Hemolytic uremic syndrome: defining the need for long-term follow-up

Background: Diarrhea-associated (D+) hemolytic uremic syndrome (HUS) is a c ommon cause of acute renal failure in children. Progressive renal insuffici ency has been documented on prolonged follow-up of selected patients. Howev er, it is uncertain whether all children recovering from varying degrees of HUS require long-term follow-up. Patients and methods: We reviewed the out come of 114 patients with D+ HUS presenting to a regional pediatric unit be tween January 1986 and December 1996. Yearly clinical review post illness i ncluded measurement of blood pressure and urinalysis for proteinuria with p lanned GFR assessments by Cr-51 EDTA slope clearance at 1 and 5 years. Resu lts: Treatment of the HUS was conservative in 27%, by peritoneal dialysis i n 62%, hemodialysis in 4% and both peritoneal and hemodialysis in 7%. Ninet y-two patients were assessed at 1 year - of these, 1 remained on chronic pe ritoneal dialysis, 5 (5%) had moderate to severe chronic renal failure (CRF ) (GFR 25 - 50 ml/min/1.73 m(2)), 20 (22%) had mild CRF (GFR 50 - 80) and 6 6 (72%) had normal renal function (greater than or equal to 80 ml/min/1.73 m(2)). Forty patients have had GFRs performed at 1 and 5 years. Of the 28 p atients with a normal GFR at 1 year, 3 deteriorated into mild CRF at 5 year s. One patient has a single kidney and one had significant proteinuria at 1 year, factors which would have led to long-term follow-up. There was a neg ative correlation between number of days of dialysis and GFR at 1 year with a Pearson's correlation coefficient of -0.453 (p < 0.01). Conclusion: We c on elude that renal function at 1 year following HUS cannot be predicted wi th any certainty from the initial illness and should be formally assessed. However, renal function was within normal limits and remained stable betwee n 1 and 5 years following HUS in most children. The results suggest that lo nger-term follow-up can probably be restricted to those with proteinuria, h ypertension, abnormal ultrasound and/or impaired GFR at 1 year.