title: Short-lived plasma blasts are the main B cell effector subset during the course of multiple sclerosis.
abstract: Multiple sclerosis is a chronic inflammatory and demyelinating disorder of the CNS with an unknown aetiology. Although intrathecal immunoglobulin G (IgG) synthesis is a key feature of the disease, little is still known about the B cell response in the CNS of multiple sclerosis patients. We analysed the phenotype and kinetics of different B cell subsets in patients with multiple sclerosis, infectious disease (IND) and non-inflammatory neurological disease (NIND). B cells were detected in the CSF of multiple sclerosis and IND patients, but were largely absent in NIND patients. In the CSF, the majority of B cells had a phenotype of memory B cells and short-lived plasma blasts (PB); plasma cells were absent from the compartment. The proportion of PB was highest in multiple sclerosis patients and patients with acute CNS infection. While PB disappeared rapidly from the CSF after resolution of infection in IND patients, these cells were present at high numbers throughout the disease course in multiple sclerosis patients. CSF PB numbers in multiple sclerosis patients strongly correlated with intrathecal IgG synthesis and inflammatory parenchymal disease activity as disclosed by MRI. This study identifies short-lived plasma blasts as the main effector B cell population involved in ongoing active inflammation in multiple sclerosis patients.
authors.affiliation: Department of Neurology, Heinrich Heine-University, Duesseldorf, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Cepok
authors.forename: Berit
authors.initials: B
authors.lastname: Rosche
authors.forename: Verena
authors.initials: V
authors.lastname: Grummel
authors.forename: Friederike
authors.initials: F
authors.lastname: Vogel
authors.forename: Dun
authors.initials: D
authors.lastname: Zhou
authors.forename: Joachim
authors.initials: J
authors.lastname: Sayn
authors.forename: Norbert
authors.initials: N
authors.lastname: Sommer
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hartung
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hemmer
mesh_terms: D001402:B-Lymphocytes / Q000276:immunology; D001899:Borrelia Infections / Q000134:cerebrospinal fluid / Q000276:immunology; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005434:Flow Cytometry; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008587:Meningitis, Viral / Q000134:cerebrospinal fluid / Q000276:immunology; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid* / Q000276:immunology* / Q000473:pathology; D009422:Nervous System Diseases / Q000134:cerebrospinal fluid / Q000276:immunology; D010950:Plasma Cells / Q000276:immunology*