A Tool to Eliminate IgM Immunoassay Interference.

Area of Science:

• Biochemistry
• Immunology
• Analytical Chemistry

Background:

• Immunoassays are crucial for bioanalysis.
• Rheumatoid factor (RF) and treatment-emergent IgM can interfere with immunoassay results.
• Accurate quantification of immune responses is essential, particularly in gene therapy studies.

Purpose of the Study:

• To evaluate a novel IgM-selective protease for bioanalytical applications.
• To demonstrate the protease's ability to eliminate RF interference and simplify IgM isotyping.
• To investigate the impact of treatment-emergent IgM on anti-capsid IgG assays.

Main Methods:

• Utilized a newly developed IgM-selective protease.
• Applied protease treatment in three distinct bioanalytical scenarios.
• Analyzed immunoassay results before and after selective IgM digestion.

Main Results:

• Protease treatment successfully eliminated rheumatoid factor interference.
• IgM isotyping was significantly simplified following protease application.
• Selective IgM digestion resolved underestimated immune responses in an anti-capsid IgG assay caused by treatment-emergent IgM.

Conclusions:

• IgM-selective proteolytic cleavage is a valuable tool for enhancing immunoassay performance.
• This protease effectively removes common interferences, improving assay accuracy and simplifying complex analyses.
• The findings highlight the importance of addressing IgM interference in gene therapy immunogenicity assessments.