Abstract
In this study we investigated rejection signs using HE and immunohistochemical staining of the transplanted lung and the recipient's spleen during the subchronic phase after homologous single lung transplantation in three Japanese monkeys.
The immunosuppressant FK605 was given after surgery, but no steroid.
Immunohistochemical staining (ABC-GO method) was performed using human antilym-phocyte monoclonal antibodies CD8, CD4 (T cell) and CD20 (B cell).
Rejection signs were observed in the transplanted lung of all three monkeys. HE staining revealed scattered infiltration of mononuclear cells in the perivascular region of the transplant-ed lung, whereas normal and recipient's lungs had no such perivascular cell infiltration.
Immunohistochemical staining confirmed the cross-reaction of human antibodies CD8 and CD20 with Japanese monkey cells, but not antibody CD4.
CD8- and CD20-positive cells infiltrated the perivascular tissue of the transplanted lung.
In the spleen of the recipient, CD8-positive cells formed an irregular population surrounding the follicles in the white pulp of the spleen and CD20-positive cells accumulated in clusters in the follicles. These T and B cell populations in the recipient's spleen were less distinct than those in the spleen of a normal monkey.
From these results, we concluded that the allo-transplanted lungs were still attacked with rejection in the subchronic phase even if an immunosuppressant was administered after transplantation. At this time the morphological features of stimulated immune response were almost absent in the recipient's spleen.
