Intravenous Fish Oil and Pediatric Intestinal Failure–Associated Liver Disease: Changes in Plasma Phytosterols, Cytokines, and Bile Acids and Erythrocyte Fatty Acids

Background: Soybean oil (SO) emulsions are associated with intestinal failure–associated liver disease (IFALD); fish oil (FO) emulsions are used to treat IFALD. SO and FO differ with respect to their fatty acid and phytosterol content. In children with IFALD whose SO was replaced with FO, we aimed to (1) quantify changes in erythrocyte fatty acids and plasma phytosterols, cytokines, and bile acids and (2) correlate these changes with direct bilirubin (DB). Design: This study enrolled IFALD children who received 6 months of FO. Blood samples were collected prior to FO, and after 2 weeks and 3 and 6 months of FO. The primary outcome was 3-month vs baseline biomarker concentrations. Results: At study initiation, the median patient age was 3 months (interquartile range, 3–17 months), and mean ± standard deviation DB was 5.6 ± 0.7 mg/dL (n = 14). Cholestasis reversed in 79% of subjects. Eicosapentaenoic and docosahexaenoic acid was greater than baseline (P <.001, all time points). Linoleic and arachidonic acid and sitosterol and stigmasterol were less than baseline (P <.05, all time points). Three- and 6-month interleukin-8 (IL-8) and total and conjugated bile acids were less than baseline (P <.05). Baseline IL-8 was correlated with baseline DB (r = 0.71, P <.01). Early changes in stigmasterol and IL-8 were correlated with later DB changes (r = 0.68 and 0.75, P <.05). Conclusion: Specific fat emulsion components may play a role in IFALD. Stigmasterol and IL-8 may predict FO treatment response.