Editing Interferon beta-1a (section)

==Medical uses==

=== Clinically isolated syndrome ===
The earliest clinical presentation of relapsing-remitting multiple sclerosis is the clinically isolated syndrome (CIS), that is, a single attack of a single symptom. During a CIS, there is a subacute attack suggestive of [[demyelination]] which should be included in the spectrum of MS phenotypes.<ref>{{cite journal | vauthors = Lublin FD, Reingold SC, Cohen JA, Cutter GR, Sørensen PS, Thompson AJ, Wolinsky JS, Balcer LJ, Banwell B, Barkhof F, Bebo B, Calabresi PA, Clanet M, Comi G, Fox RJ, Freedman MS, Goodman AD, Inglese M, Kappos L, Kieseier BC, Lincoln JA, Lubetzki C, Miller AE, Montalban X, O'Connor PW, Petkau J, Pozzilli C, Rudick RA, Sormani MP, Stüve O, Waubant E, Polman CH | display-authors = 6 | title = Defining the clinical course of multiple sclerosis: the 2013 revisions | journal = Neurology | volume = 83 | issue = 3 | pages = 278–286 | date = July 2014 | pmid = 24871874 | pmc = 4117366 | doi = 10.1212/WNL.0000000000000560 }}</ref> Treatment with [[interferon]]s after an initial attack decreases the risk of developing clinical definite MS.<ref name="pmid18970977"/><ref name="pmid21205678">{{cite journal | vauthors = Bates D | title = Treatment effects of immunomodulatory therapies at different stages of multiple sclerosis in short-term trials | journal = Neurology | volume = 76 | issue = 1 Suppl 1 | pages = S14–S25 | date = January 2011 | pmid = 21205678 | doi = 10.1212/WNL.0b013e3182050388 | s2cid = 362182 }}</ref>

=== Relapsing-remitting MS ===
Medications are modestly effective at decreasing the number of attacks in relapsing-remitting multiple sclerosis<ref>{{cite journal | vauthors = Rice GP, Incorvaia B, Munari L, Ebers G, Polman C, D'Amico R, Filippini G | title = Interferon in relapsing-remitting multiple sclerosis | journal = The Cochrane Database of Systematic Reviews | volume = 2001 | issue = 4 | pages = CD002002 | date = 2001 | pmid = 11687131 | pmc = 7017973 | doi = 10.1002/14651858.CD002002 }}</ref> and in reducing the accumulation of brain lesions, which is measured using [[gadolinium]]-[[MRI contrast agent|enhanced]] [[magnetic resonance imaging]] (MRI).<ref name="pmid18970977"/> Interferons reduce relapses by approximately 30% and their safe profile make them the first-line treatments.<ref name="pmid18970977"/> Nevertheless, not all the patients are responsive to these therapies. It is known that 30% of MS patients are non-responsive to Beta interferon.<ref name="pmid18690496">{{cite journal | vauthors = Bertolotto A, Gilli F | title = Interferon-beta responders and non-responders. A biological approach | journal = Neurological Sciences | volume = 29 | issue = Suppl 2 | pages = S216–S217 | date = September 2008 | pmid = 18690496 | doi = 10.1007/s10072-008-0941-2 | s2cid = 19618597 }}</ref> They can be classified in genetic, pharmacological and pathogenetic non-responders.<ref name="pmid18690496"/> One of the factors related to non-respondance is the presence of high levels of interferon beta neutralizing  [[antibodies]]. Interferon therapy, and specially interferon beta 1b, induces the production of  neutralizing  antibodies, usually in the second 6 months of treatment, in 5 to 30% of treated patients.<ref name="pmid18970977"/> Moreover, a subset of RRMS patients with specially active MS, sometimes called "rapidly worsening MS" are normally non-responders to interferon beta 1a.<ref>{{cite journal | vauthors = Buttinelli C, Clemenzi A, Borriello G, Denaro F, Pozzilli C, Fieschi C | title = Mitoxantrone treatment in multiple sclerosis: a 5-year clinical and MRI follow-up | journal = European Journal of Neurology | volume = 14 | issue = 11 | pages = 1281–1287 | date = November 2007 | pmid = 17956449 | doi = 10.1111/j.1468-1331.2007.01969.x | s2cid = 36392563 }}</ref><ref>{{cite journal | vauthors = Boster A, Edan G, Frohman E, Javed A, Stuve O, Tselis A, Weiner H, Weinstock-Guttman B, Khan O | display-authors = 6 | title = Intense immunosuppression in patients with rapidly worsening multiple sclerosis: treatment guidelines for the clinician | journal = The Lancet. Neurology | volume = 7 | issue = 2 | pages = 173–183 | date = February 2008 | pmid = 18207115 | doi = 10.1016/S1474-4422(08)70020-6 | s2cid = 40367120 }}</ref>

While more studies of the long-term effects of the drugs are needed,<ref name="pmid21205679"/><ref name="pmid18970977"/>  existing data on the effects of interferons indicate that early-initiated long-term therapy is safe and it is related to better outcomes.<ref name="pmid21205679">{{cite journal | vauthors = Freedman MS | title = Long-term follow-up of clinical trials of multiple sclerosis therapies | journal = Neurology | volume = 76 | issue = 1 Suppl 1 | pages = S26–S34 | date = January 2011 | pmid = 21205679 | doi = 10.1212/WNL.0b013e318205051d | s2cid = 16929304 }}</ref>