L7 Approach to anemia Edited v3.pptx.pdf

Approach to a Child
with Anemia
Selim Ahmed
Associate Professor of Pediatrics
FMHS, UMS.

Learning objectives
• Identify causes of anaemia in children
• Recognize the history and clinical feature of nutritional
anemia (iron deficiency anaemia and megaloblastic
anemia)
• Understand the basic genetics, pathophysiology, and
clinical presentations of Thalassemia
• Outline the history and clinical manifestations of
hereditary spherocytosis
• Recognize the history and clinical features of Glucose –
6 – phosphate dehydrogenase deficiency
• Define bone marrow failure syndromes

References
1. Nelson textbook of pediatrics, 21st
edition, 2020.
2. Nelson essentials of pediatrics; 8th edition, 2018
3. Illustrated textbook of pediatrics; 5th
edition, 2017
4. Current diagnosis and treatment pediatrics, 24th
edition,
2018
5. 5-minute pediatric consult; 6th
edition, 2015
6. AAP Textbook of Pediatrics, 2nd
Edition, 2017
7. Atlas of Pediatric Physical Diagnosis, 7th
Edition, 2018.
8. Robin’s pathologic basis of diseases, 10th
Edition, 2020
9. The Science of Paediatrics. MRCPCH Master Course, 2017.
10. Authentic web resources

Basics: Hematopoiesis
• In human, hematopoiesis begins in the yolk sac in the
first trimester, shifted to liver in second trimester, and
taken up by the bone marrow from third trimester
onward.
• Hematopoiesis is a complex process that begins with an
uncommitted, pluripotent hematopoietic stem cell that
progresses through a series of steps to development of
a single-lineage progenitor cell.
• Pluripotent stem cells are capable of self-renewal and
differentiation into different cell lineages. Progenitor
cells differentiate under the influence of specific
hematopoietic growth factors; e.g. erythropoietin for
erythropoiesis, granulocyte colony stimulating factors
and etc.

Figure 2
Pathophysiologic diagram of RBC production and maturation.
Problem at any stage may lead to altered production,
haemoglobin content or red cell survival leading to anemia.

Anemia: definition
• Anemia, technically, describes a condition in which
an individual’s hemoglobin level (or hematocrit) falls
two standard deviations below the average mean of
normal for individuals of same age, sex, and altitude.
• As a rough guideline, anemia should be considered:
-Neonate: Hb < 14 g/dL
-Infant: Hb <10 g/dL
-From 1 year to 12 years of age: Hb < 11 g/dL.
• The functional consequence of anemia is decreased
oxygen carrying capacity of the blood and general tissue
hypoxia.

Etiopathological classification of
anemia in children
1. Anemia due to decreased RBC production
2. Anemia due to excessive RBC destruction
(hemolytic anemias)
3. Anemia due to genetic disorders of hemoglobin
synthesis (hemoglobinopathies)
4. Anemia due to blood loss

Anemia caused by deficient
production of RBC
1. Nutritional anemia: The term ‘nutritional anemia’
is used to indicate iron deficiency anemia and
megaloblastic anemia
2. Anemia due to bone marrow disorders: leukemia,
aplastic anemia, myelodysplastic disorders
3. Anemia of chronic diseases (there is no iron
deficiency, but iron cannot be properly utilized in
presence of chronic illness and anemia results)

Anemia caused by excessive destruction
of RBC—hemolytic anemia
Hemolytic anemia can be either genetic (hereditary), or
acquired.
Genetic hemolytic anemia
1. Due to RBC membrane defect: Hereditary
spherocytosis (AD), hereditary elliptocytosis (AD),
2. Due to RBC enzyme defect: G6PD deficiency (XR)
Acquired hemolytic anemia
1. Immune hemolytic anemia (autoimmune hemolytic
anemia—warm antibody type, cold antibody type)
2. Drug-induced hemolytic anemia

Anemia due to genetic defect in hemoglobin
synthesis—hemoglobinopathies
1. Thalassemia syndromes (beta and alpha thalassemia);
2. Hemoglobin E (HbE) disease;
3. Thalassemia-HbE disease
4. Sickle cell disease (Hb S);
5. Hemoglobin S–beta-thalassemia disease
6. Hemoglobin C disease;
7. Hemoglobin S-C disease
All hemoglobinopathies are transmitted as AR disorders

Anemia due to blood loss
1. Conditions associated with small but chronic blood
loss from intestine:
a) Cow’s milk intolerance (microhemorrhage from
GIT)
b) Peptic Ulcer Disease
c) Meckel diverticulitis
d) Polyps in GI tract
e) Worm infestation (Hook worm)
2. Menorrhagia in adolescent girls

