Hemolytic uremic syndrome in a Pediatric Intensive Care Unit- Rapid review with case series

Hemolytic uremic syndrome (HUS) is a multiorgan clinical syndrome characterized by the simultaneous occurrence of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. This is the most important form of thrombotic microangiopathies in children and is considered the main cause of acute renal insufficiency in children, especially under the age of five. Over 90% of HUS in children is associated with infection, and the prodromal manifestation most often includes bloody diarrhea. Atypical hemolytic uremic syndrome (aHUS) is a rare but progressive, life-threatening condition that affects about 10% of HUS cases in children. It is predominantly caused by dysregulation of the alternative complement pathway and genetic predisposition. Conditions that enhance complement, such as some viral infections, malignancies, autoimmune diseases and transplantation may be comorbid in up to 70% of aHUS cases. The 2016 International Hemolytic Uremic Syndrome Group classification, based on the etiology, separates 4 groups: caused by infection, with coexisting conditions, due to cobalamin C disorders and due to complement dysregulation. Monoclonal antibody that effectively blocks complement activation, has significantly changed aHUS treatment and outcome. Early etiological recognition in order to start specific treatment as soon as possible is crucial for the outcome. This paper, through a rapid review and series of three children treated for HUS in our pediatric intensive care unit over a two-year period, aims to emphasize the complexity of the diagnosis and treatment of HUS, and the importance of a multidisciplinary team in order to to avoid complications, and achieve the best short- and long-term outcome