Objectives
 Be able to classify the different types of anemia
 Understand the signs and symptoms associated with
anemia.
 Being able to interpret lab abnormalities to diagnose
different causes of anemia.
Introduction to Anemia
 Anemia is a pathologic state resulting from insufficient
RBCs to carry oxygen to peripheral tissues due to
 1) Blood loss
 2) Underproduction of erythrocytes
 3) Destruction of erythrocytes (hemolysis)
 Spectrum of symptoms – Asymptomatic to
tachycardia, DoE, nail and conjunctival pallor, fatigue.
 Normal Hgb in males ranges from 14-17 g/dL and
females ranges from 12-16 g/dL.
RBC Morphologies
 Microcytosis
Iron Deficiency Anemia
 Spherocytes
Hereditary Spherocytosis, AIHA
 Macrocytes
Vitamin B12, Folate Deficiency
 Target Cells
Liver disease, Splenectomy
 Schistocytes
DIC, TTP, HUS, Microangiopathy
 Teardrop cells
Fibrosis, Marrow infiltration
 Bite Cells
G6PD Deficiency
Approach to Anemia
 Review Hgb/Hct levels to determine anemia
 Check MCV to classify micro-, normo- or macrocytic
 Calculate Reticulocyte index
 Think about the PATIENT and their RISK FACTORS
 Obtain workup laboratory studies
MCV – Average volume of RBCs
 Microcytic Anemia (MCV less than 80)
 Iron deficiency anemia, Lead poisoning, Thalassemias, Anemia of chronic
disease, Sideroblastic anemia
 Normocytic Anemia (MCV between 80-100)
 Anemia of chronic disease, Decreased EPO production from ESRD/CKD,
Hemolytic anemias, RBC membrane disorders, Enzymopathies,
Hemoglobinopathies, Drug induced, Autoimmune disease
 Macrocytic Anemia (MCV greater than 100)
 Vitamin B12, Folate Deficiency, Cirrhosis, Drug induced
Reticulocyte count
 Indication of erythrocyte production. Patients with normal bone marrow who
have lost blood or have hemolysis have increased reticulocyte counts, whereas
those with underproduction have low reticulocyte counts.
 Reticulocyte INDEX = Reticulocyte % x (Hct / 45) x 0.5
Identify Risk Factors for the Patient
 Understanding PMH and PSH for the patient may help
guide anemia workup.
 For example, patients with gastric bypass may have
vitamin deficiencies such as iron AND/OR Vitamin B12
and Folate deficiencies as they lack absorption.
MICROCYTIC Anemia
 Most common cause is iron deficiency anemia with the definitive test being
serum ferritin. Low ferritin is diagnostic of a depleted iron state
Iron
Deficiency
Anemia of
Chronic Disease
Thalassemia
Trait
Sideroblastic
Anemia
Degree
of
Anemia
Any
Seldom < 90g/L
Mild
Any
MCV
↓
N or ↓
↓↓
N, ↓ or ↑
Ferritin
DECREASED
N or ↑
Normal
↑
TIBC
↑
↓
Normal
Normal
Serum
Iron
↓
↓
Normal
↑
Marrow
Iron
Absent
Present
Present
Present
Management of Iron Deficiency Anemia
 Treat the underlying cause! Evaluate for GI bleed,
menstrual bleeding, etc.
 Iron therapy is usually given orally as it is inexpensive and
effective. Don’t forget common causes of non-compliance
including GI side effects, N/V, malabsorptive states such as
celiac disease, Whipple, bacterial overgrowth.
 Treatment with Ferrous Sulfate 325mg PO TID, may be qday depending on
severity of anemia
 Parenteral iron therapy may be given to patients who have malabsorption,
inflammatory bowel disease, anemia that is unresponsive to oral therapy
and need a quick recovery from anemia
Generally,
patients with
Thalassemias
have a lower
MCV less than
80. Think
about genetic
diseases in
patients who
have anemia
with very low
MCV!
Figure 1. Management of Thalassemias.
The anemia that is associated with
thalassemias may be severe and is
accompanied by ineffective erythropoisis
in the liver, spleen and other sites, such
as paravertebral masses. Transfusion
therapy, which is the mainstay of
treatment, allowed for normal growth and
development and suppresses ineffective
erythropoiesis. Transfusion transmitted
infections (hepatitis B and C) are an
important cause of death in countries
where proper testing is not available. Iron
overload results from both transfusional
hemosiderosis and excess GI iron
absorption. Iron deposition in the heart,
liver and multiple endocrine glands
results in severe damage to these
organs, with variable endocrine organ
failure. The endocrinopathies can be
treated with hormone replacement.