C/F of anemia
• Anemia may remain clinically silent until the
hemoglobin level falls below 8 g/dL. With continuing
falling, clinical pallor becomes evident and patients
start becoming symptomatic.
• Initial symptoms include reduced appetite, weakness,
irritability, poor growth, and shortness of breath on
exertion (play), which, if not intervened, may end up
with cardiac dilatation and congestive heart failure,
regardless of its etiology.
• Physical signs include tachycardia, tachypnea; other
signs depend on the type of anemia, e.g.,
hepatosplenomegaly in thalassemia, HS-megaly and
lymphadenopathy in leukemia, no organomegaly in
nutritional anemia and aplastic anemia.

Red cell indices
•MCV is the average volume (size) of a red cell. Normal
value: 80-95 fL (fL: Femtoliter = 10−15
L). This value is
related to normocytic, microcytic, or macrocytic RBC.
•MCH indicates the amount of hemoglobin in each each
red cell. Normal value: 27 to 33 picogram. This value is
related to normochromic or hypochromic RBC on
peripheral blood film
MCV and MCH are calculated from Hb, HCT %, and RBC
number.

Normocytic-normochromic vs
microcytic-hypochromic RBCs

Anisopoikilocytosis
•Anisocytosis refers to variation in the size of RBC
and poikilocytosis refers variation in the shape
(morphology) of RBC.
•Anisopoikilocytosis: varying size and shapes of RBC
on blood smear

‘Nutritional anemia’
•Average 200 billion RBCs are produced per day (10
billion white cells, and 400 billion platelets are
produced per day). Hence, adequate nutritional
supplies of iron, folate, and vitamin B12 are
essential for proper erythropoietic function.
•If any of these three components is inadequate,
erythropoiesis is adversely leading to ‘nutritional
anemia’

IRON DEFICIENCY ANEMIA—the commonest
nutritional anemia in children
• IDA is the commonest anemia in children across the globe.
• It is estimated that 30–50% of the global population (mostly
developing countries) has iron-deficiency anemia. In the United
States, 8–14% of children ages 1-3 yr are iron deficient , and 30%
of this group eventually progresses to iron-deficiency anemia.
Etiology of iron deficiency anemia
a. Inadequate intake—most common cause of iron deficiency. Risk
factors include prematurity, lack of breastfeeding, cow’s milk
feeding, improper complimentary feeding, and not eating
enough meat, liver, fish, eggs, or dairy products.
b. Deficient absorption from GIT (e.g. celiac disease)
c. Blood losses—from GIT, hookworm infestation, through menses

Iron transfer from mother to
fetus
•Maternal iron transfer mostly occurs close to term in
pregnancy. Hence, preterm/low-birth weight babies
have less iron transferred from mother and their iron
stores are smaller. Therefore, babies born
prematurely should be given therapeutic iron
supplementation starting from early neonatal period
and continued throughout infancy or beyond.
•Studies revealed that delayed (1-3 min) umbilical
cord clamping after delivery can improve iron store in
newborn babies.

Susceptible periods of iron
deficiency in children
When the body's iron demand exceeds that of it's supply, iron deficiency
becomes invariable
• Infants: Infancy is the fastest growing phase in human life. If the mother
has no iron deficiency, exclusive breastfeeding by a non iron-deficient
mother ensures sufficient iron for the first 6-9 mo of life. If adequate and
nutritionally balanced complementary feeding is started from six month of
life, there is no reason of iron deficiency from dietary sources in these
children. So, not breastfed and delayed introduction or inadequate
complimentary feeding puts the infants (highest physical growth demands
more RBC production) at high risk of iron deficiency.
• Toddlers: Children between 1—3 years who consume large amount of cow’s
milk, although may look ‘healthy’ are, in fact, likely to to develop iron
deficiency because bioavailability of iron in cow’s milk is low and there is
microscopic hemorrhage from GIT due to cow’s milk protein-induced colitis.
• Adolescents adolescent growth spurt is the final phase of human growth.
Poor quality diets put them in vulnerability for IDA. Globally, approximately
2% of adolescent girls have iron-deficiency anemia, largely as a result of
their adolescent growth spurt and menstrual blood loss

Effects of iron deficiency
•Growth and developmental delay
•Poor physical (motor) performance
•Poor cognitive (academic) performances
•Irritable, disruptive behaviors
•Poor attention span
•Immunodeficiency

