CHAPTER 40: THROMBOCYTOPENIA AND THROMBOCYTOSIS

Question 1

(1) The autosomal dominant disorder associated with decreased platelet production is:

a. Fanconi anemia
b. TAR syndrome
c. May-Hegglin anomaly
d. Wiskott-Aldrich anomaly

Answer 1

b. TAR syndrome

Question 2

(2) Which of the following is not a hallmark of ITP?

a. Petechiae
b. Thrombocytopenia
c. Large overactive platelets
d. Megakaryocyte hypoplasia

Answer 2

d. Megakaryocyte hypoplasia

Question 3

(3) The specific antigen most commonly responsible for the development of NAIT is:

a. Bak
b. HPA-1a
c. GP Ib
d. Lewis antigen a

Answer 3

b. HPA-1a

Question 4

(4) A 2-year-old child with an unexpected platelet count of 15,000/uL and a recent history of a viral infection most likely has:

a. HIT
b. NAIT
c. Acute ITP
d. Chronic ITP

Answer 4

c. Acute ITP

Question 5

(5) What is the first step in the treatment of HIT?

a. Start low-molecular-weight heparin therapy
b. Stop heparin infusion immediately
c. Switch to warfarin (Coumadin) immediately
d. Initiate a platelet transfusion

Answer 5

b. Stop heparin infusion immediately

Question 6

(6) A defect in primary hemostasis (platelet response to an injury) often results in:

a. Musculoskeletal bleeding
b. Mucosal bleeding
c. Hemarthroses
d. None of the above

Answer 6

b. Mucosal bleeding

Question 7

(7) When a drug acts as a hapten to induce thrombocytopenia, an antibody forms against which of the following?

a. Typically unexposed, new platelet antigens
b. The combination of the drug and the platelet membrane protein to which it is bound
c. The drug alone in the plasma, but the immune complex then binds to the platelet membrane
d. The drug alone, but only when it is bound to the platelet membrane

Answer 7

b. The combination of the drug and the platelet membrane protein to which it is bound

Question 8

(8) TAR refers to:

a. Abnormal platelet morphology in which the radial striations of the platelets are missing
b. Abnormal appearance of the iris of the eye in which radial striations are absent
c. Abnormal bone formation, including hypoplasia of the forearms
d. Neurologic defects affecting the root (radix) of the spinal nerves

Answer 8

c. Abnormal bone formation, including hypoplasia of the forearms

Question 9

(9) Neonatal autoimmune thrombocytopenia occurs when:

a. The mother lacks a platelet antigen that the infant possesses, and she builds antibodies to that antigen, which cross the placenta
b. The infant develops an autoimmune process such as ITP secondary to in utero infection
c. The infant develops an autoimmune disease such as lupus erythematosus before birth
d. The mother has an autoimmune antibody to her own platelets, which crosses the placenta and reacts with the infant’s platelets

Answer 9

d. The mother has an autoimmune antibody to her own platelets, which crosses the placenta and reacts with the infant’s platelets

Question 10

(10) HUS in children is associated with:

a. Diarrhea caused by Shigella species
b. Meningitis caused by Haemophilus species
c. Pneumonia caused by Mycoplasma species
d. Pneumonia caused by respiratory viruses

Answer 10

a. Diarrhea caused by Shigella species