title: Bilateral administration of autologous CD133+ cells in ambulatory patients with refractory critical limb ischemia: lessons learned from a pilot randomized, double-blind, placebo-controlled trial.
abstract: OBJECTIVE
  CD133+ cells confer angiogenic potential and may be beneficial for the treatment of critical limb ischemia (CLI). However, patient selection, blinding methods and end points for clinical trials are challenging. We hypothesized that bilateral intramuscular administration of cytokine-mobilized CD133+ cells in ambulatory patients with refractory CLI would be feasible and safe.
  
  
  METHODS
  In this double-blind, randomized sham-controlled trial, subjects received subcutaneous injections of granulocyte colony-stimulating factor (10 μg/kg per day) for 5 days, followed by leukapheresis, and intramuscular administration of 50-400 million sorted CD133+ cells delivered into both legs. Control subjects received normal saline injections, sham leukapheresis and intramuscular injection of placebo buffered solution. Subjects were followed for 1 year. An aliquot of CD133+ cells was collected from each subject to test for genes associated with cell senescence.
  
  
  RESULTS
  Seventy subjects were screened, of whom 10 were eligible. Subject enrollment was suspended because of a high rate of mobilization failure in subjects randomly assigned to treatment. Of 10 subjects enrolled (7 randomly assigned to treatment, 3 randomly assigned to control), there were no differences in serious adverse events at 12 months, and blinding was preserved. There were non-significant trends toward improved amputation-free survival, 6-minute walk distance, walking impairment questionnaire and quality of life in subjects randomly assigned to treatment. Successful CD133+ mobilizers expressed fewer senescence-associated genes compared with poor mobilizers.
  
  
  CONCLUSIONS
  Bilateral administration of autologous CD133+ cells in ambulatory CLI subjects was safe, and blinding was preserved. However, poor mobilization efficiency combined with high CD133+ senescence suggests futility in this approach.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA. Electronic address: anr@medicine.wisc.edu.
authors.forename: Amish N
authors.initials: AN
authors.lastname: Raval
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Eric G
authors.initials: EG
authors.lastname: Schmuck
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Girma
authors.initials: G
authors.lastname: Tefera
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Cathlyn
authors.initials: C
authors.lastname: Leitzke
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Cassondra Vander
authors.initials: CV
authors.lastname: Ark
authors.affiliation: Waisman Biomanufacturing Facility, Madison, Wisconsin, USA.
authors.forename: Derek
authors.initials: D
authors.lastname: Hei
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: John M
authors.initials: JM
authors.lastname: Centanni
authors.affiliation: National Heart and Lung Institute, Imperial College London and NIHR Cardiovascular Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom.
authors.forename: Ranil
authors.initials: R
authors.lastname: de Silva
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Jill
authors.initials: J
authors.lastname: Koch
authors.affiliation: Department of Biostatistics and Medical Informatics, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Chappell
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Peiman
authors.initials: P
authors.lastname: Hematti
mesh_terms: D000071916:AC133 Antigen; D000368:Aged; D015703:Antigens, CD; D064592:Autografts; D004311:Double-Blind Method; D005121:Extremities / Q000098:blood supply* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006023:Glycoproteins; D006801:Humans; D007511:Ischemia / Q000473:pathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010455:Peptides; D058729:Peripheral Arterial Disease / Q000473:pathology / Q000628:therapy*; D020127:Recovery of Function; D033581:Stem Cell Transplantation; D013234:Stem Cells
chemical_list: D000071916:AC133 Antigen; D015703:Antigens, CD; D006023:Glycoproteins; C000606023:PROM1 protein, human; D010455:Peptides
keywords: angiogenesis; critical limb ischemia; peripheral artery disease; stem cell