title: Detection of ectopic B-cell follicles with germinal centers in the meninges of patients with secondary progressive multiple sclerosis.
abstract: Multiple sclerosis (MS) is characterized by synthesis of oligoclonal immunoglobulins and the presence of B-cell clonal expansions in the central nervous system (CNS). Because ectopic lymphoid tissue generated at sites of chronic inflammation is thought to be important in sustaining immunopathological processes, we have investigated whether structures resembling lymphoid follicles could be identified in the CNS of MS patients. Sections from post-mortem MS brains and spinal cords were screened using immunohistochemistry for the presence of CD20+ B-cells, CD3+ T-cells, CD138+ plasma cells and CD21+, CD35+ follicular dendritic cells, and for the expression of lymphoid chemokines (CXCL 13, CCL21) and peripheral node addressin (PNAd). Lymphoid follicle-like structures containing B-cells, T-cells and plasma cells, and a network of follicular dendritic cells producing CXCL13 were observed in the cerebral meninges of 2 out of 3 patients with secondary progressive MS, but not in relapsing remitting and primary progressive MS. We also show that proliferating B-cells are present in intrameningeal follicles, a finding which is suggestive of germinal center formation. No follicle-like structures were detected in parenchymal lesions. The formation of ectopic lymphoid follicies in the meninges of patients with MS could represent a critical step in maintaining humoral autoimmunity and in disease exacerbation.
authors.affiliation: Department of Cell Biology and Neuroscience, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Roma, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Serafini
authors.forename: Barbara
authors.initials: B
authors.lastname: Rosicarelli
authors.forename: Roberta
authors.initials: R
authors.lastname: Magliozzi
authors.forename: Egidio
authors.initials: E
authors.lastname: Stigliano
authors.forename: Francesca
authors.initials: F
authors.lastname: Aloisi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001402:B-Lymphocytes; D001921:Brain / Q000276:immunology / Q000473:pathology; D002828:Choristoma / Q000473:pathology*; D016207:Cytokines / Q000096:biosynthesis; D020566:Dendritic Cells, Follicular / Q000276:immunology / Q000473:pathology; D005260:Female; D018858:Germinal Center; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008578:Meninges / Q000276:immunology / Q000473:pathology*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000276:immunology / Q000473:pathology*; D010950:Plasma Cells / Q000276:immunology / Q000473:pathology; D013116:Spinal Cord / Q000276:immunology / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology / Q000473:pathology
chemical_list: D016207:Cytokines