Deck 19: Disorders of Iron and Heme Metabolism

Question 1

Which of the following promotes increased iron absorption?

A) Repeated phlebotomy
B) Eating iron-rich foods along with those high in ascorbic acid
C) Desferrioxamine
D) Vegetarian diet

Answer 1

Eating iron-rich foods along with those high in ascorbic acid

Question 2

Most of the clinical findings in the porphyrias are related to:

A) Accumulated porphyrin compounds in tissue
B) Anemia
C) Reduction in heme production
D) Iron being unavailable

Answer 2

Accumulated porphyrin compounds in tissue

Question 3

What is the mechanism for ACI?

A) Acute phase reactants impair iron mobilization.
B) Inflammation and infections slow heme development.
C) Cytokines prevent iron incorporation into protoporphyrin.
D) Bone marrow iron stores are depleted by acute phase reactants.

Answer 3

Acute phase reactants impair iron mobilization.

Question 4

Which of the following is decreased in patients with hereditary hemochromatosis?

A) Albumin
B) Serum iron
C) Transferrin saturation
D) Ferritin

Question 5

What parameter of the routine complete blood count (CBC) is a sensitive indicator of preclinical iron deficiency?

A) Red blood cell distribution width (RDW)
B) Hematocrit
C) Mean cell hemoglobin (MCH)
D) Red blood count

Question 6

Which of following are typical laboratory results for ACI?

A) Decreased ferritin and decreased bone marrow Prussian blue staining
B) Low serum iron and high TIBC
C) Low serum iron and low TIBC
D) Increased transferrin saturation and decreased FEP

Question 7

Where is most of the iron in the body found?

A) Attached to hemoglobin in the red blood cells (RBCs)
B) Stored in macrophages in the bone marrow
C) Attached to transferrin
D) Myoglobin

Question 8

The ferritin test is being used to screen for hereditary hemochromatosis. A healthy young woman has a low ferritin. Which of the following is most likely?

A) Homozygous hemochromatosis
B) Heterozygous hemochromatosis
C) Stage 2 iron deficiency
D) ACI

Question 9

Lack of accessible iron is the mechanism for iron deficiency and which of the following?

A) Hemochromatosis
B) Hemosiderosis
C) Lead poisoning
D) Anemia of chronic inflammation (ACI)

Question 10

Why is too much iron dangerous?

A) Transferrin, which carries iron, causes cellular swelling and lysis.
B) The oxygen carried by excess iron oxidizes neurologic cells.
C) Iron's breakdown products cause excretion of vitamins C and E.
D) Free radicals and superoxide formed from ferrous iron plus oxygen damage cell membranes.

Question 11

Which group of patients is most likely to develop iron deficiency from increased need?

A) Young men
B) Infants and young children
C) Postmenopausal women
D) Middle-aged men

Question 12

How does lead exposure and the porphyrias cause anemia?

A) Cause destruction of red cells
B) Chelae iron from the body
C) Impair iron absorption
D) Interfere with heme production

Question 13

What is most likely if a 10-month-old child fed only cow's milk has the following results?
$\bullet$ Serum iron decreased
$\bullet$ Total iron-binding capacity (TIBC) increased
$\bullet$ Ferritin decreased

A) Lead poisoning
B) Chronic disease
C) Iron deficiency from increased need and inadequate diet
D) Iron deficiency from chronic blood loss

Question 14

Which of the following is the best test to distinguish iron deficiency anemia from ACI?

A) Serum iron
B) Hemoglobin
C) Free erythrocyte protoporphyrin (FEP)
D) Ferritin

Question 15

Which of the following groups is least likely to develop iron deficiency?

A) Infants
B) Young men
C) Teenage girls
D) Adult premenopausal women

Question 16

Which of the following results is or are typical in stage 3 iron deficiency anemia?

A) Elevated reticulocyte percentage
B) Thrombocytopenia
C) Macrocytic red cells
D) Low mean cell volume (MCV), MCH, and mean cell hemoglobin concentration (MCHC)

Question 17

What would be the likely findings if a bone marrow were performed in a complicated case of iron deficiency anemia?

A) Increased myeloid-to-erythroid (M:E) ratio and increased staining with Prussian blue
B) Shaggy polychromatophilic normoblasts and no staining with Prussian blue
C) Polychromatophilic normoblasts with copious pink cytoplasm and no staining with Prussian blue
D) Increased M:E ratio and increased ringed sideroblasts

Question 18

What is the most common cause of iron deficiency in men and postmenopausal women?

A) Poor diet
B) Increased need
C) Chronic blood loss
D) Paroxysmal nocturnal hemoglobinuria

Question 19

Which of the following red cell inclusions is or are often found in lead poisoning?

A) Howell-Jolly bodies
B) Basophilic stippling
C) Heinz bodies
D) Cabot rings

Question 20

Transfusion-related hemochromatosis is seen in patients who:

A) Had an adverse reaction to a blood transfusion
B) Received the wrong type of blood
C) Had life-long repeated red cell transfusions
D) Received a transfusion from a relative

Question 21

Which of the following is true of stage 3 iron deficiency?

A) Serum transferrin receptors are decreased.
B) FEP is increased.
C) The number of sideroblasts is normal.
D) The red cell count is increased, whereas the hematocrit is decreased.

Question 22

All of the following are true about hepcidin except that:

A) It is an acute phase protein.
B) It is a hormone.
C) It decreases in response to increased ferritin.
D) It increases in response to increased iron stores.

Question 23

Which of the following characterizes stage 1 iron deficiency? Anemia MCV Ferritin

A) Present Decreased Decreased
B) Present Normal Normal
C) Absent Normal Decreased
D) Absent Decreased Normal

Question 24

Which test will rise first after successful treatment for iron deficiency?

A) Reticulocyte count
B) Ferritin
C) MCV
D) Hemoglobin

Question 25

Which of the following would point to iron deficiency anemia as opposed to the ACI?

A) Anemia
B) High transferrin
C) Low serum iron
D) Elevated FEP

Question 26

Why is lead poisoning of particular concern in children?

A) Severe anemia may develop.
B) Impaired mental development may occur.
C) Secondary iron deficiency may develop.
D) FEP may accumulate.

Question 27

Blood for iron studies:

A) Should be drawn fasting in the morning
B) Should be drawn following a standard meal rich in iron
C) May be drawn at any time of the day
D) Should be drawn in the morning with no fasting necessary

Question 28

Chronic blood loss leads to:

A) Iron deficiency anemia
B) ACI
C) Megaloblastic anemia
D) Hemolytic anemia

Question 29

Ringed sideroblasts are a reflection of iron-laden:

A) Mitochondria
B) Golgi complex
C) Ribosomes
D) Rough endoplasmic reticulum

Question 30

Ringed sideroblasts are seen in:

A) Inherited sideroblastic anemia
B) Acquired hemochromatosis
C) Iron deficiency anemia
D) ACI