The imbalance between regulatory and memory B cells accompanied by an increased number of circulating T-follicular helper cells in MOG-antibody-associated demyelination

Abstract

Objective: To explore the alteration of T and B lymphocyte subsets proportions in myelin oligodendrocyte glycoprotein (MOG)-antibody-associated demyelination.

Methods: 19 MOG-antibody-positive, 25 AQP4-antibody-positive and 25 double-negative NMOSD patients in the acute phase of the diseases were included in the study, as well as 29 healthy controls. The frequencies of different lymphocyte subsets, including CD19⁺CD27⁺ memory B cells, CD19⁺CD24^hiCD38^hi, and CD19⁺CD5⁺CD1d^hi regulatory B cells, IFN-γexpressing B cells, IL-10 expressing B cells and CD4⁺CXCR5⁺ICOS⁺T-follicular helper cells (T_FH) were measured via flow cytometry and compared among the four groups.

Results: The frequencies of CD19⁺CD24^hiCD38^hi, CD19⁺CD5⁺CD1d^hi regulatory B cells as well as the IL-10 expressing B cells were significantly lower in the MOG-antibody-associated demyelination compared to the healthy controls, whereas the frequencies of CD19⁺CD27⁺ memory B cells were significantly higher in the MOG-antibody-positive group. The frequencies of T_FH were significantly higher in the MOG-antibody-positive group as compared to the healthy controls. No significant difference was detected in the above mentioned lymphocytic profile between the MOG-antibody-positive and the AQP4-antibody-positive groups.

Conclusions: The immuno-regulatory functions of B cells were significantly impaired whereas T_FH cells were markedly increased in the acute phase of MOG-antibody-associated demyelination. Despite having distinct clinical features, MOG-antibody-associated demyelination shared a similar lymphocytic profile with AQP4-antibody-positive NMOSD in the acute relapse phase.

Keywords: Memory B cell; Myelin oligodendrocyte glycoprotein (MOG); Neuromyelitis optica spectrum disorder (NMOSD); Regulatory B cell, T-follicular helper cell (T(FH)).