Escalation of Plerixafor for Mobilization of CD34+ Hematopoietic Progenitor Cells and Evaluation of Globin Gene Transfer in Patients With Sickle Cell Disease

Inclusion Criteria: * Patients must have confirmed and measurable Sickle Cell Disease, defined by SS or Sβ thalassemia confirmed by hemoglobin fractionation. * ≥ 18 to 65 years of age * Patient must have a ECOG performance status ≤2 or Karnofsky score \> 70% * Patients must have acceptable organ and marrow function as defined below: * WBC ≥ 3,000/μL * ANC ≥ 1,500/μL * platelets ≥150,000//μL * Hemoglobin ≥ 6 gm/dL * Calculated creatinine clearance ≥ 60ml/min \* \*Using the Cockcroft-gault equation \[140 - Age(yrs)\] \[Weight(kg)\] x 0.85 if Female 72 \[Serum Creatinine (mg/dL\] * Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. * Each patient must be willing to participate as a research subject and must sign an informed consent form. Exclusion Criteria: * Patients who are: * Receiving or received treatment with an investigational agent within 4 weeks prior to entering the study OR * have not recovered from adverse events due to agents administered more than 4 weeks earlier as determined by the treating physician. * Patients with ALT(SGPT) \> 2.5 X upper limit of normal * Patients with a creatinine clearance of \< 60 ml/min * Patients who have uncontrolled illness including, but not limited to: * Ongoing or active infection * Emergency room admission or hospitalization in the past 14 days * Major surgery in the past 30 days * Medical/psychiatric illness/social situations that would limit compliance with study requirements as determined by the treating physician. * Female patients who are pregnant or breast-feeding * Patients with active hepatitis B, hepatitis C, or HIV infection * Patients with poor cardiac function as defined by an ejection fraction \< 40% are excluded due to potential poor tolerance of the fluid shifts with leukapheresis (only for patients enrolled on second phase of protocol for Leukapheresis).