[Cytokines in the treatment of blood diseases]

Cytokines are a class of signal peptides which represent a major communication network in living organism. Over the last decade, the discovery, cloning and purification of hematopoietic cytokines (interleukins, hematopoietic growth factors) has increased our understanding of the regulation, proliferation, differentiation and function of hematopoietic cells. More recently, the large scale production of the recombinant forms of these molecules has enabled to treat the patients with pharmacologic doses of cytokines. The therapeutic activity of interferon-alpha (IFN-alpha) has been demonstrated in patients with chronic myeloid leukaemia and other chronic myeloproliferative syndromes. IFN-gamma is useful in the prevention of infections in patients with chronic granulomatous disease. Erythropoietin (EPO) was the first hematopoietic growth factor available for clinical use, initially to treat anaemia in renal failure patients. The next cytokines introduced into the clinic were granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage CSF (GM-CSF). They are used successfully in haematological malignant disorders to stimulate granulopoiesis after chemotherapy or bone marrow transplantation and to help mobilise marrow stem cells for peripheral blood stem cell transplantation. Interleukin (IL)-1, -2, -3, -4, -6 and -11 have been tested in clinical trials. However, the value of these agents remains to be established.