Multinucleated astrocytes in old demyelinated plaques in a patient with multiple sclerosis

Area of Science:

• Neuroimmunology
• Neuropathology

Background:

• Investigating the pathology of chronic multiple sclerosis (MS) lesions is crucial for understanding disease progression.
• The case report details a 51-year-old female with a 26-year history of MS, initially relapsing-remitting, evolving to progressive disease.

Observation:

• Post-mortem examination of MS plaques revealed fibrillary gliosis with Rosenthal fibers, lacking acute inflammatory markers like lymphocytic cuffing or foamy macrophages.
• Activated microglia were predominantly located at the plaque margins, characteristic of slowly expanding plaques.
• Multinucleated astrocytes were notably present within the plaques, particularly in areas with microglial infiltration.

Findings:

• Chronic MS plaques exhibit persistent, albeit mild, inflammatory processes.
• Microglial activation in old lesions may trigger astrocyte multinucleation.
• The presence of multinucleated astrocytes correlates with microglial infiltration within demyelinated plaques.

Implications:

• Persistent inflammation in chronic MS lesions could contribute to ongoing neurodegeneration.
• Astrocyte multinucleation may be a response to sustained inflammatory stimuli in the MS brain.
• These findings offer insights into the mechanisms underlying gradual neurological decline in advanced multiple sclerosis.