Interferons are a group of proteins that are produced in a person's body in response to an attack by a virus.
When a cell becomes infected by a virus, it releases tiny amounts of, 'interferons,' which then attach themselves to neighboring cells and prompt them to begin producing their own protective antiviral enzymes. The result of these actions is an impairment of the replication and growth of the attacking virus. Interferon has also been demonstrated to have some anti-tumor properties.
There are three known classes of interferons; alpha, beta, and gamma.
They are currently being used by doctors to treat diseases involving a person's immune system such as hepatitis, cancer, multiple sclerosis, AIDS, perianal and genital warts, as well as granulomatous disease. While interferons were discovered in the 1950's by Scottish virologist Alick Isaacs, medical use of them was not practical until recombinant DNA techniques of genetic engineering made it possible to mass produce them.
Each class of interferons has a number of effects, although their effects overlap one another.
The commercially-available forms of interferons are human ones, manufactured using recombinant DNA technology. The mechanisms involved in the actions of interferons are complex and are not very well understood at this time.
What is known is that interferons modulate the response of the human immune system to bacteria, viruses, cancer, and additional foreign substances that invade a person's body. While interferons do not directly kill cancerous or viral cells, they do boost a person's immune system in response while reducing the growth of cancer cells through regulation of the action of several genes which control the secretion of numerous cellular proteins that affect growth. Due to the fact that interferons enhance a person's immune system in a number of ways, they are used for various disease involving the immune system. Some examples include the following.
Inteferons, despite being very similar to each other, affect a person's body in different ways. Due to the varying affects, different interferons are us for different conditions. Interferon alphas are used in the treatment of viral infections and cancers, while interferon betas are used in the treatment of multiple sclerosis. Interferon gamma is used in the treatment of chronic grandulomatous disease.
Potential Side-Effects of Interferons:
People who receive treatment with interferons may experience flu-like symptoms following injections such as chills, headache, fever, malaise, muscle aches and pains. The symptoms can vary from mild to severe and occur in up to fifty-percent of people who receive treatments. The symptoms tend to diminish as the person receives repeated injections and can be managed with medications such as acetaminophen, or antihistamines such as diphenhydramine. People receiving interferon treatment may also experience tissue damage at the injection site, something that occurs more commonly with interferon beta-1b and pegylated interferon alfa-2b.
Both depression and suicide have been reported among people receiving interferon treatment. It is important to note that it is unclear whether or not depression and suicidal thoughts are caused by the diseases being treated with interferons, or the interferons themselves. People receiving interferon treatment should be observed for signs of depression and suicidal ideation.
Additional side-effects that can occur in association with interferon treatment, and may be caused by administration of higher dosages include:
Interferon alfa-2a, interferon alfa-2b, and interferon beta-1b can increase levels of zidovudine, also known as, 'AZT,' or, 'Retrovir,' in a person's blood. Although the reaction can improve the effectiveness of zidovudine, it may also increase the person's risk for liver and blood toxicity. The person's dosage of zidovudine may need to be reduced by as much as seventy-five percent while receiving interferon treatments. Interferon alfa-2a and interferon alfa-2b can increase the amount of time it takes for theophylline to be eliminated from a person's body; their dose of theophylline might need to be reduced while receiving interferon treatments.
Available forms of interferons include: