritin• Serum transferrin receptor (sTfR)/serum ferritin

[R/F ratio]• Reticulocyte haemoglobin content• Stainable iron in bone marrow

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Iron Deficiency Stages

Slide courtesy of Dr. Adlette C. Inati, MD.

Abbreviations: IDA, iron deficiency anaemia; MCH, mean corpuscular haemoglobin;MCV, mean corpuscular volume; TIBC, total iron binding capacity.

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Laboratory Indicators of Iron Deficiency

• There is a significant overlap between iron-sufficient and iron-deficient segments of a population, making the diagnosis of iron deficiency unclear

• Thus, it is necessary to combine several laboratory indicators

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Serum Ferritin Levels

• Serum ferritin is raised during acute infection and inflammation and liver disease, irrespective of the iron stores, but iron deficiency is the only cause of a low concentration

• A normal serum ferritin level doesn’t exclude an iron deficiency, but a low serum ferritin level necessarily means iron deficiency

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Iron Deficiency DiagnosisCenters for Disease Control and Prevention

• Proper anaemia screening requires not only sound laboratory methods and procedures but also appropriate haemoglobin and haematocrit cut-off values to define anaemia

• ≥2 of the following tests are abnormal:– Free erythrocyte protoporphyrin (≥1.24 μmol/L

red blood cells)– Transferrin saturation (<14% for 12- to 15-year-

olds or <15% for 16- to 39-year-olds)– Serum ferritin (<12 μg/L)

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Cut-Off Values for Iron Status by Age and Gender NHANES Survey in the United States

• Transferrin saturation (%) – 1–2 y: 9– 3–5 y: 13– 6–15 y: 14

• Serum ferritin (μg/L) – 1–5 y: 10– 6–15 y: 12

• Mean corpuscular volume (fl)– 1–2 y: 77– 3–5 y: 79– 6–11 y: 80 – 12–15 y, male: 82 – 12–15 y, female: 85

• Reference haemoglobin values (g/dL): Mean – 2DS– 1–2 y: 10.7 – 3–5 y: 10.9 – 6–11 y: 11.5– 12–15 y, male: 12 – 12–15 y, female: 11.5

Dallman PR. In: Iron Nutrition in Health and Disease. John Libbey & Company; 1996:65-71.Looker AC, et al. JAMA. 1997;277:973-976.Cogswell ME, et al. Am J Clin Nutr. 2009;89:1334-1342.Slide courtesy of Dr. Mariane de Montalembert

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Finding Microcytic Anaemia in a Child

Check the iron status

Normal

Hg electrophoresis, HPLC

Abnormal:• β-thalassaemia• HbC disease• HbE disease• HbH disease • β-thal/sickle cell disease

Normal: •Check forα-thalassaemia(molecular study)

Abnormal

Iron deficiencyDefect in iron utilisation

Graphic courtesy of Dr. Mariane de Montalembert.

Verify the blood smearLeadintoxication

Abbreviations: HbC, haemoglobin C; HbE, haemoglobin E; HbH, haemoglobin H; Hg, haemoglobin; HPLC, high performance liquid chromatography.

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Iron Deficiency Anaemia vs β-Thalassaemia Trait

Abbreviations: FEP, free erythrocyte porphyrin; HbA2, haemoglobin A2; HbF, haemoglobin F; MCV, mean corpuscular volume; RBC, red blood cells; RDW, red blood cell distribution width;TIBC, total iron binding capacity.Slide courtesy of Dr. Adlette C. Inati.

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Hypochromic Microcytic Anaemias in ChildrenIron Deficiency Defects in Iron

Utilisation1

Thalassaemia Lead Intoxication

Chronic Disease

Blood smear

Microcytosis, anisocytosis,Poikilocytosis, elliptocytosis,hypochromia

Hypochromia Microcytosis, target cells, helmets, dacryocytes

Coarse basophilic stippling

Microcytosis, hypochromia

Serum iron Normal or

Transferrinsaturation

Serum transferrinreceptor

Normal

Serum ferritin

Normal

Other diagnostic tools

Bone marrow: ringed sideroblasts

High-performance liquid

chromatography

Blood lead level Erythrocyte sedimentation rate

C-reactive protein

Iolascon A, et al. Haematologica. 2009;94:935-948.Graphic of blood smears courtesy of Dr. C. Brouzes.

