Influence of the Slow Infusion of a Soybean Oil Emulsion on Plasma Cytokines and Ex Vivo T Cell Proliferation After an Esophagectomy

Background: Lipid emulsions have been suggested to reduce immune responses, particularly in severely stressed patients. The authors investigated the influence of the slow intravenous infusion of a soybean oil–based lipid emulsion on some immune parameters in patients who had undergone an esophagectomy for esophageal cancer. Methods: Thirty-two patients who had undergone an esophagectomy were randomly divided into a lipid emulsion (LPD)–treated group and a control group. All patients received parenteral feeding with a glucose-based solution. Patients in the LPD group received 100 mL of a 20% soybean oil emulsion for 7 days after the esophagectomy in addition to the glucose-based feeding. A slow infusion rate (0.09–0.12 g/kg/h) was adopted to take account of the intrinsic degradation of infused lipids. Immune responses were measured based on lymphocyte proliferation and serum concentrations of monocyte chemoattractant protein–1 (MCP-1), interleukin-6 (IL-6), and tumor necrosis factor–α (TNF-α). The authors also measured levels of rapid turnover proteins (ie, transferrin, prealbumin, and retinol-binding protein). Results: Phytohemagglutinin- and concanavalin A–stimulated lymphocyte proliferation significantly decreased after the esophagectomy, but no significant difference was seen between the LPD and control groups. No significant difference in changes in plasma concentrations of MCP-1, IL-6 and TNF-α occurred between the 2 groups either. Plasma concentrations of rapid turnover proteins did not differ between the groups. Conclusions: These results indicate that the lipid emulsion did not affect the immune parameters measured in patients who had undergone an esophagectomy when administered at a slow rate.