Blood Cell Growth Factors

  SUMMARY Growth factors or colony stimulating factors (CSFs)recently became the subject of headlines around the world. Many published articles in the last few years indicate that the CSFs can correct anemia and pancytopenia of the great majority of patients. Recombinant CSFs are available to the many scientific and therapeutic centers in the U.S.A, Europe and Japan these days. Erythrop oietin (EPO)incre ases hemoglobin and hematocrit levels in patients with endstage renal disease, advanced cancer disease, those anemias due to chemotherapy, AIDS and chronic infections. Four highly active glycoprotein regulators, the colony stimulating factors, GM-CSF, G-CSF, M-CSF and IL3 are responsible in the formating, maturation and functional activity of Granulocytes, Monocytes and Macrophages. Each regulator is polyfunctional. While each factor has some distinctive action, to a large part CSFs overlap in their actions, and individual cells can simultaneously respond to more than one factor. The CSFs have now been isolated and purified. Their biologically active recombinant form produced. More recently, CSF membrane receptors have been recognized on individual cells. When injected in vivo. recomhinant CSFs are able to increase production of granulocytes and macrophages in a distinctive pattern of response. The functional activity of the mature granulocytes and monocytes not only is enhanced by CSFs, but also the injection of CSF has been shown to increase resistance to infections and reduce mortality from whole body irradiation or chemotherapy. Clinical trials to date have been most extensive of G.CSF and GM.CSF, both of which are able to elevate blood and bone marrow levels of granulocytes and monocytes of disease. States including AIDS. hypoplastic stage following cancer chemotherapy or marrow transplantation and the myelodys - plastic syndrome. The clearest evidence so far of the ability of CSFs to enhance resistance to infections has come from the studies on patient with cyclic or congenital neutropenia. the relative low toxicity of the CSFs indicate a future use of these agents in clinical medicine. It may effect a revolution in medicine as the introduction of antibiotics half a century ago.