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Inadequate Iron Intake

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Iron Deficiency Anaemia (IDA)

• The most common nutritional disorder worldwide• Prevalence varies with age, gender, race, dietary intake,

and socioeconomic factors• Low serum iron concentration causes insufficient

synthesis of haemoglobin and other iron-containing proteins, such as cytochromes, myoglobin, catalase, and peroxidase

• Associated with psychomotor and cognitive abnormalities and poor school performance in children in the first years of life with haemoglobin ≤10.5 g/dL but a causal relation has not been demonstrated as yet

Pollitt E. Annu Rev Nutr. 1993;13:521-537.Lozoff B, et al. J Nutr. 2007;137:683-689.McCann JC, et al. Am J Clin Nutr. 2007;85:931-945.

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Risk Factors for IDA

Children <5 years old• Preterm/low birth weight

babies• Children of immigrants• >6 months of age: exclusively

breast-fed and/or non–iron-fortified formulas with no iron supplement

• Introduction of cow’s milk <1 year of age

• Parasitic infestation (developing countries): hookworm

• Poverty

Adolescents• History of heavy menstrual

blood loss (>80 mL/mo)• Significant physical activity• Vegetarian diet• Strict fad dieting, especially in

females• Malnutrition• Parasitic infestation

(developing countries): hookworm

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Increasing Prevalence of Iron Deficiency Among Adolescent Females

• High iron needs• Tendency of girls to eat less high

iron-containing foods (such as meat) • Many adolescents are asymptomatic and

present with only anaemia

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Decreased Iron Absorption

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Main Causes of Decreased Iron Absorption

• Celiac disease

• Autoimmune atrophic gastritis

• H. pylori gastritis

• Iron Refractory Iron Deficiency Anaemia (mutation of the serine protease matriptase-2 [TMPRSS6])

• Chronic inflammationHerschko C, Skikne B. Semin Hematol. 2009;46:339-350.

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Defects in Heme Synthesis or Iron Acquisition

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Decisional Tree for the Identification of Candidate Genes in Microcytic

Hypochromatic Anaemia

• Biologic assays– Iron and haematologic status, including serum transferrin

receptor

• Diagnostics to be ruled out– Iron deficiency (nutritional, Pica, lead intoxification)– Haemoglobinopathies– Spherocytosis, elliptocytosis– Other haemolytic anaemias (red blood cells enzyme defect…)

(complementary investigations: haptoglobin and birilubin assay)– Atransferrinaemia, aceruloplasminaemia

Iolascon A, et al. Haematologica. 2009;94:935-948.

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Decisional Tree for the Identification of Candidate Genes in Microcytic Hypochromatic Anaemia

With permission from Iolascon A, et al. Haematologica. 2009;94:935-948.

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Blood Loss

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Main Causes for Blood Loss

• Polymenorrhea (>80 mL/mo)

• Parasitic infestations (hookworm) in developing countries

• Peptic ulcer

• Inflammatory bowel disease

• Meckel’s diverticulum

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Epidemiology, Prevention, and Treatment of Iron Deficiency and Iron Deficiency Anaemia

Adlette C. Inati, MDHead

Division of Pediatric Hematology-OncologyMedical Director

Children's Center for Cancer and Blood DiseasesRafik Hariri University Hospital

Beirut, Lebanon 

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Epidemiology of Iron Deficiency and Iron Deficiency Anaemia

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Prevalence (%) of Iron Deficiency and Iron Deficiency Anaemia, United States, Third National Health and Nutrition Examination

Survey (NHANES III), 1988-1994 (Both Genders)

Looker AC, et al. JAMA. 1997;277:973-976.

