Choroid plexuses at the interface of peripheral immunity and tissue repair in multiple sclerosis

Abstract

Purpose of reviewChoroid plexuses (ChPs) are key actors of the blood-to-cerebrospinal-fluid barrier and serve as brain immune checkpoint. The past years have seen a regain of interest about their potential involvement in the physiopathology of neuroinflammatory disorders like multiple sclerosis (MS). This article offers an overview of the recent findings on ChP alterations in MS, with a focus on the imaging tools able to detect these abnormalities and on their involvement in inflammation, tissue damage and repair.Recent findingsOn MRI, ChPs are enlarged in people with MS (PwMS) versus healthy individuals. This size increase is an early event, already detected in presymptomatic and pediatric MS. Enlargement of ChPs is linked to local inflammatory infiltrates, and their dysfunction selectively impacts periventricular damage, larger ChPs predicting the expansion of chronic active lesions, smoldering inflammation and remyelination failure in tissues surrounding the ventricles. ChP volumetry may add value for the prediction of disease activity and disability worsening.SummaryChP imaging metrics are emerging as possible biomarkers of neuroinflammation and repair failure in MS. Future works combining multimodal imaging techniques should provide a more refined characterization of ChP functional changes, their link with tissue damage, blood to cerebrospinal-fluid barrier dysfunction and fluid trafficking in MS.

Longitudinal enlargement of choroid plexus is associated with chronic lesion expansion and neurodegeneration in RRMS patients

“…24 This can be further exacerbated by recently demonstrated link between CP enlargement and low periventricular remyelination. 25…”

Cerebrospinal Fluid-In Gradient of Cortical and Deep Gray Matter Damage in Multiple Sclerosis

“…Disappointingly, no association between CSF-in gradient measures and CP enlargement was found. Since CP enlargement has been described from the earliest phases of MS and remains relatively stable throughout the disease course, 24 - 26 it may represent an early marker of chronic inflammation that reaches a ceiling effect over time.…”

“…[20][21][22][23] To explore possible common driving mechanisms, we correlated CSF-in damage gradient with T2hyperintense WM and GM lesion volume and atrophy measures. In addition, given increasing evidence of choroid plexus (CP) enlargement as a marker of chronic inflammation, [24][25][26] we also investigated the correlation between CP volume and CSF-in damage trends, to define possible relations between proinflammatory environment and CP remodelling observed in MS. [24][25][26] Finally, we addressed the clinical relevance of gradient abnormalities through their correlation with clinical variables (disease duration and Expanded Disability Status Scale [EDSS] score).…”