Although liver disease is a major complication of parenteral nutrition (PN) for intestinal failure (IF), its pathogenesis remains unclear. We investigated potential molecular mechanisms of liver injury in pediatric onset IF.
Liver expression of canalicular phospholipid (ABCB4), bile acid (ABCB11), and sterol (ABCG5/8) transporters, their upstream regulators LXR and FXR as well as pro-inflammatory cytokines interleukin-6 (IL6) and tumor necrosis factor (TNF) were investigated among patients with IF [age median 3.8 (IQR 1.2 to 11)] in relation to biochemical and histologic liver injury, PN, serum plant sterols, fibroblast growth factor 19, and α-tocopherol.
Patients receiving PN currently (n = 18) showed more advanced liver injury than patients after weaning off PN (n = 30). Histologic portal inflammation strongly segregated PN-dependent (44%) from weaned off patients (3%, P = 0.001) and coupled with progression of cholestasis and liver fibrosis. Patients with portal inflammation demonstrated markedly induced liver RNA expression of IL6 and TNF, repression of FXR and its canalicular bile transporter target gene RNA expression, including ABCB4 and ABCB11 as well as decreased protein expression of ABCB11 and ABCB4. Furthermore, upregulation of LXR and ABCG5/8 RNA expression was suppressed in patients with portal inflammation. Current PN, increased serum levels of plant sterols stigmasterol, avenasterol, and sitosterol along with serum citrulline, a marker of enterocyte mass, predicted portal inflammation.
In pediatric onset IF, current PN delivery synergistically with intestinal compromise promote liver inflammation, which associates with progression of biochemical and histologic liver injury, while reducing expression of canalicular bile transporters.
*Section of Pediatric Surgery, Pediatric Liver and Gut Research Group, Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
†Department of Pathology, HUSLAB, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland
‡Department of Pediatric Nephrology and Transplantation, Children's Hospital, Helsinki University Central Hospital, University of Helsinki, Helsinki, Finland.
Reprints: Mikko P. Pakarinen, MD, PhD, P.O Box 281, Stenbäckinkatu 11, 00029 HUS, Helsinki, Finland. E-mail: firstname.lastname@example.org.
This study was supported by grants from the Finnish Pediatric Research Foundation, the Sigrid Juselius Foundation and the Helsinki University Central Hospital research funds.
The authors have nothing to disclose.
The authors received no writing assistance.
Study concept and design: MPP; acquisition of data: AM; analysis and interpretation of data: AM, MPP; drafting of the manuscript: AM, MPP; critical revision of the manuscript for important intellectual content: JL, HJ; statistical analysis: AM; obtained funding: MPP; administrative, technical, or material support: HJ; study supervision: MPP. All authors have agreed on the content of the manuscript. The authors have no conflicts of interest.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.annalsofsurgery.com).