Hemolytic uremic syndrome in children — a concise review

Abstract

The hemolytic uremic syndrome (HUS) is characterized by the triad of thrombocytopenia, micro-angiopathic hemolytic anemia and acute renal failure. This review provides a comprehensive overview of the existing literature on the epidemiology, etiology, pathogenesis, clinical presentation, diagnosis and management of HUS. The ongoing controversy regarding the role of antibiotics during the acute enteric phase of the classical HUS and the challenges involved in the management of the atypical diseases are highlighted. The most common cause of HUS is systemic uptake of toxins, and develops in 5–10% of children exposed to verocytotoxin-producing Escherichia coli O157:H7. Children below the age of 5 years are the most susceptible hosts and the main route of spread is by fecal-oral transmission. Other infective agents and complement genetic abnormalities are responsible for 10% of cases, referred to as atypical HUS. The characteristic pathologic findings in HUS are renal endothelial swelling, thrombi in the arterioles and capillaries, and subendothelial fibrin deposits. After 30 years of discovering Shiga toxins and over 15 years after associating it with the development of HUS, there are neither specific predictive factors to identify the most susceptible patients after an infection with E. coli 0157:H7 nor specific treatment for HUS once it has become established. Treatment of HUS is mainly supportive. The introduction of specific toxin neutralizing agents has proven disappointing in clinical practice. Recent trials of E. coli O157:H7 O-specific conjugated polysaccharide vaccines appear promising in preventing the development of HUS.

Keywords

Hemolytic uremic syndrome - E. coli - thrombotic thrombocytopenic purpura - thrombotic microangiopathy - verotoxin