Sickle cell disease is characterized by chronic anemia and vaso-occlusive crises, which eventually lead to multi-organ damage and premature death. to assess the safety of a single injection of Plerixafor in sickle cell patients undergoing red blood cell exchange to Batimastat ic50 decrease the hemoglobin S level to below 30%. The secondary objective was to measure the efficiency of mobilization and isolation of Batimastat ic50 hematopoietic stem and progenitor cells. No adverse events were observed. Large numbers of CD34+ cells were mobilized extremely quickly. Importantly, the mobilized cells contained high numbers of hematopoietic stem cells, expressed high levels of stemness genes, and engrafted very efficiently in immunodeficient mice. Thus, Plerixafor can be safely used to mobilize hematopoietic stem cells in sickle cell patients; this finding opens up new avenues for treatment approaches based on gene addition and genome editing. (-globin) gene. As a result, an abnormal -globin protein is incorporated into hemoglobin tetramers. These mutant tetramers polymerize when the local oxygen tension is low. The sickle hemoglobin (HbS) polymers rigidify red blood cells, change these cells shape, and are responsible for structural damage to the red Batimastat ic50 blood cell membrane. In turn, this modifies the cells rheological properties, alters their flow in the microcirculation, and thus causes ischemia, stroke, multi-organ Batimastat ic50 damage, severe acute and chronic pain, and chronic hemolytic anemia. Progressive chronic organ complications become the main cause of morbidity and mortality in the third decade of life.1 SCD is endemic in Africa, and the Worlds Health Organization considers that 7% of the world population carries the trait. The only curative treatment for SCD is allogeneic hematopoietic stem cell transplantation (HSCT) from matched sibling donors; the disease-free survival rate 6 years after transplantation is reportedly 90%.2,3 Given the limited availability of suitable donors and the increase in toxicity with age, HSCT is only applied with great caution in adult SCD patients (the main target population for curative treatment). We recently demonstrated that gene therapy is applicable to SCD patients, and that the associated toxicity and morbidity rates seem to be lower than those for allogeneic HSCT, at least in the first treated patient.4 As is the case with all genetic diseases, the success of gene therapy in SCD relies on several key factors; these include the source, quality and number of transduced cells, the choice of the conditioning regimen, the level of therapeutic transgene expression, and the quality of the bone marrow (BM) microenvironment at the time of harvest and transplantation. It is generally acknowledged that 2 to 3106 CD34+ hematopoietic stem and progenitor cells (HSPC)/kg are required for a successful outcome in autologous HSCT.5 Considering the typical proportion of HSPC that can be corrected in gene therapy clinical trials (~50% of CD34+ HSPC) and an average recovery of 70% of CD34+ cells post-selection, a minimum harvest of ~6106 CD34+ cells/kg would be required. For reasons that have not been LIMK2 antibody completely elucidated, as for thalassemic patients,6C7 the recovery of HSPC from SCD patients BM is peculiarly low (M. Cavazzana, for day 30 and day 60). Apheresis was performed with the technical adjustments described in the and BM HSPC are involved in cell cycle-related processes (e.g. DNA replication, chromosome segregation, and nuclear division) C confirming that mobilized samples contain more quiescent cells, presumably HSC, than progenitors (Figure 2B, and and and and SCD patients. Overall, the study by Pantin does not cause a decrease in CD34+ cell counts. Additionally, the limited collection efficiency (30% of the circulating CD34+ cells) (Table 2) does not support.