Acquired platelet disorders

Question 1

How can a platelet disorder be acquired? Name the 2 ways and explain how they arise.

Answer 1

A prolonged continuous usage of aspirin.

• Aspirin irreversibly inhibits COX-1 and therefore TxA2. Decreased TxA2 means that platelet aggregation is impaired, meaning that a stable plug cannot be formed and bleeding time is prolonged.
• Aspirin takes its effects for 7-10 days (normal lifespan of platelets) but with prolonged use, it causes a bleeding disorder.

Due to chronic renal failure
- These patients have increased levels of phenolic acid which impairs platelet activation and also increased levels of nitric oxide which impairs platelet adhesion.

Question 2

How are these disorders treated?

Answer 2

• Stop the offending drug.

- Treat the renal failure.

Question 3

What is key when diagnosing these disorders?

Answer 3

• History, drug screen.

- Renal failure will be apparent.