Editing Multiple sclerosis (section)

=== Pathogenesis ===
MS is a clinically defined entity with several atypical presentations. Some auto-antibodies have been found in atypical MS cases, giving birth to separate disease families and restricting the previously wider concept of MS.

[[Aquaporin 4|Anti-AQP4 autoantibodies]] were found in [[neuromyelitis optica]] (NMO), which was previously considered a MS variant. A spectrum of diseases named NMOSD (NMO spectrum diseases) or anti-AQP4 diseases has been accepted.<ref name="Misu">{{cite journal | vauthors = Misu T, Fujihara K | title = Neuromyelitis optica spectrum and myelin oligodendrocyte glycoprotein antibody-related disseminated encephalomyelitis. | journal = Clinical and Experimental Neuroimmunology | date = February 2019 | volume = 10 | issue = 1 | pages= 9–17 | doi = 10.1111/cen3.12491 | doi-access = free }}</ref> Some cases of MS were presenting [[myelin oligodendrocyte glycoprotein|anti-MOG autoantibodies]], mainly overlapping with the Marburg variant. Anti-MOG autoantibodies were found to be also present in ADEM, and a second spectrum of separated diseases is being considered. This spectrum is named inconsistently across different authors, but it is normally something similar to [[Anti-MOG associated encephalomyelitis|anti-MOG demyelinating diseases]].<ref name="Misu" />

A third kind of auto-antibodies is accepted. There are several [[neurofascin|anti-neurofascin]] auto-antibodies that damage the Ranvier nodes of the neurons. These antibodies are more related to the peripheral nervous demyelination, but they were also found in chronic progressive PPMS and [[combined central and peripheral demyelination]] (CCPD, which is considered another atypical MS presentation).<ref name="Kira">{{cite journal | vauthors = Kira JI, Yamasaki R, Ogata H | title = Anti-neurofascin autoantibody and demyelination | journal = Neurochemistry International | volume = 130| pages = 104360| pmid = 30582947 | doi = 10.1016/j.neuint.2018.12.011 | year = 2019 | doi-access = free }}</ref>

In addition to the significance of auto-antibodies in MS, four different patterns of demyelination have been reported, opening the door to consider MS as a [[heterogeneous disease]].<ref name="pmid23917093">{{cite journal | vauthors = Popescu BF, Pirko I, Lucchinetti CF | title = Pathology of multiple sclerosis: where do we stand? | journal = Continuum | volume = 19 | issue = 4 Multiple Sclerosis | pages = 901–21 | date = August 2013 | pmid = 23917093 | pmc = 3915566 | doi = 10.1212/01.CON.0000433291.23091.65 }}</ref>