Fact Sheet: Daily iron
requirement
• A full-term newborn infant contains about 0.5 g of iron, compared
to 5 g of iron in adults. To achieve the ‘adult store’ of iron, at least
1mg/kg/day elemental iron should be taken for 15 years. Because
<10% of dietary iron is usually absorbed, a dietary intake of 10 mg
of iron daily is necessary to maintain iron levels
• Iron is absorbed in the duodenum. Only <10% of dietary iron
usually is absorbed; The absorption is tightly controlled according
to the need to the body so that iron overload does not happen.
• Dietary iron is available in two forms: the haem (animal source)
and non-haem forms (plants and iron-fortified foods). For
absorption in the GIT, dietary iron must be in ferrous state. Animal
iron is already in ferrous state and is directly absorbed, whereas,
plant iron exists in ferric (Fe3+
) state which requires conversion to
the ferrous (Fe2
+) state for absorption. Hence, iron from animal
source (richest sources include meat, liver, fish, eggs, dairy
products) should be preferred in children’s diet.

Facts
•Apart from synthesis of Hb, iron is an essential
component of myoglobin—’the hemoglobin in the
muscles’.
•Myoglobin, being structurally similar to a subunit of
haemoglobin, carries and stores oxygen in muscle
cells. Hence, iron is necessary for overall physical
growth
•Iron also supports metabolism of healthy
connective tissues, cellular metabolism,
neurological development and synthesis of some
hormones

Iron metabolism
•After absorption from GIT, iron binds with
transferrin—a plasma protein synthesized by the
liver.
•All plasma iron is bound to transferrin and are
transported through the blood to various tissues,
especially bone marrow (the major stakeholder)
and the liver (the major storage organ).
•The transferrin-bound iron complex turnover rate is
about ten times a day, which is essential to meet
the daily demands of erythropoiesis
Ogun AS, Adeyinka A. Biochemistry, Transferrin. In: StatPearls [Internet]. Treasure Island (FL):
StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK532928/

Storage of iron—the ferritin
•In the bone marrow, iron is taken-up from the
iron-transferrin complex for the synthesis of Hb. The
excess, unused iron is stored in the form of ferritin
inside the hepatocytes.
•Most of the ferritin are within liver cells; only a small
amount of ferritin is found in the blood (measured in
ng/ml), which serves as an indicator of stored iron in
the body.
•Serum ferritin level is low in iron deficiency states, high
in iron overload states, e.g. thalassemia.

Hemosiderin
•If iron level continues to increase, ferritin molecules
are aggregated to from hemosiderin and stored in
the liver, heart, and other organs—a state known as
hemosiderosis.
•Insoluble hemosiderin molecules produce free
radicals that causes tissue damage through lipid
peroxidation (‘free radical injury’).
•This is the mechanism of organ damage in case of
thalassemia and other transfusion-dependent
conditions associated with iron overload.

Hepcidin
•Hepcidin is a peptide hormone synthesized by liver
cells. It is considered the master regulator of iron
homeostasis.
•In conditions of iron excess, as in thalassemia,
blood hepcidin level is high which reduces/blocks
intestinal iron absorption and macrophage iron
recycling, thereby trying to maintain iron
hemostasis.
•Alternatively, in conditions of iron deficiency, as in
IDA, the blood level of hepcidin is low favoring iron
absorption and recycling.

Stages of development of IDA: understanding
iron deficiency state and IDA
• Stage I (depletion of iron stores) as reflected by low ferritin level. [Note: Ferritin is
also an acute phase reactant which may show false elevation in presence of any
acute inflammation/infection. If CRP is also high, the elevation is due to
inflammation. Level should be repeated after resolving the condition].
• Stage II (deficient erythropoiesis) is characterized by gradual reduction in RBC
synthesis but hemoglobin levels are usually maintained within the normal range.
With the depletion of iron stores, the transferrin saturation is low and total iron
binding capacity is increased (discussed later). The soluble serum transferrin
receptor (sTfR) is increased because of upregulation
• Stage III (stage of IDA): From this stage, ‘iron deficiency state’ turns into
‘iron-deficiency anemia’ which is reflected by reduced Hb and decreased hematocrit
(proportion of RBC in blood) level. Biochemically, there is no stainable iron in the
bone marrow. Ratio of protoporphyrin to heme is increased because less iron is
incorporated into the protoporphyrin ring to form heme.
• Stage IV is characterized by clinical pallor which is best appreciated in the
conjunctivae, tongue or palmar creases. With further progress, other symptoms
(easy tiredness, growth failure, tachycardia, heart failure) appear over time.
Interestingly, pica is frequently seen in children with IDA

