Thrombotic Thrombocytopenic Purpura

Question 1

What is TTP?

Answer 1

thrombotic microangiopathy in which microthrombi, consisting primarily of platelets, form + occlude arterioles + capillaries.

Question 2

What clinical pentad is seen in TTP?

Answer 2

MAHA
AKI
Thrombocytopenia
Fever
Fluctuating CNS signs: seizures, hemiparesis, LOC

Question 3

Describe the aetiology of TTP

Answer 3

Genetic or acquired deficiency of a protease (ADAMTS13) that normally cleaves multimers of VWF
Large VWF multimers form, causing platelet aggregation + fibrin deposition in small vessels leading to microthrombi

Question 4

List 5 causes of TTP

Answer 4

Idiopathic (40%)
AI (e.g. SLE)
Cancer
Pregnancy
Drug associated (e.g. quinine)

Question 5

Describe the epidemiology of TTP

Answer 5

mainly affects adult females

Mortality can be >90% if untreated (higher than HUS)

Question 6

List GI, general and renal symptoms seen in TTP

Answer 6

GI: Severe abdominal colic, watery diarrhoea (becomes bloody)
General: Malaise, fatigue, nausea, fever
Renal: Oliguria/ anuria, haematuria

Question 7

List 11 signs of TTP

Answer 7

Weakness
Impaired vision
Fits
LOC
Pallor (from anaemia)
Slight jaundice (from haemolysis)
Bruising (severe thrombocytopaenia)
Generalized oedema
HTN 
Retinopathy
Abdominal tenderness

Question 8

What will investigations show in TTP?

Answer 8

Thrombocytopenia
Low Hb
Low haptoglobin
High reticulocytes
Coombs test negative

Question 9

What would be seen on a blood film in TTP?

Answer 9

Schistocytes