Analysis of circulating immune complexes isolated from plasma, cerebrospinal fluid and urine

Area of Science:

• Biochemistry
• Immunology
• Clinical Chemistry

Background:

• Soluble immune complexes (IC) play roles in various physiological and pathological processes.
• Understanding the protein composition of IC in different body fluids is crucial for disease diagnosis.
• Existing methods for IC analysis may lack comprehensive protein characterization.

Purpose of the Study:

• To investigate the protein nature of soluble immune complexes (IC) in plasma, cerebrospinal fluid (CSF), and urine.
• To develop and apply a robust method for separating and analyzing IC from diverse biological samples.
• To assess the utility of the developed method in clinical cases.

Main Methods:

• Gel filtration chromatography (Fast Protein Liquid Chromatography) for separating free immunoglobulins G from IC in plasma and CSF.
• Polyethylene glycol precipitation for IC isolation from urine.
• Protein-A and Protein-G affinity chromatography for IC purification.
• Two-dimensional gel electrophoresis for detailed protein analysis of IC.

Main Results:

• Successfully separated and characterized soluble immune complexes from plasma, CSF, and urine.
• Demonstrated the method's applicability to samples from healthy donors and patients with conditions like macro-creatine kinase type 1, multiple sclerosis, and urinary tract infections.
• Identified distinct protein profiles of IC in different body fluids.

Conclusions:

• The combined chromatographic and electrophoretic techniques provide a powerful approach for analyzing the protein composition of soluble immune complexes in body fluids.
• This method facilitates the examination of IC with unknown protein constituents.
• The findings support the potential of IC analysis as a diagnostic tool in various clinical settings.