B LYMPHOCYTE-TARGETING THERAPIES IN MULTIPLE SCLEROSIS: A NARRATIVE REVIEW

Abstract

Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system mediated by aberrant activation of the immune system. This leads to inflammatory and degenerative processes that cause both discrete relapses and chronic progression and are mediated by T and B lymphocytes and microglial cells. B lymhocytes have emerged as critical regulators of both relapsing and progressive forms of MS and their targeting has proven to be highly effective for active disease (relapsing MS and primary active MS). Therapies that target B lymphocytes include compounds directed against the B cell surface protein cluster of differentiation 20 (CD20), which have been approved for the treatment of MS, and compounds directed against the intracellular signaling effector Bruton’s tyrosine kinase (BTK) that are currently under evaluation in randomized-controlled clinical trials. These agents are deemed to target both relapse-associated and progression-associated inflammatory pathways, albeit their efficacy in halting disease progression needs to be further evaluated. The current narrative review provides a brief outline of the roles that B cells exert in MS and highlights the safety and efficacy of B cell-targeting therapies in MS. We also provide practical recommendations regarding the use of B cell-targeting therapies in different MS subtypes.