Clinical use for expanded peripheral blood stem cells

The increasing use of haematopoietic stem and progenitor cells from the peripheral blood (PBPC) to restore haematopoiesis following high-dose chemotherapy has widely propagated the development of techniques for the ex vivo manipulation of haematopoietic cells. In particular, protocols for the ex vivo expansion of PBPC have been developed for different clinical purposes. Quantitative expansion of PBPC may provide a successful strategy for tumour cell purging of autologous grafts, or may generate sufficient cell numbers for sequential transplantation protocols. Furthermore, allogeneic transplantation of megadoses of PBPC may enable us to overcome immunological barriers, and may substantially increase the number of suitable donors for an individual patient. Clinical applications also include the use of ex vivo generated, partially differentiated, post-progenitor cells, antigen presenting cells for immunotherapy of minimal residual disease, and ex vivo transduced haematopoietic cells as attractive vehicles for genetic therapy.