Howevere, the most serious result of iron
overload is life-threatening cardiotoxicity,
for which chelation therapy is required.
Thalassemia can be cured by bone
marrow transplantation. Experimental
therapies to ameliorate the anemia that
have been or are currently under
investigation include fetal hemoglobin
modifiers and antioxidants. In the future,
gene therapy or other molecular methods
may be feasible.
MACROCYTIC Anemia
 1) Always evaluate for substances or medications that
may cause macrocytosis.
 2) Check Vitamin B12 and Folate levels (don’t forget
that both of these vitamin deficiencies may lead to
leukopenia, thrombocytopenia OR pancytopenia)
 Vitamin B12 deficiency leads to elevated MMA
 Don’t forget that medications such as Metformin can be
a cause of Vitamin B12 deficiency and a clinician should
check B12 levels before starting this medication.
 3) Evaluate for bone marrow disease
Treatment of Macrocytic Anemia
 Folate deficiency is treatment with folic acid (1-5
mg/day orally) for 1-4 months or until hematologic
recovery occurs.
 Vitamin B12 deficiency may be treated with high
dose oral cobalamin 1-2 mg/day. Parenteral
Vitamin B12 may be used for patients who have
pernicious anemia and is a dosage of 1000mcg
daily for 1 week, followed by 1mg weekly for 4
weeks. Then, if the disorder persists, 1mg monthly
for the remainder of the patients life.
Normocytic Anemia
 1) Rule out treatable causes
 Iron, Vitamin B12 and Folate deficiencies may present with normocytic anemia
 2) Evaluate for systemic diseases
 Endocrine diseases such as thyroid, adrenal, or pituitary insufficiencies may lead to
normocytic anemia due to decreased stimulation of the bone marrow by EPO.
 Anemia of chronic disease is immune driven in which cytokines released by the
inflammatory/chronic disease state induce changes in iron homeostasis, erythroid
progenitor response to EPO, EPO production, etc.
 3) Evaluate for hemolysis
 ↑Reticulocyte count, ↑Indirect Bilirubin, ↑Lactate Dehydrogenase, ↓Haptoglobin
 Think about DIC, TTP/HUS.
 4) Think about bone marrow diseases
Question 1
A 77-year-old man is evaluated for a 1-year history of extreme fatigue and
shortness of breath on exertion and an 8-week history of substernal chest
pain with exertion.
On physical examination, temperature is 36.7 °C (98.0 °F), blood pressure
is 137/78 mm Hg, pulse rate is 118/min, and respiration rate is 17/min. BMI
is 27. The patient has pale conjunctivae. Cardiopulmonary examination
reveals a summation gallop, with crackles at the lung bases.
Laboratory studies:
Hemoglobin 5.4 g/dL (54 g/L)
Leukocyte count 6400/µL (6.4 × 109/L)
Mean corpuscular volume 58 fL
Platelet count 154,000/µL (154 × 109/L)
Red cell distribution width 25 (Normal range: 14.6-16.5)
Peripheral Smear
Question 1
An echocardiogram is normal
Which of the following is the most likely diagnosis?
A. Glucose-6-phosphate dehydrogenase deficiency
B. Iron deficiency
C. Myelofibrosis
D. Thrombotic thrombocytopenic purpura
Question 1 Explanation
Educational Objective
Diagnose iron deficiency in a patient with anisopoikilocytosis.
The most likely diagnosis is iron deficiency. This patient's peripheral smear is remarkable for variations in
erythrocyte size and shape (anisopoikilocytosis) and increased central pallor. Patients with mild iron
deficiency may report fatigue, irritability, decreased exercise tolerance, and headaches before they
become anemic. This patient's clinical manifestations, including extreme fatigue, dyspnea on exertion,
and chest pain, are symptoms of decreased oxygen-carrying capacity of the blood. The peripheral blood
smear findings and complete blood count showing extreme anisopoikilocytosis and microcytosis are
consistent with iron deficiency. Thrombocytosis is noted frequently in patients with iron deficiency.
In patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency, blister (or “bite”) cells, which
are characterized by eccentrically located hemoglobin confined to one side of the cell, are present on the
peripheral blood smear. In contrast to iron deficiency, the mean corpuscular volume is often normal or
slightly increased in G6PD deficiency because of the reticulocytosis occurring in patients with G6PDmediated hemolysis.
Patients with myelofibrosis typically have signs and symptoms of anemia plus night sweats and weight
loss and exhibit a leukoerythroblastic picture, including nucleated erythrocytes and a left shift in the
leukocyte lineage. Additionally, myelofibrosis is typically associated with teardrop cells and
megathrombocytes, which are not present on this patient's peripheral blood smear.
Patients with thrombotic thrombocytopenic purpura (TTP) have fragmented erythrocytes (schistocytes)
and low platelet counts, two features not found in this patient. In addition, patients with TTP typically
have one or two additional findings, including acute kidney injury, mental status changes, and
ecchymosis.
Question 2
A 22-year-old woman undergoes a new patient evaluation. She was recently
diagnosed with systemic lupus erythematosus manifesting as painful joints, malar
photosensitive rash, oral aphthous ulcers, and a positive antinuclear antibody and
anti-Smith antibody titer. Her menstrual pattern is normal, and her medical
history is otherwise noncontributory. Her only medications are
hydroxychloroquine and a multivitamin.
On physical examination, temperature is 37.2 °C (99.0 °F), blood pressure is
126/78 mm Hg, pulse rate is 88/min, and respiration rate is 17/min. BMI is 20. The
patient has a malar rash and thinning hair, but no joint abnormalities, oral
lesions, pericardial or pleural rubs, or heart murmurs.
Laboratory studies:
Hemoglobin 8.2 g/dL (82 g/L)
Leukocyte count 3900/µL (3.9 × 109/L)
Ferritin 556 ng/mL (556 µg/L)
Iron 18 µg/dL (3.2 µmol/L)
Reticulocyte count 2%
Total iron-binding capacity 180 µg/dL (32 µmol/L)
Transferrin saturation 10%
Creatinine 1.0 mg/dL (88.4 µmol/L)
Peripheral Smear
Question 2
Which of the following is the most likely diagnosis?
A. Inflammatory anemia
B. Iron deficiency
C. Microangiopathic hemolytic anemia
D. Warm antibody-associated hemolysis
Question 2 Explanation
Educational Objective
Diagnose inflammatory anemia in a patient with systemic lupus erythematosus.
The patient has inflammatory anemia. Inflammatory anemia typically results in
mild to moderate anemia, with a hemoglobin level usually greater than 8 g/dL (80
g/L). This type of anemia is initially normocytic and normochromic but can
become hypochromic and microcytic over time. The reticulocyte count is typically
low in inflammatory anemia. Inflammatory anemia is the result of elevated
hepcidin levels that develop in response to inflammatory cytokines, including
interleukin-1, interleukin-6, and interferon. Hepcidin decreases iron absorption
from the gut and the release of iron from macrophages by causing internalization
and proteolysis of the membrane iron pore, ferroportin. Patients with
inflammatory anemia typically have normal or low serum iron levels. The
peripheral blood smear may be normal or may show microcytic hypochromic
erythrocytes as in iron deficiency; however, compared with patients with iron
deficiency, patients with inflammatory anemia have a low total iron-binding
capacity and elevated serum ferritin level. Inflammatory anemia usually does not
require specific therapy. Importantly, iron replacement is not necessary in
inflammatory anemia and will not lead to improvement in erythropoiesis.
Treating the underlying inflammatory disorder in patients with inflammatory
anemia can improve the anemia itself. Chronic infections such as tuberculosis or
osteomyelitis, malignancies, and collagen vascular diseases are associated with
inflammatory anemia. This patient has systemic lupus erythematosus (SLE).
Although microangiopathic hemolytic anemia and warm antibody-mediated
hemolysis can occur in the setting of SLE, the peripheral blood smear in these
conditions would show schistocytes and microspherocytes, respectively.
Question 3
A 17-year-old woman undergoes follow-up evaluation for
microcytic anemia that was identified on a routine complete blood
count 3 weeks ago. She is otherwise healthy. Medical and family
histories are noncontributory. Her only medication is an oral
contraceptive pill.
On physical examination, temperature is normal, blood pressure is
117/78 mm Hg, pulse rate is 88/min, and respiration rate is 17/min.
BMI is 19. She has conjunctival pallor. The remainder of the
physical examination is normal.
Laboratory studies:
Erythrocyte count 5.45 × 106/µL (5.45 × 1012/L)
Hemoglobin 11.6 g/dL (116 g/L)
Mean corpuscular volume 60 fL
Leukocyte count 5400/µL (5.4 × 109/L)
Platelet count 213,000/µL (213 × 109/L)
Red cell distribution width 15 (Normal range: 14.6-16.5)
Reticulocyte count 2.3%
Question 3
Which of the following is the most likely diagnosis?
A. Hereditary spherocytosis
B. Iron deficiency
C. Sideroblastic anemia
D. β-Thalassemia trait
Question 3 Explanation
Educational Objective
Diagnose β-thalassemia trait using erythrocyte count.
The most likely diagnosis is β-thalassemia trait. β-Thalassemia is caused by various
abnormalities in the β-gene complex. Decreased β-chain synthesis leads to impaired
production of hemoglobin A (α2β2) and resultant increased synthesis of hemoglobin
A2 (α2δ2) or hemoglobin F (α2γ2). Patients with mildly decreased expression of a single β
gene have β-thalassemia trait (β+) and present with mild anemia, microcytosis,
hypochromia, and target cells. Microcytic anemia associated with a normal or slightly
increased erythrocyte count is characteristic of β-thalassemia. The Mentzer index is a ratio
of the mean corpuscular volume (MCV) in fluid liters divided by the erythrocyte count.
Values less than 13 are associated with β-thalassemia.
Hereditary spherocytosis is characterized by a normal to increased MCV depending on the
degree of erythrocytosis and erythrocytes on peripheral blood smear that lack the normal
central pallor.
Patients with iron deficiency may note fatigue, lack of sense of well-being, irritability,
decreased exercise tolerance, and headaches, which may appear before symptoms of overt
anemia occur. They also typically have reduced erythrocyte counts and microcytic cells,
leading to an index greater than 13. These findings are not consistent with those in this
patient.
Sideroblastic anemia is characterized by a decreased erythrocyte count caused by ineffective
erythropoiesis and hypochromic normocytic or macrocytic erythrocytes with basophilic
stippling that stain positive for iron. This is not consistent with this patient's normal (or
increased) erythrocyte count.
Question 4
A 35-year-old woman is evaluated for mild fatigue with exertion, which
has remained unchanged for years. She is the mother of three children
and works full time. Her sister was evaluated for anemia. Her mother is
also anemic.
On physical examination, the vital signs and physical examination are
normal.
Laboratory studies:
Hemoglobin 11.3 g/dL (113 g/L)
Leukocyte count 5300/µL (5.3 × 109/L) with a normal differential
Mean corpuscular volume 74 fL
Platelet count 179,000/µL (179 × 109/L)
Reticulocyte count 2.9%
Iron 58 µg/dL (10.3 µmol/L)
Total iron-binding capacity 245 µg/dL (43.6 µmol/L)
Transferrin saturation 24%
Ferritin 58 ng/mL (58 µg/L)
Results of hemoglobin electrophoresis are normal.
Peripheral Smear
Question 4
Which of the following is the most likely diagnosis?
A. α-Thalassemia trait
B. β-Thalassemia minor
C. Iron deficiency
D. Sickle/β+ thalassemia (Hb Sβ+)
Question 4 Explanation
Educational Objective
Diagnose α-thalassemia trait.
The most likely diagnosis is α-thalassemia trait. Decreased or absent synthesis of normal α or β chains
resulting from genetic defects is the hallmark of the thalassemic syndromes. The result is ineffective
erythropoiesis, intravascular hemolysis caused by precipitation of the excess insoluble globin chain, and
decreased hemoglobin production. α-Thalassemia trait (-α/-α or --/αα) is associated with mild anemia,
microcytosis, hypochromia, target cells on the peripheral smear, and, in adults, normal hemoglobin
electrophoresis results. The (-α/-α) variant is found in 2% to 3% of blacks and is often mistaken for iron
deficiency. This patient's peripheral blood smear demonstrating target cells makes a thalassemic
syndrome the most likely diagnosis, and the normal hemoglobin electrophoresis results are suggestive of
α-thalassemia trait. α-Thalassemia can be more definitively diagnosed by globin gene synthesis studies
but is more often suggested by chronic microcytic anemia, target cells, normal iron studies, and normal
hemoglobin electrophoresis results. No treatment is necessary for α-thalassemia trait.
The clinical presentation and peripheral blood smear findings of β-thalassemia minor may be similar to
those of α-thalassemia trait, but the hemoglobin electrophoresis results usually show an elevated Hb
A2 (α2δ2) band.
The peripheral blood smear in patients with iron deficiency is remarkable for microcytic, hypochromic
erythrocytes, with marked anisopoikilocytosis (that is, abnormalities in erythrocyte size and shape). The
serum iron concentration is usually low in patients with iron deficiency; the total iron-binding capacity
(TIBC) is high; the percentage of transferrin saturation (iron/TIBC) is low; and the serum ferritin
concentration is low. This patient's iron studies are not consistent with iron deficiency.
Patients with sickle/β+ thalassemia (Hb Sβ+) usually have symptoms typical for sickle cell disease and
abnormal hemoglobin electrophoresis results showing Hb S, Hb A, and an elevated Hb A2band.
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