BONE-MARROW CHANGES ASSOCIATED WITH RECOMBINANT GRANULOCYTE-MACROPHAGE AND GRANULOCYTE-COLONY-STIMULATING FACTORS - DISCRIMINATION OF GRANULOCYTIC REGENERATION

The hematopoietic growth factors recombinant human granulocyte-macroph age colony-stimulating factor and recombinant human granulocyte colony -stimulating factor are associated with changes of the bone marrow. To evaluate the morphologic features and to differentiate them from leuk emia, bone marrow specimens from 12 patients who had been treated with one of these agents were evaluated. The bone marrow displayed marked promyelocytic hyperplasia and a less striking increased percentage of myeloblasts. In each of the 11 patients without leukemia at the time o f bone marrow biopsy, the percentage of promyelocytes in the bone marr ow was greater than that of myeloblasts. Cytologic features of stimula ted regeneration included diffuse cytoplasmic hypergranulation of imma ture neutrophilic precursors that had prominent perinuclear spherical clear areas representing the Colgi zones. With consideration of bone m arrow composition and careful attention to cytologic detail, the disti nction of bone marrow regeneration from acute leukemia can be made in most patients who are being treated with recombinant hematopoietic gro wth factors.