The capillaries in acute and subacute multiple sclerosis plaques: a morphometric analysis

Area of Science:

• Neuroscience
• Pathology
• Cell Biology

Background:

• Understanding the blood-brain barrier (BBB) in multiple sclerosis (MS) is crucial for developing effective treatments.
• Previous research suggests BBB dysfunction in MS, but detailed ultrastructural changes in capillary endothelial cells remain incompletely understood.

Observation:

• This study utilized computed tomography-assisted (CAT) biopsies to examine capillary endothelial cells in the brain tissue of two patients: one with MS and another with a glioma.
• Advanced microscopy techniques, including light and electron microscopy, along with morphometric analysis, were employed to assess cellular structures.

Findings:

• In the MS plaque, endothelial cell tight junctions remained closed, and mitochondria counts were similar to controls.
• A significant increase in pinocytotic vesicles was observed in the endothelial cells of the MS plaque.
• The basal lamina in the MS plaque was thinned, while endothelial cell lysosomes were infrequent, even amidst intense inflammation.

Implications:

• The increased pinocytotic vesicles suggest enhanced transcytosis across the BBB in MS, potentially contributing to inflammatory cell infiltration.
• These findings highlight specific ultrastructural alterations in MS-related BBB changes, offering targets for future therapeutic interventions.
• Further research into modulating pinocytotic activity could lead to novel strategies for managing MS progression.