Pattern II and pattern III MS are entities distinct from pattern I MS: evidence from cerebrospinal fluid analysis

Area of Science:

• Neurology
• Immunology
• Pathology

Background:

• Multiple sclerosis (MS) diagnosis relies on clinical and MRI data.
• Histopathological studies reveal four MS lesion patterns, indicating potential heterogeneity.
• This heterogeneity suggests MS may encompass distinct disease entities rather than a single condition.

Purpose of the Study:

• To investigate differences in cerebrospinal fluid (CSF) findings between MS patterns.
• To assess intrathecal IgG synthesis in relation to MS pathological patterns.
• To differentiate MS patterns from mimics like aquaporin-4-IgG and myelin oligodendrocyte glycoprotein-IgG disorders.

Main Methods:

• Retrospective analysis of 68 lumbar punctures from patients with classified MS patterns (I, II, III).
• Evaluation of CSF findings, including oligoclonal bands (OCBs) and intrathecal IgG synthesis.
• Assessment of blood-CSF barrier function using albumin CSF/serum ratio (QAlb).

Main Results:

• Oligoclonal bands (OCBs) were significantly more prevalent in Pattern I MS (88.2%) than in Patterns II/III MS (27%).
• Intrathecal IgG response (MRZ reaction) was absent in Pattern II/III MS patients.
• Elevated albumin CSF/serum ratio (QAlb), indicating impaired blood-CSF barrier, was more frequent in Pattern II/III MS.

Conclusions:

• Pattern II and III MS patients exhibit distinct CSF profiles compared to Pattern I MS.
• Differences in intrathecal IgG synthesis and blood-CSF barrier function support distinct disease entities.
• Findings support classifying Pattern II and III MS as separate from Pattern I MS.