Case Report Treatment of Shiga-Toxin Hus with Severe Neurologic Features with Eculizumab Jacob H. Umscheid , 1 Collin Nevil, 1 Rhythm Vasudeva, 1 Mohammed Farhan Ali, 1,2 and Nisha Agasthya 1 1 University of Kansas, School of Medicine, Wichita, USA 2 Children’s Mercy Hospital, Department of Nephrology, Kansas City, USA Correspondence should be addressed to Jacob H. Umscheid; jumscheid3@kumc.edu Received 16 August 2021; Accepted 5 November 2021; Published 13 November 2021 Academic Editor: Junji Takaya Copyright © 2021 Jacob H. Umscheid et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Hemolytic Uremic Syndrome (HUS) is a constellation of microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Shiga toxin-producing Escherichia coli- (STEC-) mediated HUS is a common cause of acute renal failure in children and can rarely result in severe neurological complications such as encephalopathy, seizures, cerebrovascular accidents, and coma. Current literature supports use of eculizumab, a monoclonal antibody that blocks complement activation, in atypical HUS (aHUS). However, those with neurologic complications from STEC-HUS have complement activation and deposition of ag- gregates in microvasculature and may be treated with eculizumab. In this case report, we describe a 3-year-old boy with diarrhea- positive STEC-HUS who developed severe neurologic involvement in addition to acute renal failure requiring renal replacement therapy. He was initiated on eculizumab therapy, with clinical improvement and organ recovery. is case highlights systemic complications of STEC-HUS in a pediatric patient. e current literature is limited but has suggested a role for complement mediation in cases with severe complications. We review the importance of early recognition of complications, use of eculizumab, and current data available. 1. Introduction Shiga toxin-producing Escherichia coli (STEC) is a well- known etiology for gastroenteritis and colitis; however, the toxin can traverse through the gastrointestinal system into the bloodstream causing injury to vascular endothelial cells [1, 2]. is results in a microangiopathic hemolytic anemia, thrombocytopenia, and renal failure, also known as he- molytic uremic syndrome (HUS) [1, 3]. HUS is a common cause of acute kidney injury in children, accounting for around 17% of cases and usually between the ages of 1 to 5 years (74%) [4]. is is secondary to toxin binding to the renal endothelial cells, but may extend to extrarenal tissue resulting in severe neurological complications of altered mental status, seizures, cerebrovascular accidents, and coma [5]. When neurologic complications of HUS are present, the risk of severe sequelae and mortality significantly increases [6, 7]. In a large retrospective cohort study of 3915 pediatric patients, 10.4% developed acute neurologic manifestations and had significantly worse mortality (13.9%) when com- pared to HUS patients without neurologic involvement (1.8%) [6]. Endothelial injury to small vessels through Shiga-like toxin binding to globotriaosylceramide (Gb3) receptors and microvascular thrombosis results in the majority of damage to organs in HUS [8]. e Gb3 receptor is present not only throughout renal and cerebral microvascular endothelial cells but also on neuronal cells, placing the entire central nervous system (CNS) at risk for injury [8]. Also seen is an increase in cytokine production in response to Shiga-like toxin at the blood-brain barrier resulting in cytotoxic effects to the CNS parenchyma [7, 9–11]. is increased inflam- matory response may suggest why immunomodulators, such as eculizumab, may have a role in management. Hindawi Case Reports in Pediatrics Volume 2021, Article ID 8053246, 6 pages https://doi.org/10.1155/2021/8053246