The evolution and current status of anti-B-cell therapies in autoimmune neurologic diseases.

B lymphocytes are essential to the adaptive immune system with several key functions involving antibody production, pro- and anti-inflammatory cytokine production, and antigen presentation to CD4+ T cells. These functions are critical in promoting downstream effector mechanisms underlying the pathogenesis of many autoimmune neurologic disorders. Inhibiting B cells with monoclonal antibodies has been successful in a variety of autoimmune neurologic disorders, including diseases thought to be primarily T-cell mediated. B-cell depletion is now commonly utilized in clinical practice with approved medications for multiple sclerosis and aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder. Moreover, clinical trials are underway involving several other disorders including autoimmune encephalitis. Their effectiveness has led to the development of a variety of B-cell targeting treatments that differ by antigenic target, form (humanized or chimeric), route of administration, and dosing frequency. Additionally, there has been an increase in their affordability via biosimilars, allowing for increased accessibility globally. With their increasing use, it is important to be aware of their side-effect profile, associated risk of infection, and their use in special populations. Anti-B-cell therapies have revolutionized our therapeutic approach to autoimmune disorders of the central nervous system and their high efficacy has led to an overall benefit in patients afflicted by these conditions.