title: Use of different DMSO concentrations for cryopreservation of autologous peripheral blood stem cell grafts does not have any major impact on levels of leukocyte- and platelet-derived soluble mediators.
abstract: OBJECTIVE
  Infusion of stem cell autografts can be associated with adverse effects. Necrotic normal leukocytes, cytokines or intracellular mediators released from leukocytes and platelets or the cryo-protectant dimethyl sulfoxide (DMSO) may contribute to this. Cryopreservation using 5% instead of 10% DMSO improves CD34(+) cell viability and therefore we investigated whether using less DMSO had favorable outcomes on leukocyte viability and levels of various soluble mediators in the graft supernatant.
  
  
  METHODS
  Peripheral blood autografts were harvested by 20 apheresis procedures in 16 cancer patients, and autograft samples were cryopreserved with 2%, 4%, 5% and 10% DMSO and stored for 5-6 years. After thawing, the viability of neutrophils and lymphocytes was analyzed by flow cytometry and supernatant levels of soluble mediators were determined by enzyme-linked immunosorbent assay (ELISA) analyzes.
  
  
  RESULTS
  The highest viability of both neutrophils and lymphocytes was detected with 4% and 5% DMSO, whereas decreased viability was observed with 2% and 10% DMSO. Low or undetectable levels of leukocyte-derived interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha and CXCL8, high levels of platelet-derived CCL5 and CXCL4, and high levels of monocyte-derived soluble CD14 were measured independent of the DMSO concentration, except for slightly increased CXCL8 and decreased CXCL4 levels with 2% DMSO. Perforin levels showed a significant inverse correlation with the DMSO concentration.
  
  
  CONCLUSIONS
  The use of different DMSO concentrations affects the viability of normal leukocytes in autologous peripheral blood stem cell grafts, but has only minor effects on supernatant levels of leukocyte- and platelet-derived soluble mediators.
authors.affiliation: Division of Hematology, Department of Medicine, Haukeland University Hospital and Institute of Medicine, University of Bergen, Bergen, Norway. cigdemakak@yahoo.no
authors.forename: Cigdem Akalin
authors.initials: CA
authors.lastname: Akkök
authors.forename: Knut
authors.initials: K
authors.lastname: Liseth
authors.forename: Tor
authors.initials: T
authors.lastname: Hervig
authors.forename: Anita
authors.initials: A
authors.lastname: Ryningen
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Bruserud
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Ersvaer
mesh_terms: D000328:Adult; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001792:Blood Platelets / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology*; D016207:Cytokines / Q000378:metabolism; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000187:drug effects / Q000502:physiology; D054353:Perforin / Q000378:metabolism; D014182:Transplantation, Autologous
chemical_list: D051017:Apoptosis Regulatory Proteins; D003451:Cryoprotective Agents; D016207:Cytokines; D054353:Perforin; D007770:L-Lactate Dehydrogenase; D004121:Dimethyl Sulfoxide