Pathophysiology of IDA
• Hemoglobin is composed of two moieties: heme and
globin. Heme is the oxygen carrying component of
hemoglobin which requires iron for its synthesis.
• Erythrocytes and their precursors require large amounts
of iron for the production of heme which is one of the
key component of hemoglobin structure and function.
• If there is iron deficiency, the newly produced red cells
will have decreased hemoglobin. Moreover, increased
numbers of erythrocytes are not produced in the
iron-deficient state; both the factors lead to the
development of IDA

L7 Approach to anemia Edited v3.pptx.pdf

Laboratory tests in IDA
▪ CBC with blood film: Low Hb, low RBC count, low reticulocyte
count, and low MCV & MCH (microcytic-hypochromic blood
picture). Platelets may be increased.
▪ Low level of serum ferritin
▪ Iron panel: Low serum iron, low plasma transferrin, increased
total iron binding capacity (TIBC) and low transferrin %
saturation
Best initial tests in IDA (for MCQ):
▪ CBC with film, RBC indices; Hematocrit level, Retic count, and
serum ferritin level.
▪ Best initial test for iron deficiency? S. ferritin level.
Note: Theoretically, bone marrow iron staining is the most
accurate method of diagnosing iron deficiency state, but is
invasive, expensive and never routinely done.

Red Cell Distribution Width
(RDW)
• RDW, aka Mentzer index, is important to differentiate
IDA from thalassemia minor
• RDW is a measurement of anisocytosis (variations in the
size of RBCs).
• It is calculated from MCV (in fL) divided by total RBC
count (×106
/L). This is known as Mentzer index
• Normal RDW/Mentzer index is 13 – 15%.
• A Mentzer index of >15% (i.e. high RDW) means
significant variation in RBC sizes which is typically seen
in IDA.
• In thalassemia, the Mentzer index is <13%--i.e. the RBC
sizes are not significantly variable.

Principles of treatment of IDA
•Therapeutic supplement with elemental iron (3-6 mg
elemental iron/kg/day) continued for at least 3-4
months to ensure adequate iron reserve.
•Dietary counselling: Improved diet containing good,
animal iron (specially red meat and liver), reduction
of cow’s milk consumption
•Correction of underlying cause (e.g. de-wormation,
blood loss, avoidance of excessive cow’s milk intake)

Elemental Iron
•Elemental iron is the amount of iron available for
absorption by your body.
•In medicinal iron, different preparation contains
different percentage of elemental iron. In general,
because of its higher solubility, ferrous iron in the
supplements is more bioavailable than ferric iron.
•Ferrous fumarate has 33% elemental iron by
weight, ferrous sulfate has 20% and ferrous
gluconate has 12% elemental iron by weight.
•Carbonyl iron has 100% elemental iron.

Responses to Iron Therapy in
Iron-Deficiency Anemia
Time after iron administration Response
12 – 24 hr -Subjective improvement; decreased
irritability; increased appetite (as a result of
replacement of intracellular iron enzymes);
-Increased serum iron (earlies lab parameter to
change)
36 – 48 hr Initial bone marrow response; erythroid hyperplasia
48 – 72 hr Reticulocytosis, peaking at 5-7 days
4 – 30 days Increase in hemoglobin level; increase in MCH;
increase in ferritin level
1 – 3 month Repletion of stores

Megaloblastic anemia: Etiology
• Megaloblastic anemia is basically a ‘hypovitaminosis’
anemia. Deficiency of folic acid or vitamin B12 is the
cause of megaloblastic anemia.
•Folate deficiency is much more common and develops
faster than than B12 deficiency because normally the
liver has a large reserve of vit B12 that can last for
years. On the other hand, hepatic reserve of folic acid is
limited and deficiency may develop within days of
absence of folic acid intake.
•Sometime, anti-folate drugs (e.g., methotrexate) can
also impair DNA synthesis and give rise to megaloblastic
anemia

Pathogenesis of megaloblastic
anemia
• Both folic acid and vit B12 act as coenzyme in DNA synthesis.
Deficiency of these vitamins cause impairment in DNA synthesis.
Without adequate DNA synthesis, the cell division is decreased and
a high fraction of these undivided cells undergo premature death
(via apoptosis) in the bone marrow—a phenomenon known as
‘ineffective erythropoiesis’. However, the surviving cells continue to
grow in size and become over-grown red cells (megaloblasts). When
they are released in blood, they are termed as macrocytes.
• However, as the RNA synthesis and hence protein synthesis is
unaffected, hemoglobin synthesis goes normally as well as
differentiation of the cytoplasmic organelles are relatively
unaffected, the surviving cells become enlarged (megaloblasts) with
adequate amount of hemoglobin. Although each megaloblast has
adequate hemoglobin content, anemia is produced because the
number of red blood cells are inadequate.
• Decreased DNA synthesis may affect the white cells and platelets in
the bone marrow eventually progressing to pan-cytopenia.

