The Potential Immunoregulatory Roles of Vitamin D in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an autoantibody-mediated disease affecting the central nervous system (CNS). Its pathogenesis involves both innate and acquired immune reactions; specific antibody (Aquaporin-4 antibody) and inflammatory cells cause direct damage on lesion sites, while B cell-T cell interactions facilitate the demyelination. However, its etiology is still not fully understood. Vitamin D deficiency is present in numerous autoimmune diseases, including NMOSD. Evidence suggests that low vitamin D levels mayassociate with disease activity and relapse rate in NMOSD, indicating the participation in the pathogenesis of NMOSD. The immunoregulatory roles of vitamin D in both numerous autoimmune diseases and experimental autoimmune encephalomyelitis (EAE) models are increasingly recognized. Recent studies have revealed vitamin D modulation in cytokine production, immune cell development and differentiation, as well as antibody production. By enhancing an anti-inflammatory environment and suppressing the overactivated autoimmune process, vitamin D shows its potential immunoregulatory roles in NMOSD, which could possibly introduce a new therapy for NMOSD patients.