Effect of synthetic colloids on major histocompatibility complex class II expression

Area of Science:

• Immunology
• Anesthesiology
• Pharmacology

Background:

• Synthetic colloids are widely used for perioperative fluid management.
• The impact of these colloids on immune system modulation, specifically major histocompatibility complex (MHC) class II expression, is not fully understood.
• Changes in MHC class II expression could potentially influence patient outcomes.

Purpose of the Study:

• To investigate the effect of commonly used synthetic colloids on human leukocyte antigen (HLA) expression.
• To determine if different types and concentrations of plasma expanders alter MHC class II expression on immune cells.
• To assess the influence of interferon-gamma (IFN-gamma) in conjunction with plasma expanders on HLA expression.

Main Methods:

• Healthy volunteer whole blood samples were incubated with varying concentrations of hydroxyethyl starch (HES), potato-derived HES (pHES), dextran, and polygelin (gelatine) for 24 hours.
• Samples were treated with or without human interferon-gamma (IFN-gamma) as a stimulus for MHC class II expression.
• Flow cytometry was used to analyze the expression of HLA-DR, HLA-DQ, and HLA-DP on lymphocytes and monocytes.

Main Results:

• Hydroxyethyl starch, pHES, and dextran significantly increased HLA expression on lymphocytes and monocytes, independent of their structure.
• Polygelin demonstrated a dose-dependent increase in HLA expression, with significant elevation only at the highest concentration.
• The addition of IFN-gamma reduced HLA expression when combined with high concentrations of HES and dextran.

Conclusions:

• Ex vivo laboratory experiments show that high concentrations of plasma expanders (HES, pHES, dextran) are associated with elevated HLA expression.
• Polygelin exhibits a concentration-dependent effect on HLA expression.
• Further in vivo studies are required to establish the clinical relevance of these observed changes in HLA expression.