MARKED AND REPRODUCIBLE INCREASE IN TRILINEAGE BLOOD-CELL COUNTS BY ADMINISTRATION OF GRANULOCYTE-COLONY-STIMULATING FACTOR IN A PATIENT WITH REFRACTORY-ANEMIA WITH EXCESS BLASTS IN TRANSFORMATION

We report a patient with refractory anaemia with excess blasts in tran sformation (RAEB-t) who presented with severe pancytopenia and receive d four intermittent series of granulocyte colony-stimulating factor (G -CSF) treatment over 1.5 years. In addition to the increase in mature neutrophils, platelet count and haemoglobin level were dramatically in creased. These haematological improvements were dependent on G-CSF dur ing these treatment series. Bone marrow colony assay revealed that G-C SF increased both CFU-E- and BFU-E-derived colonies in vitro. Clinical usage of G-CSF in myelodysplastic syndrome (MDS) is discussed, with p articular emphasis on mechanisms of trilineage response.