9%

3% 3%

<1% <1%

2%

Age (years)

Iron deficiency defined on basis of 2 of 3 abnormal values for erythrocyte protoporphyrin concentration, serum ferritin

concentration, and transferrin saturation

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Prospective Survey of Prevalence of Anaemia and Iron Deficiency Anaemia in Healthy 1-Year-Old Lebanese

Children (N = 3052)

• ID defined as: MCV <70 μg/mL, SF <12 ng/mL• IDA defined as Hg ≤11 g/dL plus ID

Abbreviations: Hg, haemoglobin; ID, iron deficiency; IDA, iron deficiency anaemia; MCV, mean corpuscular volume.Dr. Adlette C. Inati. Unpublished data, 2010.Graphic courtesy of Dr. Adlette C. Inati.

30Dr. Adlette C. Inati. Unpublished data, 2010.Graphic courtesy of Dr. Adlette C. Inati.

Prospective Survey of Prevalence of Anaemia and Iron Deficiency Anaemia in Healthy 1-Year-Old

Lebanese Children

No. of No. of childrenchildren

30523052

No. of No. of malesmales

16541654

No. of No. of femalesfemales

13981398

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Iron Deficiency Anaemia in Healthy 1-Year-old Lebanese Children

Dr. Adlette C. Inati. Unpublished data, 2010.Slide courtesy of Dr. Adlette C. Inati.

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Percentages of Causes of Iron Deficiency Status in Italy

• Retrospective study in 238 children

7.5 months to 16 years of age with ID

• Most common cause of ID– 7.5 months to 2 years: blood loss (57%)*– 3–10 years: malabsorption (78%)– 11–15 years, boys: blood loss (55%)– 11–16 years, girls: blood loss (48%)

Ferrara M, et al. Hematology. 2006;11:183-186.

* Often linked to cow’s milk intolerance.

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Causes for Iron Deficiency and Iron Deficiency Anaemia in Children in

Taiwan

• Retrospective study in 116 children, age <18 years, diagnosed with ID, 100 of whom had IDA

• Peak incidence of childhood ID occurred in children <2 years old and 10–18 years old

• Most common cause of ID– <2 years (n = 45): inadequate intake (55.6%)– 2–10 years (n = 13): blood loss (46.1%)– >10 years, male (n = 18): inadequate intake (38.9%)– >10 years, female (n = 40): blood loss (37.5%)

Huang SH, et al. J Pediatr Hematol Oncol. 2010;32:282-285.

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Adverse Effects of Iron Deficiency

and Iron Deficiency Anaemia

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Adverse Effects of Iron Deficiency and Iron Deficiency Anaemia

Data equivocal due to many confounding factors and difficulties in obtaining relevant tests of infant development

Anaemic schoolchildren have decreased motor activity, social

inattention, and decreased school performance1

Delayed maturation of auditory brain system responses in

6-month-old Chilean infants2

1. Grantham-McGregor S, et al. J Nutr. 2001;131:666S-668S.2. Roncagliolo M, et al. Am J Clin Nutr. 1998;68:683-690.

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Difference in results of developmental tests at 5 years of age between children with moderate iron deficiency anaemia in infancy and control group adjusted for a comprehensive set of background factors

With permission from Lozoff B, et al. N Engl J Med. 1991;325:687-694.

