Disorders of Iron Kinetics and Heme Metabolism

Question 1

1. The mother of a 4-month-old infant who is being breastfed
   sees her physician for a routine postpartum visit. She expresses concern that she may be experiencing postpartum
   depression because she does not seem to have any energy.
   Although the physician is sympathetic to the patient’s concern, she orders a CBC and iron studies seeking an organic
   explanation for the patient’s symptoms. The results are as
   follows:
   CBC: all results within reference intervals except
   RDW 5 15%
   Serum iron: decreased
   TIBC: increased
   % transferrin saturation: decreased
   Serum ferritin: decreased
   Correlate the patient’s laboratory and clinical findings.
   What can you conclude?
   a. The results of the iron studies reveal findings consistent
   with a thalassemia that was apparently previously
   undiagnosed.
   b. The patient is in stage 2 of iron deficiency, before frank
   anemia develops.
   c. The results of the iron studies are inconsistent with the
   CBC results, and a laboratory error should be suspected.
   d. There is no evidence of a hematologic explanation for
   the patient’s symptoms.

Answer 1

b. The patient is in stage 2 of iron deficiency, before frank
anemia develops.

Question 2

2. A bone marrow biopsy was performed as part of the cancer
   staging protocol for a patient with Hodgkin lymphoma.
   Although no evidence of spread of the tumor was apparent
   in the marrow, other abnormal findings were noted, including a slightly elevated myeloid-to-erythroid ratio. WBC and
   RBC morphology appeared normal, however. The Prussian
   blue stain showed abundant stainable iron in the marrow
   macrophages. The patient’s CBC revealed a hemoglobin of
   10.8 g/dL, but RBC indices were within reference intervals.
   RBC morphology was unremarkable. These findings would
   be consistent with:
   a. Anemia of chronic inflammation
   b. Sideroblastic anemia
   c. Thalassemia
   d. Iron deficiency anemia

Answer 2

a. Anemia of chronic inflammation

Question 3

2. A bone marrow biopsy was performed as part of the cancer
   staging protocol for a patient with Hodgkin lymphoma.
   Although no evidence of spread of the tumor was apparent
   in the marrow, other abnormal findings were noted, including a slightly elevated myeloid-to-erythroid ratio. WBC and
   RBC morphology appeared normal, however. The Prussian
   blue stain showed abundant stainable iron in the marrow
   macrophages. The patient’s CBC revealed a hemoglobin of
   10.8 g/dL, but RBC indices were within reference intervals.
   RBC morphology was unremarkable. These findings would
   be consistent with:

a. Anemia of chronic inflammation

3. Predict the iron study results for the patient with Hodgkin
   lymphoma described in question 2

Answer 3

D

Question 4

4. A 35-year-old white woman went to her physician complaining of headaches, dizziness, and nausea. The headaches had been increasing in severity over the past
   6 months. This was coincident with her move into an older
   house built about 1900. She had been renovating the
   house, including stripping paint from the woodwork. Her
   CBC results showed a mild hypochromic, microcytic anemia, with polychromasia and basophilic stippling noted.
   Which of the following tests would be most useful in confirming the cause of her anemia?
   a. Serum lead level
   b. Serum iron level and TIBC
   c. Absolute reticulocyte count
   d. Prussian blue staining of the bone marrow to detect iron
   stores in macrophages

Answer 4

a. Serum lead level

Question 5

5. In men and postmenopausal women whose diets are adequate,
   iron deficiency anemia most often results from:
   a. Increased need associated with aging
   b. Impaired absorption in the gastric mucosa
   c. Chronic gastrointestinal bleeding
   d. Diminished resistance to hookworm infections

Answer 5

c. Chronic gastrointestinal bleeding

Question 6

6. Which one of the following individuals is at greatest risk for
   the development of iron deficiency anemia?
   a. A 15-year-old boy who eats mainly fast food and junk
   food
   b. A 37-year-old woman who has never been pregnant and
   has amenorrhea
   c. A 63-year-old man with reactivation of tuberculosis from
   his childhood
   d. A 40-year-old man who lost blood during surgery to
   repair a fractured leg

Answer 6

a. A 15-year-old boy who eats mainly fast food and junk
food

Question 7

7. Which of the following individuals is at the greatest risk for
   the development of anemia of chronic inflammation?
   a. A 15-year-old girl with asthma
   b. A 40-year-old woman with type 2 diabetes mellitus
   c. A 65-year-old man with hypertension
   d. A 30-year-old man with severe rheumatoid arthritis

Answer 7

d. A 30-year-old man with severe rheumatoid arthritis

Question 8

8. In what situation will increased levels of free erythrocyte
   protoporphyrin be present?
   a. Gain of function mutation to one of the enzymes in the
   heme synthesis pathway
   b. A mutation that prevents heme attachment to globin so
   that protoporphyrin remains free
   c. Any condition that prevents iron incorporation into protoporphyrin IX
   d. When red blood cells lyse, freeing their contents into the
   plasma

Answer 8

c. Any condition that prevents iron incorporation into protoporphyrin IX

Question 9

9. In the pathogenesis of the anemia of chronic inflammation, hepcidin levels:
   a. Decrease during inflammation and reduce iron absorption from enterocytes
   b. Increase during inflammation and reduce iron absorption from enterocytes
   c. Increase during inflammation and increase iron
   absorption from enterocytes
   d. Decrease during inflammation and increase iron
   absorption from enterocytes

Answer 9

b. Increase during inflammation and reduce iron absorption from enterocytes

Question 10

10. Sideroblastic anemias result from:
    a. Sequestration of iron in hepatocytes
    b. Inability to incorporate heme into apohemoglobin
    c. Sequestration of iron in myeloblasts
    d. Failure to incorporate iron into protoporphyrin IX

Answer 10

d. Failure to incorporate iron into protoporphyrin IX

Question 11

11. In general, the hereditary hemochromatoses result from
    mutations that impair:
    a. The manner in which developing red cells acquire and
    manage iron
    b. The hepcidin-ferroportin iron regulatory system
    c. The TfR-Tf endocytic iron acquisition process for body
    cells other than blood cells
    d. The function of divalent metal transporter in enterocytes and macrophages

Answer 11

b. The hepcidin-ferroportin iron regulatory system

Question 12

12. In the erythropoietic porphyrias, mild anemia may be
    accompanied by what distinctive clinical finding?
    a. Gallstones
    b. Impaired night vision
    c. Unintentional nighttime leg movements
    d. Heightened propensity for sunburn

Answer 12

d. Heightened propensity for sunburn