Is Plasma Exchange Efficacious in Shiga Toxin-Associated Hemolytic Uremic Syndrome? A Narrative Review of Current Evidence.

Shiga toxin-associated hemolytic uremic syndrome (STEC-HUS) is associated with significant mortality and morbidity. Case fatalities are often associated with severe neurological involvement in children and advanced age in adults but specific treatment is currently unavailable. Plasma exchange (PE) could theoretically enable removal of Shiga toxins, pro-inflammatory cytokines, and prothrombotic factors and has been used in deteriorating patients with STEC-HUS but the efficacy remains uncertain. In order to assess efficacy of PE in STEC-HUS, a literature review was performed. PubMed, Web of Science, Embase, and LiLACS were searched for reports describing the outcomes of patients with STEC-HUS treated with PE and 16 reports were included. Reports ranged from case reports to cohort studies and one case-control study with the largest study population coming from the 2011 German STEC-HUS outbreak. Outcomes were variable but seemed to point towards lower case fatality rates in the elderly and improved outcomes in children with STEC-HUS, treated with PE early in the course. However studies were mostly of low quality with risk of observation bias and confounding. Currently no definitive answers concerning the efficacy of PE in STEC-HUS can be given, highlighting the need for well performed randomized controlled trials.