Deck 15: Hemolytic Anemia: Enzyme Deficiencies

Question 1

A 53-year-old Italian male was hospitalized with increased fatigue and hemoglobinuria.Patient history revealed his last ingested meal contained fava beans.G6PD levels were performed 3 months later, and the result was 5%.Based on these findings, which class of G6PD variant is most likely affected?

A)Class I
B)Class II
C)Class III
D)Class IV

Answer 1

Class II

Question 2

Which molecule is responsible for the neutralization of harmful peroxides?

A)G6P
B)Glutathione
C)HK
D)PK

Answer 2

Glutathione

Question 3

The mode of inheritance for G6PD deficiency is:

A)Autosomal recessive.
B)Autosomal dominant.
C)No established inheritance pattern.
D)Sex-linked.

Answer 3

Sex-linked.

Question 4

Which of the following is a quantitative test for G6PD?

A)Fluorescent spot test
B)Quantitative NADP rate reduction test
C)NADP dye reduction test
D)Ascorbate cyanide test

Question 5

Exposure to which of the following can induce hemolysis due to G6PD deficiency?

A)Primaquine
B)Fava beans
C)Divicine
D)All of the above

Question 6

For proper diagnosis of G6PD deficiency, timing of the testing is critical.When should testing occur?

A)Several months after a hemolytic attack
B)Within a week after a hemolytic attack
C)During compensatory reticulocytosis
D)After transfusion therapy

Question 7

Pyruvate kinase is responsible for the conversion of:

A)NADPH to ATP.
B)Glucose to glucose 6 phosphate.
C)PEP to pyruvic acid.
D)Pyruvic acid to lactic acid.

Question 8

The common erythrocyte enzyme disorder G6PD deficiency is due to a gene mutation on which chromosome?

A)23
B)9
C)X
D)Y

Question 9

The presence of which poikilocyte in the peripheral blood could indicate G6PD deficiency?

A)Schistocyte
B)Spherocyte
C)Blister cell
D)Elliptocyte

Question 10

Which of the following lab tests is used to confirm G6PD deficiency?

A)Fluorescent spot test
B)PB smear
C)NADP rate reduction test
D)Reticulocyte count

Question 11

Which of the following is used to screen for G6PD deficiency?

A)Supravital stain
B)Fluorescent spot test
C)PB smear
D)Cytochemical staining

Question 12

Which of the following is the most common RBC enzymopathy?

A)PK
B)HK
C)G6PD
D)GPI

Question 13

Intrinsic erythrocyte enzyme deficiencies lead to:

A)Increased erythrocyte oxidative susceptibility.
B)Exacerbated immune response against erythrocytes.
C)Increased opsonization of erythrocytes.
D)Increased extravascular hemolysis.

Question 14

The majority of glucose catabolism occurs via the:

A)Hexose monophosphate shunt.
B)Embden-Meyerhof pathway.
C)Luebering-Rapoport pathway.
D)Synthesis of nucleotides.

Question 15

What process catabolizes approximately 10% of the glucose essential for maintaining adequate concentrates of reduced glutathione?

A)Glycolytic pathway
B)Metabolic pathway
C)Hexose-monophosphate shunt
D)Nucleotide pathway

Question 16

G6PD deficiency was first recognized during the Korean War, when what drugs were administered to the soldiers?

A)Sulfonamides
B)Nitrofurans
C)Analgesics
D)Antimalarials

Question 17

Which of the following supports the diagnosis of G6PD deficiency?

A)Presence of Heinz bodies with new methylene blue stain
B)Reticulocytosis
C)Hemolytic morphology during oxidative event
D)All of the above

Question 18

What morphologic characteristics are found on a blood smear in G6PD deficiency?

A)Leukopenia and echinocytes
B)Thrombocytopenia and reticulocytosis
C)Reticulocytosis and blister cells
D)Döhle bodies and Heinz bodies

Question 19

What are the two main metabolic pathways that erythrocytes use to break down glucose?

A)Glycolytic and hexose monophosphate shunt
B)Glycolytic and Luebering-Rapaport pathway
C)Krebs cycle and electron transport system
D)Hexokinase and Krebs cycle

Question 20

Why are blister cells NOT seen in PK deficiency?

A)Because Heinz bodies are not formed in PK deficiency
B)Because G6PD deficiency causes hemolysis, and PK does not
C)Because G6PD deficient erythrocytes are prone to oxidative damage, and PK deficient erythrocytes are not
D)All of the above

Question 21

Which G6PD variant has normal activity and no hemolysis present?

A)G6PD-Mediterranean
B)Minnesota
C)Iowa
D)G6PD-B

Question 22

Why are Heinz bodies seen in G6PD deficiency?

Question 23

In PK deficiency there is a loss of _______which causes failure of the cation pumps in the RBC.

A)G6PD
B)PEP
C)Glucose
D)ATP

Question 24

What is the purpose of the HMP shunt, and why is it important?

Question 25

Female heterozygotes for G6PD deficiency have one population of cells that is normal and one that is G6PD deficient because:

A)There is random inactivation of one X chromosome.
B)There is random inactivation of one Y chromosome.
C)There is random activation of one X chromosome.
D)There is random activation of one Y chromosome.

Question 26

What is the poikilocyte typically seen in PK deficiency?

A)Heinz bodies
B)Acanthocytes
C)Spherocytes
D)Echinocytes

Question 27

What are the principles of the tests listed below?

A)Fluorescent spot test
B)Dye reduction test
C)Ascorbate cyanide test
D)Rate reduction test

Question 28

Class IV G6PD enzymes include which of the following?

A)G6PD-Mediterranean
B)G6PD-B and G6PD-A+
C)G6PD-Iowa
D)G6PD-Canton

Question 29

Why are echinocytes seen in PK deficiency?

Question 30

Bite cells are produced during :

A)Removal of Doehle bodies by macrophages.
B)Passage of RBCs through fibrin strands.
C)Removal of Holly-Jolly bodies by the spleen.
D)Removal of Heinz bodies by macrophages.

Question 31

Increased bilirubin in the blood can lead to ________, and is seen in _________.

A)Hemoglobinuria; acute, acquired hemolytic anemia
B)Hemosiderinuria; congenital, nonspherocytic hemolytic anemia
C)Kernicterus; neonatal hyperbilirubinemia
D)Kernicterus; congenital, nonspherocytic hemolytic anemia

Question 32

PK deficiency causes which of the following to occur in the erythrocyte?

A)Denatured hemoglobin to precipitate
B)Splenic sequestration of normal erythrocytes
C)Premature apoptosis due to lack of ATP formed
D)Membrane instability with excessive sodium and calcium influx

Question 33

The erythrocyte morphology associated with pyruvate kinase deficiency is:

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

Question 34

How do Heinz bodies differ morphologically from other erythrocyte inclusions?

Question 35

Which of the following can result from a deficiency of pyruvate kinase in the erythrocyte?

A)Gain of ATP
B)Erythrocyte membrane failure with loss of potassium
C)Sodium and calcium depletion
D)Overhydration