Research: B cell follicles driving progression

#MSBlog: Is EBV the cause of MS? I think so. 

Epub:  Magliozzi et al. B-Cell Enrichment and Epstein-Barr Virus Infection in Inflammatory Cortical Lesions in Secondary Progressive Multiple Sclerosis. J Neuropathol Exp Neurol. 2012 Dec

Background: Gray matter lesions are thought to play a key role in the progression of disability and cognitive impairment in MSers, but whether gray matter damage is caused by inflammation or secondary to axon loss in the white matter, or both, is not clear. 


Methods: In an analysis of postmortem brain samples from 44 cases of secondary progressive MS, 26 cases were characterized by meningeal inflammation with ectopic B-cell follicles and prominent gray matter pathology; subpial cortical lesions containing dense perivascular lymphocytic infiltrates were present in 11 of these cases. Because intracortical immune infiltrates were enriched in B-lineage cells and because we have shown previously that B cells accumulating in the MS brain support an active Epstein-Barr virus (EBV) infection, we investigated evidence of EBV in the infiltrated cortical lesions. 

Results: Cells expressing EBV-encoded small RNA and plasma cells expressing EBV early lytic proteins (BZLF1, BFRF1) were present in all and most of the intracortical perivascular cuffs examined, respectively. Immunohistochemistry for CD8-positive cells, granzyme B, perforin, and CD107a indicated cytotoxic activity toward EBV-infected plasma cells that was consistently observed in infiltrated cortical lesions, suggesting active immune surveillance. 

Conclusions: These findings indicate that both meningeal and intraparenchymal inflammation may contribute to cortical damage during MS progression, and that intracortical inflammation may be sustained by an EBV-driven immunopathologic response, similar to findings in white matter lesions and meninges.

Temporal profile of serological changes post EBV infection. The anti-EBNA1 response is predictive of disease activity.

"These results will almost certainly be controversial. Other researchers can't seem to reproduce this groups findings. We will need to wait and see if these results are reproduced. Despite this controversy there is mounting evidence that EBV is strongly associated with MS and some investigators, including myself, believe this association is causal. That has therapeutic implications in that if you prevent EBV infection you may be able to prevent MS or if you target EBV with an anti-viral drug you may suppress MS disease activity. This is what we are trying to do with the Charcot Project." 

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