Long-term prognosis of hemolytic uremic syndrome and effective renal plasma flow

The long-term prognosis of diarrhea-associated hemolytic uremic syndrome (D + HUS) was evaluated in a cohort of 127 of 149 children who had survived th e acute phase. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were estimated by serial Cr-51-EDTA and (123)iodine-hippurate c learances. All children had acute renal failure during the initial phase an d 74% of patients were dialyzed. During the Ist year, mean GFR and ERPF inc reased continuously until a plateau was reached. In the 2nd year after the diagnosis of HUS, GFR was below 80 and ERPF below 515 ml/min per 1.73 m(2) in 16% and 47% of patients, respectively. At the end of a median follow-up of 5.0 (range 2.0-13.2) years, the proportion of children with renal sequel ae such as proteinuria greater than or equal to 300 mg/l, hypertension, or a GFR <80 ml/min per 1.73 m(2) was 23%. Anuria of more than 7 days' duratio n and hypertension during the acute phase were statistically significant ri sk factors for an unfavorable outcome. A reduced ERPF in the 2nd year was f ound in 93% of patients with sequelae. Mean filtration fraction (SD) in the se patients was 0.26 (+/-0.07) versus 0.19 (+/-0.05) in patients without se quelae (P<0.0001). These data suggest that loss of nephrons during the acut e phase may implicate hyperfiltration in the residual functioning kidney ma ss leading to progressive renal disease. ERPF in the 2nd year after D+ HUS may serve as an excellent parameter to detect patients with a high risk of an unfavorable long-term outcome.