Deck 12: Anemias of Disordered Iron Metabolism and Heme Synthesis

Question 1

A term used to describe anemia characterized by deficient iron for hemoglobin synthesis is:

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

Answer 1

Sideropenic

Question 2

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

Answer 2

Serum transferrin receptor

Question 3

The hereditary form of sideroblastic anemia is most commonly the result of:

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

Answer 3

Abnormal ALAS

Question 4

What organ is the primary storage depot for iron?

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

Question 5

Iron-deficiency anemia can occur from 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

Question 6

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

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

Question 7

Which of the following is the correct progression of iron-deficiency anemia?

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 8

Which 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 9

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 10

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 11

A storage form of iron is:

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

Question 12

Anemia of chronic disease is characterized by:

A) A block in globin synthesis
B) An 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 13

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 14

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

Question 15

An unknown sample reveals 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) Cannot be determined based on the information given

Question 16

Accumulation of heterogeneous aggregates of iron is called:

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

Question 17

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 18

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 19

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

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

Question 20

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

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

Question 21

Erythropoietic porphyrias are associated with:

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

Question 22

Criteria for the diagnosis of hemochromatosis in adult males include transferrin saturation ________ and ferritin ________.

A) >80%, <200 mcg/l
B) >45%, >300 mcg/l
C) <40%, <300 mcg/l
D) >60%, >100 mcg/l

Question 23

Differentiate between primary and secondary hemochromatosis.

Question 24

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 25

The first peripheral blood marker to show an abnormal result in iron deficiency anemia is:

A) Retic absolute
B) CHr or Ret-He
C) Retic %
D) MCV

Question 26

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

A) Abnormal ALAS
B) Plumbism
C) Autosomal recessive transmission
D) Decreased folate

Question 27

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

Question 28

Alcoholics have an increased incidence of sideroblastic anemia because of 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 29

Explain the absorption and assimilation of nonheme iron into hemoglobin in the RBC.

Question 30

Hypochromic, microcytic anemia is found in which stage of iron deficiency?

A) 1
B) 2
C) 3

Question 31

The most common form of hereditary hemochromatosis is the result of which gene mutation?

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

Question 32

A bone marrow aspirate is performed on a patient with sideroblastic anemia. The smear is stained with Prussian blue iron. The expected findings in this patient would be that 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 33

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) Reticulocyte count
D) Osmotic fragility

Question 34

Before treating a patient for IDA, it is important to rule out thalassemia. Explain why that is and using 3 parameters, differentiate between the two disease states.

Question 35

The diagnostic test for IRIDA is:

A) Transferrin saturation
B) CHr
C) Sequencing the TMPRSS6 gene
D) ALAS

Question 36

Explain the difference between the chemical composition of hemosiderin and that of ferritin.

Question 37

Explain how lead inhibits heme synthesis.

Question 38

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 39

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 40

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