Abstract

Multiple sclerosis (MS) can be considered a disease that appears in genetically predisposed persons who, by chance, are also affected by some unknown environmental factor, probably infectious, that sets in motion an abnormal immune response leading to an autoimmune disease. Infectious agents are involved in the appearance of autoreactive T cells against myelin via various mechanisms, such as molecular mimetism or acting as superantigens. Numerous possible microorganisms have been suggested, including bacteria like Chlamydophila pneumoniae and many viruses, e.g., canine distemper virus, measles, varicella zoster, human herpes virus 6 (HHV-6) and Epstein-Barr virus (EBV). The association with EBV is the best studied over recent years. The frequency (incidence and prevalence) of MS seems to be increasing, which is better explained by the effect of some environmental factor. In this study we analyze some of the infectious agents that have been associated with the disease and discuss the hygiene hypothesis, which is one of the possible explanations for the epidemiological changes reported over recent decades.

Keywords: Microbes, immunity, multiple sclerosis, Chlamydophila pneumoniae, HHV-6, EBV, T cells, autoimmune disease, superantigens, canine distemper virus, varicella zoster, human herpes virus 6, Epstein-Barr virus, central nervous system, immune response, genetics, cerebrospinal fluid, immunoglobulins, humoral immunity, T lymphocytes, CD4+ T cells, oligodendrocytes, Histocompatibility Complex, syncytial virus, adenovirus type, human papilloma virus, Mycobacterium leprae, Pseudomonas aeruginosa, Haemophilus influenza, polyclonal T cells, staphylococcic enterotoxins, Th-1 cells, panencephalitis, leukoencephalopathy, Spirocheta myelophthora, Treponema denticola, Spherula insularis, Rickettsia, parotiditis, Carp's agent, coronavirus, Borrelia burgdorferi, Hodgkin lymphoma