A Gradient of neuronal loss and meningeal inflammation in multiple sclerosis.
OBJECTIVE
Prominent inflammation with formation of ectopic B-cell follicle-like structures in the meninges in secondary progressive multiple sclerosis (MS) (SPMS) is associated with extensive cortical pathology and an exacerbated disease course. Our objective was to evaluate the cellular substrates of the cortical damage to understand the role of meningeal inflammation in MS pathology.


METHODS
Using >600 tissue blocks from 37 cases of SPMS and 14 non-neurological controls, we carried out a detailed quantitative analysis of cortical atrophy and layer-specific changes in cell populations in SPMS cases with (F(+) SPMS) and without (F⁻ SPMS) B-cell follicle-like structures.


RESULTS
B-cell follicle-like structures were detected in the inflamed meninges of 20 of 37 SPMS cases (54%) and were associated with increased subpial cortical demyelination and cortical atrophy. A clear gradient of neuronal loss was observed in grey matter lesions and normal-appearing grey matter in the motor cortex of F(+) SPMS cases. The density of pyramidal neurons was significantly reduced in layers III and V of the motor cortex. Neuronal loss was accompanied by glia limitans damage with astrocyte loss and an opposite gradient of increased density of activated microglia. No gradient of neuronal loss was seen in F⁻ SPMS cases.


CONCLUSIONS
We demonstrate substantial cortical neurodegeneration and generalized cell loss in progressive MS in association with meningeal inflammation and lymphoid tissue formation, supporting the hypothesis that cytotoxic factors diffusing from the meningeal compartment contribute to grey matter pathology and the consequent increase in clinical disability.
Centre for Neuroscience, Imperial College, Faculty of Medicine, London, United Kingdom.
Roberta
R
Magliozzi
Owain W
OW
Howell
Cheryl
C
Reeves
Federico
F
Roncaroli
Richard
R
Nicholas
Barbara
B
Serafini
Francesca
F
Aloisi
Richard
R
Reynolds
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015703:Antigens, CD / Q000378:metabolism; D001253:Astrocytes / Q000473:pathology; D001402:B-Lymphocytes / Q000378:metabolism / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D016923:Cell Death / Q000502:physiology; D002540:Cerebral Cortex / Q000473:pathology; D005260:Female; D006801:Humans; D020287:In Situ Nick-End Labeling / Q000379:methods; D007249:Inflammation / Q000209:etiology* / Q000276:immunology / Q000473:pathology*; D008297:Male; D008578:Meninges / Q000473:pathology*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000150:complications* / Q000276:immunology / Q000473:pathology*; D009185:Myelin Proteins / Q000378:metabolism; D018992:Myelin-Associated Glycoprotein / Q000378:metabolism; D063308:Myelin-Oligodendrocyte Glycoprotein; D009457:Neuroglia / Q000473:pathology; D009474:Neurons / Q000473:pathology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D000070798:Nogo Proteins; D010751:Phosphopyruvate Hydratase / Q000378:metabolism
D015703:Antigens, CD; C571326:MOG protein, human; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D063308:Myelin-Oligodendrocyte Glycoprotein; D000070798:Nogo Proteins; C000603199:RTN4 protein, human; D052247:Nitric Oxide Synthase Type II; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D053148:Caspase 3; D010751:Phosphopyruvate Hydratase