Total interleukin-6 in plasma measured by immunoassay

Area of Science:

• Biochemistry
• Immunology
• Biotechnology

Background:

• Immunoassays for cytokine quantification face challenges from analyte heterogeneity and interfering proteins.
• Accurate measurement of interleukin-6 (IL-6) is crucial for understanding various biological processes and diseases.

Purpose of the Study:

• To develop an ultrasensitive enzyme immunoassay for accurate determination of total IL-6.
• To address and overcome common interference issues in cytokine measurements, specifically from cytokine-binding proteins.

Main Methods:

• Development of a novel enzyme immunoassay utilizing monoclonal antibodies and acetylcholinesterase tracer.
• Investigation of antibody recognition of different IL-6 forms (recombinant, glycosylated, dimeric).
• Assessment and mitigation of interference from soluble IL-6 receptor (sIL-6R) through heat treatment.

Main Results:

• The immunoassay demonstrated equal recognition of recombinant and glycosylated IL-6 forms.
• Heat treatment effectively eliminated interference from high concentrations of soluble IL-6 receptor (sIL-6R).
• Validation using plasma matrix calibrators confirmed accurate total IL-6 measurement in diverse serum and plasma samples.

Conclusions:

• The developed ultrasensitive enzyme immunoassay provides a reliable method for quantifying total IL-6.
• The assay effectively overcomes biochemical heterogeneity and protein interference, enabling accurate measurements in clinical samples.
• This method offers improved accuracy for IL-6 determination in both normal and pathological conditions.