Инфекция и иммунитет (Jun 2019)
MICROBIAL AGENTS AS TRIGGERS OF MULTIPLE SCLEROSIS DEVELOPMENT
Abstract
Multiple sclerosis (MS) is currently an urgent medical and social problem. This is due to the high prevalence of this pathology among neurological diseases with the predominant lesion of young people and subsequent rapid disability. This disease still remains a mystery for medicine in view of its ambiguous etiology, polymorphism of clinical manifestations and unstable course. Despite the significant development of modern instrumental diagnostic methods, for multiple sclerosis, pathognomonic signs have not yet been identified that make it possible to diagnose the disease with high accuracy in the early stages. At the moment, we can only say with confidence that MS is a neurodegenerative disease accompanied by rapid demyelination and death of nerve cells. Complex and diverse pathogenetic mechanisms suggest a multifactorial nature of the disease, which develops with a combination of external factors and hereditary predisposition, which causes a violation of immune tolerance. The most substantiated is the polygenic theory of MS, which implies that the genotype of MS patients consists of many genes, each of which contributes to the development of the disease. More than 100 genes associated with MS have been identified, among which a special place is occupied by the HLA system (human leukocyte antigen), which controls the interaction of immunocompetent cells and carries out an immune response. In addition, new candidate genes have been identified that contribute to the development of MS: genes of interleukin 2 and 7 receptors (IL-2R, IL-7R), differentiation cluster 6 (CD6) and 58 (CD58), tumor necrosis factor α, interferon regulatory factor 8 (IRF8), interleukin 12А (IL12A) and others.However, to realize genetic predisposition, the influence of external trigger factors is necessary. The activation of the demyelinating process is quite often initiated by various infectious agents, among which the most studied viruses are Epstein-Barr, John-Cunningham, acute encephalomyelitis, and human endogenous retroviruses. Particular attention in the development of neurodegenerative disorders deserves a change in the intestinal microbiota, by counting microorganisms such as Candida albicans, Staphylococcus aureus, Acinetobacter calcoaceticus, Bacteroides, Proteobacteria and Firmicutes. This imbalance has a significant effect on the functioning of the immune and nervous systems, taking part in the processes of neurogenesis, myelination, activation of the cellular and humoral types of the immune response. This review presents and analyzes latest data from domestic and foreign literature on the study of the epidemiological features of MS, as well as microbiological risk factors for the development of the disease.
