Therapeutic uses of cytokines

Interferons

Interferons (IFN) are cytokines released by the body in response to viral infections and neoplasia. They are classified according to cellular origin and the type of receptor they bind to. IFN-alpha and IFN-beta bind to type 1 receptors whilst IFN-gamma binds only to type 2 receptors.

IFN-alpha

produced by leucocytes
antiviral action
useful in hepatitis B & C, Kaposi's sarcoma, metastatic renal cell cancer, hairy cell leukaemia, cutaneous T-cell lymphoma, Condylomata accuminata
adverse effects include flu-like symptoms and depression

IFN-beta

produced by fibroblasts
antiviral action
reduces the frequency of exacerbations in patients with relapsing-remitting MS or secondary progressive MS

IFN-gamma

produced by T lymphocytes & NK cells
weaker antiviral action, more of a role in immunomodulation particularly macrophage activation
may be useful in chronic granulomatous disease and osteopetrosis

Other SEs of interferons include : Arthralgia/ myalgia, leukopenia and thrombocytopenia

The toxicity profiles of the two interferons used in medicine are given in the following chart:

Toxicity	Interferon-α	Interferon-β
Common	Flu-like symptoms, Rash, Pancytopenia, Hepatits, Depression, suicide, psychosis, CHF	Flu-like symptoms, Rash, Pancytopenia, Hepatits, Depression, suicide, psychosis, CHF
Different	Hemolysis, metallic taste, insomnia, ?hair loss, fatigue	Seizures, hypothyroidism

Granulocyte macrophage colony stimulating factor (GM-CSF)

correction of cytopenias e.g. during chemoRx