Cytokines and biologic response modifiers are polypeptide hormones mediating cellular interaction. GM-CSF, G-CSF, M-CSF, interleukin-1, interleukin-3, and erythropoietin are hemopoietic growth factors. Systemic application of GM-CSF or G-CSF increases the production of neutrophils. This effect can be exploited to decrease the incidence of infection after cytotoxic therapies or in states of bone marrow failure. Interleukin-3 additionally stimulates erythropoiesis and thrombopoiesis. Erythropoietin specifically stimulates erythropoiesis and can be clinically useful in patients with renal anemia. Interferon-alpha is already broadly used in the clinic. It has antiviral and antiproliferative effects. It is effective in B-cell neoplasia (e.g. low-grade NHL, multiple myeloma, early-stage CLL, or hairy cell leukemia). Furtheron, interferon-alpha is active in chronic myeloproliferative disease, CML, and in a variety of solid tumors. Tumor necrosis factor can be given locally for malignant ascites or pleural effusion. In combination with interferon-alpha it is also effective for renal cell carcinoma. Interleukin-2 is a potent activator of T cells and NK cells. It is effective in immunotherapy of renal cell carcinoma and malignant melanoma. In general the clinical use of cytokines is in its first steps of a very promising way.
