Interferons (IFNs ) are a
group of signaling proteins made and released by host cells in
response to the presence of several viruses. In a typical scenario,
a virus-infected cell will release interferons causing nearby cells
to heighten their anti-viral defenses.
- Interferon medication is used to treat various
cancers (e.g., leukemia, melanoma, AIDS-related Kaposi's
sarcoma). It is also used to treat virus infections (e.g., chronic
hepatitis B, chronic hepatitis C, condylomata acuminata).
- IFNs belong to the large class of proteins known as
cytokines, molecules used for communication between cells
to trigger the protective defenses of the immune system that help
to eradicate pathogens. Interferons are named for their
ability to "interfere" with viral replication by protecting cells
from virus infections.
- IFNs also have various other functions: they activate
immune cells, such as natural killer cells and
macrophages; they increase host defenses by up-regulating
antigen presentation .
- Certain symptoms of infections, such as fever, muscle pain and
"flu-like symptoms", are also caused by the production of IFNs and
other cytokines.
- Types of Interferon
- Interferon Type 1 : Are produced when the body
recognizes a virus that has invaded it. They are produced by
fibroblasts and monocytes. All type I IFNs bind to a specific cell
surface receptor complex known as the IFN-alpha/ beta receptor (
IFNAR ) .IFN alpha is used to treat hepatitis B and C
infections, while IFN-beta can be used to treat multiple
sclerosis.
- Interferon type II (IFN-γ in humans): This is also
known as immune interferon and is activated by
Interleukin-12.
- Interferon type III: Discovered more recently than
type I and type II IFNs, recent information demonstrates the
importance of Type III IFNs in some types of virus or
fungal infections.
- Interferon beta-1a and interferon beta-1b are used to
treat and control multiple sclerosis, an
autoimmune disorder. This treatment may help in reducing attacks in
relapsing-remitting multiple sclerosis and slowing disease
progression and activity in secondary progressive multiple
sclerosis.
- Interferon therapy is used (in combination with chemotherapy
and radiation) as a treatment for some cancers. This treatment can
be used in hematological malignancy, such as in leukemia and
lymphomas including hairy cell leukemia, chronic myeloid leukemia,
nodular lymphoma, and cutaneous T-cell lymphoma.
- Patients with recurrent melanomas receive recombinant IFN-alpha
2b. Both hepatitis B and hepatitis C are treated with IFN-alpha,
often in combination with other antiviral drugs. Some of those
treated with interferon have a sustained virological response and
can eliminate hepatitis virus. Hepatitis C genotype I virus can be
treated with a 60-80% success rate.
- Biopsies of patients given the treatment show reductions in
liver damage and cirrhosis. Some evidence shows giving interferon
immediately following infection can prevent chronic hepatitis C,
although diagnosis early in infection is difficult since physical
symptoms are sparse in early hepatitis C infection. Control of
chronic hepatitis C by IFN is associated with reduced
hepatocellular carcinoma.
- Interferon eye drops may be an effective treatment for people
who have herpes simplex virus epithelial keratitis, a type of eye
infection.