title: Simultaneous donor marrow cell transplantation with reduced intensity conditioning prevents tracheal allograft obliteration in a bronchiolitis obliterans murine model.
abstract: OBJECTIVE
  Prolonged survival of transplanted kidney or liver allografts has been associated with prolonged chimerism resulting from donor-origin leukocytes carried within the allograft parenchyma. The present study, performed in a murine model, examined whether simultaneous administration of donor bone marrow cells after reduced intensity conditioning allows acceptance of heterotopic tracheal allografts and prevents the formation of the airway fibroproliferative lesion, which mimics bronchiolitis obliterans (BO).
  
  
  METHODS
  Allogeneic tracheal allografts from C57BL/6 mice were grafted subcutaneously into BALB/c mice (n = 6) [day 0]. Conditioning consisted of total lymphoid irradiation (200 cGy) at day - 1, donor marrow cells (3 x 10(7)) administered IV on day 0, intraperitoneal cyclophosphamide (200 mg/kg) on day 1 to eliminate alloreactive marrow cells, followed by a repeated dose of donor marrow cells on day 2. Control groups consisted of one group (n = 4) that underwent similar conditioning without donor marrow cells, and another group (n = 4) that received syngeneic BALB/c marrow cells. None of these groups were administered maintenance immunosuppression. Grafts were harvested and histopathology findings were evaluated semiquantitatively at day 28, day 55, and day 95.
  
  
  RESULTS
  Tracheal allografts from donor marrow cell recipients still maintained a patent airway with intact airway epithelium at 95 days after transplant. However, grafts from control animals not receiving donor marrow cells or mice administered syngeneic marrow cells had lumen obliteration by 28 days after transplant. Chimerism in animals receiving allogeneic bone marrow was confirmed. Graft vs host disease did not develop in animals receiving allogeneic marrow cells.
  
  
  CONCLUSIONS
  Further investigation may verify this approach to be applicable for the prevention of posttransplantation BO.
authors.affiliation: Lung Cellular and Molecular Biology Laboratory, Hadassah University Hospital, PO Box 12072, Jerusalem, Israel, 91120. samjack@shani.net
authors.forename: Samir
authors.initials: S
authors.lastname: Nusair
authors.forename: Reuven
authors.initials: R
authors.lastname: Or
authors.forename: Samer
authors.initials: S
authors.lastname: Junadi
authors.forename: Gail
authors.initials: G
authors.lastname: Amir
authors.forename: Raphael
authors.initials: R
authors.lastname: Breuer
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation / Q000379:methods*; D001989:Bronchiolitis Obliterans / Q000601:surgery*; D004195:Disease Models, Animal; D005260:Female; D006084:Graft Rejection / Q000517:prevention & control*; D006085:Graft Survival; D006086:Graft vs Host Disease / Q000473:pathology* / Q000517:prevention & control; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D012680:Sensitivity and Specificity; D014132:Trachea / Q000473:pathology / Q000637:transplantation*; D019172:Transplantation Conditioning / Q000379:methods*; D014184:Transplantation, Homologous