Measles virus polypeptide-specific antibody profile in multiple sclerosis

Area of Science:

• Neuroimmunology
• Virology
• Immunology

Background:

• Elevated measles virus (MV) antibody titers are common in multiple sclerosis (MS).
• The origin of intrathecal MV antibodies in MS remains unclear, with hypotheses including B cell activation, direct MV antigen recognition, or molecular mimicry with myelin antigens.

Purpose of the Study:

• To investigate the source of intrathecal MV antibodies in MS by examining reactivity to specific MV polypeptides.
• To differentiate between polyclonal B cell activation and antigen-specific responses within the central nervous system (CNS).

Main Methods:

• Analysis of antibody reactivity against purified MV polypeptides in serum and cerebrospinal fluid (CSF).
• Comparison of antibody profiles in MS patients, subacute sclerosing panencephalitis (SSPE) patients, other neurologic disease (OND) patients, acute MV infection, and healthy controls.
• Assessment of intrathecal antibody synthesis using established methods.

Main Results:

• All subjects showed serum reactivity to MV and its polypeptides.
• CSF reactivity to MV was significantly higher in MS patients (20/21) and SSPE patients (5/5) compared to OND patients (3/11).
• Intrathecal MV antibody synthesis was confirmed in 11/21 MS patients and 5/5 SSPE patients, with 9/21 MS patients showing intrathecal synthesis against specific MV polypeptides, particularly the F polypeptide.

Conclusions:

• The findings support the hypothesis of polyclonal B cell activation within the CNS in MS.
• The heightened response to the MV F polypeptide may indicate cross-reactivity with an endogenous antigen relevant to MS pathogenesis.