Haemolytic uraemic syndrome

Question 1

What is haemolytic uraemic syndrome (HUS)?

Answer 1

Haemolytic uraemic syndrome (HUS) is characterised by microangiopathic haemolytic anaemia, thrombocytopenia, and acute kidney injury.

Question 2

What are the risk factors for HUS?

Answer 2

> ingestion of contaminated food or water
known community outbreak of toxicogenic E coli
exposure to infected individuals in institutional settings
genetic predisposition (atypical HUS)

Question 3

What are the signs and symptoms of HUS?

Answer 3

> Diarrhoea (with blood)
> Young age
> Shiga toxin e coli contaminated food
> Pregnancy
> Previous bone marrow transplant
> FHx

Question 4

What is the epidemiology of HUS?

Answer 4

Shiga toxin-producing Escherichia coli (STEC) HUS is most common in young children (<5 years), but it can be seen at any age with decreasing frequency in older children and adults.

The annual incidence in the US in children <5 years is 2 to 3 per 100,000. In Europe, the prevalence of atypical or recurrent HUS is 3.3 per million children <18 years of age

Question 5

What investigations do you do for HUS?

Answer 5

> FBC- anaemia, thrombocytopenia
peripheral blood smear- schistocytes
creatinine- increased
serum electrolytes- deranged
PT, PTT- normal
LDH- high
haptoglobin- low
stool culture on sorbitol-MacConkey agar to detect Shiga toxin-producing Escherichia coli
polymerase chain reaction (PCR) to detect Shiga toxin 1/Shiga toxin 2
proteins involved in complement regulation- abnormal if atypical HUS