Rapid hematopoietic recovery after coinfusion of autologous-blood stem cells and culture-expanded marrow mesenchymal stem cells in advanced breast cancer patients receiving high-dose chemotherapy.

PURPOSE: Multipotential mesenchymal stem cells (MSCs) are found in human bone marrow and are shown to secrete hematopoietic cytokines and support hematopoietic progenitors in vitro. We hypothesized that infusion of autologous MSCs after myeloablative therapy would facilitate engraftment by hematopoietic stem cells, and we investigated the feasibility, safety, and hematopoietic effects of culture-expanded MSCs in breast cancer patients receiving autologous peripheral-blood progenitor-cell (PBPC) infusion. PATIENTS AND METHODS: We developed an efficient method of isolating and culture-expanding a homogenous population of MSCs from a small marrow-aspirate sample obtained from 32 breast cancer patients. Twenty-eight patients were given high-dose chemotherapy and autologous PBPCs plus culture-expanded MSC infusion and daily granulocyte colony-stimulating factor. RESULTS: Human MSCs were successfully isolated from a mean +/- SD of 23.4 +/- 5.9 mL of bone marrow aspirate from all patients. Expansion cultures generated greater than 1 x 10(6) MSCs/kg for all patients over 20 to 50 days with a mean potential of 5.6 to 36.3 x 10(6) MSCs/kg after two to six passages, respectively. Twenty-eight patients were infused with 1 to 2.2 x 10(6) expanded autologous MSCs/kg intravenously over 15 minutes. There were no toxicities related to the infusion of MSCs. Clonogenic MSCs were detected in venous blood up to 1 hour after infusion in 13 of 21 patients (62%). Median time to achieve a neutrophil count greater than 500/microL and platelet count >/= 20,000/microL untransfused was 8 days (range, 6 to 11 days) and 8.5 days (range, 4 to 19 days), respectively. CONCLUSION: This report is the first describing infusion of autologous MSCs with therapeutic intent. We found that autologous MSC infusion at the time of PBPC transplantation is feasible and safe. The observed rapid hematopoietic recovery suggests that MSC infusion after myeloablative therapy may have a positive impact on hematopoiesis and should be tested in randomized trials.

Bone marrow-derived mesenchymal stem cells remain host-derived despite successful hematopoietic engraftment after allogeneic transplantation in patients with lysosomal and peroxisomal storage diseases.

Human bone marrow contains mesenchymal stem cells (MSCs) that can differentiate into various cells of mesenchymal origin. We developed an efficient method of isolating and culture expanding a homogenous population of MSCs from bone marrow and determined that MSCs express alpha-L-iduronidase, arylsulfatase-A and B, glucocerebrosidase, and adrenoleukodystrophy protein. These findings raised the possibility that MSCs may be useful in the treatment of storage disorders. To determine if donor derived MSCs are transferred to the recipients with lysosomal or peroxisomal storage diseases by allogeneic hematopoietic stem cell (HSC) transplantation, we investigated bone marrow derived MSCs of 13 patients 1-14 years after allogeneic transplantation. Highly purified MSCs were genotyped either by fluorescence in situ hybridization using probes for X and Y-chromosomes in gender mis-matched recipients or by radiolabeled PCR amplification of polymorphic simple sequence repeats. Phenotype was determined by the measurement of disease specific protein/enzyme activity in purified MSCs. We found that MSCs isolated from recipients of allogeneic HSC transplantation are not of donor genotype and have persistent phenotypic defects despite successful donor type hematopoietic engraftment. Whether culture expanded normal MSCs can be successfully transplanted into patients with storage diseases and provide therapeutic benefit needs to be determined.