Related Experiment Video
Updated: Apr 28, 2026
Author Spotlight: Novel Assay for Studying B-Cell Responses in Multiple Sclerosis Research
Published on: December 1, 2023
Immunoglobulin M oligoclonal bands: biomarker of targetable inflammation in primary progressive multiple sclerosis
Luisa M Villar1, Bonaventura Casanova, Nadia Ouamara
1Immunology and Neurology Service, Multiple Sclerosis Unit, Ramón y Cajal University Hospital, Madrid, Spain.
Objective:
To identify a biomarker distinguishing patients who, despite a primary progressive multiple sclerosis (PPMS) clinical course, may nonetheless benefit from immune therapy.
Methods:
The presence or absence of both immunoglobulin (Ig) G and IgM oligoclonal bands (OCB) was blindly examined in paired cerebrospinal fluid (CSF) and serum samples from a large PPMS patient cohort, and related to clinical and imaging evidence of focal inflammatory disease activity.
Results:
Using both cross-sectional samples and serial sampling in a subgroup of patients followed prospectively as part of the placebo-controlled OLYMPUS study of rituximab in PPMS, we found that the presence of CSF-restricted IgM OCB (but not of IgG OCB) is associated with an active inflammatory disease phenotype in PPMS patients. This finding was confirmed in an independent, multicenter validation cohort.
Interpretation:
The presence of CSF IgM OCB may be a biomarker for a subset of PPMS patients with more active inflammatory disease, who may benefit from immune-directed treatments.
