[Shore-term stimulation with myeloid growth factors expands bone marrow hematopoiesis. A magnetic resonance...

The present study is intended to investigate the expansion of haematopoiesis by localised volume selective proton magnetic resonance spectroscopy (MRS) during treatment with myeloid growth factors. Six consecutive patients were treated with daily subcutaneous injections of recombinant human granulocyte colony-stimulating factor (rhG-CSF, n = 2) or granulocyte-macrophage colony-stimulating factor (rhGM-CSF, n = 4) for five days before marrow harvest. MRS investigations were performed prior to treatment (day 0), day 5 and day 12. The patients responded with a rise in blood absolute neutrophil count from median 3.3 x 10(9)/l (range 1.3-7.3 x 10(9)/l) before to 15.6 x 10(9)l (range 6.8-22.0 x 10(9)/l) after treatment. Concomitantly an increase in bone marrow cellularity and myeloid:erythroid ratios documented the stimulation of myelopoiesis. During priming, the light-density cell proliferation rate in marrow samples increased from median 21.9 (range 4.5-31) x 10(3) cpm to 54.7 (range 13.9-94) x 10(3) cpm and the total number of myeloid progenitors enumerated as day 7/14 GM-CFUs per volume aspirated marrow increased from median 11/8 x 10(3) (range 4.0-87.5/2.2-103.0) to 64/76. x 10(3) (range 28.4-1180.6/23.2-2850.0). MRS detected a significant increase in bone marrow "relative water content" day 12, one week after myeloid growth factor treatment was stopped, from median 30.5% (range 16-45) to 79% (range 56-93) (p < 0.05). Haematopoiesis was concommittantly detected in new areas of femur.(ABSTRACT TRUNCATED AT 250 WORDS)