title: Spontaneous circulation of myeloid-lymphoid-initiating cells and SCID-repopulating cells in sickle cell crisis.
abstract: The only curative therapy for sickle cell disease (SCD) is allogeneic hematopoietic stem cell (HSC) transplantation. Gene therapy approaches for autologous HSC transplantation are being developed. Although earlier engraftment is seen when cells from GCSF-mobilized blood are transplanted than when bone marrow is transplanted, administration of GCSF to patients with SCD can cause significant morbidity. We tested whether primitive hematopoietic progenitors are spontaneously mobilized in the blood of patients with SCD during acute crisis (AC-SCD patients). The frequency of myeloid-lymphoid-initiating cells (ML-ICs) and SCID-repopulating cells (SRCs) was significantly higher in blood from AC-SCD patients than in blood from patients with steady-state SCD or from normal donors. The presence of SRCs in peripheral blood was not associated with detection of long-term culture-initiating cells, consistent with the notion that SRCs are more primitive than long-term culture-initiating cells. As ML-ICs and SRCs were both detected in blood of AC-SCD patients only, these assays may both measure primitive progenitors. The frequency of ML-ICs also correlated with increases in stem cell factor, GCSF, and IL-8 levels in AC-SCD compared with steady-state SCD and normal-donor sera. Because significant numbers of ML-ICs and SRCs are mobilized in the blood without exogenous cytokine treatment during acute crisis of SCD, collection of peripheral blood progenitors during crisis may yield a source of autologous HSCs suitable for ex-vivo correction by gene therapy approaches and subsequent transplantation.
authors.affiliation: Stem Cell Institute, Division of Gastroenterology, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: Christopher E D
authors.initials: CE
authors.lastname: Lamming
authors.forename: Lance
authors.initials: L
authors.lastname: Augustin
authors.forename: Mark
authors.initials: M
authors.lastname: Blackstad
authors.forename: Troy C
authors.initials: TC
authors.lastname: Lund
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hebbel
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Verfaillie
mesh_terms: D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000628:therapy; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D016179:Granulocyte Colony-Stimulating Factor / Q000097:blood; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000097:blood; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D016209:Interleukin-8 / Q000097:blood; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D019089:Stem Cell Factor / Q000097:blood
chemical_list: D016209:Interleukin-8; D019089:Stem Cell Factor; D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor