PANCE Blueprint Hematology (5%)

Iron deficiency (Lecture)

Patient will present a → a 30-year-old obese white female presents with fatigue and generalized weakness for several weeks. Physical exam reveals pale nail beds, spoon nails, mucosal pallor and an atrophic tongue. Upon further questioning, the patient reveals a "craving for ice and inanimate objects." Laboratory data shows a microcytic, hypochromic appearance to the RBCs, an elevated TIBC, low serum iron of 16 µg/dl, and a low plasma ferritin of 12 µg/dl.

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What is the earliest finding in iron deficiency anemia?
Low serum ferritin (stores are low)
What is the latent finding in iron deficiency anemia?
Change in the indices – microcytic/hypochromic changes in the RBC

↓ MCV (microcytic), ↑ TIBC, ↓ Ferritin (low iron stores) ↓ MCH (hypochromic)

Iron deficiency is the most common cause of anemia and usually results from blood loss

  • In men, the most frequent cause is chronic occult bleeding, usually from the GI tract.
  • In premenopausal women, menstrual blood loss is a common cause
  • Another possible cause of blood loss in men and women is chronic intravascular hemolysis
  • Fatigue with exercise, palpitations, shortness of breath, weakness, headaches, and tinnitus
  • Tachycardia, tachypnea on exertion, pallor, glossitis, angular cheilitis, pica, koilonychia, jaundice, and splenomegaly

RBCs tend to be microcytic and hypochromic, and iron stores are low as shown by low serum ferritin and low serum iron levels with high serum total iron binding capacity

"Lead poisoning is a common question on the PANCE/PANRE look for Basophilic stippling and remember treatment is with EDTA."

Other causes of ↓ MCV include lead poisoning (look for this in a patient with neurological symptoms), sideroblastic anemia, basophilic stippling, and thalassemia. Treatment is with EDTA.

CBC

  • Reticulocyte count: low
  • RDW: high

Iron Studies

  • Decreased serum iron, ferritin, and transferrin saturation
  • Increased TIBC
  • Ferritin <15 ng/mL (diagnostic)

Check hemoglobin and Hematocrit

  • Check at 12 and 18 mo, 12 y (females)
  • Hgb/Hct <2× standard deviation of normal
  • Hgb <13.5 g/dL or → Hct <39% (men)
  • Hgb <12 g/dL or Hct <37% (women)

Peripheral smear: poikilocytes (pencil or cigar-shaped cells)

  • Rarely bone marrow examination
  • Hemoccult if indicated

  • Ferrous sulfate 3 mg/kg once or twice daily (20% elemental iron) – Give between meals with juice (not milk)
  • Ferrous fumarate (33% elemental iron) 100-200 mg/day in 2-3 doses
  • Ferrous gluconate (12% elemental iron) 3-6 mg/kg/day in 3 doses

Side Effects

  • Liquid preparations—gray staining of teeth or gums
  • Brush teeth or rinse with water after administration
  • GI upset (ferrous gluconate better tolerated)

Pearls

  • Six weeks to correct anemia
  • Six months to replete iron stores
  • Recheck blood counts every 3 months x 1 year

Iron can be provided by various iron salts (eg, ferrous sulfate, gluconate, fumarate) or saccharated iron PO 30 min before meals (food or antacids may reduce absorption)

  • A typical initial dose is 60 mg of elemental iron (eg, as 325 mg of ferrous sulfate) given once/day or bid
  • Larger doses are largely unabsorbed but increase adverse effects especially
  • Ascorbic acid either as a pill (500 mg) or as orange juice, when taken with iron, enhances iron absorption without increasing gastric distress
  • The response to treatment is assessed by serial Hb measurements until normal RBC values are achieved
  • Hgb rises little for 2 weeks but then rises 0.7 to 1 g/wk until near normal, at which time rate of increase tapers
  • Anemia should be corrected within 2 mo
  • Increasing reticulocyte count is an indication that iron is working
  • A subnormal response suggests continued hemorrhage, underlying infection or cancer, insufficient iron intake, or, very rarely, malabsorption of oral iron

IM_PHM_IronDeficiencyAnemia_v1.5_ Iron deficiency anemia accounts for more than half of anemia cases worldwide. It is typically caused by malnutrition (decreased ingestion of meat, eggs, iron-fortified foods and leafy greens), as well as malabsorption (IBD, parasitism, celiac disease). Hemorrhage is another reason for this type of anemia, which may be caused by heavy menstruation, parasitism, malignancy or ulceration. This is a microcytic, hypochromic anemia which is caused by decreased heme synthesis. Labs typically show decreased reticulocytes, and decreased ferritin, which is an iron-storing protein. There is also an increased red cell distribution width, which helps distinguish iron deficiency anemia from thalassemia.

