Measurement of thrombopoietic levels: clinical and biological relationships

Platelet production is primarily regulated by the thrombopoietic cytokine t hrombopoietin (TPO), In most cases thrombopoietin serum levels are determin ed by the rate of c-mpl receptor-mediated degradation after TPO uptake into platelets and megakaryocytes. The contribution of increased TPO protein sy nthesis by a translational mechanism was recently appreciated as the cause for hereditary thrombocythemia and will have to be elucidated in other cond itions of thrombocytosis in association with increased TPO levels. (C) 2000 Lippincott Williams & Wilkins, Inc.