Accumulation of class switched IgD-IgM- memory B cells in the cerebrospinal fluid during neuroinflammation

Inflammatory diseases of the central nervous system (CNS) are characterized by cerebrospinal fluid (CSF) pleocytosis often involving the recruitment of B cells. Little is known about the phenotype of B cells that are present in the CSF during neuroinflammation. To address the phenotype of these B cells, we studied the distribution of the major B cell subsets in peripheral blood (PB) and CSF of 25 patients with inflammatory diseases of the nervous system by flow cytometry. Six different B cell subsets were identified in PB and CSF according to the surface expression of IgM, IgD, CD27 and CD19. In all patients ana…