ABSTRACT
The fact that blood cell production is controlled by a complex network of biomolecule-cell interactions has been elucidated mainly through cell culture technology. The genes for these cytokines have been isolated and cloned using recombinant DNA technology and the gene-expressed recombinant molecules purified. It is this sequence of events which allowed the production of high enough quantities of cytokines for further evaluation of their efficacy of action in vivo. The excitement thus far is that molecules shown to be active myelopoietic agents in vitro have shown activity in vivo, in many cases closely mimicking in vivo the activity predicted from actions in vitro. The myelodysplastic syndromes are a group of stem cell disorders identified by defects in maturation which give rise to inefficient blood cell production and with cytopenias refractory to treatment that can lead to infection, blood loss, and that carry an increased risk of leukemic transformation.
