Thrombotic Thrombocytopenic Puprura (TTP)

Question 1

What is TTP. (2)

Answer 1

It is an acute autoimmune disorder mediated by antibodes against ADAMTS-13.
It is a disorder in which thrombosis is accompanied by paradoxical thrombocytopenia.

Question 2

What is the pentad of findings you can get in TTP. (5)

Answer 2

Thromboyctopenia.
Microangipathic haemolytic anaemia (severe, often with jaundice).
Neurological sequelae (seizures, hemiparesis, reduced consciousness, reduced vision).
Fever.
Renal impairment.
This classical pentad is rarely seen.

Question 3

What does ADAMTS-13 normally do.

Answer 3

It is an enzyme that normally cleaves vWF multimers to produce normal functional units.

Question 4

What occurs when ADAMTS-13 cannot work properly (as in TTP).

Answer 4

It’s deficiency results in large vWF multimers which cross-link platelets.

Question 5

What are the main features of TTP.

Answer 5

Microvascular occlusion by platelet thrombi affecting key organs, principally the brain and kidneys.

Question 6

What is the incidence of TTP.

Answer 6

It is a rare disorder (1 in 750,000 cases per annum).

Question 7

What are the causes of TTP. (6)

Answer 7

Primary. 
Drugs (ticlopidine, clopidogrel, oral contraceptive). 
HIV infection. 
Shiga toxin. 
Pregnancy. 
Malignancy.

Question 8

What is the untreated mortality rate for TTP.

Answer 8

90% in the first 10 days.

20-30% at 6 months (even with appropriate therapy).

Question 9

What percentage of TTP cases are associated with HIV.

Answer 9

More than 90%.

Question 10

What age group is most commonly affected by TTP.

Answer 10

Young adults.