Megaloblastic anemia: Lab tests
• The peripheral blood smear shows macrocytic,
normochromic blood film and hyper-segmented
neutrophils (>5 lobes).
• Pancytopenia is usual because all blood cells in the
marrow—the RBC, WBC, and platelets are affected by
deficient DNA synthesis.
• A serum folate level <2 ng/mL is diagnostic for folate
deficiency and serum vitamin B12 level <200 pg/mL,
indicates vitamin B12 deficiency
• Methylmalonic acid (MMA) levels is elevated in vit B12
deficiency but not observed in folate deficiency.
• The homocysteine levels and LDH levels are elevated.

Megaloblastic anemia blood film
Large size RBC with characteristic hyper-segmented
neutrophil

Treatment
•Replacement of the deficient component—folic
acid or vitamin B 12.
•Ideally, folic acid and vitamin B12 levels should be
checked and treatment is targeted accordingly. This
is important because, if vitamin B12-deficient
megaloblastic anemia is treated by folic acid, the
neurological symptoms associated with vit B12
deficiency (subacute combined degeneration of the
cord) may deteriorate.
•However, practically, both folic acid and vitamin
B12 are given concomitantly.

Hemoglobinopathies:
understanding Hb synthesis
•Hb molecule has two components—heme and globin.
•Heme is synthesized by a porphyrin ring and a ferrous
(Fe2+) iron. Heme is responsible for binding with
oxygen. The genetic defect in assembling porphyrins
with iron gives rise to a rare group of genetic disorders,
known as hereditary porphyrias.
•Globin consists of two linked pairs of polypeptide
chains—α and non-α (β, γ, and δ) chains. The synthesis
of globin chain is genetically controlled. The genes
responsible for synthesis of α-globin chain is present
on chromosome 16 and that of β, γ, and δ are located
on chromosome 11.

Globin chain combination in different
hemoglobin
•Each Hb molecule consists of four heme prosthetic
group attached to four globin polypeptide chains
•The globin chain is arranged in pairs i.e. four globin
chain arranged as 2 α-globin chains and 2 non-
α-globin chains with the following configuration:
✔2 α-globin chains + 2 γ globin chain = HbF
✔2α globin chain + 2 β-globin chain = Hb A
✔2α globin chain + 2 δ-globin chain = Hb A2

Hemoglobin appears in Pro-E stage

Erythropoiesis
•Erythropoiesis refers to an orderly process of cell
division, differentiation, and maturation of the
erythrocytes—from multipotent hematopoietic
stem cell to mature red blood cell. It occurs mostly
in bone marrow and ends in blood stream.
•Hemoglobin appears at pro-E stage
•The average time taken for completion of
erythropoiesis is 20—25 days.
•Normal percentage of retics in blood: 0.5% to 2.5%

Pathophysiology of β thalassemia
• Impaired synthesis of globin chain due to genetic mutation is the
key pathophysiologic component of thalassemia—defect affecting
β globin chain synthesis results in β-thalassemia, and defect in α
globin chain synthesis gives rise to α-thalassemia.
β thalassemia
• Normally, amount of alpha and beta chains are equal in amount in
each red cell; this is necessary for normal function of Hb. In β
thalassemia, synthesis of β chain is deficient and a part of α chain
remains unpaired. This causes an imbalance between α chain and
the β chain, making a relative excess of α globin chain.
• The excess, unpaired alpha chains precipitate inside the RBC as
insoluble inclusions that hemolyze the RBC. Hence, the
developing RBCs are unable to complete their maturation in bone
marrow and succumb to premature death through intramedullary
apoptosis. In other words, the process of erythropoiesis becomes
ineffective—this phenomenon is known as ineffective
erythropoiesis, which is the key phenomenon in the pathogenesis
of beta thalassemia.

