Heterogeneity of atypical haemolytic uraemic syndromes.

Atypical, non-diarrhoea associated haemolytic uraemic syndrome (D-HUS) is a heterogeneous disorder with a generally poor outcome, although this view has now been questioned. The clinical and laboratory features of 23 children with D-HUS, representing a third of all patients with HUS seen during the last 26 years, were examined. The median age was 4.9 years (range 3 days-13.8 years). Twenty one children (91%) survived the initial phase. All patients except six infants aged < 18 months required dialysis (74%). Hypertension (43%), cardiomyopathy (43%), and cerebral convulsions (48%) were common. Nineteen (83%) children were followed up for a median period of 5.5 years (range 0.5-23.4). Only five (26%) patients, among them four infants, recovered completely. Six (32%) patients had one to 10 recurrences, including two siblings with neonatal onset, and eight (42%) developed end stage renal failure. Five children underwent cadaveric renal transplantation, with recurrence and subsequent graft failure in two. Four children died, resulting in an overall mortality of 26%. Atypical HUS is heterogeneous with regard to epidemiology, pathophysiology, and outcome. Children with a recurrent, familial, or neonatal course have worse outcomes; in contrast, infants not requiring dialysis in the acute phase have a better prognosis.