Effect of IDA in Infancy on Developmental Tests at 5 Years of Age

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Treatment of Iron Deficiency and Iron Deficiency Anaemia

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Treatment of IDADietary Measures 

• Iron-containing dietary sources– Heme: fish, poultry, meat – Non-heme: grains, fruits, vegetables, cereals, bread

• Iron from heme sources has a higher bioavailability (3x more) than that from non-heme sources but comprises a small portion of dietary iron in most diets

• Ascorbic acid, meat, orange juice, and fish enhance iron absorption of non-heme sources

• Calcium, phytates, cereals, milk, bran foods rich in phosphates, and tannates (teas) in food impair iron absorption to a variable degree

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Treatment of IDAIron Replacement Therapy

• Not always required and should be prescribed only if diagnosis is certain

• When indicated, treatment with a cost-effective oral iron preparation with minimal side effects will suffice

• The cheapest preparation is iron sulfate liquid/tablets• Iron dose: 3–6 mg/kg/d for infants and children and

60–120 mg/d for school-age children and adolescents → increase in haemoglobin of 0.25–0.4 g/dL/d or 1%/d rise in haematocrit

• Duration: 3–4 months after reversal of anaemia to replenish body iron stores

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Response to Iron

• 4–7 days: reticulocytosis

• 1–4 week: increase in haemoglobin level

• 1–4 months: repletion of iron stores

Failure of response after 2 weeks of oral iron requires re-evaluation for• Poor compliance with oral iron• Other acquired causes associated with gastrointestinal blood loss, such as celiac

disease, autoimmune atrophic gastritis, H. pylori, inflammatory bowel disease • Genetic anaemias

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Treatment of IDAParenteral Iron Therapy

• Indications– Poor tolerance to iron tablets (nausea, diarrhoea)– Poor iron absorption– Continued iron loss – Need for quick management (haemodynamic instability)

• Dose: 50–100 mg/d IV and only in hospital (risk of anaphylactic shock)

• Iron to be injected (mg) = (15-Hg/g%) x body weight(kg) x 3

• Use with caution (anaphylaxis and bioactive iron reactions)

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Treatment of IDA Blood Transfusion

• Rarely necessary even for severe IDA with haemoglobin concentrations of 4–5 gm/dL

• Should be reserved for patients in cardiorespiratory distress, lethargy, and very poor nutritional intake

• Needs to be given slowly to avoid heart failure

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IDA Diagnosticand Treatment Algorithm

Hg/Hct

Low Hgapparently

healthy child

Normal

ReassurefamilyTreat with oral iron and

repeat Hg in 2–4 wkCounsel parents

about diet

An ↑ in Hg ≥1g/dL after 2–4 wk of iron replacement confirms IDA

diagnosis

Failure of responseafter 2–4 wk of

iron replacement

Continue iron replacement for 3–4 mo

Reinforcedietary

counseling

Recheck Hg/Hctat end of

treatment and 6 mo later

Re-evaluate for poor compliance, inadequate iron dose, or other

causes

Do additional lab tests

Graphic courtesy of Dr. Adlette C. Inati.

Abbreviations: Hct, haematocrit; Hg, haemoglobin; IDA, iron deficiency anaemia.

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Benefits of Correcting Iron Deficiency and Iron Deficiency Anaemia in Early

Childhood Increase in haemoglobin concentration, related to

Baseline status Exposure to anaemia risk factors in addition to iron

deficiency (ie, malaria…)

Decrease in the number of upper respiratory tract infections in a controlled study in children age5–10 years in Sri Lanka

Controversial results on development; effect, if present, is modest

In most studies, no significant growth effect or limited to anaemic children

Martin S, et al. Cochrane Data Base of Systematic Reviews. 2001;2. Iannotti LL, et al. Am J Clin Nutr. 2006;84:1261-1276. Domellof M. Nestle Nutr Workshop Ser Ped Program. 2010;65:153-162. de Silva A, et al. Am J Clin Nutr. 2003;77:234-241.

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Risks of Correcting Iron Deficiency and Iron Deficiency Anaemia in Early Childhood

Adverse growth effect in iron-replete children

(inhibition of other growth-promoting nutrients?)

Increased risk for severe malaria infections in

children who are iron sufficient

Martin S, et al. Cochrane Data Base of Systematic Reviews 2001;2. Iannotti LL, et al. Am J Clin Nutr. 2006;84:1261-1276. Domellof M. Nestle Nutr Workshop Ser Ped Program 2010;65:153-162. de Silva A, et al. Am J Clin Nutr. 2003;77:234-241.

