College Answer

a)          What is the most likely diagnosis? Provide 3 reasons.

TTP

Reasons: Low platelets, renal dysfunction, presence of schistocytes suggestive of MAHA and neurological symptoms.

b)         What definitive treatment needs to be instituted urgently?

Plasma exchange

Discussion

Thrombotic thrombocytopenic purpura is discussed in greater detail elsewhere.

Characteristic features of TTP are as follows:

• Anaemia
• Thrombocytopenia
• Microangiopathic haemolytic anaemia
• Schistocytosis
• Neurological symptoms
• Fever
• Renal failure

The presence or raised bilirubin suggests that intravascular hameolysis is taking place, and the presence of serious renal failure lends itself to the idea that a haemolytic-uremic syndrome may also be in play here. Those two have been together in the same category before (TTP/HUS). Nowadays, TTP and HUS and HELLP are all recognised as a spectrum of thrombotic microangiopathies.

The definitive treatment for it is plasma exchange, aiming to remove the ADAMTS-13 inhibitor while replacing the missing ADAMTS-13 protein with FFP.

Not much else can be added to this brief answer, the third in a three-part question, which is valued at ten points in total (thus one has 3.333 minutes to dedicate to it).