Multifocal inflammatory demyelination in a patient with rheumatoid arthritis and treatment complications

Area of Science:

• Neurology
• Rheumatology
• Immunology

Background:

• Rheumatoid arthritis (RA) and multiple sclerosis (MS) are autoimmune diseases with shared pathogenesis.
• MS development in RA patients, particularly without anti-tumor necrosis factor-alpha therapy, is infrequently reported.
• The potential under-recognition of MS in RA patients may stem from clinically silent MS and limited central nervous system autopsy data.

Observation:

• An autopsy case revealed multifocal inflammatory demyelination in a RA patient with a history of prolonged methotrexate and hydroxychloroquine use.
• The patient also experienced hydroxychloroquine-induced myopathies and heart failure.
• Neuropathological findings were consistent with MS, albeit with modified features like smaller lesions and reduced inflammatory cell infiltration.

Findings:

• The neuropathological features presented characteristics of MS.
• Altered inflammatory demyelination was noted, including smaller lesions and less T-cell infiltration.
• RA treatment, specifically with hydroxychloroquine and methotrexate, may modify the presentation of inflammatory demyelination.

Implications:

• This case suggests a potential link between RA treatments and altered MS characteristics.
• The findings highlight the importance of considering MS in RA patients, even with atypical neuropathological presentations.
• Further research is warranted to understand how RA therapies influence the course and pathology of MS.