title: Effects of cryopreservation on the immunogenicity of porcine arterial allografts in early stages of transplant vasculopathy.
abstract: BACKGROUND
  The number of revascularization procedures including coronary and lower extremity bypass, have increased greatly in the last decade. It suggests a growing need for vascular grafts. Cryopreserved allografts could represent a viable alternative but their immunologic reactivity remains controversial.
  
  
  METHODS
  71 pigs (40 recipients and 31 donors) were used. Two femoral grafts per recipient animal were implanted for 3, 7, and 30 days. Types of grafts: fresh autograft as a control graft (n=19), fresh allograft (n=31) and cryopreserved allograft (n=30). Histological and immunohistochemical studies were performed.
  
  
  RESULTS
  Fresh allografts compared to autografts showed intimal inflammatory infiltration at 3 days (328 vs. 0 macrophages/mm2; P<0.05) and 7 days (962 vs. 139 T lymphocytes/mm2; P<0.05) post-transplantation. At 30 days, there was a loss of endothelial cells, presence of luminal thrombus and aneurismal lesions (total area=15.8 vs. 8.4 mm2; P<0.05). Cryopreservation did not reduce these lesions nor modify endothelial nitric oxide synthase (eNOS) expression nor modify the number of animals that developed anti-SLA antibodies. Moreover, at 7 days, cryopreserved allografts compared to fresh allografts showed a higher expression of P-selectin (5 out of 5 vs. 1 out of 5; P<0.05) and, at 30 days, a greater inflammatory reactivity (2692 vs. 1107 T lymphocytes/mm2 in media; P<0.05) with a trend towards a higher presence of multinucleated giant cells than in the fresh ones.
  
  
  CONCLUSIONS
  The cryopreservation method used maintained immunogenicity of allografts and increased the inflammatory reactivity found in fresh allografts up to 30 days of vascular transplantation.
authors.affiliation: Institut de Malalties Cardiovasculars, IDIBAPS (Institut d'Investigacions Biomèdiques Agustí Pi Sunyer), Barcelona, Spain. nsolanes@clinic.ub.es
authors.forename: Núria
authors.initials: N
authors.lastname: Solanes
authors.forename: Montserrat
authors.initials: M
authors.lastname: Rigol
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Khabiri
authors.forename: Manuel
authors.initials: M
authors.lastname: Castellà
authors.forename: José
authors.initials: J
authors.lastname: Ramírez
authors.forename: Mercè
authors.initials: M
authors.lastname: Roqué
authors.forename: Elba
authors.initials: E
authors.lastname: Agustí
authors.forename: Eulàlia
authors.initials: E
authors.lastname: Roig
authors.forename: Fèlix
authors.initials: F
authors.lastname: Pérez-Villa
authors.forename: Joaquim
authors.initials: J
authors.lastname: Segalés
authors.forename: José Luís
authors.initials: JL
authors.lastname: Pomar
authors.forename: Pablo
authors.initials: P
authors.lastname: Engel
authors.forename: Anna
authors.initials: A
authors.lastname: Massaguer
authors.forename: Jaume
authors.initials: J
authors.lastname: Martorell
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Rodríguez
authors.forename: Ginés
authors.initials: G
authors.lastname: Sanz
authors.forename: Magda
authors.initials: M
authors.lastname: Heras
mesh_terms: D000783:Aneurysm / Q000473:pathology; D000818:Animals; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D005263:Femoral Artery / Q000276:immunology* / Q000473:pathology / Q000637:transplantation*; D006098:Granulocytes / Q000187:drug effects / Q000276:immunology; D007518:Isoantibodies / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis; D019007:P-Selectin / Q000096:biosynthesis; D013552:Swine; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D013927:Thrombosis / Q000473:pathology; D013997:Time Factors; D014181:Transplantation Immunology; D014182:Transplantation, Autologous / Q000276:immunology / Q000379:methods; D014184:Transplantation, Homologous / Q000276:immunology* / Q000379:methods
chemical_list: D003451:Cryoprotective Agents; D007518:Isoantibodies; D019007:P-Selectin; D052250:Nitric Oxide Synthase Type III