Chapter 29: Alterations of Leukocyte, Lymphoid, and Hemostatic Function

Question 1

Thrombotic thrombocytopenic purpura is characterized by __________ _______________ in which platelets aggregate and cause occlusion of arterioles and capillaries within the microcirculation.

Answer 1

thrombotic microangiopathy

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Question 2

There are 2 forms of TTP: _________ and ________ (_________).

Answer 2

familial
acquired (idiopathic)

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Question 3

Acquired TTP is more common than familial TTP, as well as more acute and severe. It occurs mostly in ______ in their _________ and is rarely observed in infants or older adults.

Answer 3

females in their thirties

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Question 4

Acute idiopathic TTP is characterized by a pathognomonic pentad of symptoms:

Answer 4

extreme thrombocytopenia (<20,000)
intravascular hemolytic anemia
ischemic signs and symptoms most often involving the CNS (i.e. memory disturbances, behavioral irregularities, headaches, or coma)
kidney failure
fever 

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Question 5

What % of people with TTP have the whole pentad of symptoms?

Answer 5

20 - 30%

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Question 6

What organs are most susceptible to the damaging effects of TTP?

Answer 6

kidney, brain, and heart

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Question 7

The thrombi formed in TTP are primarily composed of…..

This feature differentiates from thrombi formed in….

Answer 7

…..platelets with minimal fibrin and red cells.

…..intravascular coagulation.

(p. 1040)

Question 8

What are most cases of TTP due to?

Answer 8

A malfunction of the metalloprotease ADAMTS13.

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Question 9

What does ADAMTS13 normally do?

Answer 9

The enzyme ADAMTS13 is responsible for digesting large precursor molecules of von Willebrand factor produced by endothelial cells into smaller molecules. Too little ADAMTS13 results in expression of large-molecular-weight vWF on the endothelial cell surface which causes platelets to stick together.

(p. 1040)

Question 10

Most individuals with TTP have less than __% of normal plasma ADAMTS13 levels.

Answer 10

5%

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Question 11

TTP also is commonly associated with an ___ ________ against ADAMTS13 that is able to neutralize the enzyme’s activity and accelerate its clearance from the plasma.

Answer 11

IgG autoantibody

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Question 12

Untreated acute TTP has a death rate of __%, which can be reduced to 10 - 20% with prompt treatment.

Answer 12

90%

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Question 13

What is the first line treatment for TTP?

Answer 13

plasma exchange and steroids