MS Active Source

Interferons are proteins that are found naturally in the body. There are three types - interferon alpha, interferon beta and interferon gamma. Interferons are produced by the immune system, they help to control viral infections and repair any damage that may result. However, the interferons have different effects on inflammation (swelling) in the body. Interferon alpha and interferon beta both have a moderating effect while interferon gamma increases inflammation.

Interferon beta has proved the most useful of the three compounds in terms of the benefits for people with MS. Interferon betas used to treat MS are genetically engineered copies of the proteins that occur in the body. They are injected under the skin (subcutaneous administration) or into a muscle (intramuscular administration). The table below summarises the different types available:

Interferon beta acts in a number of ways to moderate the effect of MS on the body by helping to:

• Stops cells attacking the myelin sheath that insulates nerves
• Prevent the production of more myelin destroying cells
• Prevent the release of substances that inflame the myelin sheath
• Promotes the production of substances that prevent inflammation

People with different types of MS respond differently to treatment with interferon beta.  People with relapsing remitting MS seem to benefit the most. Studies show that in this group of people interferon beta reduces the number of relapses a person has by about a third. Some studies also show that interferon beta reduces the severity of relapses. (refT14)

Some people with secondary progressive MS may also benefit from treatment with interferon beta, but only if their relapses are the cause of increasing disability. People who are already disabled by MS and are unable to walk are unlikely to benefit.

Unfortunately people with primary progressive MS are not helped by treatment with interferon beta.