Online Articles: Clinical and Laboratory ObservationsHemophagocytic Lymphohistiocytosis in Total Parenteral Nutrition Dependent Children Description of 5 Cases and Practical Tips for ManagementPastore, Serena MD; Barbieri, Francesca MD; Leo, Grazia Di MD; Valencic, Erica MSc, PhD; Tommasini, Alberto MD, PhD; Ventura, Alessandro MD Author Information *Department of Pediatrics, University of Trieste †Institute for Maternal and Child Health, IRCCS Burlo Garofolo, Trieste, Italy The authors declare no conflict of interest. Reprints: Serena Pastore, MD, Department of Pediatrics, University of Trieste, via dell’Istria 65/1, Trieste 34137 Italy (e-mail: [email protected]). Received March 6, 2013 Accepted May 24, 2013 Journal of Pediatric Hematology/Oncology 36(7):p e440-e442, October 2014. | DOI: 10.1097/MPH.0b013e31829f381b Buy Metrics Abstract Although total parenteral nutrition (TPN) is mandatory in children with intestinal failure, this treatment is not risk free. The main complications of TPN include catheter-related sepsis, thrombosis, hepatic cholestasis and cirrhosis, metabolic bone disease, and, rarely, reactive hemophagocytic lymphohistiocytosis (HLH). The pathogenesis of HLH in patients with TPN is not known, although some authors hypothesized that it can result from the activation of macrophages because of “fat overload.” We reported 5 cases of HLH that occurred in patients with 4 different underlying disorders, all requiring TPN for a long term. In our series, an underlying immunological defect or a serious infection (sepsis) can have triggered HLH. Therefore, it could be reasonable to hypothesize that besides TPN in itself, minor immune defects and infections may act together by overcoming a threshold of immune stimulation, which ultimately leads to HLH. Copyright © 2014 Wolters Kluwer Health, Inc. All rights reserved.