Iron Deficiency Anemia Picmonic

IM_MED_MicrocyticAnemiaCauses_V1.7_ASSETS Microcytic anemia is defined as an anemic state with a red blood cell MCV < 80 fL and is caused by a decrease in hemoglobin synthesis. Hemoglobin is composed of both heme, which contains iron and protoporphyrin, and globin chains, so anything that affects the synthesis of these precursors can cause a microcytic anemia. The most commonly tested causes of microcytic anemia include late-stage iron deficiency, anemia of chronic disease, thalassemias, lead poisoning, and sideroblastic anemia.

Microcytic Anemia Causes Picmonic

Question 1
A 35 year-old female presents with fatigue. CBC results reveal the following: WBC: 6,300/microliter Hgb: 9.5 g/dl Hct: 28% MCV: 75 fL MCHC: 32 g/dl MCH: 24 pg Platelets: 550,000/mL Which of the following is the best treatment option for this patient?
A
folic acid
Hint:
Vitamin B12 and folate deficiency present with macrocytic cells and are treated with vitamin B12 and folate respectively.
B
vitamin B12
Hint:
See A for explanation.
C
prednisone
Hint:
Prednisone is used to treat immune-mediated hemolytic anemias which present with normocytic, normochromic red blood cells.
D
ferrous sulfate
Question 1 Explanation: 
Iron deficiency anemia is a microcytic, hypochromic anemia and is treated with ferrous sulfate.
Question 2
A mean corpuscular volume (MCV) of less than 80 cubic microns is a manifestation of which of the following diagnoses?
A
Iron deficiency
B
Vitamin B12 deficiency
Hint:
Vitamin B12 deficiency is associated with macrocytic anemia.
C
Folate deficiency
Hint:
Folate deficiency is associated with macrocytic anemia.
D
G6PD deficiency
Hint:
G6PD deficiency is not associated with a low MCV.
Question 2 Explanation: 
Iron deficiency is associated with microcytic anemia.
Question 3
A 46 year old man presented with symptoms of anemia. Hb and MCV done were 9g/dl and 72 FL respectively. Which of the following is not a likely cause of his anemia?
A
Iron deficiency
Hint:
causes of microcytic anemia.
B
Anemia of chronic disease
Hint:
causes of microcytic anemia.
C
Sideroblastic anemia
Hint:
causes of microcytic anemia.
D
Folate deficiency
Question 3 Explanation: 
Folate deficiency is a cause of megaloblastic anemia. The patient presented has microcytic anemia.
Question 4
Causes of iron deficiency anemia do not include
A
Chronic gastrointestinal blood loss
Hint:
The most important cause of iron deficiency anemia in adults is chronic blood loss, especially gastrointestinal blood loss.
B
Celiac disease
Hint:
Celiac disease is an occult cause of iron deficiency through poor absorption in the gastrointestinal tract.
C
Excessive vomiting
D
Zinc deficiency
Hint:
Zinc deficiency is causes of poor iron absorption
Question 4 Explanation: 
Excessive vomiting cannot lead to iron deficiency but rather dehydration and electrolyte derangement.
Question 5
The result of a patient’s iron studies showed: reduced serum iron, reduced serum ferritin, absent iron in bone marrow. What is the patient’s most likely diagnosis?
A
Anemia of chronic disease
Hint:
reduced serum iron, normal or raised serum ferritin, Iron present in bone marrow.
B
Iron deficiency anemia
C
Sideroblastic anemia
Hint:
raised serum iron, raised serum ferritin, Iron present in bone marrow.
D
Thalassemia trait
Hint:
normal serum iron, normal serum ferritin, Iron present in bone marrow.
Question 5 Explanation: 
Iron studies of a patient Iron deficiency anemia: reduced serum iron, reduced serum ferritin, absent Iron in bone marrow.
Question 6
The most useful test to initially monitor the response of a patient with iron deficiency anemia to iron therapy is
A
Ferritin level
B
Reticulocyte count
C
Haptoglobin level
D
Transferrin level
Question 6 Explanation: 
Reticulocyte response to iron therapy is usually evident within a week. The other options, while reasonable, will have a slower response to therapy.
Question 7
Which of the following statements about iron deficiency anemia is incorrect?
A
Can present as pica, koilonychia, cheilosis, and dysphagia.
Hint:
See B for explanation
B
The reticulocyte count may be high.
C
Is treated with ferrous sulfate.
Hint:
See B for explanation
D
Can be caused by zinc deficiency.
Hint:
See B for explanation
Question 7 Explanation: 
Reticulocyte count in iron deficiency anemia is usually low or inappropriately normal.
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G6PD deficiency (Prev Lesson)
(Next Lesson) Vitamin B12 deficiency (Lecture)
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