Hemolytic uremic syndrome: long term renal injury

Introduction: Hemolytic uremic syndrome (HUS) is the most frequent cause of non-prerenal acute renal failure in pediatrics and it is usually secondary to acute infectious diarrhea, generally due to Shiga-toxin producing E. coli. It is characterized by acute renal failure, hemolytic anemia and thrombocytopenia. It can lead to renal sequels in the long term and to end-stage renal disease. Methods: The aim of this retrospective study is to describe and analyze renal sequels and their prognostic factors in pediatric patients suffering from HUS in a Spanish tertiary hospital during the last 28 years. Results: 43 children with this condition were admitted, with 38 of them having presented with diarrhea previously. Among those with a follow-up longer than 3 months, 21.6% (8/37) had a reduction in glomerular filtration rate (GFR) in the last visit. Including proteinuria and hypertension, we found up to 35.1% (13/37) prevalence of chronic kidney disease, with 8.1% (3/37) of the patients with end-stage renal disease. We found the following to be prognostic factors for renal injury in the long term in a univariate logistic regression: hypertension, a longer stay in the hospital, more prolonged anuria, more severe leukocytosis and lower GFR at discharge. Multivariate logistic regression showed an association with time in anuria. Conclusions: Approximately one third of our cases of hemolytic uremic syndrome developed some degree of chronic kidney disease in the long term. A deeper and longer initial renal disfunction is associated with a higher probability of subsequent renal problems. (C) 2009 Asociacion Espanola de Pediatria. Published by Elsevier Espana, S.L. All rights reserved.