Defining the full therapeutic potential of recombinant growth factors in the post radiation-accident environment: the effect of supportive care plus administration of G-CSF.

Radiation accidents are uncontrolled and ill-defined, the exposure is nonuniform and may be partial body, forecasting a variable dose distribution and sparing of hematopoietic stem cells. We propose that the "best" treatment protocol available now for severely irradiated personnel with acute hematopoietic syndrome is the combination of supportive care and administration of recombinant cytokines as soon as possible after irradiation. Herein, we demonstrate the significant effect of G-CSF administration on lethally irradiated canines. G-CSF administered early and continuously after irradiation increased neutrophil recovery and survival over a lethal and supralethal dose range. The respective LD50/30 for the control, supportive care-alone cohorts of 338 cGy, was increased to 488 cGy with administration of G-CSF. Clearly, the use of supportive care and G-CSF enhanced recovery of myelopoiesis and survival after lethal doses of irradiation.