Albuminuria and Estimated GFR 5 Years After Escherichia coli O157 Hemolytic Uremic Syndrome: An Update
Received 29 July 2007; accepted 22 October 2007. published online 28 January 2008.
Background
Knowledge of the long-term prognosis of patients with diarrhea-associated hemolytic uremic syndrome (HUS) is important for patient counseling and follow-up. Estimates in the literature are highly variable, and previous studies did not use a healthy control group to establish outcomes attributable to HUS.
Study Design
Prospective cohort study.
Setting & Participants
19 children who recovered from HUS after contamination of their municipal water supply by Escherichia coli O157:H7.
Predictor
Outcomes of children who recovered from HUS were compared with a control group of 64 children who were healthy at the time of the outbreak. Both groups were similar in their demographics and follow-up testing.
Outcomes & Measurements
Proteinuria, blood pressure, glomerular filtration rate (GFR) estimated by using serum creatinine or cystatin C level, and biochemical measures 5 years after the outbreak.
Results
More children who recovered from HUS showed microalbuminuria than controls (20% versus 3%; relative risk, 6.0; 95% confidence interval, 1.1 to 32.8). There were no differences between groups in blood pressure or GFR when estimated by using serum creatinine level. GFR estimated by using cystatin C level was lower after HUS compared with controls (100 versus 110 mL/min/1.73 m2; P = 0.02), but no child had a GFR less than 80 mL/min/1.73 m2. Other results, including fasting glucose, albumin, and C-reactive protein levels, did not differ between groups.
Limitations
Although the homogenous nature of this outbreak is a strength, long-term results may generalize less well to patients with other strains of toxigenic E coli or in other settings.
Conclusions
The prognosis of patients with HUS in this cohort was better than in other studies. Ongoing follow-up will clarify the clinical relevance of microalbuminuria and mild decreases in GFR 5 years after HUS recovery.
1Division of Nephrology, University of Western Ontario, London, Canada
2Department of Epidemiology and Biostatistics, University of Western Ontario, London, Canada
3Division of Pediatric Infectious Diseases, University of Western Ontario, London, Canada
4Division of Pediatric Nephrology, University of British Columbia, Vancouver, Canada.
Address correspondence to Amit X. Garg, MD, PhD, Associate Professor, Medicine & Epidemiology, University of Western Ontario, Kidney Clinical Research Unit, Rm ELL-101, Westminster Tower, London Health Sciences Centre, 800 Commissioners Rd East, London, Ontario N6A 4G5, Canada.
A list of the Walkerton Health Study Investigators appears at the end of this article.
ABSTRACT