Haemolytic uraemic syndrome (HUS)

• What is Haemolytic Uraemic Syndrome (HUS)
• Statistics on Haemolytic Uraemic Syndrome (HUS)
• Risk Factors for Haemolytic Uraemic Syndrome (HUS)
• Progression of Haemolytic Uraemic Syndrome (HUS)
• Symptoms of Haemolytic Uraemic Syndrome (HUS)
• Clinical Examination of Haemolytic Uraemic Syndrome (HUS)
• How is Haemolytic Uraemic Syndrome (HUS) Diagnosed?
• Prognosis of Haemolytic Uraemic Syndrome (HUS)
• How is Haemolytic Uraemic Syndrome (HUS) Treated?
• Haemolytic Uraemic Syndrome (HUS) References

What is Haemolytic Uraemic Syndrome (HUS)

Haemolytic Uraemic Syndrome is a disorder marked by kidney failure, hemolytic anemia, thrombocytopaenia (platelet deficiency), coagulation defects, and variable nervous system disorders.

Statistics on Haemolytic Uraemic Syndrome (HUS)

This condition primarily affects young children and infants, occurring more rarely in other age groups. It most commonly follows an infections such as diarrhoea (90%) and the common respiratory tract infections such as colds and flu (10%.) In the US, the incidence in children under 5 years old has been estimated at 2.65 per 100,000 per year.

Risk Factors for Haemolytic Uraemic Syndrome (HUS)

1. Diarrhoeal infection – Certain strains of E. Coli are more likely to induce the syndrome.
2. Respiratory tract infection

Progression of Haemolytic Uraemic Syndrome (HUS)

This condition is most often preceded by a respiratory tract or diarrhoeal infection. This infection is thought to damage the lining of blood vessels throughout the body, resulting in an inappropriate reaction by the body to produce microscopic deposits on the damaged blood vessels of the kidney. The deposits eventually disturb the flow of blood to the kidney itself and will finally result in kidney failure that must be managed in hospital.

How is Haemolytic Uraemic Syndrome (HUS) Diagnosed?

Blood tests will be required to diagnose HUS and gauge the severity of illness. This will allow assessment of the diagnostic features of this condition including low platelets (thrombocytopoenia), red blood cell destruction (haemolysis) and kidney failure. Urine samples will be taken, and will demonstrate haematuria and proteinuria is HUS is present.

Prognosis of Haemolytic Uraemic Syndrome (HUS)

When good medical therapy is available, 95% of patients will recover from this condition. Between 10-50% of patients, however, will have some long-term kidney impairment as a result of this disease. The likelihood of disease occurring again is also increased.

How is Haemolytic Uraemic Syndrome (HUS) Treated?

There are many treatment available for HUS, however, many of them have not been adequate proven in controlled drug trials. The benefit of patient support through acute renal failure is undoubted, however, the benefit of other therapies is still questionable.

Such questionable treatments include anticoagulation agents, antiplatelet agents and synthetic prostacyclins. Provided that the patient is supported through acute renal failure, (which may require dialysis if it cannot be controlled with conservative means) recovery should be anticipated with a variable degree of long term kidney impairment following resolution.

Haemolytic Uraemic Syndrome (HUS) References

[1] Braunwald, Fauci, Kasper, Hauser, Longo, Jameson. Harrison’s Principles of Internal Medicine. 15th Edition. McGraw-Hill. 2001
[2] Corrigan J, Boineau F: Hemolytic-uremic syndrome. Pediatr Rev 2001 Nov; 22(11): 365-9
[3] Cotran, Kumar, Collins 6th edition. Robbins Pathologic Basis of Disease. WB Saunders Company. 1999.
[4] Kumar P, Clark M. CLINICAL MEDICINE. WB Saunders 2002 Pg 545-549.
[5] Longmore M, Wilkinson I, Torok E. OXFORD HANDBOOK OF CLINICAL MEDICINE. Oxford University Press. 2001
[6] Robinson MJ., Roberton DM., Practical Paediatrics 4th Edition. Churchill Livingstone 1999.