title: Effects of exposure to gradient magnetic fields emitted by nuclear magnetic resonance devices on clonogenic potential and proliferation of human hematopoietic stem cells.
abstract: This study investigates effects of gradient magnetic fields (GMFs) emitted by magnetic resonance imaging (MRI) devices on hematopoietic stem cells. Field measurements were performed to assess exposure to GMFs of staff working at 1.5 T and 3 T MRI units. Then an exposure system reproducing measured signals was realized to expose in vitro CD34+ cells to GMFs (1.5 T-protocol and 3 T-protocol). CD34+ cells were obtained by Fluorescence Activated Cell Sorting from six blood donors and three MRI-exposed workers. Blood donor CD34+ cells were exposed in vitro for 72 h to 1.5 T or 3 T-protocol and to sham procedure. Cells were then cultured and evaluated in colony forming unit (CFU)-assay up to 4 weeks after exposure. Results showed that in vitro GMF exposure did not affect cell proliferation but instead induced expansion of erythroid and monocytes progenitors soon after exposure and for the subsequent 3 weeks. No decrease of other clonogenic cell output (i.e., CFU-granulocyte/erythroid/macrophage/megakaryocyte and CFU-granulocyte/macrophage) was noticed, nor exposed CD34+ cells underwent the premature exhaustion of their clonogenic potential compared to sham-exposed controls. On the other hand, pilot experiments showed that CD34+ cells exposed in vivo to GMFs (i.e., samples from MRI workers) behaved in culture similarly to sham-exposed CD34+ cells, suggesting that other cells and/or microenvironment factors might prevent GMF effects on hematopoietic stem cells in vivo. Accordingly, GMFs did not affect the clonogenic potential of umbilical cord blood CD34+ cells exposed in vitro together with the whole mononuclear cell fraction.
authors.affiliation: Department of Transfusion Medicine, Institute of Hematology, Università Cattolica, Rome, Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Iachininoto
authors.affiliation: Occupational Medicine/Health Technology Assessment and Safety Research Unit, Clinical-Technological Innovations Research Area-Bambino Gesù Children's Hospital IRCCS, Rome, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Camisa
authors.affiliation: Institute of Human Physiology, Università Cattolica, Rome, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Leone
authors.affiliation: ENEA, Italian Agency for New Technologies, Energy, and Sustainable Economic Development, Division of Health Protection Technologies, Casaccia Research Centre, Rome, Italy.
authors.forename: Rosanna
authors.initials: R
authors.lastname: Pinto
authors.affiliation: ENEA, Italian Agency for New Technologies, Energy, and Sustainable Economic Development, Division of Health Protection Technologies, Casaccia Research Centre, Rome, Italy.
authors.forename: Vanni
authors.initials: V
authors.lastname: Lopresto
authors.affiliation: ENEA, Italian Agency for New Technologies, Energy, and Sustainable Economic Development, Division of Health Protection Technologies, Casaccia Research Centre, Rome, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Merla
authors.affiliation: Immunology Unit, Immunology and Pharmacotherapy Research Area-Bambino Gesù Children's Hospital IRCCS, Rome, Italy.
authors.forename: Ezio
authors.initials: E
authors.lastname: Giorda
authors.affiliation: Immunology Unit, Immunology and Pharmacotherapy Research Area-Bambino Gesù Children's Hospital IRCCS, Rome, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Carsetti
authors.affiliation: Occupational Medicine/Health Technology Assessment and Safety Research Unit, Clinical-Technological Innovations Research Area-Bambino Gesù Children's Hospital IRCCS, Rome, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Zaffina
authors.affiliation: Institute of Human Physiology, Università Cattolica, Rome, Italy.
authors.forename: Maria Vittoria
authors.initials: MV
authors.lastname: Podda
authors.affiliation: Department of Transfusion Medicine, Institute of Hematology, Università Cattolica, Rome, Italy.
authors.forename: Luciana
authors.initials: L
authors.lastname: Teofili
authors.affiliation: Institute of Human Physiology, Università Cattolica, Rome, Italy.|San Raffaele Pisana Scientific Institute for Research, Hospitalization and Health Care, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Grassi
mesh_terms: D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D003114:Colony-Forming Units Assay; D041905:Erythroid Cells / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D060526:Magnetic Fields / Q000009:adverse effects*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology
chemical_list: D018952:Antigens, CD34
keywords: CD34+ cells; clonogenic potential; complex magnetic field waveforms; occupational exposure assessment