Year: 2023
Type: article
Abstract: The study was designed to examine microglia morphology in early and late forms of multiple sclerosis (MS). Archival paraffin embedded tissue samples from 25 cases were examined immunohistochemically. Pío del Río Hortega reported that phagocytes in acute focal destructive CNS lesions develop from microglia with no early contribution from infiltrating monocytes. In this study, we were unable to identify the changes cited by del Río Hortega in support of his theory. Instead, myelin phagocytes in MS appear to originate chiefly from infiltrating monocytes. In 4 cases, walls composed of MHC class II antigen-positive "wall microglia" were observed at plaque margins separating demyelinated and bordering myelinated tissue. Wall microglia in 2 plaques were accompanied by AQP4-positive fiber-forming astrocytes. In chronic but not early disease MS cases, microglia were seen to interact with infiltrating monocytes to form microglial nodules of several types. Also, MHC II-positive "activated" microglia in bordering intact tissue were exceptionally prominent where there was little evidence of ongoing myelin loss. It is concluded that myelin phagocytes in MS derive entirely from infiltrating MRP14-positive monocytes and not from resident microglia and that Río Hortega's microglia play an anti-inflammatory role in MS and not the destructive role favored by the current literature.
DOI: 10.1093/jnen/nlad046
Authors: John W Prineas, Sandra Lee
Institution: The University of Sydney
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,796
Funders: U.S. Department of Veterans Affairs, National Multiple Sclerosis Society, Multiple Sclerosis Society, Multiple Sclerosis Australia, University of Sydney, Medical Research Council, National Health and Medical Research Council, National Institute of Mental Health, National Cancer Institute, National Institute of Neurological Disorders and Stroke
OpenAlex ID: W4381599059