Immunosuppressant-free allotransplantation of the trachea: the antigenicity of tracheal grafts can be reduced by removing the epithelium and mixed glands from the graft by detergent treatment.
OBJECTIVE
To develop a method for eliminating the epithelium and mixed glands from tracheal grafts by detergent treatment and evaluate these grafts for immunosuppressant-free allotransplantation in dogs.


METHODS
Fresh canine tracheal grafts were treated with a detergent (1% Triton X-100 t-octylphenoxypolyethoxyethanol; T-9284; Sigma Chemical Co, St Louis, Mo) at 4 degrees C for 48 hours. The grafts were then used for intrathoracic 5-ring tracheal replacement in other dogs without immunosuppressant treatment (n = 6, detergent treatment group). In the control group (n = 6) fresh untreated canine tracheal segments were implanted as allografts. All the implanted grafts were covered with an omental pedicle.


RESULTS
In the detergent treatment group the chondrocytes in the graft had a similar appearance to those in the fresh trachea, indicating that the chondrocytes remained viable after the detergent treatment. In 5 of the 6 grafts, the epithelium and mixed glands had been removed completely. After transplantation, these 5 grafts were incorporated by the host trachea without stenosis. In the remaining treated tracheal graft, in which removal of the epithelium was incomplete, moderate stenosis was observed at the fourth week after implantation, although this was not progressive. In the control group, granulation tissue of the graft and significant stenosis were observed after transplantation.


CONCLUSIONS
The antigenicity of tracheal grafts can be greatly reduced by removing the epithelium and mixed glands by the use of detergent treatment. The epithelium and mixed glands of the graft appear to be the determining elements involved in rejection after tracheal allotransplantation.
Liu
Y
Y
Department of Bioartificial Organs, Institute for Frontier Medical Sciences, Kyoto University, Kyoto, Japan. lyu@frontier.kyoto-u.ac.jp
Nakamura
T
T
Yamamoto
Y
Y
Matsumoto
K
K
Sekine
T
T
Ueda
H
H
Shimizu
Y
Y
D000818:Animals; D003902:Detergents; D004285:Dogs; D004702:Endocrine Glands / Q000276:immunology; D004848:Epithelium / Q000276:immunology; D005088:Exocrine Glands / Q000276:immunology; D007165:Immunosuppression Therapy; D017830:Octoxynol; D014132:Trachea / Q000276:immunology* / Q000637:transplantation*; D014181:Transplantation Immunology
D003902:Detergents; D017830:Octoxynol