title: Transplantation of purified CD34+ cells in the treatment of critical limb ischemia.
abstract: BACKGROUND
  This study investigated the feasibility, safety, and efficacy of the intramuscular injection of CD34+ cells isolated from peripheral blood mononuclear cells (PB-MNCs) mobilized by granulocyte colony-stimulating factor (G-CSF) for the management of patients with critical limb ischemia (CLI) who were considered unlikely to have successful long-term revascularization with open bypass or endovascular methods. Cell therapy represents a new treatment modality for this subgroup of patients with CLI. To date, bone marrow or PB-MNCs have usually been used for transplantation. The current pilot study investigated whether the transplantation of purified CD34+ cells only would be competent in ischemia relief and limb salvage.
  
  
  METHODS
  From May 2009 to July 2011, 25 patients (mean age, 44 ± 12 years) were enrolled, and 25 lower extremities and three upper extremities were treated. After subcutaneous administration of G-CSF for 5 days at a dose of 5 to 10 μg/kg, apheresis and immunomagnetic separation were performed to acquire the isolated CD34+ cells, which were then intramuscularly injected into the ischemic sites. The patients were divided into three groups: low-dose, 10(5)/kg; medium-dose, 5 × 10(5)/kg; and high-dose, 10(6)/kg. The overall outcomes among all patients and the comparison among the groups were evaluated.
  
  
  RESULTS
  During the follow-up of 6 to 33 months, the overall outcomes showed that the Wong-Baker FACES pain rating scale score (WFPRSS) decreased from 7 ± 2 to 3 ± 3 (P < .001) and 1 ± 2 (P < .001) at 1 and 2 months, respectively; at 3 and 6 months, respectively, the peak pain-free walking time increased from 4 ± 3 to 13 ± 7 (P < .001) and 18 ± 6 minutes (P < .001), the ankle-brachial index increased from 0.46 ± 0.21 to 0.60 ± 0.17 (P = .003) and 0.67 ± 0.15 (P = .001), and the transcutaneous partial oxygen pressure increased from 27 ± 10 to 41 ± 11 (P < .001) and 55 ± 12 mm Hg (P < .001). Ulcers were healed in 10 of the 14 patients; four patients required above-knee or below-knee amputation ≤ 3 months. The Kaplan-Meier estimate of the rate of freedom from major amputation at 6 months was 84% (95% confidence interval, 63%-94%). The comparison among the three groups (low-dose, 5; medium-dose, 11; high-dose, 9) revealed no significant difference, except that the WFPRSS improvement at 1 month from baseline in the high-dose group (6.3 ± 1.7) was significantly superior to that in the low-dose (3.2 ± 3.3; P = .0487) and medium-dose (3.7 ± 2.8; P = .0352) groups.
  
  
  CONCLUSIONS
  Transplantation of CD34+ cells isolated from G-CSF-mobilized PB-MNCs appears to be feasible and safe, showing encouraging outcomes in the treatment of CLI patients who appear to have compromised options for long-term revascularization.
authors.affiliation: Department of Vascular Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Dong
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.forename: Weiguo
authors.initials: W
authors.lastname: Fu
authors.forename: Yuqi
authors.initials: Y
authors.lastname: Wang
authors.forename: Daqiao
authors.initials: D
authors.lastname: Guo
authors.forename: Zheng
authors.initials: Z
authors.lastname: Wei
authors.forename: Xin
authors.initials: X
authors.lastname: Xu
authors.forename: Farrell Owen
authors.initials: FO
authors.lastname: Mendelsohn
mesh_terms: D000328:Adult; D000368:Aged; D000671:Amputation, Surgical; D055109:Ankle Brachial Index; D018952:Antigens, CD34 / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D016638:Critical Illness; D005080:Exercise Test; D017079:Exercise Tolerance; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation; D007511:Ischemia / Q000097:blood / Q000175:diagnosis / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000637:transplantation*; D023821:Limb Salvage; D035002:Lower Extremity / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010865:Pilot Projects; D011237:Predictive Value of Tests; D020127:Recovery of Function; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D034941:Upper Extremity / Q000098:blood supply*; D016138:Walking; D014945:Wound Healing; D055815:Young Adult
chemical_list: D018952:Antigens, CD34; D015415:Biomarkers