Ex vivo expansion of hematopoietic precursor cells

The availability of several newly described recombinant human hematopoietic growth factors has improved the technique of ex vivo expansion of CD34+ hematopoietic progenitor cells. Of particular interest are the strategies for the cytokine-mediated expansion of primitive progenitor cells. Moreover, various techniques have been proposed for the differential expansion of CD34+ progenitors toward selective hematopoietic lineages, including myeloid and megakaryocytic progenitors and post-progenitors. In addition, there are several approaches to selectively generate dendritic cells from CD34+ progenitor cells for potential clinical use. Finally, the first clinical applications of ex vivo generated progenitor cells to support hematopoiesis after high-dose chemotherapy were reported recently. This article briefly summarizes the recent technical developments as well as the first clinical trials with ex vivo expanded hematopoietic progenitors.