Structural study on immunoglobulin G solution after pasteurization with and without stabilizer.

Area of Science:

• Biochemistry
• Biotechnology
• Virology

Background:

• Intravenous immunoglobulin (IVIG) therapy requires safe and effective viral inactivation methods.
• Pasteurization is a potential method for viral inactivation in protein therapeutics.

Purpose of the Study:

• To evaluate pasteurization for viral inactivation in immunoglobulin preparations.
• To determine the impact of pH, protein concentration, and stabilizers on immunoglobulin G (IgG) structure during pasteurization.

Main Methods:

• Investigated IgG solutions from Cohn's fraction II.
• Analyzed structural changes (secondary, tertiary, polymerization) using spectrophotometry, circular dichroism, and size exclusion chromatography.
• Varied pH, protein concentration, and presence of stabilizers (glycine, sucrose, sorbitol).

Main Results:

• Minimal structural changes in IgG at 10 g/L (pH 4.5-5.5) without stabilizers.
• Minimal structural changes in IgG at 50 g/L with stabilizers (glycine, sucrose, sorbitol) at pH 5.5.
• IgG concentrations below 20 g/L were stable at pH 4.5 without stabilizers.
• Higher IgG concentrations required stabilizers to prevent denaturation.

Conclusions:

• Pasteurization is a viable method for viral inactivation in IVIG preparation.
• Specific pH ranges and the use of stabilizers like glycine, sucrose, or sorbitol are crucial for maintaining IgG structural integrity during pasteurization.
• Optimized pasteurization conditions can ensure the safety and efficacy of IVIG products.