CIRCULATING HEMATOPOIETIC PROGENITOR CELLS IN POLYCYTHEMIA-VERA - THEIN-VIVO EFFECT OF HYDROXYUREA

The in vivo effects of hydroxyurea (HU) on circulating erythroid (BFU- E) and granulocyte-macrophage progenitors (CFU-GM) in patients with po lycythemia vera (PV) have been evaluated, HU induced a strong decrease of both BFU-E and CFU-GM in the first month of treatment, During the following 4 months of treatment the level of circulating progenitors r emained at very low values, until the end of the period of observation . HU activity involved both erythroid and myeloid committed progenitor s and both erythropoietin-stimulated (normal) and endogenous (derived from the abnormal PV clone) BFU-E.