Progress in clinical application of use of progenitor cells expanded with hematopoietic growth factors.

The ability to isolate and expand the cells capable of reconstituting hematopoiesis and immunity holds great promise to improve the outcomes of patients treated with autologous and allogeneic transplantation. The morbidity caused by prolonged neutropenia resulting from myeloablative therapy in the transplant setting leaves patients at risk to develop serious infections. Peripheral blood progenitor cells (PBPC) have supplanted bone marrow in autologous and allogeneic transplantation as a source of hematopoietic reconstitution mainly because of a reduction in the duration of neutropenia. Regardless, neutrophil recovery times continue to range between 7 to 10 days and platelet recovery times range between 12 to 24 days, after infusion of PBPC. Thus, ex vivo culture of PBPC has been evaluated for the purpose of providing a larger number of hematopoietic cells intended to accelerate the rate of recovery after myeloablative therapy. Moreover, expansion of alternative hematopoietic stem cell sources, including umbilical cord blood, has been tested in clinical trials.