Haemolytic Uraemic Syndrome

Question 1

What is haemolytic uraemic syndrome?

Answer 1

Is a syndrome of a triad of symptoms caused by infection.
Symptoms include:
-Haemolytic anaemia 
-Thromboycytopenia
-AKI

Question 2

What is the most common cause of HUS?

Answer 2

It is most commonly caused by E.coli with antigen 157.

This strain produces the shiga toxin, HUS is the systemic response to the circulating toxin.

It can also be caused by:
-Shigella dysentriae type 1

Question 3

How does HUS present>

Answer 3

Commonly associated with diahorrea as both are caused by E.coli.

Severe diahorrea which turns bloody after a few days.
There is often fever, abdominal pain and vomiting.

Question 4

What are the implications for non-diahorrea associated HUS?

Answer 4

Suggests it is atypical and not caused by infection.

Could be caused by:

• Drug reaction (cyclosporins)
• SLE
• Malignancies
• Genetic conditions

Tends to be a much worse prognosis with mortalities up to 25% and 50% progressing to end stage CKD.