Clinical pathogenesis of β-thalassemia: From
Robbin pathology; 10 Edn.
• Unpaired α chains precipitate within red cell precursors in
bone marrow, forming insoluble inclusions. These
inclusions cause membrane damage and many red cell
precursors diminishing their survival and ultimately
undergo apoptosis. In severe β-thalassemia, it is estimated
that 70% to 85% of red cell precursors suffer this fate,
which leads to ineffective erythropoiesis.
• Some red cells can manage to escape destruction in the
marrow, but the inclusions the carry make them prone to
splenic sequestration and extravascular hemolysis.
• Even the fortunate RBCs who survived destruction have
less Hb than normal (Impaired β-globin synthesis results in
impaired HbA synthesis); these “under-hemoglobinized”
red cells have subnormal oxygen transport capacity.
Essentially, the patient remains persistently anemic

“Extramedullary hematopoiesis”
• Because of persistent anemia, body tissues signal to demand
adequate oxygen supply. This signal results in excessive secretion
of erythropoietin by the kidneys. The bone marrow responds
with its maximum effort to produce more RBCs. As a result,
massive erythroid hyperplasia occurs in the marrow and the
marrow cavity in all blood-forming bones expand. In effect, the
cortex of long bones become thin (which fractures easily) and
the flat bones in head and face region widen—this produces the
characteristic facial features seen in thalassemia and other
transfusion-dependent patients.
• When bone marrow maximizes its productive ability, other
organs who were once used to take part in blood formation in
intrauterine life, such as liver, spleen, are again called upon to
resume blood-forming function once again—this phenomenon is
called extramedullary hematopoiesis—hematopoiesis outside
bone marrow. [Contextually: Intrauterine hematopoiesis begins
in the yolk sac (until 12 wk), then in the liver (until 24 wk), and
then in the bone marrow for rest of life].

Other consequences
• The metabolically active erythroid progenitor cells steal nutrients
from other tissues that are already oxygen-starved, causing
severe growth failure in untreated patients.
• Another serious complication of ineffective erythropoiesis is
excessive absorption of dietary iron. Ineffective erythropoiesis
suppresses hepcidin, a critical negative regulator of iron
absorption. Increased absorption of iron from the gut due to low
hepcidin levels coupled with the iron load from repeated blood
transfusions inevitably lead to severe iron
accumulation—secondary hemochromatosis.
• As already mentioned, excessive irons in the body are deposited
as hemosiderin which are toxic to liver cells and other
tissues—notably the heart, endocrine glands, pancreas
• An irony is that thalassemia patients do not die of the disease,
rather die of the complications of ‘treatment’

Clinical presentations
•Usual age of presentation: 6-12 months, depending
on the extent of deficiency of beta globin chain
synthesis.
•Common presenting symptoms are pallor, lethargy,
failure to thrive and hepatosplenomegaly
•Severity of Beta thalassemias vary depending on
the extent of deficiency of globin chain synthesis.
For example, in β thalassemia major, β chain
synthesis is either absent (β0
), or variably reduced
(β+
)

Why does β thalassemia major
present in infancy?
• At birth, the Hb profile is: HbF 70%, HbA 30%, HbA2 <1%.
• After birth, synthesis of HbF stops and that of HbA gradually
increases so that by 6-12 months of age, HbF is almost
completely replaced by HbA giving rise to adult Hb pattern
of: HbA 95-98%; HbA2 <3.5%; HbF <1%.
• In thalassemia, because of the genetic defect in β globin
chain synthesis, HbA (α2-β2) can’t be synthesized so that
HbF (α2-γ2) continues to be synthesized.
• This is the reason why beta thalassemia major patients
usually presents around the age of 6-12 months and why
HbF is the predominant Hb in thalassemia major.
• Patients with beta thalassemia intermedia usually present
somewhat later—around 3-4 years of age.

Lab investigations for thalassemia
• FBC with peripheral blood film study: Anemia; marked
anisopoikilocytosis and microcytic-hypochromic blood film.
Target cells (so called because hemoglobin collects in the
center of the cell), basophilic stippling, and fragmented red
cells are common
• Iron profile (S ferritin-high, TIBC-low, total iron-high)
• Haemoglobin analysis, either by High-performance liquid
chromatography (HPLC) or by gel electrophoresis, is the
confirmatory test. Typical findings include: markedly
decreased or absent HbA; markedly increased HbF and
decreased or absent HbA2.
• Blood grouping, red cell phenotyping, and infection
screening (HIV, Hep B&C, VDRL) before first transfusion
• DNA analysis

Hb HPLC or gel electrophoresis reports in
different hemoglobinopathies
•In Beta thalassaemia major – only or mostly HbF
•In Beta thalassaemia trait –increased level of HbA2
;
rest are normal
•In Alpha thalassaemia trait – Hb HPLC is normal
•In sickle cell disease – HbS and no HbA
•In thalassemia-HbE disease – variable combination
of HbF and HbE

