Although the CD34 molecule is expressed on virtually all haemopoietic progenitors, including multipotent stem cells, its function within haemopoiesis is still unknown. The CD34+ cell population is extremely heterogeneous in surface antigenic expression and these cells can be detected in bone marrow as well as in human umbilical cord blood and peripheral blood. Marked increases of circulating CD34+ cells occur during the recovery phase after myelosuppressive chemotherapy and/or growth factor administration. These cells, which can be estimated by flow cytometry, collected on a large scale by leucapheresis and cryopreserved for transplantation, are able to reconstitute haemopoiesis after myeloablative therapy. Peripheral blood haematopoietic progenitor transplantation is increasingly used for treating several malignancies such as leukaemia, lymphoma, myeloma or solid tumors. In fact, peripheral haematopoietic progenitor cell transplant usually provides earlier neutrophil and platelet recovery, less need for blood products and parenteral antibiotics and shorter hospitalization than bone marrow rescue. The restricted expression of CD34+ to haemopoietic stem/progenitor cells has been used for transplantation studies. Several techniques have been developed to select cells expressing CD34+ from haemopoietic tissues. Alternatively, CD34+ cells may be expanded in vitro by incubation with synergistic cytokine combinations before being reinfused. Finally an intriguing new development has been the use of purified populations of CD34+ cells as targets for gene therapy protocols.
|Translated title of the contribution||CD34+ hematopoietic progenitor cells|
|Number of pages||11|
|Journal||Trasfusione del Sangue|
|Publication status||Published - 1998|
ASJC Scopus subject areas
- Immunology and Allergy