Interferon (IFN) is an antiviral substance that was discovered about 50 years ago. The advance in the basic research of IFN has revealed the action mechanism of its antiviral effect at a molecular level and provided wide clinical applications.
IFN is known to have various biological activities including antiviral effects. Major biological activities include cell growth inhibition and immune regulation. Anti-tumor effect of IFN develops by integration of the various biological activities. IFN is considered to exert its antiviral effect by not only directly inhibiting viral proliferation, but also stimulating cytotoxic T cells, natural killer cells, and macrophages (Jean, 1999).
Interferon Therapy
“Common to almost all autoimmune diseases is their polygenic inheritance, incomplete penetrance, and evidence for the role of environmental factors, particularly viral infection. In addition, they are characterized by increased numbers of circulating autoreactive T- and B-cells. Endogenously produced or therapeutically applied IFN-alpha can tilt the usually tightly controlled balance towards activation of these autoreactive cells via a vast array of mechanisms. The genetic susceptibility factors determine which type of autoimmunity will develop.” (Web, 1)
This important antifibrogenic effect of interferon has not been recognized until recently. The Studies of IFN therapy in tumors have in the majority of cases been conducted using various preparations of IFN-alpha. Early studies in osteosarcoma gave promising results and showed that rather crude preparations of leukocyte (natural) IFN-alpha at doses of 3 million units 3 times a week could be given for months-years without causing intolerable side effects (Jean, 1999). Similarly, the early trials showed that larynx papilloma could be successfully treated with these preparations although relapses after cessation of treatment were common.
With the advent of recombinant DNA technology it became possible to produce large quantities of IFN and trials in various malignant diseases were greatly extended.............