Pattern of Hb in normal subject
and in thalassemia
Courtesy: Sunflower Book; 5th
Edition

Importance of DNA analysis in
thalassemia
•The Hb pattern in beta-thalassemia varies
according to beta-thalassemia type. In β0
thalassemia (beta thalassemia major), HbA is
absent and HbF constitutes the only hemoglobin. In
β+
thalassemia and β+
/β0
thalassemia (thalassemia
intermedia), HbA levels vary between 10 and 30%
and HbF between 70-90%.
•Therefore, genetic analysis of β gene provides
important clinical guideline in terms of
management and counselling

How to identify thalassemia carrier
state
•Levels of Hb A2
(normal 1.5 – 3.5%) is helpful in
identifying thalassemia carrier state where both HbA
and HbF is normal, only HbA2
level is elevated
•In concomitant iron-deficiency anemia, the level of
HbA2
may be low (< 1.5%) in a thalassemia carrier
patient and is a source of wrong lab report. In such
case, blood iron profiles and Mentzer index are helpful.
Moreover, a therapeutic trial with oral iron is
recommended where iron treatment compensates for
iron deficiency and level of HbA2
will subsequently
become normalized.

Causes of microcytic
hypochromic anemia
•Iron deficiency anemia
•Thalassemia
•Lead poisoning
•Pyridoxin deficiency

Outline of management of thalassemia
(plus self-reading from peds protocol)
•Regular blood transfusion and iron chelation therapy
are the mainstay of treatment in transfusion
dependent thalassaemia
•Adjunct therapies (regular folic acid, dietary
restrictions, other supplements, etc)
•Hematopoietic Stem Cell Transfusion—only curative
option; but limited by availability of HLA-matched
suitable donor
•Genetic Counselling
•Monitoring and treatment of organ dysfunctions
from iron overload
•Monitoring of adverse effects of iron chelators

G6PD deficiency
•A X-linked recessive disorder.
•Generally, females are carrier and males are
affected (although females can be affected under
certain conditions)
•Like sickle cell anemia and thalassemia, global
distribution of this disorder also parallels that of
malaria. Both heterozygous females homozygous
males are resistant to falciparum malaria

Pathogenesis
•G6PD is an enzyme required for glucose metabolic
pathway (hexose monophosphate pathway) of RBCs.
This enzyme helps RBC membrane to withstand
oxidative stresses during infection, intake of certain
drugs (antimalarial, antibiotics, anthelminthic and
some other drugs) and certain foods (e.g. fava beans).
•In G-6-PD deficiency, this process becomes deficient
and RBC membrane becomes vulnerable to damage
when red cells are exposed to oxidant agents leading
to acute hemolysis.

Clinical Presentation
This disease may clinically manifest in the form of:
• Neonatal jaundice which may be severe enough
requiring exchange transfusion
• Beyond neonatal period, episodic acute hemolysis
following after exposure to a precipitating factor that
includes infection (commonest precipitating factor),
certain drugs [antimalarial, antibiotics (sulphonamide
including co-trimoxazole, quinolone (ciprofloxacin,
nalidixic acid), nitrofurantoin]; fava beans (broad beans
only, other types of beans do not cause haemolysis),
and naphthalene in mothballs

Clinical Presentation cont…
• Hemolysis occurs 24 to 72 hours after exposure to
oxidant stress
• During episode of hemolysis there are signs of acute
intravascular haemolysis (jaundice, pallor, and dark urine
due to hemoglobinuria and excess urobilinogen); there
may be fever, malaise, and right upper quadrant
abdominal pain and tenderness (due to
hyperbilirubinemia and cholelithiasis)
• There is abrupt fall of Hb level, as low as 5 mg/dL over
24 hours to 48 hours.
• In between episodes, almost all patients are absolutely
normal

Diagnosis, course and treatment
• The diagnosis is made by measuring G6PD activity in red
blood cells.
• Neonatal screening is universally available
• Hemolysis is transient and self-limiting; patients recover
completely in 1-2 weeks. Hemolytic episodes destroy aging
RBCs that have the lowest levels of G6PD; new RBCs
produced to compensate for anemia contain high levels of
G6PD. Moreover, young RBCs are not vulnerable to oxidative
damage and hence limit the duration of hemolysis.
• Blood transfusion is rarely required, even during acute
hemolysis
• The mainstay of treatment, therefore, is counselling. Provide
a list of drugs, chemicals, and food to avoid.

