Interferon is the drug of choice for treating several chronic forms of viral hepatitis, including hepatitis B and C. It may also be used to treat a more unusual type of hepatitis called hepatitis D, which is a co-infection, that can occur with type B hepatitis, often in injection drug users.
Interferons are proteins that are secreted by the cells when the body is being attacked by a virus like hepatitis B, C, or D. Genetically engineered interferon, given by injection, stops the hepatitis virus from replicating itself and provides a boost to the immune system. Different forms of interferon are needed to treat hepatitis B, hepatitis C, and hepatitis D.
Without treatment, chronic hepatitis inflames and damages the liver and can lead to:
- Cirrhosis of the liver
- Liver cancer
- Liver failure (requiring a liver transplant or causing death)
How Interferon Works
A person's cells begin secreting interferon when they detect viral infection. Interferon alerts all nearby cells that a viral infection is under way, triggering the production of proteins that block viral replication. Interferon also causes cells to stop producing proteins that viruses need to replicate and thrive. Doctors suspect interferon also protects cells against viruses through other means; research into the way it works is on-going.
Different Types of Interferon
Doctors have found that different forms of chronic viral hepatitis respond to different types of man-made interferon:
- Hepatitis B. Interferon alpha-2b is the form of the drug that works against chronic viral hepatitis B infection. The U.S. Food and Drug Administration (FDA) also has approved the use of PEGylated interferon for treatment of hepatitis B. PEGylation is a chemical process that makes the therapy more efficient.
- Hepatitis C. A number of different forms of interferon are FDA-approved for treatment of hepatitis C, including PEGylated interferon, PEGylated interferon alpha-2b (PEG-intron), interferon alpha-2b (Intron A, Rebetol), interferon alpha-2a (Roferon), and interferon aphacon-1 (Infergen).
- Hepatitis D. Chronic cases of hepatitis D are usually treated with PEGylated interferon.
Interferon Pros and Cons
Interferon has proven very successful in treating hepatitis B, C, and D, although it only produces a complete cure in a certain percentage of patients. It is more effective when combined with broad-spectrum (meaning they work against many viruses) antiviral medications like ribavirin, particularly in the treatment of hepatitis C.
Because interferon is a natural part of your immune system, treatment that boosts your interferon levels can cause a range of side effects:
- The most common side effect of interferon involves severe, flu-like symptoms such as fever, fatigue, and muscle pains.
- Interferon can also cause abnormal blood counts, with patients showing reduced levels of hemoglobin, white cells, and platelets.
- Interferon has psychological side effects and may prompt depression and suicidal feelings. Aggression, psychosis, hallucinations, and mania have also been reported.
- High levels of interferon can cause system-wide damage to vital parts of the body, such as the kidneys, liver, bone marrow, and heart.
If you are put on interferon treatment, you’ll need to be closely monitored by your doctor for any of these side effects.
Who Shouldn’t Get Interferon
Certain people should not receive interferon therapy or should receive it under the close supervision of a doctor. These include people who have:
- Depression or another mental illness
- Another infection along with their hepatitis, either from a bacterial, viral, or fungal source
- An autoimmune disorder
- Bone marrow disease
- Heart problems
- Eye disorders
Interferon can be a life-saving drug. However, it is also extremely potent, and not for everyone. It’s important to be aware of any potential side effects. Ask your doctor to help you prepare a coping strategy for dealing with any side effects you may experience during your treatment.
Last Updated: 1/7/2010