In the broad field of autoimmunity and clinical immunology, experimental evidence over the past few years have demonstrated several connections between the immune system and the nervous system, both central and peripheral, leading to the definition of neuroimmunology and of an immune-brain axis. Indeed, the central nervous system as an immune-privileged site, thanks to the blood-brain barrier, is no longer a dogma as the barrier may be altered during chronic
inflammation with disruptive changes of endothelial cells and tight junctions, largely mediated by
adenosine receptors and the expression of CD39/CD73. The diseases that encompass the neuroimmunology field vary from primary nervous diseases such as
multiple sclerosis to systemic conditions with neuropsychiatric complications, such as
systemic lupus erythematosus or vasculitidies. Despite potentially similar clinical manifestations, the pathogenesis of each condition is different, but the interaction between the ultra-specialized structure that is the nervous system and
inflammation mediators are crucial. Two examples come from anti-dsDNA cross-reacting with anti-
N-Methyl-d-Aspartate receptor (NMDAR)
antibodies in neuropsychiatric lupus or the new family of antibody-associated neuronal
autoimmune diseases including classic
paraneoplastic syndromes with
antibodies directed to intracellular
antigens (Hu, Yo, Ri) and
autoimmune encephalitis. In the case of
multiple sclerosis, the T cell paradigm is now complicated by the growing evidence of a B cell involvement, particularly via
aquaporin antibodies, and their influence on Th1 and Th17 lineages. Inspired by a productive AARDA-sponsored colloquium among experts we provide a critical review of the literature on the pathogenesis of different immune-mediated diseases with
neurologic manifestations and we discuss the basic immunology of the central nervous system and the interaction between immune cells and the peripheral nervous system.