The Choroid Plexus Is Permissive for a Preactivated Antigen-Experienced Memory B-Cell Subset in Multiple Sclerosis.

The role of B cells in multiple sclerosis (MS) is increasingly recognized. B cells undergo compartmentalized redistribution in blood and cerebrospinal fluid (CSF) during active MS, whereby memory B cells accumulate in the CSF. While B-cell trafficking across the blood-brain barrier has been intensely investigated, cellular diapedesis through the blood-CSF barrier (BCSFB) is incompletely understood.

Hypovitaminosis D upscales B-cell immunoreactivity in multiple sclerosis.

Background: While vitamin D is increasingly recognized as a potential immune regulator of MS disease activity, its impact on B lymphocytes, however, remains ill-defined.

Methods: We assessed the impact of vitamin D on B-cell proliferation and cytokine secretion ex vivo and screened for effects of hypovitaminosis D and vitamin D supplementation on the compartmentalized distribution of B-cell subtypes in peripheral blood and cerebrospinal fluid (CSF) from patients with relapsing remitting MS (n=95) and various neurologic and healthy controls (n=57).

Results: B cells from MS patients with 25(OH)D serum levels <20ng/ml, displayed enhanced immunoreactivity ex vivo as a consequence of more vigorous responses of CD27(+) memory phenotypes.

Th17 cells: A prognostic marker for MS rebound after natalizumab cessation?

Background: Multiple sclerosis (MS) patients are at risk of renewed disease activity after discontinuing natalizumab (NAT) treatment.

Objective: Assessing the implication of T helper 17 (Th17) cells in MS reactivation after NAT cessation.

Methods: We monitored frequencies of Th17 cells and interleukin (IL)-17 cytokine levels in blood samples of 57 MS patients, without, during, and after NAT exposure.