Haemolytic Uraemic Syndrome (Hus) In Children

Potentially harmful

May increase the release of Shiga-like toxins during the diarrheal illness

May decrease the duration of E. coli O157:H7 infection

Associated with high mortality and/or longer duration of diarrhoea

There are some antibiotics, especially fosfomycin, which may reduce the risk of developing HUS

Avoid use of antibiotics unless HUS is associated with an entero-invasive species of Shigella

Anti-hypertensive therapy may be necessary

Blood transfusion to raise haemoglobin up to 70 g/L (not to normal)

Avoid anti-motility agents, narcotics and non-steroidal anti-inflammatory drugs during the acute phase

Dialysis may be required if anuria persist longer than 24-48 hrs

They require dialysis therapy more often

More likely to require prolonged hospitalisation or have persistent thrombocytopenia

Less likely to require platelet transfusions and need less packed red blood cell transfusions

Infection caused by S pneumoniae accounts for nearly 40% of cases of non-enteropathic HUS

The long-term prognosis for recovery of renal function appears to be good

Shiga-like toxins (Stx-1 and Stx-2) produced by STEC are responsible for the systemic complications of HUS

Shiga toxins bind to host cells which express the neutral glycolipid receptors bearing a terminal globotriaosylceramide (Gb3) moiety

The basis for the multi-organ system disease in HUS is endothelial cells damage via the inhibition of protein synthesis, activation to produce inflammatory mediators, and amplification of the pro-thrombogenic state

Young children express low levels of Stx receptors in their renal glomeruli

Stx receptors may become down-regulated by the effects of LPS and cytokines in adults and older children

Complications in the acute phase of HUS can include intussusception, renal failure, hypertension, encephalopathy, pancreatitis and seizures

Insulin-dependent diabetes mellitus may present as a long term complication

2.5% to 10% will either die during the acute illness or have permanent renal failure

Patients with atypical HUS are more likely to develop complications with recurrent disease episodes, severe hypertension, pancreatitis, hepatitis, cardiac failure, chronic and end-stage renal failure

Patients with genetic HUS have an alarmingly high risk of graft loss from disease recurrence or thrombosis

Atypical- or non-Shiga toxin-associated HUS can be either sporadic or familial

Up to 50% of cases of aHUS involve abnormalities of the complement regulatory genes including factor H (CFH), membrane cofactor protein (MCP; CD46), and factor I (IF)

Other cases are caused by Von Willebrand factor-cleaving protease (ADAMTS 13) mutations, as well as intracellular defect in vitamin B12 metabolism

Factor B mutants leading to formation of hyper-functional C3-convertase and mutations of serum thrombomodulin occurs in about 5% of patients with atypical HUS

Patients with the CFH mutation have the most severe prognosis, with 60% of them developing end-stage renal disease (ESRD) or dying within one year

The functional state of PMN

Duration of anuria or oliguria

Renal function assessment for a minimum of one year after HUS should be routinely conducted on all patients

Long-term follow-up is required for children with proteinuria, hypertension, abnormal ultrasound and/or impaired GFR at 1 year

The presence of factor H (CFH) and factor I (IF) mutations have been associated with a high incidence of graft failure while membrane cofactor protein (MCP) is associated wit a more favourable outcome