Interferons are proteins produced naturally by the human body. They are released by white blood cells to alter the immune system's response to infections.
Gamma interferon, which is released at the start of an immune response, encourages inflammation in the tissue under attack. Beta interferon (sometimes referred to as interferon beta), released at the end of an immune attack, blocks the action of gamma interferon and helps to reduce inflammation and the body's immune reaction.
Five beta interferon drugs have been developed to treat relapsing multiple sclerosis:
- Avonex (interferon beta 1a)
- Rebif (interferon beta 1a)
- Plegridy (peginterferon beta 1a)
- Betaferon (interferon beta 1b)
- Extavia (interferon beta 1b)
In the past, the term 'beta interferons' has sometimes been loosely applied to all of the original disease modifying drugs for MS, which included Copaxone (glatiramer acetate). Although Copaxone has a similar effect, it is not an interferon.
Some people with multiple sclerosis develop antibodies (known as neutralising antibodies) to the beta interferon drugs that may reduce the effectiveness of treatment.