Aim. The article presents a review of immune-mediated diseases of the nervous system .Review: For a long time the central nervous system (CNS) has been thought to be immunologically passive. Among potential reasons of the CNS immune passivity the following have been listed: the presence of the blood-brain barrier (BBB), lack of lymphatic drainage, absence of dendritic cells capable of antigen presentation, low expression of antigens of the major histocompatibility complex (MHC), and short lifetime of immune cells entering the CNS. However, many data suggest that the state of the CNS immune passivity is not absolute: a) diffusion of intraparenchymatous fluid from the brain into lymphatic nodules and peripheral blood is possible, b) activated T and B cells are capable of crossing the BBB, c) immune-modulating molecules (antibodies, cytokines) can get into the CNS, d) in response to a variety of stimuli microglial and astroglial cells express MHC class I and II molecules, e) the CNS cells are capable of cytokine secretion.
Conclusions. There is an increasing body of evidence confirming the role of immune response in the pathogenesis and course of many pathological conditions of the nervous system, including polyneuropathies, demyelinating syndromes, neuromuscular disorders, paraneoplastic syndromes.