CHARACTERIZATION OF HUMAN MEGAKARYOCYTE COLONY-STIMULATING FACTOR IN THE URINARY EXTRACTS FROM PATIENTS WITH APLASTIC-ANEMIA AND IDIOPATHIC THROMBOCYTOPENIC PURPURA
Using procedures effective in the purification of human urinary erythropoietin (Epo), initial purification of megakaryocyte colony-stimulating factors [MEG-CSF] in urinary extracts from patients with aplastic anemia (AA) and idiopathic thrombocytopenic purpura (ITP) was attempted. Comparison of colony stimulation by purified human Epo and crude urinary extracts revealed that the pure Epo augments megakaryocyte colony formation in culture and that MEG-CSF activity is also present in materials other than Epo in the crude urinary extracts from the 2 types of patients. Similar to purification of Epo, ethanol precipitation and sulfopropyl-Sephadex chromatography provided 2- and 3-fold increases in the specific activity of MEG-CSF, respectively. In contrast to Epo, significant inactivation of MEG-CSF activity was seen with phenol treatment. The elution profile of MEG-CSF seen on hydroxylapatite chromatography of urinary extracts was different from that of Epo. A basis for initial steps for purification of MEG-CSF was provided, and the notion that MEG-CSF is distinct from Epo is supported.