Albuminuria and Estimated GFR 5 Years After Escherichia coli O157 Hemolytic Uremic Syndrome: An Update

Garg, Amit X.; Salvadori, Marina; Okell, Justin M.; Thiessen-Philbrook, Heather R.; Suri, Rita S.; Filler, Guido; Moist, Louise; Matsell, Douglas; Clark, William F.; Walkerton Health Study Investigators,

doi:10.1053/j.ajkd.2007.10.042

« Previous Next »American Journal of Kidney Diseases
Volume 51, Issue 3 , Pages 435-444, March 2008

Albuminuria and Estimated GFR 5 Years After Escherichia coli O157 Hemolytic Uremic Syndrome: An Update

Amit X. Garg, MD, PhD
- Division of Nephrology, University of Western Ontario, London, Canada
- Department of Epidemiology and Biostatistics, University of Western Ontario, London, 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.
Marina Salvadori, MD
- Division of Pediatric Infectious Diseases, University of Western Ontario, London, Canada
Justin M. Okell, BSc
- Division of Nephrology, University of Western Ontario, London, Canada
Heather R. Thiessen-Philbrook, MMath
- Division of Nephrology, University of Western Ontario, London, Canada
Rita S. Suri, MD
- Division of Nephrology, University of Western Ontario, London, Canada
Guido Filler, MD
- Division of Nephrology, University of Western Ontario, London, Canada
Louise Moist, MD, MSc
- Division of Nephrology, University of Western Ontario, London, Canada
- Department of Epidemiology and Biostatistics, University of Western Ontario, London, Canada
Douglas Matsell, MD
- Division of Pediatric Nephrology, University of British Columbia, Vancouver, Canada.
William F. Clark, MD
- Division of Nephrology, University of Western Ontario, London, Canada
Walkerton Health Study Investigators

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.

Index Words: Cohort study, Escherichia coli O157, hemolytic uremic syndrome, hypertension, proteinuria, chronic kidney disease, diabetes