Deck 25: Extrinsic Defects Leading to Increased Erythrocyte Destruction Nonimmune Causes

Question 1

A mild intravascular hemolytic anemia resulting from forceful repeated effect of the feet on hard surfaces is called

A)traumatic cardiac hemolytic anemia.
B)exercise-induced hemoglobinuria.
C)bartonellosis.
D)thrombotic thrombocytopenic purpura.

Answer 1

exercise-induced hemoglobinuria.

Question 2

Which of the following infections is responsible for the most deaths worldwide?

A)malaria
B)Babesia infection
C)Bartonella infection
D)clostridial septicemia

Answer 2

malaria

Question 3

Which of the following decreases the ability of malaria species to infect RBCs?

A)Duffy-positive phenotype
B)heterozygosity for hemoglobin S (Hb S)
C)hereditary spherocytosis
D)Rh-negative genotype

Answer 3

heterozygosity for hemoglobin S (Hb S)

Question 4

Why does Plasmodium falciparum infection result in the most serious hemolysis of the various forms of malaria?

A)Only reticulocytes are invaded.
B)Reticulocytes and RBCs less than 10 days old are invaded.
C)Only mature RBCs are invaded.
D)RBCs of all ages are invaded.

Question 5

A patient's red cells show globular fragmentation,budding,and microspherocytes.To what have the red cells probably been exposed?

A)heat
B)chemicals
C)oxidant drugs
D)bartonellosis

Question 6

Which of the following techniques most often diagnoses malaria and Babesia infections?

A)polymerase chain reaction (PCR)
B)observing the organisms in blood films
C)serologic tests
D)culture

Question 7

Which of the following is an expected finding in MAHA?

A)elevated platelets
B)schistocytes or red cell fragments
C)low white count
D)extravascular hemolysis

Question 8

A patient has crescent- or banana-shaped malarial gametocytes.Which of the following is probably true regarding the species of malaria and its clinical course?

A)Plasmodium malariae, which is benign and needs no treatment
B)Plasmodium ovale, which is found mostly in Southern United States and is usually fatal
C)Plasmodium falciparum, which is the most clinically serious
D)Plasmodium vivax, which is the most clinically serious

Question 9

Thick blood films for malaria diagnosis are best used for which purpose?

A)initial screening
B)determination of the percent of parasitemia
C)speciation
D)identification of stages

Question 10

What is the pathogenesis of MAHA?

A)Microthrombi and fibrin formed on damaged endothelial cells trap and break red cells.
B)Chemicals or heat destroy red blood cells (RBCs).
C)The spleen sequesters red cells in an attempt to remove abnormal inclusions.
D)Antibodies that activate complement are formed and destroy the red cell membrane.

Question 11

Renal failure is a prominent feature of

A)hemolytic uremic syndrome.
B)thrombotic thrombocytopenic purpura.
C)Plasmodium malariae infection.
D)march hemoglobinuria.

Question 12

Which of the following conditions is associated with a deficiency of von Willebrand factor (VWF)-cleaving protease?

A)hemolytic uremic syndrome
B)thrombotic thrombocytopenic purpura
C)march hemoglobinuria
D)DIC

Question 13

All of the following are examples of microangiopathic hemolytic anemias (MAHAs)except

A)thrombotic thrombocytopenia purpura
B)hemolytic uremic syndrome
C)disseminated intravascular coagulation (DIC)
D)immune thrombocytopenia purpura

Question 14

MAHA is often secondary to all of the following conditions except

A)infections, especially sepsis.
B)obstetric complications.
C)renal disease.
D)cancer.