Mechanisms of intralipid effect on polymorphonuclear leukocytes

Area of Science:

• Immunology
• Nutritional Science
• Cell Biology

Background:

• Intralipid is a lipid emulsion vital for total parenteral nutrition.
• Patients receiving parenteral nutrition are susceptible to infections.
• The impact of Intralipid on immune cell function requires clarification.

Purpose of the Study:

• To investigate the in vitro effects of Intralipid on polymorphonuclear leukocytes (PMNL).
• To determine if Intralipid affects PMNL oxidative metabolism, phagocytosis, and Fc receptor expression.

Main Methods:

• PMNL were preincubated with Intralipid.
• Metabolic assays were performed to assess oxidative burst and phagocytosis.
• Fc receptor expression on PMNL was quantified.

Main Results:

• Preincubation with Intralipid depressed PMNL oxidative metabolism and phagocytic functions.
• Intralipid preincubation decreased Fc receptors on PMNL.
• Intralipid stimulated the respiratory burst when added at the start of assays, suggesting activation and exhaustion of pathways.

Conclusions:

• Intralipid acts as a particulate stimulus, potentially exhausting PMNL metabolic pathways.
• Intralipid may reduce PMNL's ability to combat pathogens by decreasing Fc receptors.
• Observed PMNL dysfunction could explain increased infection rates in patients on parenteral hyperalimentation with Intralipid.