A sensitive and selective ELISA methodology quantifies a demyelination marker in experimental and clinical samples

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• Sciatic nerve chronic constriction injury (CCI) in rodents causes demyelination through proteolysis of myelin basic protein (MBP).
• Proteolysis releases a cryptic MBP epitope, a marker of demyelination, which is normally hidden within the intact MBP structure.
• The link between proteolytic release of this cryptic MBP autoantigen and increased circulating autoantibodies post-injury remained unestablished.

Purpose of the Study:

• To develop and validate an enzyme-linked immunosorbent assay (ELISA) for quantifying circulating autoantibodies against the cryptic MBP84-104 epitope.
• To investigate the presence and dynamics of these autoantibodies in rat serum following CCI.
• To assess the applicability of the developed ELISA for detecting demyelination and quantifying autoantibodies in human patients.

Main Methods:

• Developed a novel ELISA using the cryptic 84-104 MBP sequence (MBP84-104) as bait to capture specific autoantibodies.
• Quantified circulating IgM and IgG autoantibodies in rat serum at various time points post-CCI.
• Validated ELISA’s intra-assay precision and inter-assay repeatability, and assessed its specificity using intact MBP and the isolated epitope.

Main Results:

• Circulating IgM autoantibodies against MBP84-104 were detectable from day 7 post-CCI, with levels increasing up to day 28.
• The developed ELISA demonstrated high precision (2.87% intra-assay) and repeatability (4.58% inter-assay).
• The ELISA successfully detected both IgG and IgM autoantibodies in a pilot study of human patients with demyelinating conditions.

Conclusions:

• The novel ELISA effectively quantifies circulating autoantibodies against the pathogenic MBP84-104 peptide, facilitating demyelination identification in experimental and clinical settings.
• This assay may aid neurologists in recognizing patients with painful neuropathy and demyelinating diseases, enabling personalized treatment strategies.
• The findings establish a new biomarker for monitoring demyelination and autoimmune responses in neurological disorders.