Lack of efficacy of a short ex vivo incubation of human allogeneic donor marrow with recombinant human GM-CSF prior to its infusion into the recipient.

Ten patients with haematological malignancy receiving allogeneic transplants from donors other than HLA-identical siblings were prepared for marrow transplantation with antithymocyte globulin, cyclophosphamide 120 mg/kg and fractionated total body irradiation 12 Gy, and were given cyclosporin, methotrexate and prednisolone as prophylaxis against graft-versus-host disease post-transplant. The harvested T replete donor marrow was incubated with recombinant human (rh) GM-CSF 10 micrograms/ml (supersaturating concentration) for 1 h at 37 degrees C on a gently shaking rocker platform. After incubation the marrow was washed twice in 5% human serum albumin/normal saline and infused into the recipient. Before and after incubation, there was no significant difference in cell viability, the nucleated cell count, the CFU-GM content nor the proportion of cells in S phase of the cell cycle. Compared with a preceding cohort of 16 patients treated on the same protocol but in whom the marrow was not incubated with GM-CSF, there was no difference in the incidence of graft failure or rate of neutrophil recovery.