Hereditary Spherocytosis
• Mode of inheritance AD.
• Basic genetic defect is mutation in one of five genes that
encode RBC membrane proteins (mainly spectrin and
ankyrin) which are essential for maintaining normal
bi-concave shape of RBC.
• In absence of the structural membrane protein, RBCs
cytoskeleton become unstable with loss of erythrocyte
surface area which leads to the production of spherical
RBCs, the spherocytes, whose presence in the peripheral
blood film is the hallmark diagnostic findings.
• The spherocytes are culled rapidly from the circulation by
the spleen; hence hemolysis primarily is confined to the
spleen and that explains why splenomegaly is a cardinal
sign in HS and why splenectomy is the treatment of choice.

Clinical Presentation & Diagnosis
• HS is a heterogenous condition that may range from
asymptomatic condition to fulminant hemolytic anemia
• May present in newborn period in the form of neonatal
jaundice
• Beyond neonatal period, usual presentations include
variable degree of anemia and jaundice, splenomegaly
and gall stone (due to increased bilirubin excretion).
• Diagnosis is usually by blood film (spherocytes are
characteristics), increased MCHC (another characteristic
feature) and increased osmotic fragility

Treatment
• Most children have chronic mild haemolytic anaemia and only require
regular oral folic acid (they need more folic acid because of increased RBC
production) to avoid concomitant megaloblastic anemia
• Aplastic crisis from parvovirus B19 infection may occur in patients with HS
and may require one or two blood transfusions over the 3-week to 4-week
period when no red blood cells are produced.
• Splenectomy is the definitive treatment but is only indicated for adverse
health consequences from anemia, such as poor growth, severe tiredness,
loss of vigor. However, splenectomy is better to defer until after 7 years of
age because of the risks of post-splenectomy bacterial sepsis.
• Prior to splenectomy all patients should be have been vaccinated against
Haemophilus influenzae (Hib), meningitis C and Streptococcus pneumoniae.
After splenectomy, lifelong daily oral penicillin prophylaxis is required.
• Symptomatic cholelithiasis may require cholecystectomy

Marrow failure
•Intrinsic failure: Aplastic anemia
•Infiltration:
-Leukemias
-Lymphoma
-Myeloproliferative disorders

Bone marrow failure syndrome in children:
Pure red cell aplasia
There are three main causes of pure red cell aplasia in children:
1) Congenital red cell aplasia (‘Diamond–Blackfan anaemia’) aka Congenital
Hypoplastic Anemia: AD inheritance (80% de novo mutation); Most cases
present between birth to 1 year, usually by 2 to 3 months of age, with
macrocytic anemia with reticulocytopenia with or without other congenital
anomalies, such as short stature or abnormal thumbs. Treatment options
include oral steroids; monthly red blood cell transfusions if steroid
unresponsive; yet some may need stem cell transplantation.
2) Transient erythroblastopenia of childhood (TEC), thought to be a transient
autoimmune disorder, usually follows a viral infection. It is usually seen in
children 6 months to 4 years and is is a relatively common cause of acquired
anemia in early childhood. The anemia develops slowly and is well-tolerated;
children with hemoglobin levels as low as 4–5 g/dL may definitely look pale, but
otherwise remarkably well. It always recovers fully within weeks.
3) Parvovirus B19 infection: this infection only causes red cell aplasia in children
with inherited haemolytic anemias and not in healthy children.
The diagnostic clues to red cell aplasia include i) low Hb and low retic count; ii)
absence of hemolytic features (normal bilirubin, negative Coombs test); and iii)
absent red cell precursors on bone marrow examination.

Aplastic anemia
• It is associated with pancytopenia due to
Immunosuppression of hematopoiesis where
hematopoietic elements of the bone marrow are
replaced by fat.
• It is mostly idiopathic, but can be secondary to drugs,
such as chloramphenicol and felbamate (an
anticonvulsant) or by toxins such as benzene
• Presentation includes features of
pancytopenia—anemia, recurrent fever (sign of
infection), and thrombocytopenic bleeding.
• Diagnosis requires bone marrow biopsy
• Treatment is supportive (transfusion, antibiotic); HSCT
is the definitive treatment.

Anemia workout flow diagram 1
Courtesy: Sunflower Book, 5th
Edn

Anemia workout flow diagram 2.
Courtesy: The Royal Children Hospital Melbourne

L7 Approach to anemia Edited v3.pptx.pdf

More Related Content

Similar to L7 Approach to anemia Edited v3.pptx.pdf (20)

Recently uploaded (20)

L7 Approach to anemia Edited v3.pptx.pdf