Deck 9: Anemias of Disordered Iron Metabolism and Heme Synthesis

Question 1

All of the following disorders will have normal-to-elevated ferritin levels except:

A)Iron-deficiency anemia.
B)Anemia of chronic disease.
C)Sideroblastic anemia.
D)Lead poisoning.

Answer 1

Iron-deficiency anemia.

Question 2

Name the molecule that is responsible for oxidizing ferrous iron to ferric iron to be combined with transferrin.

A)DCytB
B)DMT1
C)Ferroportin
D)Hephaestin

Answer 2

Hephaestin

Question 3

Iron-deficiency anemia can occur by what three mechanisms?

A)Impaired iron absorption, blood loss, inadequate iron intake
B)ALAS deficiency, blood loss, decreased transferrin
C)Mutation of HFE gene, decreased transferrin, increased hepcidin
D)Inadequate iron intake, impaired iron absorption, decreased hepcidin

Answer 3

Impaired iron absorption, blood loss, inadequate iron intake

Question 4

The hereditary form of sideroblastic anemia is most commonly due to:

A)Decreased hepcidin synthesis.
B)Mutation of the HFE gene.
C)Abnormal ALAS.
D)Increased absorption of iron.

Question 5

A storage form of iron is:

A)Pappenheimer bodies.
B)Hemoglobin.
C)Ferritin.
D)Transferrin.

Question 6

This laboratory test measures the maximum amount of iron able to be bound to transferrin in the serum.

A)Ferritin
B)Percent transferrin saturation
C)Serum iron
D)TIBC

Question 7

What is the percent transferrin saturation and UIBC in a patient with a serum iron of 85 ug/dL and a TIBC of 280 ug/dL?

A)45%; 280 ug/dL
B)30%; 195 ug/dL
C)55%; 195 ug/dL
D)32%; 280 ug/dL

Question 8

What enzyme is responsible for reducing ferric iron to the ferrous state at the enterocyte brush border?

A)Apoferritin
B)DcytB
C)Ferritin
D)Transferrin

Question 9

Accumulation of heterogeneous aggregates of iron is called:

A)Hemosiderosis.
B)Sideroblastosis.
C)Ferritinemia.
D)Transferrinuria.

Question 10

A term used to describe impaired utilization of iron as seen in ACD is:

A)Sideropenic.
B)Sideroblastic.
C)Sideroachrestic.
D)Siderocyte.

Question 11

Regulation of iron entering the body occurs mainly through which mechanism?

A)Transfer of iron in the enterocyte into the blood
B)Absorption of dietary iron into the enterocyte
C)Excretion of excess iron from the intestine into the urine
D)Chelation of dietary iron in the intestine

Question 12

What measurements are used in the percent saturation calculation?

A)Transferrin and ferritin
B)Ferritin and bone marrow iron
C)Serum iron and TIBC
D)Serum iron and ferritin

Question 13

An unknown sample reveals a low serum iron, high TIBC, low ferritin, low hemoglobin and a microcytic hypochromic picture in the peripheral blood.Which stage of IDA is this?

A)Stage 1 IDA
B)Stage 2 IDA
C)Stage 3 IDA
D)It cannot be determined based on the information given.

Question 14

The primary storage depot for iron is in what organ?

A)Bone marrow
B)Duodenum
C)Stomach
D)Liver

Question 15

Anemia of chronic disease is characterized by:

A)A block in globin synthesis.
B)Inadequate intake of iron.
C)A block in insertion of iron into the porphyrin ring of heme.
D)A block in iron release from macrophages.

Question 16

What is the typical PB picture in a patient with stage 1 IDA?

A)Normocytic normochromic
B)Microcytic hypochromic
C)Macrocytic normochromic
D)Normocytic hypochromic

Question 17

Which laboratory test would be most helpful in differentiating iron-deficiency anemia from anemia of chronic disease?

A)Hemoglobin
B)Serum iron
C)Percent transferrin saturation
D)Serum transferrin receptor

Question 18

A 4-year-old boy who primarily eats grilled cheese sandwiches and tomato soup can suffer from iron-deficiency anemia due to:

A)Increased need.
B)Inadequate intake.
C)Impaired utilization.
D)Increased need and inadequate intake.

Question 19

Choose the correct progression of iron-deficiency anemia from the choices below.

A)Storage depletion, iron-poor hemoglobin production, transport depletion
B)Storage depletion, transport depletion, iron-poor hemoglobin production
C)Iron-poor hemoglobin production, transport depletion, storage depletion
D)Iron-poor hemoglobin production, storage depletion, transport depletion

Question 20

Which of the following acts as the chief regulator of iron absorption in the intestines?

A)HFE
B)Hepcidin
C)Duodenal cytochrome-B reductase
D)Ferroportin

Question 21

What is the most probable diagnosis based on these clinical findings and patient history?

A)Lead poisoning
B)Iron-deficiency anemia
C)Sideroblastic anemia
D)Hereditary hemochromatosis

Question 22

Explain the difference in the chemical composition of hemosiderin and ferritin.

Question 23

The most common form of hereditary hemochromatosis is due to which gene mutation?

A)HFE
B)hepcidin gene
C)Ferroportin gene
D)HJV

Question 24

How is sideroblastic anemia confirmed by laboratory analysis? Explain your answer.

Question 25

Alcoholics have an increased incidence of sideroblastic anemia due to which of the following?

A)Impaired utilization of globin chains
B)Abnormal stem cells
C)Abnormal activity of enzymes of heme synthesis
D)Impaired transport of iron into erythroid precursors

Question 26

Iron overload exists when ferritin levels are higher than:

A)100 ng/mL.
B)200 ng/mL.
C)50 ng/mL.
D)24 ng/mL.

Question 27

What reflex laboratory tests would be helpful to identify the cause of this anemia?

A)Serum iron studies
B)vitamin B₁₂
C)Bone marrow aspirate
D)Cytogenetic studies

Question 28

The patient was found to have normal serum iron studies.What other reflex test(s) should be done?

A)Blood lead level
B)Porphyrin studies
C)Reticulocte count
D)Osmotic fragility

Question 29

Explain how lead inhibits heme synthesis.

Question 30

Differentiate primary and secondary hemochromatosis?

Question 31

Hypochromic, microcytic anemia is found in this stage of iron deficiency:

A)1.
B)2.
C)3. Correct

Question 32

A defect in the HFE gene would cause which of the following to occur?

A)Increased iron absorption in the intestines
B)Decreased iron absorption in the intestines
C)Increased erythropoiesis in the bone marrow
D)Increased transferrin synthesis

Question 33

Explain the absorption and assimilation of non-heme iron into hemoglobin in the RBC.

Question 34

Which of the following is NOT characteristic of iron deficiency anemia?

A)Decreased ZPP
B)Decreased serum iron
C)Increased TIBC
D)Decreased serum ferritin

Question 35

A bone marrow aspirate is performed on a patient with sideroblastic anemia.The smear is stained with Prussian blue iron stain.What would be the expected findings in this patient? Iron stores:

A)Will be decreased as compared with the normal control.
B)Will be the same as those in the normal control.
C)Will be increased as compared with the normal control.
D)Cannot be determined based on the diagnosis alone.

Question 36

Erythropoietic porphyrias are associated with:

A)Abnormal iron metabolism.
B)Abnormal enzymes in the heme biosynthetic pathway.
C)Abnormal globin synthesis.
D)DMT1 mutations.