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Prevention and Screening

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Prevention

• The key to reducing the morbidity associated with iron deficiency includes prevention of iron deficiency and the identification and treatment of children who are iron deficient

• Primary prevention means ensuring an adequate intake of iron, which can meet an infant’s and child’s nutritional requirements for optimal growth and development

• Secondary prevention entails screening for, diagnosing, and treating iron deficiency anaemia

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Primary Prevention American Academy of Pediatrics (AAP)

Recommendations (2005) CDC Criteria for Anemia in Children

and Childbearing-Aged Women • Continuing breastfeeding for at least the first 4–6 months of life and

beyond

• Introducing iron-rich solid foods at around 6 months of age

• Iron supplementation before 6 months of age for preterm and low birth weight infants and infants with haematologic disorders and/or inadequate iron stores at birth

• Giving iron-fortified infant formula, and not cow's milk, for infants weaned before 12 months of age

• Encouraging adolescent girls to eat iron-rich foods and foods that enhance iron absorption

American Academy of Pediatrics. Pediatrics. 2005;115:496-506.Wall CR, et al. Arch Dis Child. 2005; 90:1033-1038.MMWR. 1993;47 (RR-3):1-29.

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Recommendations for Composition of Infant Formula

ESPGHAN Coordinated InternationalExpert Group (IEG)

• The IEG strongly recommends breastfeeding for infants• Proposed iron composition of infant formula

– 0.3–1.3 mg/100 Kcal (cow’s milk protein and protein hydrolysate-based formula)

– 0.45–2.0 mg/100 Kcal (soy protein isolate-based formula)

• After the age of 6 months – Introducing foods containing highly bioavailable iron

– Introducing fortified formula with iron content from 0.3 mg/100 Kcal to 1.3 mg/100 Kcal (for populations with a high risk of iron deficiency)

– Practicing caution with iron supplementation since regulation of iron absorption is immature before the age of 9 months

Koletzko B, et al. J Pediatr Gastroenterol Nutr. 2005;41:584-599.

50Dr. Adlette C. Inati. Unpublished data, 2010.Graphic courtesy of Dr. Adlette C. Inati.

Impact of Milk Formula and Iron Supplements on Prevalence of Iron Deficiency Anaemia

FF = iron fortified formulaNF+ = non-iron fortified formula + iron supplementNF- = non-iron fortified formula and no iron supplementsBF+ = breast milk plus iron supplementBF- = breast milk and no iron supplement

N = 3052

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Screening American Academy of

Pediatrics Recommendations (2005) • Screening haemoglobin or haematocrit between 9 and 12 months of

age then 6 months later, and, for patients at high risk, once a year from age 2–5 years

• Screening haemoglobin and/or haematocrit in infants age 6-12 months who are living in poverty, or who are black, Native American, or Alaska Native, immigrants from developing countries, preterm and low birth weight infants, and infants whose principal dietary intake is unfortified cow's milk

• Annual screening of menstruating girls and screening boys once during the peak growth period by measuring haemoglobin concentration or haematocrit

American Academy of Pediatrics. Pediatrics. 2005;115:496-506.

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Iron Deficiency and Iron Deficiency AnaemiaConclusions

• Causes of childhood ID and IDA are age- and gender-dependent

• Diet is a reasonable predictor of iron status in late infancy and early childhood

• Preventing rather than treating iron deficiency is a priority

• Primary healthcare providers can help prevent and control ID and IDA by counseling individuals and families about diet and iron, and by screening persons for ID risk and treating affected individuals

• Treatment of ID and IDA should not be undertaken until the actual etiologic diagnosis is ascertained

• Early initiation of iron replacement therapy will correct IDA but may not prevent its long-term systemic complications

• Further studies are needed to determine the effects of mild IDA on infant and child neurocognitive development

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